# Best Practices Guidebook for Greenhouse Gas Reductions in Freight Transportation

Final Report

Prepared for

U.S. Department of Transportation via Center for Transportation and the Environment

Prepared by

H. Christopher Frey and Po-Yao Kuo Department of Civil, Construction, and Environmental Engineering North Carolina State University Raleigh, North Carolina 27695-7908 USA

October 4, 2007i 

### ACKNOWLEDGMENTS/ DISCLAIMER

This work is supported by the U.S. Depart ment of Transportation via Center for Transportation and the Environment. The author s are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of either the U.S. Department of Tran sportation or the Center for Transportation and the Environment at the time of publication. This report does not constitute a standard, specification, or regulation.ii 

### TABLE OF CONTENTS

EXECUTIVE SUMMARY........................................................................................................ES-1 ES.1 Background....................................................................................................... ES-1 ES.2 Study Methodology........................................................................................... ES-1
ES.3 Identification of Best Practices and Their Estimated Reductions in GHG Emissions, Energy Use and Refrigerant Use .................................................... ES-4 ES.4 Quantitative Assessment Results .................................................................... ES-10 ES.5 Major Findings................................................................................................ ES-12
ES.6 Recommendations........................................................................................... ES-13
1.0 PURPOSE AND BACKGROUND .....................................................................................1 1.1 Purpose of This Guidebook .................................................................................... 1 1.2 Background............................................................................................................. 2 1.3 Using This Guidebook ............................................................................................ 4
2.0 DEFINITION OF KEY CONCEPTS ..................................................................................7
2.1 “Best Practices” for Greenhouse Gas Reduc tions in Freight Transportation ......... 7 2.2 Modes of Freight Transportation ............................................................................ 7 2.3 Subgroup................................................................................................................. 9 2.4 Responsible Parties ................................................................................................. 9 2.5 Target Parties......................................................................................................... 10
2.6 Greenhouse Gas Emissions ................................................................................. 10 2.7 Strategy Types for Reducing Greenhouse Gas Emissions .................................... 10 2.7.1 Technological Strategies ...............................................................................10 2.7.2 Operational Strategies...................................................................................10
2.8 Practice Goals ........................................................................................................11 2.9 Developmental Status ............................................................................................11
3.0 METHODOLOGY ............................................................................................................12
3.1 Literature Review.................................................................................................. 12 3.2 Reductions in GHG Emissions, and Energy or Refrigerant Use, for Individual
Best Practices........................................................................................................ 12 3.3 Quantitative Assessments of Best Practices.......................................................... 14 3.3.1. Quantifying Cost Implications...................................................................14 3.3.2 Summarizing and Reporting the Results....................................................15 3.4 Qualitative Assessments of Best Practices............................................................ 18 3.5 Aggregated Reductions in GHG Emissi ons, Energy or Refrigerant Use for Multiple Best Practices ......................................................................................... 18iii 

### 3.6 Intermodal Substitution......................................................................................... 22
4.0. BEST PRACTICES FOR THE TRUCK MODE ..............................................................23 4.1 Anti-Idling............................................................................................................. 23 4.1.1 Best Practice 1-1: Off-Board Truck Stop Electrification.........................24
4.1.2 Best Practice 1-2: Truck-Bo ard Truck Stop Electrification.....................24 4.1.3 Best Practice 1-3: Auxiliary Power Units................................................24
4.1.4 Best Practice 1-4: Direct-Fired Heaters...................................................25
4.1.5 Best Practice 1-5: Direct-Fir ed Heaters with Thermal Storage
Units...........................................................................................................25 4.2 Air Conditioning System Improvement................................................................ 26 4.2.1 Best Practice 1-6: Enhanced Air Conditioning System I - for
Direct Emissions ........................................................................................26 4.2.2 Best Practice 1-7: Enhanced Air Conditioning System II - for
Indirect Emissions......................................................................................26
4.2.3 Best Practice 1-8: Alte rnative Refrigerants - CO 2 

### ...................................26
4.2.4 Best Practice 1-9: Altern ative Refrigerants - HFC-152a.........................27 4.2.5 Best Practice 1-10: Alternative Refrigerants - HC ..................................27 4.3 Aerodynamic Drag Reduction .............................................................................. 27 4.3.1 Best Practice 1-11: Vehicle Profile Improvement I - Cab Top Deflector, Sloping Hood and Cab Side Flares ...........................................28
4.3.2 Best Practice 1-12: Vehicle Pr ofile Improvement II - Closing and Covering of Gap between Cab and Trailer or Van, Aerodynamic Bumper, Underside Air Baffle s, and Wheel Well Covers..........................28 4.3.3 Best Practice 1-13: Vehicle Profile Improvement III - Trailer or Van Leading and Trailing Edge Curvatures ......................................................28 4.3.4 Best Practice 1-14: Pneumatic Aerodynamic Drag Reduction................28
4.3.5 Best Practice 1-15: Planar Boat Tail Plates on a Tractor-Trailer .............29 4.3.6 Best Practice 1-16: Vehicle Load Profile Improvement ..........................29 4.4 Tire Rolling Resistance Improvement .................................................................. 29
4.4.1 Best Practice 1-17: Automa tic Tire Inflation Systems ............................30
4.4.2 Best Practice 1-18: Wide-Base Tires .......................................................30 4.4.3 Best Practice 1-19: Low-Rolling-Resistance Tires..................................30
4.4.4 Best Practice 1-20: Pneumatic Blowing to Reducing Rolling
Resistance ..................................................................................................31 4.5 Hybrid Propulsion

― Best Practice 1-21: Hybrid trucks ................................... 31 4.6 Weight Reduction

― Best Practice 1-22: Li ghtweight Materials ...................... 31iv 

### 4.7 Transmission Improvement................................................................................... 32
4.7.1 Best Practice 1-23: Advanced Transmission ...........................................32
4.7.2 Best Practice 1-24: Transmi ssion Friction Reduction through Low-Viscosity Transmission Lubricants....................................................33 4.8 Diesel Engine Improvement ................................................................................. 33 4.8.1 Best Practice 1-25: Engi ne Friction Reduction through Low-Viscosity Engine Lubricants..............................................................33
4.8.2 Best Practice 1-26: Increas ed Peak Cylinder Pressures...........................33
4.8.3 Best Practice 1-27: Im proved Fuel Injectors ...........................................34
4.8.4 Best Practice 1-28: Turboc harged, Direct Injection to Improved Therma l Management................................................................34
4.8.5 Best Practice 1-29: Usi ng Thermoelectric Technology to Recovery Waste Heat .................................................................................34 4.9 Accessory Load Reduction ................................................................................... 35
4.9.1 Best Practice 1-30: Electric Auxiliaries...................................................35
4.9.2 Best Practice 1-31: Fuel-C ell-Operated Auxiliaries ................................35
4.10 Modifications in Driv er Operational Practice

― Best Practice 1-32: Truck Driver Training Program....................................................................................... 36
4.11 Alternative Fuel

― Best Practice 1-33: B20 Biodiesel Fuel............................... 36 4.12 Summary of Potential Best Practices for the Truck Mode.................................... 37 4.13 Comparisons of Modal GHG Emissions Reductions for the Best Practices ........ 37 4.14 Quantitative Cost Results for Selected Best Practices.......................................... 50
5.0. BEST PRACTICES FOR THE RAIL MODE...................................................................52 5.1 Anti-Idling............................................................................................................. 52
5.1.1 Best Practice 2-1: Combined Diesel Powered Heating and Auto Engine Start/Stop Systems ................................................................52 5.1.2 Best Practice 2-2: Battery-Dies el Hybrid Switching Locomotive...........53 5.1.3 Best Practice 2-3: Plug-In Units ..............................................................53 5.2 Weight Reduction

― Best Practice 2-4: Lightweight Materials ........................ 53 5.3 Rolling Resistance Improvement

― Best Practice 2-5: Lubrication Improvement......................................................................................................... 54
5.4 Alternative Fuel

― Best Practice 2-6: B20 Biodiesel Fuel for Locomotives .... 54 5.5 Summary of Potential Best Practices for the Rail Mode ...................................... 54 5.6 Comparisons of the Modal GHG Emissions Reductions for the Best Practices... 54 5.7 Quantitative Cost Results for the Selected Best Practices.................................... 58
6.0. BEST PRACTICES FOR THE AIR MODE .....................................................................60v 

### 6.1 Aerodynamic Drag Reduction .............................................................................. 61
6.1.1 Best Practice 3-1: Surface Grooves .........................................................61 6.1.2 Best Practice 3-2: Hybrid Laminar Flow Technology.............................61 6.1.3 Best Practice 3-3: Blended Winglet.........................................................62 6.1.4 Best Practice 3-4: Spiroid Tip..................................................................62 6.2 Air Traffic Management

― Best Practice 3-5 ...................................................... 62 6.3 Weight Reduction.................................................................................................. 64 6.3.1 Best Practice 3-6: Airframe Weight Reduction .......................................64 6.3.2 Best Practice 3-7: Non-Essential Weight Reduction ...............................64 6.4 Ground Support Equipment Improvement............................................................ 65
6.4.1 Best Practice 3-8: Ground-Base d Equipment as an Alternative to Auxiliary Power Units ...........................................................................65
6.4.2 Best Practice 3-9: Electric or Hybrid Heavy Duty Delivery Trucks .......65 6.5 Engine Improvement

― Best Practice 3-10: Improved Engine Overall Efficiency.............................................................................................................. 65 6.6 Summary of Potential Best Practices for the Air Mode........................................ 66 6.7 Comparisons of the Modal GHG Emissions Reductions for the Best Practices... 66
7.0 BEST PRACTICES FOR THE WATER MODE...............................................................72 7.1 Propeller System Improvement............................................................................. 72 7.1.1 Best Practice 4-1: Off-Center Propeller...................................................72 7.1.2 Best Practice 4-2: Propelle r Boss Cap with Fins (PBCF)........................73 7.1.3 Best Practice 4-3: Auxiliary Free-Rotating Propulsion Device behind the Main Propeller..........................................................................73 7.2 Anti-Idling

― Best Practice 4-4: Shoreside Power for Marine Vessels
at Ports .................................................................................................................. 73
7.3 Alternative Fuel

― Best Practice 4-5: B20 Bi odiesel Fuel for Ships ................. 74 7.4 Summary of Potential Best Practices for the Water Mode.................................... 75 7.6 Comparisons of the Modal GHG Emissions Reductions for the Best Practices... 75 7.7 Quantitative Cost Results for the Water Mode ..................................................... 75
8.0 BEST PRACTICES FOR THE PIPELINE MODE...........................................................82 8.1 Process Control Device Improvement .................................................................. 82
8.1.1 Best Practice 5-1: Convert Na tural Gas Pneumatic Controls to
Instrument Air ............................................................................................82 8.1.2 Best Practice 5-2: Replace Hi gh-Bleed Natural Gas Pneumatic
Devices with Low-Bleed Pneumatic Devices............................................83 8.2 Connecting Method

― Best Practice 5-3: “Hot Tap” Pipeline Connectingvi 

### Method .................................................................................................................. 83
8.3 Maintenance.......................................................................................................... 83 8.3.1 Best Practice 5-4: Transfer Compression ................................................83
8.3.2 Best Practice 5-5: Inline Inspection.........................................................83 8.4 Summary of Potential Best Practices for the Pipeline Mode................................ 84 8.5 Comparisons of the Modal GHG Emissions Reductions for the Best Practices... 84 8.6 Quantitative Cost Results for the Pipeline Mode.................................................. 84
9.0 SUMMARY AND COMPARISON OF GHG EMISSIONS REDUCTIONS
FOR ALL FREIGHT TRANSPORTATION MODES.......................................................89
9.1 Truck Mode........................................................................................................... 89
9.2 Rail Mode.............................................................................................................. 92
9.3 Air Mode............................................................................................................... 97
9.4 Water Mode........................................................................................................... 97 9.5 Pipeline Mode ..................................................................................................... 101 9.6 Intermodal Comparisons..................................................................................... 101
9.6.1 Total Modal GHG Emissions Reductions................................................101 9.6.2 Comparisons of Best Practices Whose Costs Are Assessed Quantitatively...........................................................................................105
9.6.3 Intermodal Substitutions ..........................................................................107
10.0. CONCLUSIONS AND RECOMMENDATIONS...........................................................110
10.1 Conclusions..........................................................................................................110
10.2 Recommendations for Future Research Needs....................................................111
REFERENCES

..................................................................................................... 

### 113 APPENDIX A. DETAILS OF INPUT DATA, ASSUMPTIONS, AND
ESTIMATION RESULTS FOR TRUC K MODE BEST PRACTICES ..........................135 Appendix A.1 Best Practice 1-1: Of f-Board Truck Stop Electrification ................... 135 Appendix A.2 Best Practice 1-2: Truc k-Board Truck Stop Electrification ............... 142 Appendix A.3 Best Practice 1-3: Auxiliary Power Units .......................................... 143 Appendix A.4 Best Practice 1-4: Direct-Fired Heaters ............................................. 148 Appendix A.5 Best Practice 1-5: Di rect-fired Heaters with Thermal Storage Units....................................................................................................... 153 Appendix A.6 Best Practice 1-6: Enhanced Air Conditioning System I - for
Direct Emissions ................................................................................................. 154 Appendix A.7 Best Practice 1-7: Enhanced Air Conditioning System II - for
Indirect Emissions............................................................................................... 155 Appendix A.8 Best Practice 1-8: Alternative Refrigerants - CO 2 

### ............................. 156vii 

### Appendix A.9 Best Practice 1-9: A lternative Refrigerants - HFC-152a ................... 157 Appendix A.10 Best Practice 1-10: Alternative Refrigerants - HC........................... 158 Appendix A.11 Best Practice 1-11: Vehicle Profile Improvement I - Cab Top Deflector, Sloping Hood and Cab Side Flares .................................................... 159 Appendix A.12 Best Practice 1-12: Vehi cle Profile Improvement II - Closing and Covering of Gap between Tractor and Trailer, Aerodynamic Bumper, Underside Air Baffles, and Wheel Well Covers.................................................. 160 Appendix A.13 Best Practice 1-13: Vehicl e Profile Improvement III - Trailer or Van Leading and Trailing Edge Curvatures........................................................ 161 Appendix A.14 Best Practice 1-14: Pn eumatic Aerodynamic Drag Reduction......... 162 Appendix A.15 Best Practice 1-15: Planar Boat Tail Plates on a Tractor-Trailer...... 163 Appendix A.16 Best Practice 1-16: Vehicle Load Profile Improvement................... 164 Appendix A.17 Best Practice 1-17: Au tomatic Tire Inflation Systems..................... 165 Appendix A.18 Best Practice 1-18: Wide-Base Tires................................................ 166 Appendix A.19 Best Practice 1-19: Low-Rolling-Resistance Tires .......................... 167 Appendix A.20 Best Practice 1-20: Pn eumatic Blowing to Reducing Rolling
Resistance ........................................................................................................... 168 Appendix A.21 Best Practice 1-21: Hybrid Trucks ................................................... 169 Appendix A.22 Best Practice 1-22: Lightweight Materials....................................... 175 Appendix A.23 Best Practice 1-23: Advanced Transmission.................................... 176 Appendix A.24 Best Practice 1-24: Tr ansmission Friction Reduction through Low-Viscosity Transmission Lubricants............................................................. 177 Appendix A.25 Best Practice 1-25: Engine Friction Reduction through Low-Viscosity Engine Lubricants....................................................................... 178 Appendix A.26 Best Practice 1-26: In creased Peak Cylinder Pressures ................... 179 Appendix A.27 Best Practice 1-27: Improved Fuel Injectors.................................... 180 Appendix A.28 Best Practice 1-28: Turboc harged, Direct Injection to Improved Thermal Management ......................................................................................... 181 Appendix A.29 Best Practice 1-29: Th ermoelectric Technology to Recovery
Waste Heat .......................................................................................................... 182 Appendix A.30 Best Practice 1-30: Electric Auxiliaries ........................................... 183 Appendix A.31 Best Practice 1-31: Fu el-Cell-Operated Auxiliaries......................... 184 Appendix A.32 Best Practice 1-32: Truck Driver Training Program ........................ 185 Appendix A.33 Best Practice 1-33: B20 Biodiesel Fuel for Trucks.......................... 186 APPENDIX B. DETAILS OF INPUT DATA, ASSUMPTIONS, AND
ESTIMATION RESULTS FOR RAIL MODE BEST PRACTICES...............................191viii 

### Appendix B.1 Best Practice 2-1: Comb ined Diesel Powered Heating System and Auto Engine Start/Stop System.................................................................... 191 Appendix B.2 Best Practice 2-2: Battery- Diesel Hybrid Switching Locomotive ..... 197 Appendix B.3 Best Practice 2-3: Plug-in Unit........................................................... 203 Appendix B.4 Best Practice 2-4: Light Weight Materials ......................................... 210 Appendix B.5 Best Practice 2-5: Lubrication Improvement ......................................211 Appendix B.6 Best Practice 2-6: B 20 Biodiesel Fuel for Locomotives.................... 212 APPENDIX C. DETAILS OF INPUT DATA, ASSUMPTIONS, AND
ESTIMATION RESULTS FOR AIR MODE BEST PRACTICES .................................217 Appendix C.1 Best Practice 3-1: Surface Grooves.................................................... 217 Appendix C.2 Best Practice 3-2: Hybrid Laminar Flow Technology........................ 218 Appendix C.3 Best Practice 3-3: Blended Winglet ................................................... 219 Appendix C.4 Best Practice 3-4: Spiroid Tip ............................................................ 220 Appendix C.5 Best Practice 3-5: Ai r Traffic Management Improvement................. 221 Appendix C.6 Best Practice 3-6: Airframe Weight Reduction.................................. 222 Appendix C.7 Best Practice 3-7: Non-Essential Weight Reduction.......................... 223 Appendix C.8 Best Practice 3-8: Ground- Based Equipment as an Alternative to Auxiliary Power Units ........................................................................................ 224 Appendix C.9 Best Practice 3-9: Elec tric or Hybrid Heavy Duty Delivery
Trucks 225 Appendix C.10 Best Practice 3-10: Im proved Engine Overall Efficiency................ 226 APPENDIX D. DETAILS OF INPUT DATA, ASSUMPTIONS, AND
ESTIMATION RESULTS FOR WATER MODE BEST PRACTICES ..........................227 Appendix D.1 Best Practice 4-1: Off-Center Propeller ............................................. 227 Appendix D.2 Best Practice 4-2: Propeller Boss Cap with Fins ............................... 228 Appendix D.3 Best Practice 4-3: Auxi liary Free-rotating Propulsion Device behind the Main Propellers ................................................................................. 229 Appendix D.4 Best Practice 4-4: Shoresid e Power for Marine Vessels at Ports ....... 230 Appendix D.5 Best Practice 4-5: B20 Biodiesel Fuel for Ships................................ 231 APPENDIX E. DETAILS OF INPUT DATA, ASSUMPTIONS, AND
ESTIMATION RESULTS FOR PIPELI NE MODE BEST PRACTICES ......................239 Appendix E.1 Best Practice 5-1: Convert Natural Gas Pneumatic Controls to
Instrument Air ..................................................................................................... 239 Appendix E.2 Best Practice 5-2: Re place High-Bleed Natural Gas Pneumatic
Devices with Low-Bleed Pneumatic Devices..................................................... 247 Appendix E.3 Best Practice 5-3: “Hot Tap” Method................................................. 252ix 

### Appendix E.4 Best Practice 5-4: Transfer Compression ........................................... 257 Appendix E.5 Best Practice 5- 5: Inline Inspection.................................................... 258 APPENDIX F. FUEL PROPERTIES, CO 2 

### EMISSIONS COEFFICIENTS FOR FULES, AND AVERAGE UNIT FUEL COSTS FOR GUIDEBOOK ...........................259 APPENDIX F.1 Properties of Different Fuels ............................................................. 259 F.1.1 Definitions of Fuel Properties..................................................................259
F.1.2 Diesel Fuel ...............................................................................................260
F.1.3 Jet Fuel.....................................................................................................262
F.1.4 Biodiesel ..................................................................................................263
F.1.5 Residual Fuel Oil .....................................................................................263
F.1.6 Natural Gas ..............................................................................................264
APPENDIX F.2 CO 2 

### Emissions Coefficients for Different Fuels ............................... 264
F.2.1 Diesel Fuel ...............................................................................................265
F.2.2 Jet Fuel.....................................................................................................265
F.2.3 Biodiesel ..................................................................................................265
F.2.4 Residual Fuel Oil .....................................................................................265
F.2.5 Natural Gas ..............................................................................................265 F.2.6 Comparison of CO 2 

### Emissions Coefficients of Different Fuels ..............266 APPENDIX F.3 Average Unit Costs for Different Fuels............................................. 266
F.3.1 Diesel Fuel ...............................................................................................266
F.3.2 Jet Fuel.....................................................................................................266
F.3.3 Biodiesel ..................................................................................................266
F.3.4 Residual Fuel Oil .....................................................................................267
F.3.5 Natural Gas ..............................................................................................267 F.3.6 Comparison of Average Unit Cost of Different Fuels..............................267x 

### LIST OF TABLES

Table ES- 1. Potential Best Practices and Their Potent ial Reductions in Modal GHG Emissions and Energy Use................................................................................ ES-5 Table ES- 2. Summary of Potential GHG Emissions Reductions, Energy Use Reduction, Net Savings, Unit Net Savings, and Simp le Pay-back Periods of Selected
Best Practices.................................................................................................. ES-11
Table 1- 1. Greenhouse Gas Emissions from th e Freight Transportation Sector in 2003......... 3
Table 1- 2. A Scenario of GHG Emissions from Freight Transportation from 2003 to
2025......................................................................................................................... 4 Table 2- 1. Truck Classifications by Weight, Number of Axles, and Number of Tires ............ 9
Table 3- 1. Contribution of Select ed Greenhouse Gases to Total Modes

......................... 

### 13 Table 3- 2. The Format of Standardized Reporting Table....................................................... 16
Table 3- 3. A Standardized List of Re sponsible Parties and Target Parties ............................ 19 Table 3- 4. The Format of Simplified Summary Table ........................................................... 21 Table 4- 1. List and Description of Potent ial Best Practices for the Truck Mode................... 38 Table 4- 2. Summary Table for the Comparison of the Quantitative Cost Results for
Selected Best Practices for the Truck Mode ......................................................... 51 Table 5- 1. List and Description of Pote ntial Best Practices for the Rail Mode ..................... 55 Table 5- 2. Summary Table for the Comparison of the Quantitative Cost Results for
Selected Best Practices for the Rail Mode............................................................ 59 Table 6- 1. List and Description of Pote ntial Best Practices for the Air Mode....................... 67 Table 7- 1. List and Description of Pote ntial Best Practices for the Water Mode .................. 76 Table 7- 2. Summary Table for the Comparison of the Quantitative Cost Results for A
Selected Best Practices for the Water Mode ......................................................... 81 Table 8- 1. List and Description of Potent ial Best Practices for the Pipeline Mode............... 85 Table 8- 2. Summary Table for the Comparison of the Quantitative Cost Results for Selected Best Practices for the Pipeline Mode ..................................................... 88
Table 9- 1. Potential Best Practices for the Truck Mode and the Estimated Reductions in GHG Emissions and Energy Use...................................................................... 93
Table 9- 2. Potential Best Practices for the Rail Mode and the Estimated Reductions in GHG Emissions and Energy Use...................................................................... 96
Table 9- 3. Potential Best Practices for th e Air Mode and the Estimated Reductions in GHG Emissions and Energy Use.......................................................................... 98
Table 9- 4. Potential Best Practices for the Water Mode and the Estimated Reductions in GHG Emissions and Energy Use.................................................................... 100xi 

### Table 9- 5. Potential Best Practices fo r the Pipeline Mode and the Estimated Reductions in GHG Emissions and Energy Use................................................. 102 Table 9- 6. Quantitative Summary of Reduc tions in GHG Emissions, Energy Use, and
Costs of Selected Best Practices ........................................................................ 106xii 

### LIST OF FIGURES

Figure 1- 1 Overview of the Organiza tion and Content of This Guidebook. .............................5 Figure 4- 1. Reductions in Modal GHG Emissi ons for the Best Practices for the Truck
Mode ......................................................................................................................49 Figure 5- 1. Reductions in M odal GHG Emissions for the Best Practices for the Rail Mode ..57 Figure 6- 1. Reductions in Modal GHG Emissions for the Best Practices for the Air Mode.....71 Figure 7- 1. Reductions in Modal GHG Emissi ons for the Best Practices for the Water
Mode ......................................................................................................................80 Figure 8- 1. Reductions in M odal GHG Emissions for Best Practices for the Pipeline Mode..87 Figure 9- 1. Total Modal 2025 GHG Emissi ons Reductions Based on Simultaneous Implementation of Multiple Best Practices in Each Mode ..................................104 Figure 9- 2. Magnitudes of the Total Modal 2025 GHG Emissions Reductions Based on Simultaneous Implementation of Multiple Best Practices for Each Mode..........105 Figure 9- 3. Estimated GHG Emissions per Un it of Freight Transport of Each Mode ...........108ES-1 

### EXECUTIVE SUMMARY

ES.1 Background
Freight transportation is compri sed of five major modes: truck, rail, air, water, and pipeline. Freight transportation accounts for approximately 9% of total greenhouse gas (GHG)
emissions in the United States. 1-3 

### The individual contributions of each of the five freight transportation modes to tota l freight transportation GHG emissions are 60, 6, 5, 13, and 16 percent, respectively. Energy use for all modes could increase by 75% from 2003 to 2030, based on a long-term energy tr end scenario in the Energy Information Administration’s Annual Energy Outlook 2006

. 4 

### Since energy use for freight transportation is expected to increase significantly in the next 25 year s, and because GHG emissions are largely based on energy use, GHG emissions will also increase significantly. Governments and the freight industry recognize the need for solutions to meet future challenges for GHG emissions reductions. 2,5 

### There are a growing number of technological and operational strategies, existing or developing, th at could reduce GHG emissions. Disseminating information regarding these tech nological and operational stra tegies can facilitate decision making to achieve reductions in energy use and GHG emissions. This guidebook presents a survey of potential best pr actices for reducing energy use and GHG emissions in freight transportation. The report characterizes each pot ential best practice in order to serve the
information needs of decision ma kers and responsible parties.

ES.2 Study Methodology
The methodology includes reviewing literatu re to identify best practices, assessing
maximum reductions in GHG emissions and ener gy or refrigerant use for individual best practices and of multiple best practices, assessing cost savings, and summarizing and reporting
assessment results. The GHG emissions of interest here are CO 2 

### , methane (CH 4 

### ), and refrigerants. CO 2 

### has a global warming potential (GWP) of 1. Methane has a global warming potential of 21. The currently widely used refrigerant, HFC-134a, has a GWP of 1,300. However, methane and refrigerant are emitted in smaller mass amounts than CO 2


### . A potential best practice is an existing or developing strategy or technology that is expected to lead to reductions in energy use, refrigerant use, and greenhouse gas emissions. Potential best practices are identified based on lite rature review. The poten tial best practices are categorized by subgroups based on the factors that the practices can improve, or the technologies that vehicles or devices may apply, to reduce GHG emissions.ES-2 

### The potential reduction in GHG emission and en ergy or refrigerant use for each potential best practice is estimated based on what may be achievable by 2025. Reductions are compared
to estimated 2025 GHG emissions if none of these best practices are adopted. While the scope of this work includes estimate of GHG emissions, energy use, and refrigerant use, in most cases, significant reductions in GHG emissions achievable w ith potential best pract ices are associated with reductions in energy use. . The potential per-device reductions in GHG em issions, energy or refrigerant use for an individual potential best pract ice are estimated based on the results of literature review. Per-device reductions for each potential best practic e, except for alternative fuel strategies, are estimated based on the differences in per-device emissions, energy use or refrigerant use with and without the use of this potentia l best practice. Reductions for alternative fuel strategies are estimated based on life cycle invent ories. Each practice may only be applicable to a fraction of
all devices within a mode. Identified potential best practices are categor ized with respect to developmental status: commercially available, pilot tests, and new c oncepts. Commercially available systems can be purchased or implemented now. Potential best pr actices based on pilot tests may be available within five to ten years, whereas those that ar e new concepts may require research, development, and demonstration that could vary in duration. An assumption is made that each potential best practice reaches a best estimate of maximum mark et penetration by 2025. Technical, practical, and cost barriers are not quantified here. Ac tual market penetration may be lower than estimated. However, the estimates provide a us eful upper bound as to wh at might be achieved if adoption of such practices is encouraged. Potential best practices are grouped by subgroup. Subgroups are based on similar objectives or methods. An example is aerodyn amic drag reduction. Aggregate reductions in modal GHG emissions and energy or refrigeran t use for a subgroup are estimated based on a simple linear combination of the reductions fo r multiple potential best practices within the subgroup, except in some situations. In some cas es, two or more practic es within a subgroup are mutually exclusive because they cannot be us ed simultaneously. In the case of mutual exclusion, the practice with the highest estimated reduction is used in the estimate of total reductions for the subgroup. For example, thr ee alternative refrigerants for air conditioning systems that could be used as potential best practi ces are mutually exclusive. Only one refrigerant can be used in an air conditioning system. CO 2 

### is chosen here because it has the lowest GWP compared to the other candidate refrigerants and its potential reductions in modal GHG emissions are the highest. Thus, the estim ates do not double count mutually exclusive practices. For some potential best practices, it is possible that they could be implementedES-3 

### simultaneously but that they may interact. Thus , the total reduction may not be a simple linear
combination of the reductions of each practice. An example w ould be several practices that reduce aerodynamic drag of a truck. However, th ere is a lack of data upon which to quantify
the overall reduction associated with interactions among multiple practices with in a subgroup. Therefore, these interactive ef fects are not quantified. The linear combination may tend to overestimate the maximum possible reduction for the subgroup. Such situations are noted. For all potential best practices, a quantitative estimate is made of the potential reductions in energy use, GHG emissions, and refrigerant leakage. However, for many potential best practices, inadequate data are available for as sessment of cost. Quantitative assessments for cost effectiveness are performed, where sufficient data are available for: practice cost; energy or refrigerant cost reduction; and total net cost savings. Total net cost savings is the difference between annual energy or refriger ant cost savings and the annualized costs, the latter of which include levelized capital costs and annual operati on and maintenance costs. Net savings per unit
of GHG emissions reductions are estimated by normalizing total net savings with respect to GHG emissions reductions. A positiv e value of net savings means th at the practice will pay for itself over some period of time, whereas a negative value means that the annualized costs exceed savings associated with reductions in energy use or refrigerant use. A standardized reporting table, which includes three parts, is used to re port the quantitative characteristics and assessment results of individual potential best practices. The first part summarizes characteristics, including: practice name; applicable mode type; subgroup; responsible part ies; target parties; targeted GHGs; strategy type; pr actice goals; developmental stat us; and practice summary The second part includes: the magnitude of transpor t activity for the whole mode; the magnitude of transport activity to which the practice is a pplicable; total annual modal reductions in GHG emissions, energy use, and refrigerant use; and re ductions of each per unit of freight transport. The third part includes: annuali zed costs; energy or refrigeran t costs savings; net savings per unit of reductions in GHG emissions and energy or refrigerant use; and simple payback periods. The effects of the potential best practices wh ere cost quantitative data are not available are discussed qualitatively in a structured approach. A simplified summary table, which includes four parts, is used to report the qualitative assessment results. The first part is technological information, including: prac tice name; applicable mode type; subgroup; responsible parties; target parties; target GHGs of interest; strategy type; practice goals for GHG emissions reduction; developmental status; and a brief summary of the practice. The second part includes quantitative estimat es of the potential modal reductions in GHG emissions, energy use or refrigerant use for individua l potential best practices. The third part is cost information, which can be any available knowledge, such as assumptions regarding capital cost, costES-4 

### premiums or cost savings, and retail price impact s reported in the literat ure. The fourth part describes the benefits and the drawbacks of the practice.

ES.3 Identification of Potential Best Prac tices and Their Estimated Reductions in GHG Emissions, Energy Use and Refrigerant Use
A total of 59 strategies have been identifi ed as potential best practices in freight transportation. There are 33, 6, 10, 5, and 5 potential best practices fo r the truck, rail, air, water, and pipeline modes, respectively. Over half of the total number of potential best practices is for the truck mode. Reduction in energy use is the basis of GHG emissions reductions for 51 of the potential best practices. One practice can reduce direct GHG em issions but increases direct energy use. For 3 practices, life cycle GHG em issions are reduced but life cycle energy use may be increased. Four strategies, which are potential best practices for the air conditioning system improvement subgroup for the truck mode, can reduce GHG emissions by reducing refrigerant leakage rate or by using low global-warming-potential refrigerants. Table ES-1 summarizes key aspects of the characteristics and potential reductions in modal GHG emissions and energy use for individual potential best practices. The magnitude of aggregate reductions in 2025 for each subgroup is also summarized in Table ES-1. The reported reductions are the difference between 2025 GHG emissions (or energy use) with and without use of potential be st practices in a subgroup. For cases of mutual exclusivity within a subgroup, one estimate of the reductions is given. For cases of multiple practice interaction, a simple linea r combination of the reductions is applied, which may tend to overestimate the maximum possible reduction for the subgroup. The potential total GHG emissions reduction by 2 025 for all 59 potential best practices is
estimated as 4.6 × 10 8 

### tons CO 2 

### eq. If no potential best practices are implemented, the total GHG emissions by 2025 for the freight tran sportation are estimated to be 11.0 × 10 8 

### tons CO 2 

### eq. If all potential best practices are implemented, the total GHG emissions for the freight transportation are estimated to be 6.4 × 10 8 

### tons CO 2 

### eq. Thus, total estimated GHG emissions reductions by 2025 for all poten tial best practices, 4.6×10 8 

### tons CO 2 

### eq., is estimated to be 42% of 2025 GHG emissions if no potential best practic e is implemented. Most of these estimated reductions (4.4 × 10 8 

### tons CO 2 

### eq. out of a total reduction of 4.6 × 10 8 

### tons CO 2 

### eq.) are attributed
to an estimated ener gy use reduction of 4.5 × 10 15 

### BTU. A small portion of these estimated reductions (0.18 × 10 8 

### tons CO 2 

### eq.) is attributed to refrigerant leakage rate reduction or use of low global-warming-potential refrigerants.ES-5 

### Table ES- 1. Potential Best Practices and Their Potential Reductions in Modal GHG Emissions and Energy UseMode Subgroup a I.D. No. Brief Name of Potential Best PracticeDevelopmental StatusbPotential Reduction in ModalGHG EmissionscPotential Reduction in ModalEnergy UsedThe Magnitude of AggregateGHG Emissions Reductions in2025 for Each Subgroup(106Tons CO2eq.)eThe Magnitude of AggregateEnergy Use Reduction in 2025for Each Subgroup(1015BTU)f

1-1 Off-Board Truck Stop Electrification C L L

1-2 Truck-Board Truck Stop Electrification C L L 1-3 Auxiliary Power Units C M M 1-4 Direct-Fired Heaters C M M Anti-Idling (E)

1-5 Direct-Fired Heaters with Thermal Storage Units P M M 15.0 0.19

1-6 Enhanced Air Conditioning System I - for Direct Emissions P L -

1-7 Enhanced Air Conditioning System II - for Indirect Emissions C L L

1-8 Alternative Refrigerants - CO 2 N M -

1-9 Alternative Refrigerants - HFC-152a N M -Truck

Air Conditioning System Improvement (B)

1-10 Alternative Refrigerants - HC N M - 19.2 g 0.02



### Continued on next page

a Some best practices within a subgroup are mutually exclusiv e or have interactions. (E) = mutually exclusive within a subgroup; (I) = interaction within a subgr oup; and (B) = some best practices ar e mutually exclusive and some have interactions within a subgroup. b Developmental status: N = new concepts; P = pilot tests; C = commercially available systems. New concepts include basic research activities, applied research activities, and expe riments at laboratory level. Pilot tests include testing prototype vehicles and demons tration projects. Commercially available sy stems can be purchased or implemented now.

c Potential reductions in modal GHG emi ssions are estimated based on the differe nce in 2025 modal emissions with and without the selected best practice divide d by the total modal emissions if no be st practices are implemented. These potential reductions are categorized into three ranges: low (L) (0% - 1%), medium (M) (1% - 4%), and high (H) (> 4%). d Potential reductions in modal energy us e are estimated based on the difference in 2025 modal energy use with and without the selected best practice divided by the total modal energy use if no best practices are implemented. These potential reductions are categorized into four ranges: low (L) (0% - 1%), medium (M) (1% - 4%), high (H) (> 4%), and negative (NG) (energy increases). “- ” refers to no reduction.

e These reductions are estimated based on the difference between 2025 modal emissions with and without implementation of the representative best practices of the subgroup. As noted in the text, only one best prac tice is selected if multiple practices within a subgroup are mutually exclusive. For cases of multiple interactions, a simple linear combination of the reductions is applied.
f These reductions are estimated based on the difference between 2025 modal energy use with and without implementation of the representative best practices of the subgroup.

g Of the reported value, 17.8 × 10 6 tons CO 2 eq. aggregated GHG emission reduction is attrib uted to refrigera nt leakage rate reduction or use of low global-w arming-potential refrigerants.ES-6 

### Table ES-1. ContinuedMode Subgroup a I.D. No. Brief Name of Potential Best PracticeDevelopmental StatusbPotential Reduction in ModalGHG EmissionscPotential Reduction in ModalEnergy UsedThe Magnitude of AggregateGHG Emissions Reductionsin 2025 for Each Subgroup(106Tons CO2eq.)eThe Magnitude of AggregateEnergy Use Reduction in2025 for Each Subgroup(1015BTU)f

1-11 Cab Top Deflector, Sloping Hood and Cab Side Flares C M M

1-12 Closing and Covering of Gap Between Tractor and Trailer, Aerodynamic Bumper, Underside Air Baffles, and Wheel Well Covers C M M

1-13 Trailer Leading and Trailing Edge Curvatures C M M

1-14 Pneumatic Aerodynamic Drag Reduction N M M

1-15 Planar Boat Tail Plates on a Tractor-Trailer N M M Aerodynamic Drag

Reduction (B)

1-16 Vehicle Load Profile Improvement C L L 66.6 0.83

1-17 Automatic Tire Inflation Systems C L L 1-18 Wide-base Tires C M M 1-19 Low-Rolling-Resistance Tires C M M Tire Rolling Resistance Improvement (E) 1-20 Pneumatic Blowing to Reducing Rolling Resistance N L L 28.3 0.35

Hybrid Propulsion 1-21 Hybrid trucks N M M 24.5 0.30 Weight Reduction 1-22 Lightweig ht Materials P H H 33.3 0.41 1-23 Advanced Transmission P L LTruck

Transmission Improvement (I) 1-24 Transmission Friction Reduction through Low-Viscosity Transmission Lubricants C L L 13.6 0.17

1-25 Engine Friction Reduction through Low-Viscosity Engine Lubricants C M M

1-26 Increased Peak Cylinder Pressures C M M 1-27 Improved Fuel Injectors P H H

1-28 Turbocharged, Direct Injection to Improved Thermal Management C L L Diesel Engine Improvement (I)

1-29 Thermoelectric Technology to Recovery Waste Heat N H H 118.3 1.47

1-30 Electric Auxiliaries C M M Accessory Load Reduction (B) 1-31 Fuel-Cell-O p erated Auxiliaries N H H 39.6 0.49 Driver Operation

Improvement 1-32 Truck Driver Training Program C M M 22.3 0.28Truck

Alternative Fuel 1-33 B20 Biodiesel Fuel for Trucks C H NG 30.8 -0.37 Total for the Truck Mode 411.5 4.14 

### Continued on next pageES-7 

### Table ES-1. ContinuedMode Subgroup a I.D. No. Brief Name of Potential Best PracticeDevelopmental StatusbPotential Reduction in ModalGHG EmissionscPotential Reduction in ModalEnergy UsedThe Magnitude of AggregateGHG Emissions Reductionsin 2025 for Each Subgroup(106Tons CO2eq.)eThe Magnitude of AggregateEnergy Use Reduction in2025 for Each Subgroup(1015BTU)f

Anti-Idling (E) 2-1 Combined Diesel Powered Heating System and Auto Engine Start/stop System P M M 3.4 0.04

2-2 Battery-Diesel Hybrid Switching Locomotive C M M
2-3 Plug-In Units C L L Weight Reduction 2-4 Light We ight Materials C H H 3.0 0.04 Rolling Resistance

Improvement 2-5 Lubrication Improve ment P M M 2.6 0.03Rail

Alternative Fuel 2-6 B20 Biodiesel Fuel for Locomotives N H NG 3.5 -0.04

Total for the Rail Mode 12.6 0.07

3-1 Surface Grooves P M M

3-2 Hybrid Laminar Flow Technology N H H 3-3 Blended Winglet C M M Aerodynamic Drag

Reduction (E)
3-4 Spiroid Tip P M M 5.7 0.06

Air Traffic Management 3-5 Air traffic Management Improvement N H H 3.5 0.04 3-6 Airframe Weight Reduction N M M Weight Reduction 3-7 Non-Essential Weight Reduction N L L 1.8 0.02

3-8 Ground-Based Equipment as an Alternative to Auxiliary Power Units P Ground Support

Equipment Improvement 3-9 Electric or Hybrid Heavy Duty Delivery Trucks P M M 1.7 0.02Air

Engine Improvement 3-10 Improved Engine Overall Efficiency C H H 7.7 0.08

Total for the Air Mode 20.4 0.21
4-1 Off-Center Propeller C M M 4-2 Propeller Boss Cap with Fins C M M Propeller System Improvement (E) 4-3 Auxiliary Free-Rotating Propulsion Device behind the Main Propeller C M M 3.7 0.04

Anti-Idling 4-4 Shoreside Power for Marine Vessels at Ports P L NG 0.2 > -0.01Water

Alternative Fuel 4-5 B20 Biodiesel Fuel for Ships N M NG 1.5 -0.02 Total for the Water Mode 5.3 0.03 

### Continued on next pageES-8 

### Table ES-1. ContinuedMode Subgroup a I.D. No. Brief Name of Potential Best PracticeDevelopmental StatusbPotential Reduction in ModalGHG EmissionscPotential Reduction in ModalEnergy UsedThe Magnitude of AggregateGHG Emissions Reductionsin 2025 for Each Subgroup(106Tons CO2eq.)eThe Magnitude of AggregateEnergy Use Reduction in2025 for Each Subgroup(1015BTU)f

5-1 Convert Natural Gas Pneumatic Controls to Instrument Air C L L Process Control Device Improvement 5-2 Replace High-Bleed Natural Gas Pneumatic Devices with Low-Bleed Pneumatic Devices C L L 1.4 < 0.01

Connecting Method 5-3 “ Hot Tap” Method C M L 2.5 < 0.01 5-4 Transfer Compression C L LPipeline

Maintenance 5-5 Inline Inspection C M L 1.8 < 0.01
Total for the Pipeline Mode 5.7 0.01ES-9 

### Within each mode, multiple potential best pr actices can be applied simultaneously to
achieve total 2025 modal GHG emissi ons reductions (compared to projected emissions if no potential best practices are used) of 57, 19, 34, 4, a nd 4 percent for the truck, rail, air, water, and pipeline modes, respectively. In making th ese estimates, we do not double count mutually exclusive potential best practices and we consider linear combinations of reductions for multiple potential best practices that c ould synergistically interact. The potential best practices also vary substa ntially in terms of th eir potential percentage
reductions in modal GHG emissions. The varia tions in reductions am ong individual practices range from 0.2 to 5.5 percent for the truck mode , 0.6 to 5.5 percent for the rail mode, 1.0 to 13.0 percent for the air mode, 0.2 to 3.0 percent for the water mode, a nd 0.1 to 1.9 percent for the pipeline mode. The average reductions for a potential best practic e are 2.2, 3.4, 2.3, 1.6 and 1.3 percent for the truck, rail, air, wate r, and pipeline modes, respectively. There is also substantial variability among the potential best practices in terms of their contributions to percentage decreases or increases in modal energy use. The range of these changes among individual potential best practices are from a 4.3 percent increase to a 5.7 percent decrease for the truck mode, a 5.3 percent increase to a 4.8 percent decrease for the rail mode, a 1.0 to 13.0 percent decrease for the air mode, a 1. 3 percent increase to a 3.0 percen t decrease for the water mode, and a 0.02 to 0.5 percent decrease fo r the pipeline mode. The averages of these changes are 1.8, 1.5, 2.3, 1.0, and 0.2 percent for the truc k, rail, air, water, and pipeline modes, respectively. Several potential best practices in the truck, rail, and water modes are based on alternative fuels. Alternative fuel strategies consume more energy than conventional petroleum fuel, based on life cycle inventories. Thus, the average percentage reductions in modal energy use among all potential best practi ces for truck, rail and water, which range from 1.0 to 1.8 percent, are significantly smaller than their average percentage redu ctions in modal GHG emissions, which range from 1.6 to 3.4 percent. The magnitude of the estimated potential GHG emissions reductions for the truck mode in 2025, which is 410 × 10 6 

### tons CO 2 

### eq., is significantly higher than for any of the other four modes, which range from approximately 5 × 10 6 

### to 20 × 10 6 

### tons CO 2 

### eq. The truck mode is estimated to contribute 66 percent of freight transportation GHG emissions in 2025 if none of the potential best practices are adopted. The total GHG emissions of this mode in 2025 are estimated to increase 67 percent over 2003 levels. If all identified potentia l best practices are implemented aggressively, 2025 GHG emissions could be reduced by as much as 28 percent compared to 2003 levels. Of other modes, each of the other four modes is estimated to contribute 12 percent or less to total frei ght GHG emissions in 2025. If no potential best practices are implemented, modal GHG emissions in 2025 from the rail, air, water, and pipelineES-10 

### modes are estimated to increase 49, 65, 28, and 15 per cent, respectively, compared to 2003 levels. If all identified potential best practices ar e implemented aggressively, 2025 GHG emissions could increase by 20, 8, 22, and 9 percent, resp ectively, compared to 2003 levels, which is smaller than the increase if no poten tial best practices are implemente d. In sum, if all identified practices are implemented aggressively, the possible net decrease in total freight transportation GHG emissions from 2003 to 2025 is 11%, even if energy use increases as currently projected. The magnitude of the estima ted potential energy use reductio n for the truck mode in 2025 is also significantly higher than for the other four modes. If no poten tial best practices are implemented, the truck mode is estimated to cons ume 70 percent of freight transportation energy in 2025. The truck mode energy use in 2025 is es timated to increase by 67 percent compared to 2003 levels. If all identified potential best pr actices are implemented aggressively, 2025 energy
use could be reduced by as much as 12 percent compared to 2003 levels. Each of the other four modes are estimated to consume 12 percent or less of total freight energy consumption in 2025 If no best practices are implemented, total modal energy use in 2025 from the rail, air, water, and pipeline modes are estimated to increase 49, 65, 28, and 15 percen t, respectively, compared to
2003 levels. If all iden tified potential best pr actices are implemented aggressively, these increases in energy use are estimat ed at 36, 8, 25, and 13 percent, respective ly, compared to 2003 levels. These energy use increases with the implementation of all identified potential best practices are significantly less than those energy use increases without the implementation of all identified potential best practices.

ES.4 Quantitative Assessment Results
To date, sufficient information has been obtai ned to assess the costs of 13 potential best practices quantitatively. Table ES-2 summar izes: reductions in GHG emissions and energy use; net savings; net savings per unit of GHG em issions reduction; and net savings per unit of energy use reduction, and simple pay-back peri ods of selected poten tial best practices. These 13 potential best practices vary subs tantially in terms of annual reductions in modal GHG emissions and energy use within their individual modes. Four best practices for the truck mode, which include auxiliary power units , direct-fired heaters, hybrid trucks, and B20 biodiesel, have the poten tial to achieve substantial GHG emissions reductions (8 × 10 6 

### ton CO 2 

### eq./year or more). Two best practices for the truck mode, auxiliary power units and hybrid, also have the potential to reduce energy use substantially, by 185 × 10 12 

### BTU or more. These 13 potential best practices vary substant ially regarding their cost- effectiveness and simple pay-back periods. The most cost-effective best practices are: plug-in units for the rail mode; direct-fired heater for th e truck mode; and combined diesel powered heating system andES-11 

### Table ES- 2. Summary of Potential GHG Emi ssions Reductions, Energy Use Reduction, Net Savings, Unit Net Savings, and Simp le Pay-back Periods of Selected Best
Practices aMode 

### I.D. No. Practice NameModal GHG EmissionReduction(106ton CO2eq./year)Modal Energy UseReduction(1012BTU /year)Net Saving($106/year)Net Saving per Unit ofGHG Emission Reduction($/ton CO2eq.)Net Saving per Unit ofEnergy Use Reduction($/106BTU)Simple Pay- back period(year)



### 1-1 Off-Board Truck Stop Electrification 2.4 27 330 138 12 N/A c


### 1-3 Auxiliary Power Units 15 185 440 29 2.3 3.2 1-4 Direct Fire Heaters 7.6 94 1350 178 14 0.6 1-21 Hybrid Trucks 24.5 300 3190 130 11 2.1Truck



### 1-33 B20 Biodiesel for Trucks 30.8 -370 -3300 -108 N/A b 

### N/A d



### 2-1 Combined Diesel Powered Heating System and Auto Engine Start/stop System 2.3 29 390 167 14 2.1

2-2 Battery Diesel Hybrid Switching Locomotive 1.1 14 70 65 5.2 5.5 2-3 Plug-In Unit 0.4 4 135 364 38 0.8Rail



### 2-6 B20 Biodiesel for Locomotives 3.5 -42 -380 -109 N/A b 

### N/A dWater 

### 4-5 B20 Biodiesel for Ships 1.5 -18 -180 -120 N/A b 

### N/A d



### 5-1 Convert Natural Gas Pneumatic Controls to Instrument Air 0.7 1 12 18 9.6 0.3

5-2 Replace High-Bleed Natural Gas Pneumatic Devices with Low-Bleed Pneumatic Devices 0.8 2 13 18 8.8 0.9Pipeline



### 5-3 “Hot Tap” Method 2.5 5 40 16 7.8 0.2

a These assessments are based on the assumptions th at these best practices reach their potential maximum market shares in 2025.
b This practice has no energy use reduction due to an increase in energy use, and it has no net saving due to high annualized cost and no energy cost saving.

c There is no pay-back period for this best practi ce because there is no initial capital cost to users.
d There is no pay-back period for this b est practice because there is no net saving.ES-12 

### auto engine start/stop system for the rail mode. The least cost-effective best practices are B20 biodiesel for the truck, rail and water modes. Fi ve best practices have simple pay-back periods of less than 1 year. From a national policy perspective, cons ideration of the potential magnitude of reductions is important. From an individual owner or operator perspective, consideration of cost savings and cost effectiveness may be more important. Even larger percentage reductions are possible if in termodal shifts, such as from truck to rail, are possible. The complete rail-truck intermoda l shift could reduce GHG emissions for the truck mode by 85 percent, if no potential best practi ces are implemented for either mode. Whether intermodal shift is possible depends on site-specific characteristics.

ES.5 Major Findings
Many potential best practices exist to reduce energy and refrigerant use, which could lead to reductions in GHG emissions. If potential best practices are aggressively implemented, it is possible for there to be a net decrease in total GHG emissions and energy use in freight transportation. Potential additional reductions might be possible if certain intermodal shifts are encouraged where possible. Limited quantitative data is available upon wh ich to base assessments of the costs of potential best practices. For thirteen potentia l best practices for which adequate data are available, the normalized cost sa vings per unit of GHG emissions reduction was highly variable. Ten of these potential best pract ices produce net cost savings b ecause of significant energy cost savings. Three of them have net cost increases because they involve subs titution of alternative fuel. Switching from petroleum to biodiesel ca n reduce GHG emissions but increase total costs, based on recent fuel prices. Governments and individual owners or operat ors are encouraged to carefully compare their options. From a national po licy perspective, some potential best practices, such as direct
fired heaters and B20 biodiesel for the truck mode , offer greater potential for large magnitudes in reduction of total GHG emissions, but may not be as cost-effective as other practices. Additional research and developm ent might result in reduced cost s. From an individual owner or operator perspective, considerat ion of cost savings and cost ef fectiveness are more important. Some potential best practices ma y be a “no regrets” proposition and the owner or operator can realize a net cost savings. This guidebook makes no recommendations about the use of specific strategies as best practices because typically information for best practices is incomplete and does not enable situation-specific assessment and comparison. While it is clear that many potential bestES-13 

### practices will not be considered by potential adopters until adequate cost data is available upon which to estimate costs reliably, at this time insufficient data are available to characterize costs reliably for most of the best practices identified here.

ES.6 Recommendations
Information given here can be updated as new information becomes available. In this work, costs could be assessed for only 13 best practices. Sinc e potential adopters of best practices need cost data for all of the possible best practices, there is a critical need for more cost information. Ongoing work is recomme nded to obtain or devel op cost estimates for best practices for which costs are not reported here, as well as to update cost estimates reported
here as new data become available. The impact of variations of key assumptions, su ch as market penetration rates, fuel prices, capital costs, and operation and maintenance co sts, can be assessed via sensitivity analysis. Developing tools to support decision maki ng regarding best practices are also recommended. Effective best practices are developed based on the conditions faced by a specific decision-maker, such as local fuel costs. It is critical to develop a decision support framework that will allow such parties to compare multiple best practices on the basis of representative and relevant important assumptions. A decision tree is helpful in situations of complex multistage decision problems for choosing best practices and can be applied to assist individuals in choosing from among many best practices. A decision tr ee involves a hierarchical ca scade of questions to guide decision-maker toward promising be st practices appropriate to th eir situations. The decision tree could be implemented in an interactive we b-based format and may be publicly accessible.1 

### 1.0 PURPOSE AND BACKGROUND Freight transportation is compri sed of five major modes: truck, rail, air, water, and pipeline. Greenhouse gas (GHG) emissions from freight trans portation account for approximately 9% of total greenhouse gas emissions in the United States. 1,2,3 

### The contributions
of these modes to total frei ght transportation GHG emissions are 60, 6, 5, 13, and 16 percent, respectively. Energy use for all freight modes, based on a long-term energy trend scenario, is estimated to increase approxi mately 75% from 2003 to 2030. 4 

### Given this expected increase in the next quarter of this cent ury, and since GHG emissions are largely based on energy use, GHG emissions from freight transportation are also exp ected to increase significantly in the future. There are a growing number of technological and ope rational strategies that could reduce GHG emissions from the freight sector. Ho wever, knowledge of these technological and operational strategies is not widespread. The objectives of this proj ect are to review and investigate existing technological and operational emission reduction strategies, and to develop a guidebook summarizing potential best practices within the freight transportation sector. The objectives of this guidebook are to: (1) review existing technological an d operational strategies to reduce greenhouse gas emissions, di rectly or indirectly , within the freight transportation sector; (2) develop a list of innovative technological and operational stra tegies (ongoing or completed) that can be considered as pot ential best practices; and (3) su mmarize and compare the various potential best practices.

1.1 Purpose of This Guidebook
A growing number of technological and opera tional strategies could reduce GHG emissions from the freight tr ansportation sector. 6-10 

### For example, as shown later, 14 identified energy efficiency strategies for the truck mode have the potential to reduce 3 billion gallons of fuel use
and 33 million tons CO 2 

### eq. annually in 2010, 11 

### which is about 7% of the 2010 greenhouse gas
emissions from the truck mode in the Unite d States. These tec hnological and operational strategies could offer freight transport owners an d operators added benefits, such as: (1) lower fuel costs (if the program helps reduce fuel usag e); (2) lower refrigerant costs (if the program helps reduce HFC usage); and (3) lower emissions of GHG and of air pollutants. Reductions in fuel or refrigerant usage would provide direct cost benefits to owners and operators, thereby creating at least partial incentives to adopt such technologies and programs. However, knowledge of existing technologic al and operational strategies, and their effectiveness at reducing greenhouse gas emissi ons, is not widespread throughout the freight transport community. An investigation of these strategies is needed to provide a consistent2 

### basis for identification and compar ison of methods that are availa ble to the freight sector to reduce GHG emissions. In addition, some technol ogical and operational strategies, such as fuel and refrigerant saving strategies , that could have significant greenhouse gas reduction benefits, may not have originally been developed with resp ect to an objective of GHG emissions reduction. Efforts to reduce fuel or refrigerant use typi cally provide an added benefit of reducing GHG
emissions. Thus, identifying and fostering the applicatio n of technological and op erational strategies that can reduce GHG emissions, and fostering similar efforts, can provide multiple benefits of enabling choices that lead to reductions in greenhouse gas emissi ons. Such choices may often also reduce fuel use, other air pollutant emissions, and co sts. This project supports knowledge-sharing through a guidebook on current be st technological and ope rational strategies within the freight transp ortation sector. Best practices ar e typically undertaken by responsible parties at the local, state, and Federal government levels, or at the levels of individual or fleet owners and operators. This best practice guidebook is intended to provide information useful to responsible parties in the frei ght transportation sector in id entifying, evaluating, and adopting similar technological and operational strategies.

1.2 Background
The freight transportation s ector contributes significantly to greenhouse gas (GHG)
emissions in the United States. The most important greenhouse ga s is carbon dioxide (CO 2 

### ), which is produced primarily from combustion of fossil fuels. 1,5 

### Other important greenhouse gases include methane (CH 4 

### ), nitrous oxide (N 2 

### O), and hydrofluorocarbons (HFCs). 1,12



### HFC-134a is the most common HFC. Greenhous e gases are often compared based on their global warming potentials (GWPs). Global warmi ng potentials are an indicator of the globally averaged relative radioactive forcing impacts of a particular GHG. CO 2 

### is assumed as a datum
with a GWP = 1. The GWPs of CH 4 

### , N 2 

### O, and HFC-134a are 21, 310, and 1,300, respectively. 1,13 

### These GWPs are used to convert the mass emissions of CH 4 

### , N 2 

### O, and HFCs to an equivalent mass of CO 2 

### with the same overall global warming impact. 1 

### In 2003, total greenhouse gas emissions in the United States were estimated as 7,789 × 10 6



### tons CO 2 

### eq., including 94 × 10 6 

### tons CO 2 

### eq. emissions from international aviation and marine transportation activities. The freight transporta tion sector in the United States emitted more
than 719.8 × 10 6 

### tons CO 2 

### eq. Thus, the freight transpor tation section is responsible for approximately 9.1 percent of the estimated total GHG emissions in the United States. 1-3 

### The truck mode emits approximately 60% of GHGs in freight transportation, which is approximately 5.4% of U.S. GHG emissions. The freight transpor t activities and GHG emi ssions in the freight3 

### transportation sector are summarized in Table 1-1. 1-3



### Table 1- 1. Greenhouse Gas Emissions from the Freight Transportation Sector in 2003 GHG Emissions (10 6 

### Tons CO 2 

### eq.) 1-3 

### Mode of Freight Transportation Freight Transport Activity (Billion Ton-miles) CO 2 

### CH 4 

### N 2 

### O HFCs Total

Trucks 1256 419.5 0.1 1.9 10.4 431.9

Rail 1550 42.9 0.1 0.3 - 43.3
Air 34 35.8 + 0.3 - 36.1
Water 1588 95.0 0.1 0.2 - 95.3 Pipeline 278 38.3 74.9 - - 113.2

Total 4706 631.5 75.2 2.7 (10.4) a 

### 719.8 a: Data here only include the amount of HFC emissions for the truck mode. 1 No detailed data are

currently available for the amount of HFC emissions for the other four modes. Thus, the number shown here is a lower bound on freig ht transportation HFC emissions.



### These emissions are typically associated with combustion processes or leaks, the latter of which are also known as fugitive emissions. For example, CO 2 

### is emitted primarily as a result of combustion of carbonaceous fuels (e.g., diesel fuel , jet fuel, residual fuel oil and natural gas). Methane can be emitted as a result of incomplete combustion of fuels and because of leaks in natural gas pipelines. N 2 

### O is emitted partly as a product of combustion and partly as a byproduct produced in some catalytic emission c ontrol systems. HFCs are typically emitted because of leakages in refrigeration and air conditioning systems. Of these four GHGs, the
most reliable data are for CO 2 

### . HFCs emissions for truck mode have been estimated, but there are not readily available HFC emissi ons data for other freight modes. 1



### The data in Table 1-1 indicate that the majority of freight-related CO 2 

### and N 2 

### O emissions
are associated with trucks, whereas the majority of CH 4 

### emissions are attributed to natural gas pipelines. Thus, GHG reduction strategies may be prioritized within these areas. Those modes that involve the use of refrigeration or air conditioning systems w ould be a priority for technological and operational st rategies that could reduce HFC emissions. However, when considering the total global warming impact, CO 2 

### emerges as the highest priority among the four GHGs considered here. Thus, CO 2 

### emissions from trucks are a major focus area. A scenario of total freight-related GHG emissions over time, which is shown in Table 1-2, is developed based on estimated GHG emissions in 2003 and an energy trend scenario for all modes. The latter comes from a long-term en ergy trend scenario, “2005 Technology Case,” in the Energy Information Administration’s Annual Energy Outlook 2006 , in which freight4 

### transportation energy use is estimated to in crease approximately 52% from 2003 to 2025. 4 

### Since energy use for freight transportation will in crease significantly in the next quarter of this century, and GHG emissions are largely based on energy use, GHG emissions from freight transportation are also estimated to increase significantly in the future. According to the scenario, greenhouse gas emissions for freight transportation are es timated to increase approximately 52% from 2003 to 2025.

Table 1- 2. A Scenario of GHG Emissions from Freight Transportation from 2003 to
2025 Annual GHG Emissions (10 6 

### Tons CO 2 

### eq.) Mode of Freight

Transportation 2003 2010 2015 2020 2025 Growth
2025 vs. 2003
Truck 432 520 588 649 721 67%
Rail 43 50 53 58 65 49%
Air 36 44 52 57 59 65%
Water 95 108 111 118 122 28% Pipeline 113 107 121 131 130 14%

Total 720 828 925 1012 1096 52%

Governments and the freight industry recognize the need for technological and operational strategies as to meet future challenges. 2 

### There are a growing number strategies, either existing or developing, that could reduce GHG em issions from the freight sector. There is a need to
review and characterize these strategies in order to support decision making regarding their potential adoption.

1.3 Using This Guidebook
This guidebook presents a survey of potential best practices for reducing energy use and GHG emissions in freight transportation. The surv ey includes characterization of each potential best practice in order to serve the information needs of responsible parties and decision makers. The organization and contents of this guide book are summarized in Figure 1-1. Brief descriptive information regardi ng each potential best practice, which are sorted by subgroup, are described in Chapters 4 to 8 for the truck, rail, air, water, and pipeline modes, respectively. The potential reductions in GHG em issions and energy or refrig erant use for all modes are summarized in Chapter 9. Intermodal comparisons and intermodal shifts are discussed in5 

### Definitions and Concepts Chapter 2 Methodology Chapter 3 Fuel Properties Appendix F 

### Background and Methodology

Assessments of Individual and Subgroups of Best Practices by Mode

Mode Summary Material Supporting Details Truck Chapter 4 Appendix A Rail Chapter 5 Appendix B Air Chapter 6 Appendix C Water Chapter 7 Appendix D Pipeline Chapter 8 Appendix E

Summaries of and Comparisons Between Modes Chapter 9 Conclusions and Recommendations Chapter 10



### Figure 1- 1. Overview of the Organiz ation and Content of This Guidebook.

Chapter 9. For the potential best practices for which quantitative cost data are not available, they are assessed qualitatively. Assessment results for these are given in simplified summary tables in Appendices A through E for the truck, rail, air, water, and pipeline modes, respectively. For the best practices for which quantitative cost data are available, they are assessed quantitatively. Assessment results are given in standardized reporting ta bles. Details of the analyses of these practices are gi ven in Appendices A through E for the truck, rail, air, water, and pipeline modes, respectiv ely. The properties, CO 2 

### emissions coefficients and average unit costs of fuels discussed are given in Appendix F. This guidebook is intended as a starting point of choosing and implementing strategies for the freight transportation sector in order to reduce GHG emissions. This guidebook is aimed at providing useful information to responsible and target parties rega rding opportunities for6 

### reducing energy use, refrigeran t use, and GHG emissions, as well as regarding the possible magnitude of such reductions. This guidebook contains brief information for many potential best practices in order to provide a comprehe nsive introduction to po ssible choices. This guidebook makes no recommendations regarding the use of specific strategies as best practices. Typically, information for best practices is in complete and does not enable situation-specific assessment and comparison.7 

### 2.0 DEFINITION OF KEY CONCEPTS

This Chapter defines key terms concepts pe rtaining to “best practices,” transportation modes, organizations responsible for adoptin g best practices, greenhouse gases, types of strategies of best practices, and the de velopmental status of these strategies.

2.1 “Best Practices” for Greenhouse Gas Reductions in Freight Transportation
Best practices for greenhouse gas reductions in freight transportation are defined here as strategies within the freight transportation sect or, whether they are technological or operational (see Section 2.4 for definitions), that are, or ca n be, implemented by responsible parties and that have been demonstrated to reduce, or have the potential to achieve reductions in, GHG
emissions. 14 

### Since the best practices identified are often of potential future applicability, they are referred to as potential best practices. Within the broad category of all best practices, there are disti nguishing criteria that can be used to compare and evaluate specific practices. A framework for categorization and characterization of each best practi ce is described in Section 3.1. Best practices typically achieve GHG emissi ons reductions by reducing the use of energy, refrigerants, or both. Thus, this guidebook explicitly considers the capability of potential best practices to reduce GHG emissions, en ergy use, and refrigerant use.

2.2 Modes of Freight Transportation
Freight transportation, defined as the transpor tation of commodities, is comprised of five major modes: truck, rail, air, water, and pipeline. 15 

### Highway transportation of freight is us ually referred to as the “truck” mode. 16 

### The standard measure of the activity of the truck mode is vehicle miles traveled (VMT). FHWA breaks down VMT figures by vehicle types. FHWA defines two types of trucks: (1) single-unit, 2-axle 6-tire,or 3+ axle trucks; and (2) combination trucks (single trailer and multiple trailer). 2,17 

### Trucks can also be classified based on othe r vehicle characteristics, such as cab type, body type, vehicle size, and gros s vehicle weight, which are defined by U.S. Bureau of
Census. 18-19 

### Classifications by cab type include: conventional cab (with sleeper, without sleeper, and others); cab over engine (with sleeper , without sleeper, and ot hers); and cab forward of engine (cab beside engine and others). 18 

### Classifications by body type include: (1) single-unit trucks, such as van, tank, and crane; and (2) truck-tractors, which have many types of trailers, such as automob ile carrier, livestock, van, ta nk, and mobile home toter. 188 

### Classifications by vehicle size include: lig ht, medium, light-heavy, and heavy-heavy. 18 

### Classifications by gross ve hicle weight (GVW) are su mmarized in Table 2-1. 18-19 

### The relationship among vehicle size, gross vehicle wei ght, number of axles, and number of tires are
summarized in Table 2-1. 18,20-21 

### Following the definitions of FHWA and U.S. Bureau of Census, the truck mode excludes trucks whic h gross vehicle weights are smaller than 10,000 pounds (Class 1 and Class 2 trucks). Railroad freight transportation is referred to the “rail” mode. This mode includes freight transport on Classes I, II, and III railroads, as well as switching and terminal carriers. 2 

### Class I railroads, which had operating revenues of at least $277.7 million in 2003, concentrate on long-haul, high-density intercity tr affic lanes, and account for 93 perc ent of U.S. freight railroad
revenue. Class II railroads are line-haul railroads w ith at least 350 route-miles, with revenues between $40 million and the Class I threshold, or both. Class II railroads are also called regional railroads because they t ypically serve a region located in two to four states. Class II railroads account for 3 percent of U.S. freight railroad revenue. Class III railroads operate less than 350 route-miles and earn less than $40 million per year. Class III railroads are also called
local line-haul carriers because they typically serve a single st ate. Class III railroads account for 2 percent of U.S. freight railroad revenue . Switching and terminal carriers account for 2 percent of U.S. freight railroad revenue. 22 

### Class I railroads consume more than 94 percent of
railroad fuel. 2 

### Thus, a priority for greenhouse gas reduction within the rail mode is the Class I
railroads. Air freight is transported in dedicated cargo ai rcraft and in cargo space of passenger aircraft. The latter is referred to as belly cargo. Both t ypes of aircraft carry a significant amount of air cargo. In order to estimate aircraft emissions at tributable to freight al one, it is customary to apportion passenger aircraft into passenger and freight components based on passenger and cargo weight. 2 

### Water (or waterborne) freight transportation includes domestic commerce and international trade, 16 

### and includes ships, barges, shallow draft vessels and deep draft vessels. 23 

### Foreign trade accounts for 58 percent of waterbor ne tonnage, with import tonnage nearly 2.7 times more than export tonnage. Domestic wa terborne tonnage is primarilyinland movements (rivers and canals), with smaller amounts moving along the coas ts, in the Great Lake s, and within ports. 2


### In 2003, domestic water trade consumed 797 Tera BTU of energy, including 302 Tera BTU of
distillate fuel oil and 495 Te ra BTU of residual fuel oil. 1, 3 

### Foreign water trade, at consumed 322 Tera BTU of energy, including 83 Tera BTU of distillate fuel oil and 239 Tera BTU of
residual fuel oil. 1 

### The pipeline mode includes the movement of natural gas and oil. However, this guidebook refers only to the movement of natural gas via the pipeline mode because of insufficient9 

### Table 2- 1. Truck Classifications by Weight , Number of Axles, and Number of Tires 19,21 

### Vehicle Size Class Gross Vehicle Weight (lbs) Number of Axles Number of Tires 1 <6,000 2 4 Light 2 6,000-10,000 2 4 3 10,000-14,000 2 6 4 14,000-16,000 2 6 Medium

5 16,000-19,500 2 6 Light-Heavy 6 19,500-26,000 3 6 7 26,000-33,000 3 10 Heavy 8 >33,000 3
3 + 10
10 +

information for the movement of oil. 3 

### The well-to-use of the pipeline system includes several stages: production, pro cessing, transmission and st orage, and distribution. 1 

### In this guidebook, the transmission and distribution stages of the pipeline mode are considered. The pipeline mode emits carbon dioxide from burning methane as the fuel for powering the pipeline systems, and it also directly emits methane to the atmosphere, which includes fugitive emissions and
vented emissions. Most of the methane emissi ons in the freight transportation are from the pipeline mode.

2.3 Subgroup
A subgroup within a mode is a collection of poten tial best practices in a mode that have either common goals or attributes. Subgroups are defined based on the fact ors that the practices can improve (e.g., in the case of the truck mode, id ling, aerodynamics, rol ling resistance, vehicle weight), or the technologies th at vehicles or devices may a pply (e.g., hybrid diesel-electric propulsion system, alternative fu els), to reduce GHG emissions.

2.4 Responsible Parties
A responsible party is a person or organizati on who has the authority to develop, promote, or select a best practice. Respons ible parties can be classified as individuals (vehicle owners or operators), companies (fleet owne rs or manufacturers), and governme nts (local, state, and central governments in the United States and in other countri es). When the strategies are in conceptual or developmental stages, academic institutions and non-governmental organizations may be also involved as responsible parties. For example, many universities are i nvolved in projects to10 

### study strategies that have the potential to reduce energy use and GHG emissions, such as anti-idling, hybrid vehicles , and alternative fuels.

2.5 Target Parties
A target party is a person or organization w ho may implement a best practice. Target parties are classified as individuals (vehicle ow ners or operators) and co mpanies (fleet owners).

2.6 Greenhouse Gas Emissions
The operation of freight transportation is re sponsible for the emissions of four major greenhouse gases: carbon dioxide (CO 2 

### ), methane (CH 4 

### ), nitrous oxide (N 2 

### O), and hydrofluorocarbons (HFCs), which have different GWPs, as discussed in Section 1.2. These four gases are considered. Howe ver, priority is given to CO 2 

### since it is emitted in the largest quantity with respect to global warming potential.

2.7 Strategy Types for Reducing Greenhouse Gas Emissions
There are two general types of best practi ce strategies. A strategy can be either technolgical or operational. 2 

### These two categories are defined here.

2.7.1 Technological Strategies Technological strategies modify, re place, or enhance a pi ece or system of equipment, its fuel, or its refrigerant to reduce GHG emissions. As examples, technol ogical strategies may involve replacing an existing engi ne with a new one, converting diesel -powered equipment to electrical power, using alternative fu els or refrigerants, repl acing older freight equipm ent, having an engine repaired or rebuilt, or improving fuel economy. 2



### 2.7.2 Operational Strategies Operational strategies change the way that vehicles and freight transportation systems operate, resulting in fewer GHG emissions. These st rategies may reduce fuel or refrigerant uses and result in lower operating cost s for the equipment owner. These strategies may involve improving freight operating efficiency (e.g., mini mizing “empty mileage,” which refers to the movement of empty commercial ve hicles) through improved freight logistics results in greater fuel productivity and more ton-miles of fr eight moved per unit of fuel consumption), 2 

### reducing congestion, reducing unnecessary idling, reducing empty mileage, increasing load factors, eliminating circuitous routing, a nd others. Assessing the effect of these operational strategies on emissions, however, can be difficult because there may be little relevant quantitative11 

### information. In some cases, extensive modeling of the performance of an integrated freight transportation system could be required, which is beyond the scope of this work. 2



### 2.8 Practice Goals
Practice goals include the percentage reductions in GHG emissions, energy use or refrigerant use. The goals may be specific to pa rticular transportation te chnologies or devices. A particular practice may only be applicable to a fraction of all devices within a mode. For example, anti-idling strategies for the truck mode are only applicable for long-haul trucks with sleeper cabs that typically have extended idli ng for mandatory driver rest periods. This particular type of truc ks contributes only a fraction of all fr eight transport activity within the
truck mode. Percentage reductions in GHG emissions, energy use or refrigerant use are estimated based on the difference in 2025 modal GHG emissions, ener gy use, or refrigerant use with and without the selected potential best prac tice, divided by the total modal emissions if no potential best practice is implemented.

2.9 Developmental Status
Developmental status include s new concepts, pilot tests, and commercially available systems. New concepts include basic resear ch activities, applied research activities, and experiments at the laboratory level. Pilot te sts include prototype vehi cles and demonstration projects. Commercially available systems can be purchased or implemented now.12 

### 3.0 METHODOLOGY

The methodology for characterizing and evalua ting potential best practices includes: reviewing literature to identify existing or deve loping potential best practices and to develop a preliminary list of potential best practices; cat egorizing and characterizing potential best practices; assessing their reductions in GHG emissi ons, energy use or refrigerant use; assessing annualized practice costs, and energy or refriger ant costs reductions; assessing cost savings; and summarizing and reporting assessment results. The potential best practices identified here ar e often of potential future applicability, since many of them have not been implemented widely and some are preliminary concepts. Thus, in many cases, there is not adequate data available with which to quantify cost. Therefore, the methodology includes both qualitati ve and quantitative approaches.

3.1 Literature Review
A list of potential best practices was identified, mostly based on literature review. Most data and information regarding potential best practices was ta ken from published technical and policy reports, books, and engineering journal pa pers, although some information was collected
from websites. Some information was collect ed from personal communications with experts via email and telephone.

3.2 Reductions in GHG Emissions, and Energy or Refrigerant Use, for Individual Best
Practices
Quantitative assessments were made for reductions in GHG emissions, energy use or refrigerant use in all cases, and for practice cost, energy or refrig erant cost reduction, and cost savings, where sufficient data were available. Where quantitative cost data were not available, the resource implications of the practices are di scussed qualitatively in a structured approach. The percentage contributions of CO 2 

### , CH 4 

### , N 2 

### O and HFCs emissions to the total GHG
emissions in terms of CO 2 

### equivalent for all five modes are listed in Table 3-1, based on the results of Table 1-1. The total GHG emissions for the truck mode are mainly contributed by
CO 2 

### emissions from fuel use. A small fracti on of the total freight truck GHG emissions is contributed by HFCs emissions from refr igerant use. The contributions of CH 4 

### emissions and
N 2 

### O emissions to the total freight truck GHG emission are insignificant. Thus, the opportunities to significantly reduc e freight truck GHG emissions ar e based on reductions in CO 2 

### and HFC emissions.13 

### Table 3-1 . Contribution of Selected Greenhouse Gases to Total Modal Greenhouse Gas
Emissions Percentage Contribution to Each Freight Transport Mode (%) Greenhouse
Gases Truck Rail Air Water Pipeline

CO 2 

### 97.1 99.1 99.2 99.7 33.8
CH 4 

### 0.0 0.2 0.0 0.1 66.2
N 2 

### O 0.4 0.7 0.8 0.2 N/A a


### HFC 2.4 N/A a 

### N/A a 

### N/A a 

### N/A a

a 

### No data are currently available.

The total GHG emissions for the rail, air and water modes are mainly contributed by CO 2 

### emissions from fuel use, which are also illust rated in Table 3-1. The contributions of CH 4 

### emissions, N 2 

### O emissions and HFC emissions to the to tal GHG emission are e ither insignificant or having no available data currently. Thus, the opportunities to significantly reduce GHG
emissions for these three modes are based on reductions in CO 2 

### emissions.
CH 4 

### is larger contributor to total GHG em issions for the pipeline mode than CO 2 

### , as shown in Table 3-1. For potential best practices for the pipeline mode, the reductions in GHG
emissions are based on reductions in CH 4 

### emissions. Reductions in GHG emissions and energy use fo r all potential best practices, except those
based on alternative fuel stra tegies, are estimated based on di rect emissions inventories. Reductions for alternative fuel strategies ar e estimated based on life cycle inventories. Reductions in refrigerant use are estimated base d on estimates of the re frigerant leakage rate reduction or the GWP difference between low globa l-warming-potential refrigerants and original refrigerants. While the scope of this work includes the estimate of GHG emissions, energy use, and refrigerant use, for simplicity and brevity we simply use the term “emissions” in this section. Per-device reductions for each po tential best practice, except for alternative fuel strategies, are estimated based on the differences in per-devi ce emissions with or wit hout use this potential best practice divided by per- device emissions if no potential best practice is implemented. Reductions for alternative fuel strategies ar e estimated based on life cycle inventories. The potential reductions in modal GHG emissi ons and energy or refrigerant use for an identified potential best practice are estimated based on the difference in 2025 modal emissions with and without the selected potential best pr actice divided by the tota l modal emissions if no potential best practice is implemented. Since a particular practice may onl y be applicable to a fraction of all devices within a mode and these ap plicable devices contribute only a fraction of all14 

### freight transport activity within this mode, the re ductions in modal emissions for this practice is also a fraction of its per-device reductions. For example, trucks of all types are estimated to carry 2.1 trillion ton-miles per year. Long-haul trucks with sleeper cabs, which are a portion of all trucks, carry 450 b illion ton-miles per year. Since stra tegies aimed at avoiding extended idling during rest periods can be only adopted by these long-haul trucks, these strategies are only applicable to, at most, 21 percen t of total truck freight movement. The transport activity to which anti-idling strategies are applicable is, ther efore, a portion of the tr ansport activity of the freight truck industry. An assumption is made that each potential best practice can reach a potential best estimate of maximum market penetr ation by 2025. Technical, practical, and cost barriers are not quantified here. Actual market penetration ma y be lower than estimated. However, the estimates provide a useful upper bound as to what mi ght be achieved if adoption of such practices is given practically. Details of these assumptions are given in Appendices A through E.

3.3 Quantitative Assessmen ts of Best Practices
For all potential best practices , quantitative estima tes are given for reductions in GHG emissions, energy use, and refrigerant leakage or GWPs. Furthermore, where sufficient data are available, quantitative assessments for cost ef fectiveness are performed for: practice cost; energy or refrigerant cost reduction; net savi ngs per unit of reductions in GHG emissions and energy or refrigerant use; and simple payback period. The characteris tics and the assessment results of the potential best practices are su mmarized in standardized reporting tables.

3.3.1. Quantifying Cost Implications The methods for estimating the reductions in GHG emissions, energy use or refrigerant use
are described in Section 3.2. Total net savings of implementing a potential be st practice is the difference between annual energy or refrigerant costs savings and the annualized costs, the latter of which includes levelized capital costs and annual operation and maintenan ce costs. Net savings are normalized per unit
of reduction in GHG emissions or energy or refrigerant use. A positive value of net savings means that the potential best practice will pay for itself over some period of time, whereas a negative value means that the annualized costs exceed savings associated with reductions in energy use, refrigerant use, or both. Simple payback periods are estimated based on the number of years required to recoup any additional capital or initial costs that lead to re ductions in energy or refr igerant use (or any other cost-saving benefits). Such estimates are base d on a discount rate of zero. These estimates are15 

### made where adequate data are available.

3.3.2 Summarizing and Reporting the Results For each potential best practice for which su fficient information is available for a quantitative assessment, a standard ized reporting table, which incl udes three parts, is used to report its quantitative characteristics and assessm ent results. The standard ized reporting table is given in the format of Table 3-2. The first part of the table summarizes the ch aracteristics of the potential best practice, including: practice name; applicable mode type; subgroup; responsible parties and target parties; targeted GHGs; strate gy type; practice goals; devel opmental status; and practice summary. Each of these is briefly explained. (1) Practice name: The name of the technology or operation. (2) Mode type: Mode types are sorted by code : 1 = truck; 2 = rail; 3 = air; 4 = water; and 5 = pipeline. (3) Subgroup: Each mode type can be di vided into two or more subgroups based on the factors that the practices can improve or the technologies that devices may apply. For example, the truck mode is divided into anti-idling, air conditioning system improvement, aerodynamics impr ovement, tire rolling resistance improvement, and other subgroups. (4) Responsible parties: These are categor ized by individuals, companies, research institutions, local governments, state governments, and Federal government. A standardized list of responsible pa rties is given in Table 3-3. (5) Target parties: These are categorized by individuals and companies. As noted in Section 2.4, target parties may differ fr om responsible parties. A standardized list of target parties is also given in Table 3-3. (6) Target GHGs: CO 2 

### , CH 4 

### , N 2 

### O, HFCs, or combinations of these. (7) Strategy type: Technology, operational, or both. (8) Practice goals: Practice goals include the types of devices that can adopt this practice and percentage reductions in GHG emissions, energy use or refrigerant use. Devices that can adopt this practic e may be only a portion of all devices in the industry. (9) Developmental status: Developmental stages are sorted by code: N = new concepts; P = pilot tests; and C = commercially available systems. (10) Practice summary: A br ief description of the imple mentation of the practice.16 

### Table 3- 2. The Format of Standardized Reporting Table
Characteristics of the Practice Description

Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary Emissions, Energy Use, and Refrigerant Use Unit Value

Annual Transport Activity for the Mode (ATAM) 10 9 ton-miles/year Annual Transport Activity to Which a Practice Is Applicable (ATAP) a 10 9 ton-miles/year Annual GHG Emissions Reductions(AGR) 10 6 ton CO 2 eq./year Annual Energy Use Reduction (AER) 10 12 BTU /year Annual Refrigerant Use Reduction (ARR) lbs/year Unit GHG Emissions Reductions (UGER) b 10 -3 lb CO 2 eq./ton-mile Unit Energy Use Reduction (UER) c BTU /ton-mile Unit Refrigerant Use Reduction (URR) d lbs/ton-mile Practice Costs

Capital Cost (C) 10 6 USD ($) Discount Rate (r) % 10% Technical Lifetime of Technology (L) years Fixed Charge Factor (a) e year -1 Annual O & M Cost (AOM) $10 6 /year Annualized Cost (AC) f $10 6 /year Annual Energy Cost Saving (AECS) $10 6 /year Annual Refrigerant Cost Saving (ARCS) $10 6 /year Net Savings (NS) g $10 6 /year Net Savings per Unit of GHG Emissions Reductions (NSGR) h $/ton CO 2 eq. Net Savings per Unit of Energy Use Reduction (NSER) i $/10 6 BTU Net Savings per Unit of Refrigerant Use Reduction (NSRR) j $/lb Simple Payback Period (SPP) k years 

### a: Each practice may only be applicable to a fraction of all devices w ithin a mode. Thus, annual transport activity to which a practice is appli cable (ATAP) is the transport activity performed by the fraction of all devices within a mode to which a practice can be applied, and ATAP is a fraction of annual transport ac tivity for the mode (ATAM).

b: 

## ( ) ATAP AGR UGER ductions Re Emissions GHG Unit = 

### (Continued on next page)17 

### (Table 3-2. continued)

c: 

### ( ) ATAP AER UER duction Re Use Energy Unit =



### d: 

## ( ) ATAP ARR URR duction Re Use frigerant Re Unit = 

### e: Fixed charge factor depends on the disc ount rate (r) and the technical lifetime (L). 

## ( )
( )                

+ = 

## ∑

= L

1 i i r 1 1 1 a Factor e arg Ch Fixed



### f: 

## ( )( ) AOM a C AC Cost Annualized + × = 

### g: 

## ( ) 

# ( ) ( ) AOM a C ARCS or AECS NS Savings Net

− ×

− =


### h: 

## ( ) AGR NS NSGR ductions Re Emissions GHG of Unit per Savings Net =



### i: 

### ( ) AER NS NSER duction Re Use Energy of Unit per Savings Net =


### j: 

### ( ) ARR NS NSRR duction Re Use t Refrigeran of Unit per Savings Net =



### k: 

### ( ) 

# ( ) AOM ARCS or AECS C SPP Period Payback Simple

− =18 

### The second part of the standa rdized reporting table includes: the magnitude of transport activity for the entire mode; the magnitude of transport activity to which the practice is applicable; total GHG emissions reductions per y ear; total energy use re duction per year; total refrigerant use reduction per year; and reducti ons per unit of freight transport (e.g., GHG emissions reductions per unit of freight transport, which has the unit of lb CO 2 

### eq. per ton-mile). The third part of the standard ized reporting table focuses on co st. This part includes: annualized costs; energy or refr igerant costs savings; net savings per unit of reduction in GHG emissions and energy or refrigeran t use; and simple payback period.

3.4 Qualitative Assessments of Best Practices
For each potential best practice for which there is a lack of adequate quantitative data and detailed information, qualitative assessments re sults are summarized in a simplified summary table, which is given in the format of Table 3-4. A simplified summary table includes: (a) technological information; (b) percentage reductions in GHG emissions, energy use or refrigerant use; (c) cost information; and (d) a description of benefits and drawbacks of the practice. Technological information incl udes: practice name; appli cable mode type; subgroup; responsible parties; target parties; target GHGs of interest; strategy type; practice goals for GHG emissions reduction; developmental status; a nd a brief summary of the practice. The information for these items has been explained in Section 3.3.2. The second part of the table includes the potential reductions in modal GHG emissions, energy use or refrigerant use for individual potential best pract ices, which are quantitatively. Cost information is any available knowledge, such as capital co st assumptions, cost premiums or cost savings assumptions and retail price impacts reported in the literature. Benefits and drawbacks of the potential best practice are also discussed and summarized. However, typically such information is incomple te and does not enable estimation of net cost savings in the same manner as fo r those practices for which detailed quantitative information is
available.

3.5 Aggregated Reductions in GHG Emissions, Energy or Refrigerant Use for Multiple
Best Practices
Aggregate reductions in modal GHG emissions , energy use, or refrigerant use for an individual subgroup are estimated based on a simple linear comb ination of the reductions for multiple best practices within the su bgroup, except as noted below.19 

### Table 3- 3. A Standardized List of Re sponsible Parties and Target Parties24 Mode Category Responsible Parties Target Parties

Individuals 1. 2. 3. 4. Individual truck drivers Fleet truck drivers Truck loading operators Truck maintenance workers 1. 2. 3. 4. 5. Individual truck drivers Fleet truck drivers Truck loading operators Truck maintenance workers Truck goods shippers

Companies 5. 6. 7. 8.

9.

10. 11

. 12. 13. 14. 15. Truck operating companies Truck manufacturing companies Truck trailer manufacturing companies Electrical and electronic equipment manufacturing companies Transmission and power train parts manufacturing companies Metal stamping companies Air-conditioning manufacturing companies Truck maintenance companies Truck stop or rest area owners Fuel companies Lubricant companies 6. 7.

8. Truck operating companies Truck maintenance companies Truck stop or rest area

owners

Research Institutions 16. 17. 18. 19. University Non-governmental organization National laboratory Private research institution Truck

Governments 20. 21. 22. Local governments State governments Federal government

Individuals 23. 24. 25. Locomotive drivers and crews Railroad operators Railroad maintenance workers 8.

9. 10. Locomotive drivers and

crews Railroad operators Railroad maintenance workers

Companies 26. 27.

28. 29. 30. Railroad companies Railroad rolling stock manufacturing companies Railroad goods shippers Fuel companies Lubricant companies 11. 12.

13. Railroad companies Railroad maintenance companies Railroad goods shippers

Research Institutions 31. 32. 33. 34. University Non-governmental organization National laboratory Private research institution Rail

Governments 35. 36. 37. Local governments State governments Federal government Air Individuals 38. 39. 40. Aircraft pilots and crews Airport operators Aircraft maintenance workers 14. 15. 16. Aircraft pilots and crews Airport operators Aircraft maintenance workers 

### Continued on Next Page.20 

### Table 3-3. Continued.

Mode Category Responsible Parties Target Parties

Companies 41. 42. 43.

44.

45. 46. 47. Aircraft companies Aircraft manufacturing companies Aircraft engine and engine parts manufacturing companies Aircraft parts and auxiliary equipment manufacturing companies Airport operation companies Fuel companies Lubricant companies 17. 18. 19. Aircraft companies Airport operation companies Aircraft goods shippers

Research Institutions 48. 49. 50. 51. University Non-governmental organization National laboratory Private research institution Air

Governments 52. 53. 54. Local governments State governments Federal government

Individuals 55. 56. 57. Ship captains and crews Port operators Ship maintenance workers 20. 21. 22. Ship captains and crews Port operators Ship maintenance workers

Companies 58. 59. 60. 61. 62. Shipping companies Ship building and repairing companies Port operation companies Fuel companies Lubricant companies 23. 24. 25. Shipping companies Port operation companies Ship goods shippers

Research Institutions 63. 64. 65. 66. University Non-governmental organization National laboratory Private research institution Water

Governments 67. 68. 69. Local governments State governments Federal government

Individuals 70. 71. Pipeline system operators Pipeline system maintenance workers 26. 27. Pipeline system operators Pipeline system maintenance workers

Companies 72.

73. Natural gas pipeline operation companies Natural gas pipeline system manufacturing companies 28.

29. Natural gas pipeline operation companies Natural gas shippers

Research Institutions 74. 75. 76. 77. University Non-governmental organization National laboratory Private research institution Pipeline

Governments 78. 79. 80. Local governments State governments Federal government21 

### Table 3- 4. The Format of Simplified Summary Tables Attribute Description

Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary Potential Reductions in Modal GHG Emissions Potential Reduction in Modal Energy Use Potential Reduction in Modal HFC Use Cost Information Benefits and Drawbacks



### Within a subgroup, it is possible that two or more best practi ces may be mutually exclusive in serving similar functions or requiring installation on the same lo cation of a vehicle or system. In the case of mutual exclusion, the best practice with the highest estimated reduction is used in
the estimate of total modal re ductions for the subgroup. Fo r example, thre e alternative refrigerants for air conditioning systems that c ould be used as best practices are mutually exclusive. Only one refrigerant can be used in an air conditioning system. CO 2 

### is chosen here because it has the lowest GWP compared to th e other candidate refrigerants and its potential
reductions in modal GHG emissi ons are the highest. Thus, the estimates do not double count mutually exclusive best practices. In a subgroup, it is possible that several best practices are not mutua lly exclusive and could be implemented simultaneously. However, th e total reduction may not be a simple linear
combination of the reductions of each indivi dual practice because the practices may have interactive effects. For example, the combin ed reduction in aerodynamic drags of several best practices would not be a linear sum of the drag reduction of each practi ce individually. Since there is a lack of data upon wh ich to quantify the overall reductio n associated with interactions among multiple best practices with in a subgroup, each interactive ef fect are not quantified. The linear combination may tend to overestimate the maximum possible reduc tions for the subgroup.
Total reductions in modal GHG emissions and energy or refrigerant use for all best practices are estimated based on summing the redu ctions of each subgroup. The contribution of a subgroup to total reduc tions in modal GHG emissions and energy or refrigerant use is22 

### estimated, and it is normalized by dividing the aggregate reductions for a subgroup by total
modal reductions for all best practices for this mode.

3.6 Intermodal Substitution
In some situations, it may be possible to substitute one mode for another for a given shipment, either partially or fully. From the estimates of 2003 freight transport activities and GHG emissions for individual modes in Section 1.2, the unit GHG emissions of each of these modes are 0.69, 0.06, 2.15, 0.12, and 0.81 lb CO 2 

### per ton-mile for truck, rail, air, water, and pipeline, respectively. If it were possible to subs titute some or all of a trucking or air trip with transport by rail or water-borne vessel, ther e could be a reduction in GHG emissions. For example, instead of transporting goods by truck from the origin to the destination, it may be possible to transport the goods by tr uck from the origin to a rail te rminal, continue the shipment by rail for most of the mileage of the trip, and offload the goods to a local truck for delivery at
the destination. An upper-bound estimate of the reduction in GHG emissions from inter-modal substitution of rail for trucking can be deve loped by assuming that all of th e truck transport ton-miles are replaced by the same amount of ra il transport ton-miles. In real ity, the substitution would not be complete, since some truck miles would likely be required at the origi n, destination, or both. The methodology for assessment of intermodal substitutions is described in Section 9.6.3.23 

### 4.0. BEST PRACTICES FO R THE TRUCK MODE

This chapter identifies and characterizes 33 poten tial best practices applicable to the truck mode. These best practices are di vided into 11 subgroups, including:

• reduction in fuel use and emi ssions during extended idling,

• air conditioning system improvement,

• reduction in aerodynamic drag,

• reduction in tire rolling resistance,

• hybrid propulsion,

• weight reduction,

• improved transmission efficiency,

• improved diesel engine efficiency,

• reduction in accessory load,

• modifications in driver operational practices, and

• alternative fuels. Additional details regarding all of these best practices are in Appendix A, including the basis for estimated reductions in GHG emissions, energy use, and refrigerant use. For five of these practices, sufficient data were available to quantify costs.

4.1 Anti-Idling
Long distance truck drivers are re quired to take mandatory re st stops. These rest stops are intended to promote safety by reducin g driver fatigue. Approximately 0.68 million long-haul trucks are equipped sleeper cabs. 3 

### Sleeper cabs contain a small living environment with sleeping accommodations. The advantage of a sl eeper cab is that the driver can take rest stops at any location where the truck can be parke d, rather than have to stay at a hotel. Such compartments require heating, ventilation or air conditioning (HVAC), often have small appliances such as refrigerators and microwav e ovens, and have electri cal outlets to support other auxiliary loads such as television or comp uters. Conventionally, the heating, cooling, and power requirements for the sleeper cab during driver rest time are supplied by the diesel-fueled base engine of the truck. These engines are run under extended idling conditions for continuous periods of many hours. According to the lite rature, a typical base engine may consume 0.85 gallons of fuel pe r hour during idle. 25 

### The actual amount of fuel consumption varies among different engines and depends on the HVAC a nd electrical loads. A number of so-called “anti-idling” techniques have b een introduced. The objective of these techniques is to avoid24 

### use of the base engine during extended idle by substituting alternative sources of HVAC and electricity during rest stops. Some techniques involve insta llation and operation of on-board systems, while others require connecting the truck to a “shore-based” facility.

4.1.1 Best Practice 1-1: Off-Board Truck Stop Electrification Off-board truck stop electrification is a comme rcially available system that can avoid the need for idling of the truck base engine while a truck is parked at a truck stop. This external system enables a truck driver to switch off the ba se engine by connecting the truck to a specially designed service module. This module provides heating, air conditioning and electricity to the truck cab, and it is installed tem porarily through a window of the truc k. This system is reported to consume less energy than the base engine and emits less CO 2


### . 26-29 

### A commercially available example of this is the IdleAire system. 30 

### The projected 2025 modal GHG emissions are
721×10 6 

### tons of CO 2 

### eq., and the potential reduction in modal GHG emissions are 2.4 ×10 6 

### tons of CO 2 

### eq. Thus, the estimated potential reduction in moda l GHG emissions are 0.3%. Trucks cannot use this alternative unless they ar e parked at a truck stop with this type of electrification system.

4.1.2 Best Practice 1-2: Truck-Board Truck Stop Electrification In contrast to Best Practice 1-1, which invol ves an external service module, truck stop
electrification can be as simple as connecting the truck to a shore-based power supply via an electrical cable. This type of system is effect ive in situations where the HVAC system of the sleeper cab is entirely electricall y operated and, thus, is independent of the base engine. This system is connected to the elec trical grid. Thus, the energy us e and emissions for this best practice are associated with those of the power gr id. Compared to use of the base engine, this type of electrification is reported to consume less energy and emits less CO 2


### . 28-29,31 

### The estimated potential reduction in modal GHG em issions are 0.4%. Trucks cannot use this alternative unless they are parked at a truck st op with this type of electrification system.

4.1.3 Best Practice 1-3: Auxiliary Power Units Auxiliary power units (APUs) are commercia lly available systems that can avoid the need for idling of a truck’s base engine. An AP U is installed on a truck and consists of a small diesel engine that provides power for an HVAC system and electrical outlets that service the sleeper cab. APUs are advertised as consuming less fuel under typical lo ad conditions than the base engine. There are some practical questions regarding whether APUs are sufficiently quiet for use while a driver is sleeping, especially if they cycle on and off to meet intermittent A/C compressor demand, regarding their ability to rapidly cool-down the cab on very hot days, and25 

### their actual fuel effici ency relative to base engines. Ba sed on available information, APUs are estimated to consume less diesel fuel than the base engine and emit less CO 2


### . 27,32 

### The estimated potential reduction in modal GHG em issions are 2.1%. One disadvantage of this practice is its high capital cost. The capital co st of this practice may be even higher if it requires tailpipe emissions control devices. Th ere is uncertainty regarding the real world relationship between fuel use rates of APUs co mpared to those of truck base engine, which confounds the ability to accurate ly estimate the fuel saving po tential of this practice.

4.1.4 Best Practice 1-4: Direct-Fired Heaters Direct-fired heaters are commercially avai lable systems for heating a sleeper cab by burning diesel fuel. Heat from combustion ga ses passes through a heat exchanger that warms the air inside the sleeper cab. In addition, these heater systems can be configured to provide heat for the base engine to maintain readiness for base engine restart in cold weather. Unlike the previous three best practices described above, this system is only applicable to heating in cold weather and does not provide cooling in hot weather. Furthermore, this system does not provide electrical power; instead, electrical power is drawn from the truck’s existing battery. Direct-fired heaters are reported to consume less di esel fuel than the base diesel engines and to
emit less CO 2


### . 27 

### The estimated potential reducti on in modal GHG emissions are 1.1%.

4.1.5 Best Practice 1-5: Direct-Fired Heaters with Thermal Storage Units Thermal storage systems consist of a phase cha nge material that can be heated or cooled from the truck cab air conditioning unit or heating system while the base engine is operating. These systems are demonstrated. The thermal storage system can be used as a means of providing warm or cool air to the sleeper cab vi a a heat exchanger and a blower unit when the base engine is off. In order to supplement the heating capability, thermal storage systems can be coupled with direct-fired he aters to store more thermal ener gy that is available for warming
interior cabin air even when th e direct-fired heater is not operating. This system supplies heating and cooling, but no electri cal power, to the sleep er compartment when the base engine is off. Furthermore, similar to Best Practice 1- 4, this system does not pr ovide electrical power; instead, electrical power is drawn from the tr uck’s existing battery. The combination of
direct-fired heaters and thermal storage units is reported to c onsume less energy than the base diesel engines and to reduce CO 2 

### emissions. The potential re duction in modal GHG emissions may be as large as 2.9%. 27 

### The disadvantage of this practice is that it supplies no electricity, and requires power from the vehicle’s batteries.26 

### 4.2 Air Conditioning System Improvement
Mobile air conditioning systems cause "direc t" and “indirect” GHG emissions. Direct GHG emissions are due to refrigerant leakage. Indirect GHG emissions are additional exhaust
CO 2 

### emissions that result from the engine load due to operation of the air conditioning system compressor. Refrigerant leakage rate reductio n or use of low global-warming-potential (GWP) refrigerants can reduce direct emissions. Increasing the energy efficiency of air conditioning system can reduce indirect emissions. The estimates of potential reduction in modal GHG emissions for best practices within this subgro up are mainly based on a California governmental report. 33



### 4.2.1 Best Practice 1-6: Enhanced Air Conditioning System I - for Direct
Emissions Enhanced air conditioning systems, which ar e undergoing testing, can reduce direct GHG emissions by reducing the leakage rate of th e commonly used HFC-134a refrigerant. The refrigerant leakage rates of th ese systems may be decreased th rough the use of low permeable hoses, improved hose ends and connectors, and improved compressor shaft seals. 12,33-35 

### The estimated potential reductions in modal GHG emissions are 0.9%. 33 

### There is not as yet a standard method for testing and certifying the leak age rate of an enhanced system is in the developmental stage.

4.2.2 Best Practice 1-7: Enhanced Air Conditioning System II - for Indirect
Emissions Enhanced air conditioning systems fo r reducing indirect GHG emissions are commercially available. These systems can d ecrease base engine load requirements from mobile air conditioning systems by replacing fixed displacement compressors (FDCs) with externally controlled variable displacement compressors (VDC), using improved control systems, and using improved condensers and evaporators. By reducing the engine load requirements,
exhaust CO 2 

### emissions can be reduced

. 33,36-37 

### The benefit of reduci ng engine load is only available in hot weather when the A/C system is used. The estimated potential reductions in
modal GHG emissions are 0.2%. 33



### 4.2.3 Best Practice 1-8: Al ternative Refrigerants - CO 2 

### The GWP of leaking refrigerant can be reduced by using an alternative low GWP refrigerant. The current widely used re frigerant, HFC-134a, has GWP = 1,300, whereas CO 2 

### has GWP = 1. Therefore, CO 2 

### is being investigated as an alternative refrigerant. This system27 

### is in the developmental stage. Engineers are wo rking to improve the relia bility and efficiency of systems that use CO 2 

### refrigerant. 12,33-34,36 

### The estimated potential reductions in modal GHG
emissions are 2.5%. 33 

### Safety assessment and potential risk mitigation may be needed because of different safety characteristics of this alternative refrigerant compared to HFC-134a.

4.2.4 Best Practice 1-9: Altern ative Refrigera nts - HFC-152a HFC-152a is another promising low GWP refrigerant. HFC-152a has a lower GWP (120) than that of HFC-134a. The transition from one HFC to a nother, such as from HFC-134a to HFC-152a, would be relatively easy (compared a transition to CO 2 

### ) since these two refrigerants have similar properties an d A/C system components would need less
modification. 26,27,42 

### The estimated potential reductions in modal GHG emissions are 2.4%. 33 

### The flammability of this alternative refriger ant, although moderate, motivates the need for additional safety assessment and potential risk mitigation.

4.2.5 Best Practice 1-10: Alt ernative Refrigerants - HC Propane has been proposed as an alternativ e refrigerant for vehicle air conditioners. Propane has a lower GWP (20) than that of HFC-134a. 38 

### This mobile hydrocarbon system has had more than 400,000 accumulated unit-years of ope rating experience in Australia. However, a propane-based refrigerant system uses more energy for operation and increases indirect GHG emissions, thus there is some trade-off. 34 

### Furthermore, there is c oncern regarding its safety. 36 

### If such systems are accepted for use in the U. S., the estimated potential reductions in modal
GHG emissions are 2.5%. 33 

### The flammability of this alterna tive refrigerant motivates the need for additional safety assessment and potential risk mitigation. Release of propane to the atmosphere may also increase tropospheric ozone formation.

4.3 Aerodynamic Drag Reduction
Typical heavy-duty trucks n eed to use a significant por tion of fuel to overcome aerodynamic drag. Since higher speed cause s larger aerodynamic drag, the effect of aerodynamic drag on fuel economy is higher at highw ay speeds compared to local road speeds. Thus, reduction of aerodynamic drag may significan tly improve the fuel efficiency of trucks, especially during highway speed operations. 39 

### Aerodynamic drag can be significantly reduced by installing add-on devices to improve the vehi cle profile, pneumatic blowing systems, and boat tail plates, or by improving vehicle load profile.28 

### 4.3.1 Best Practice 1-11: Vehicle Profil e Improvement I - Cab Top Deflector, Sloping Hood and Cab Side Flares Truck tractor aerodynamic dr ag reduction options, includi ng cab top deflector, sloping hood, and cab side flares, have been introduced into the market. These add-on devices are estimated to reduce the aerodynamic drag of medi um- and heavy-duty trucks and increase their fuel efficiency and reduce GHG emissions. 32 

### Taking into account that these devices reduce only a fraction of aerodynamic dr ag, the estimated potential reductions in modal GHG emissions are 1.4%. Although this best prac tice increases truck weight slig htly, the estimated reduction in
fuel use and GHG emissions takes this into account.

4.3.2 Best Practice 1-12: Vehicle Pr ofile Improvement II - Closing and Covering of Gap between Cab and Trailer or Van, Aerodynamic Bumper, Underside Air Baffles, and Wheel Well Covers Truck side and underside aerodynamic drag reduction options, incl uding closing and covering the gap between a trac tor and trailer (or van), aerodynamic bumper, underside air baffles, and wheel well covers, are commerci ally available technologies for medium- and heavy-duty trucks. Aerodynamic drag that result s from the tractor-trailer gap can be reduced by installing gap covering add-on devices. Drag underneath the vehicle can be reduced by installing a lower bumper and underside air baffle s. Wheel well covers enclose the open space between the wheels and the truck body, which str eamlines the side of the truck. From the results of field tests, combining these opti ons is estimated to reduce energy use and GHG
emissions. 11,32 

### The estimated potentia l reductions in modal GHG emissions are 2.4%. Although this best practice increases truck weight slightly, the estimated reduction in fuel use
and GHG emissions takes this into account.

4.3.3 Best Practice 1-13: Vehicle Prof ile Improvement III - Trailer or Van Leading and Trailing Edge Curvatures Truck trailer (or van) aerodynamic drag reduc tion options, including the improvement of their leading and trailing edge curvatures, are commercially available strategies. Aerodynamic drag can be reduced by the redesign of leading a nd trailing edges, such as rounded front corners
and rounded aft corners. 40 

### The estimated potential reducti ons in modal GHG emissions are
1.2%. 32



### 4.3.4 Best Practice 1-14: Pneumatic Aerodynamic Drag Reduction Pneumatic blowing systems are being tested as add-on devices that reduce aft-end29 

### aerodynamic drag. This type of system blows air from slots at the rear of the trailers of heavy-duty vehicles in order to smooth air fl ow over the trailer surf aces and reduce aft-end aerodynamic drag. This results in reduction in vehicle fuel energy requirements. From the results of full-scaled tests, this system reduc es energy use for an i ndividual truck by 3.9% to
4.8%. 32,41-42 

### However, based on the results of field test s, some truck configurations, such as the dimensions of the tractor-trailer gap, may i nhibit the reduction of aerodynamic drag achievable via this system. 43 

### This best practice is suitable for co mbination trucks that have van trailers, which are a portion of the total truck fleet. Th erefore, the estimated potential reductions in
modal GHG emissions are 2.2%. If used in comb ination with another be st practice, such as Best Practice 1-12, there may be a negative synergistic effect in that the total improvement in aerodynamics is less than the linear sum of improvements from individual practices.

4.3.5 Best Practice 1-15: Planar Boat Tail Plates on a Tractor-Trailer Planar boat tail plates are being tested as add-on devices that reduce aft-end aerodynamic drag. These devices are rectangular plates mounted to the after-end of a trailer in an attempt to
reduce the wake of trucks. The formation of a wake requires energy; thus, reducing the wake can energy consumption. From a full-scaled te st for a tractor-van trailer, this practice significantly reduces aerodynamic drag, and it was found to reduce average energy use by approximately 8.3% over a 10,000 mile trip. 44 

### This best practice is suitable for combination
trucks that have van trailers , which are a portion of the tota l truck fleet. Therefore, the estimated potential reductions in modal GHG emissions are 3.8%. The drawback of this practice is that it may interf ere with loading and unloading op erations, depending on the design.

4.3.6 Best Practice 1-16: Vehicle Load Profile Improvement Aerodynamic drag can be reduced by the use of a streamlined load profile for a trailer, which is a low-tech option. This practice keeps th e load profile of a tra iler as low as possible and secures tarpaulins to smooth air flow and reduce energy use. 11 

### The estimated potential
reductions in modal GHG emissions are 0.4%. Th e drawback of this practice is that extra work for loading and unloading operations may be required.

4.4 Tire Rolling Resistance Improvement
Tire rolling resistance refers to a frictional ef fect associated with th e contact of the tread of the tire with the road surface, and the flexing of the tread. Given that many trucks have a large number of tires in contact with the road (e.g., 18 wheels), this effect can be significant. Thus, rolling tire resistance is an important com ponent of the total engine power demand on a30 

### truck. Rolling resistance can be reduced by avoi ding under-inflation of ex isting tires (to reduce unnecessary flexing), substituting one wide-tire for a pair of dual tires (leading to a net reduction in total tread area, sidewall flexing, or both), us e of alternative tire mate rials to reduce rolling resistance, or use of pneumatic blowing. Each of these are discussed. To the extent that rolling resistance can be reduced, total engine power demand is also reduced. This, in turn,
leads to reductions in fuel use and exhaust CO 2 

### emission from the truck.

4.4.1 Best Practice 1-17: Automatic Tire Inflation Systems With properly inflated tires, tire rolling resistance is decr eased and fuel use is reduced compared to under-inflation. Automatic tire infl ation (ATI) systems are commercially available and are intended to keep vehicle tires properly inflated. These systems continually monitor and adjust the level of pressurized air in tires. The estimated potential reductions in modal GHG
emissions are 0.6%. 11,45



### 4.4.2 Best Practice 1-18: Wide-Base Tires Combination trucks usually have two sets of dua l tires at each end of an axle. Dual tires are heavy and also produce high rolling resistance. Single wide-base tires, which are commercially available products, ca n replace these dual tires. Wi de-base tires that have lower weight (e.g., there are only two sidewalls for one tire, versus f our sidewalls for two tires) and produce lower rolling resistance reduce energy use. From the results of interstate field tests, using wide-base tires can increase fuel economy for a typical long-haul combination truck by
3%. 11,32,46 

### This best practice is suitable for combination trucks that have van trailers, which are a portion of the total truck fleet. Therefore, the estimated potential reductions in modal GHG emissions are 2.0%. By using single instead of dua l tires, there is a need for increased attention to tire inflation pressure for safety reasons.

4.4.3 Best Practice 1-19: Low-Rolling-Resistance Tires Compared to conventional tires, lower rolling resistance tire s are commercially available from most tire companies, and trucks with these tires are more fuel-efficient because of the reduction of rolling resistance by the use of new materials, such as the combination of silica and synthetic elastomer. 47 

### Based on the results of interstate field tests, using low-rolling-resistance
tires can reduce en ergy use by 2.9%. 32 

### Such tires could be used on any truck. Therefore, the estimated potential reduction in modal GHG emi ssions is 2.8%. The fuel saving advantage
tends to be reduced when these low-resistance tires wear down.31 

### 4.4.4 Best Practice 1-20: Pneumatic Blowing to Reducing Rolling Resistance Pneumatic blowing is a technology under deve lopment that can reduce aerodynamic drag (Best Practice 1-14, Pneumatic Aerodynamic Drag Re duction) and tire rolling resistance. The system for Best Practice 1-14 can also blow st reams of air under the truck. Since tire rolling resistance is directly proporti onal to loaded weight on the wheels times the tire friction coefficient, these air streams provide a slight li ft that unloads the tire s and reduces tire rolling
resistance. 48 

### Based on the results of full-scaled tests, this tec hnology reduce energy use for a combination truck by 1.2% when accounting for the energy to compress and deliver pressurized
air versus the benefits of reduced rolling resistance. 32,42 

### This best practice is suitable for
combination trucks that have van trailers, which are a portion of th e total truck fleet. Therefore, the estimated potential reductions in modal GH G emissions are 0.5%. However, this system may slightly increase dust pollution by dislodgin g particles on the road surface.

4.5 Hybrid Propulsion

― Best Practice 1-21: Hybrid trucks
Stop-and-go truck driving incl udes a fraction of idling cond itions during which the truck base engine consumes fuel but produces no eco nomically useful output (e.g., movement of goods, or repositioning of the truck to a new location). Hybrid propulsion systems, which are in the development stage for trucks, shut off the engi ne under idling conditions or situations of low engine power demand. They also recover or r ecycle energy from braki ng and deceleration. Trucks that have high fractions of stop-and-go freight transport activities within their driving cycles, such as medium-duty package and beve rage delivery trucks, are good candidates for hybridization. Most heavy-duty trucks and a fraction of medi um-duty trucks are long-haul trucks. Long-haul trucks have a lower proporti on of short-term idling or low engine power demand in their duty cycles because of traffi c conditions or frequency stops compared to medium-duty trucks in local services. Based on the results of hybridization effects modeling, medium-duty trucks in local service (e.g., delivery) can reduce energy use by 41.5%

. 20,49 

### This best practice is considered to be more su itable for medium duty trucks because of the characteristics of their duty cycles. Therefor e, the estimated potentia l reductions in modal
GHG emissions are 3.4%. The effect of additiona l weight associated w ith the battery set is accounted for in the estimates given here. A ke y disadvantage is the initial capital cost and uncertainty regarding the life of the batte ry pack and battery replacement costs.

4.6 Weight Reduction

― Best Practice 1-22: Lightweight Materials
The energy consumed by a truck depends on ma ny factors, including the tare weight of the vehicle itself. Substitution of light-weight materials for conventional materials (e.g., steel)32 

### can reduce the total vehicle we ight. High-strength, lightweight materials include aluminum, plastics, high strength steel all oys, and others. Since fuel use is directly proporti onal to truck weight, trimming 3,000 pounds (about 4% of truck weight) from a heavy-duty truck by using lighter-weight components improves fuel econo my by 3%, and every 10% reduction in truck weight is estimated to re duce fuel use by 5 to 10%. 50 

### In one study, mass reduction was estimated to reduce energy use by 4.8% or more. 51 

### The estimated potential reductions in modal GHG emissions are 4.6%. However, current light-weight materials are costly and with no
satisfied material characteristics. Further rese arch and development for advanced materials are
needed.

4.7 Transmission Improvement

Traditional truck transmissions are designed to provide di screte engine-wheel speed ratios. Transmission operation is associated with mechanical losses, leading to additional fuel consumption of the vehicle. Improving tran smission systems, such as by using advanced high-efficiency transmission technologies and lo w-viscosity transmission lubricants, have the potential to reduce mechanical losses and reduce energy consumption. 5,32



### 4.7.1 Best Practice 1-23: Advanced Transmission Advanced transmission technologies, such as the optimization of transmission engine-wheel speed ratios and re duction of mechanical losses, can reduce truck fuel use. A
traditional transmission has a fixed number of gears that do not often achieve maximum efficiency. A continuously variable transmi ssion (CVT) has belt-conne cted pulleys that can optimize transmission speed-load conditions and reduce fuel consumption. Mechanical losses
in a transmission can be redu ced by the reduction of gear surface roughness, the use of low-friction coatings, the use of new gear materials, and the us e of a lock-up torque converter that eliminates slip at cruising speed. In one study, advanced transmission and improved lubricants were estimated to reduce energy use by 2%. 51 

### Since improved transmission lubricants, which is described in Section 4.7.2, is estimated to reduce energy use by 1%, 52 

### this practice is estimated to reduce fuel use by 1.0% on average for all conditions. The estimated potential reductions in modal GHG emissions are 1.0%. Driver training may be needed to
avoid the confusion because the so und of the engine w ith traditional transmissions changes for acceleration operations but the sound of the engi ne with improved transmission does not change
in the condition of acceleration.33 

### 4.7.2 Best Practice 1-24: Transmissi on Friction Reduction through Low-Viscosity Transmission Lubricants Lubricants can reduce gear contact friction in transmissions, but they also reduce fuel efficiency because of their viscosity. 53 

### Low-viscosity transmissi on fluid can be adopted to
decrease transmission friction and also reduce fuel consumption. Assuming that all trucks can adopt low-viscosity transmission fluids, this practice is estim ated to reduce energy use by approximately 1.0%. 52 

### The estimated potential reductions in modal GHG emissions are 0.9%. Low-viscosity transmission fluid typically costs more than conventional lubricants.

4.8 Diesel Engine Improvement
The overall fuel efficiency of a diesel engine of a Class 8 trucks w ith a typical long-haul driving cycle is about 40%. The remaining 60% of fuel energy becomes waste heat. Some factors limit diesel engine efficiency, such as engine friction, peak cyli nder pressure, combustion efficiency, and engine thermal management. 53 

### Technologies that can improve the impacts of
these factors can reduce fuel consumption significantly. 5,32,51,53



### 4.8.1 Best Practice 1-25: Engine Fricti on Reduction through Low-Viscosity Engine Lubricants Some energy losses in an engine are because of mechanical friction. Reduction in internal engine friction can be achieved using improved lubric ants. Low-viscosity engine lubricants are made from synthetic or mineral oil blends for the purpose of reducing internal engine friction. Low-viscosity engine lubricants can redu ce energy use by 1.9%. 32,52 

### The estimated potential reductions in modal GHG em issions are 1.8%. Low-vi scosity engine fluid typically costs more than conventional lubricants.

4.8.2 Best Practice 1-26: Increased Peak Cylinder Pressures Diesel engine thermal efficien cy is proportion to the peak pr essures that can be achieved in the engine cylinders. However, the peak cy linder pressures are constr ained by the strength and durability of the engine materials over the de sign service life of the e ngine. Measures that result in better materials that enable higher peak pressures can lead to higher engine efficiency. 53-54 

### The development of new materials and associated new engine designs is an emerging area of work. This practice is commer cially available and it is estimated to reduce energy use for heavy-duty trucks by 3.9%. 51 

### Although this practice is lik ely to be applicable to all diesel engines in the long-r un, its initial application is expe cted to focus on heavy-duty34 

### trucks 124 

### Therefore, the estimated potential redu ctions in modal GHG em issions are 3.1%.

4.8.3 Best Practice 1-27: Improved Fuel Injectors Incorrect fuel injection causes a reduction of combustion effi ciency and an increase of emissions. The improvement of fuel injection via better control is expected to reduce truck fuel use. For example, advanced fuel injection syst ems, such as electronic unit injectors or common rail injectors with increased fuel injection pressure , are estimate to result in better control of the fuel injection rate and injection timing, and to produce finer vaporization of the fuel

spray. 32,51,54-55 

### The estimated potential reductions in modal GHG emissions are 5.5%. However, a drawback of higher injection pressure s is the need to have stronger fuel-injection system and other engine components that withst and the higher pressures. The improved high pressure injectors may have leakage problem after a period of operation time. Regular diagnosis is needed to identif y and address this problem.

4.8.4 Best Practice 1-28: Turbocharged, Direct Injection to Improved Thermal Management Turbocharging utilizes the exhaust air flow fr om engine to drive a turbine and then drive an air compressor to increase engine air intake. Advanced turbochargers that drive more air into the cylinder increase combustion efficiency a nd allow direct injectors to inject more fuel into cylinders. Most heavy-duty trucks have turbochargers, but medium-duty trucks do not. In one study, turbocharged, direct injectio n diesel engines was estimated to increase medium-duty truck fuel economy by 5 to 8%. 51 

### Taking account that this practice is suitable for medium-duty trucks, the estimated potential re ductions in modal GHG em issions are 0.8%.

4.8.5 Best Practice 1-29: Using Thermoele ctric Technology to Recovery Waste
Heat Overall engine thermal efficiency can be in creased if new materials and technologies can be developed and implement for improved thermal management. An example is the conversion of engine waste heat to electrical energy. Such systems are not commercially available and are undergoing development. Comb ining thermoelectric materials and advanced heat exchangers may recover waste heat in orde r to produce electricity. Based on the results of laboratory tests, a thermoelectric generator with a heat exchanger is projected to reduce energy use by 6.5%. 56 

### The intended application of this best practice is for heavy duty trucks. The estimated potential reductions in modal GHG emissions are 5.2%. 51 

### Thermoelectric converter technology needs further research and developm ent (R & D) to incr ease its currently low conversion efficiency. The estimates reported he re presume that such R & D will be successful.35 

### 4.9 Accessory Load Reduction
Truck auxiliary loads, such as the air-conditioning compressor, air compressor, fans, hydraulic pump, and coolant pump, are typically gear - or belt-driven and t hus directly consume energy provided by the base engi ne. Full electrification of these mechanically driven auxiliaries can reduce engine load and use less energy. 32 

### Using fuel cell units as the electricity
source for electric auxiliaries can reduce more en ergy than using a generator to power electric
auxiliaries. 32,49



### 4.9.1 Best Practice 1-30: Electric Auxiliaries Most mechanical auxiliaries operate when ever truck base engines are running, which waste energy when the auxiliaries are not needed. The replacement of gear- or belt-driven auxiliaries by electrically driven systems can decouple mechanical loads from the base engine and reduce energy use. Since the average engine loads from mechanical auxiliaries are higher than those from a small generator that supplies electri city to electric auxilia ries, base engine fuel
can be reduced. Based on a full-scale test of a prototype truck that used a small generator to produce electricity, full electrification of auxiliaries reduced fuel use by 2%. 57 

### The estimated potential reductions in modal GHG emissions are 1.4%. 32 

### The smaller generator for this practice may need pollution control de vices in order to comply with future emissions standards.

4.9.2 Best Practice 1-31: Fuel-Cell-Operated Auxiliaries Fuel cells are an emerging technology for conver ting chemical energy in a fuel directly to electricity. The advantage of fuel cells over conventional engine and alternator technology is that they have substantially hi gher thermal efficiency. Among th e barriers to practical use of fuel cells are the cost of preci ous materials used for their internal components and the need for conversion of readily available transportation fuel s to a form that can be processed by the fuel cell. This best practice is base d on the use of a small fuel cell sized to provide the requirements
of all of the electrical auxiliaries, and is complementary to a base diesel engine used to supply the energy requirements of the power train. Th is best practice uses electrically-operated
auxiliaries similar to those of Best Practice 1-30 (see Section 4.9.1). This system could be available in the market by 2012 with acceptable capital cost, according to some estimates. 32,49 

### The estimated potential reductions in modal GH G emissions are 5.5%. This practice has high thermal efficiency, but further R & D is needed in order to reduce cost.36 

### 4.10 Modifications in Driver Operational Practice

― Best Practice 1-32: Truck Driver Training Program

The behavior of truck driver s can significantly impact fuel efficiency. For example, unnecessarily frequent shifting, rapid accelerati on and stops and starts increase fuel use. 58 

### Drivers can be encouraged to modify behaviors th at unnecessarily increase fuel use via training programs that aim to convey better skills and hab its. Furthermore, driver performance can be monitored and incentives can be provided to rewa rd preferred behaviors. In one study, driver training and monitoring were estim ated to reduce energy use by 3.8%. 11 

### In several other studies in Europe and Canada, the effect of driver training, monitoring and incentive programs was estimated to increase fuel economy by 5 to 20%. 11,58-59 

### Taking into account that a fraction of truck companies are likely to adopt these programs, 11 

### the estimated potential reductions in modal
GHG emissions are 3.1%.

4.11 Alternative Fuel

― Best Practice 1-33: B20 Biodiesel Fuel
An alternative fuel has the potential to reduce GHG emissions, although it may not lead to overall reductions in energy consumption. A fuel that is derived from renewable resources (e.g., biomass) can lead to reductions in the net amount of carbon dioxi de released to the atmosphere. However, the substitution of one fuel for another leads to changes in emissions not only for the truck, but also for th e entire fuel life cycle. Ther efore, comparisons of different fuels must be done on a life cycle basis, which is the approach taken here.
Some alternative fuels that have a lower ratio of carbon-to-hydroge n can also lead to
reductions in the net amount of carbon dioxide released while trucks are operating. However, these fuels may not have reduc tions in the net amount of CO 2 

### emissions on a life-cycle basis. For example, liquefied natural gas (LNG) contai ns less carbon per unit of heating value than diesel fuel, thereby reducing tailpipe CO 2 

### emissions by approximately 15%. However, when fuel recovery, processing, transportation, and di stribution are taken into account, the life-cycle
CO 2 

### emissions for LNG are estimated to increase by approximately 4% compared to that of petroleum diesel. 60 

### For this reason, LNG is not further co nsidered as a useful alternative fuel for purposes of GHG emissions reductions. Howeve r, if the fuel cycle emissions are reduced,
then LNG could be reconsidered in the future. Biodiesel fuels are produced based on vegetabl e oils or animal fats that have been
transesterized in order to achieve a viscosity similar to that of petroleum diesel. B100 refers to a biodiesel blend stock comprise d of 100% vegetable or animal fat derived fuel. The carbon in B100 is essentially from renewable resources, depending on the configuration of the fuel production process. Thus, resultant CO 2 

### emissions from combustion of biodiesel do not37 

### contribute to a net increase in ambient CO 2 

### concentrations, assuming th at the amount of carbon sequestered to produce biofuels is equal to th at emitted. However, under the current fuel infrastructure in the U.S., a si gnificant portion of energy consumed in the production of biodiesel is based on consumption of petr oleum diesel (e.g., for transport) or emissions associated with electrical energy consumption. Furthermore, B 100 is not practical for direct use because of issues with handling. Instead, a more common a pproach is to use a bl end of 20% blend stock and 80% petroleum diesel, referred to as B20. This blend has many of the handling advantages of petroleum diesel, while also offering some reduction in net CO 2 

### emissions. The life-cycle CO 2 

### emissions coefficient is estim ated to decrease by 0.0069 tons CO 2 

### eq. per 10 6 

### BTU for B20 versus petroleum diesel. This alternative fuel is commercially available in limited amounts, but interest in biodiesel appe ars to be increasing. The estimated potential
reductions in modal GHG emissions are 4.4%. 61-64 

### The estimated potential modal increase in energy use from substitution of B20 for petroleum diesel is 4.3%. 61 

### The potential disadvantages of biodiesel fuel depend on the percentage of blend stock used, the source of the blend stock, and whet her the blend stock complies with the ASTM
standard for B100. For B20 biodiesel ba sed on a compliant B100 blend stock, the disadvantages to the vehicle operator are likely to be minor in warm climates, and include the need to replace and possibly enlarge the fuel filte r and to manage fuel storage so as to avoid biofouling. In colder climates, there are potentia l problems with coagulation of biofuel because of its higher cloud point compared to petroleum di esel. However, the severity of this problem also depends on the percentage of blend stoc k used. Because biodiesel has a lower energy density than petroleum diesel, vehicle operato rs may experience a modest (approximately 5%) reduction in maximum power.

4.12 Summary of Potential Best Practices for the Truck Mode
All 33 potential best practices, sorted by 11 subgr oups, for the truck mode are summarized in Table 4-1. They are in ta ble format for the convenience of readers.

4.13 Comparisons of Modal GHG Emissions Reductions for the Best Practices
Figure 4-1 illustrates the vari ability among the potential best practices with respect to
estimated reductions in modal GHG emissions. There percentage reductions in modal GHG emissions range from 0.2 to 5.5 percent when comparing individual best practices. Ho wever, these percentage reductions cannot be
summed to obtain a total GHG emission reduction. So me best practices ar e mutually exclusive or have interactions with others. Furthermore, some practices may have s ubstantial technical or38 

### Table 4- 1. List and Description of Po tential Best Practices for the Truck Mode

. Subgroup Type of Strategies Description

Technology 1-1. Off-Board Truck Stop Electrification Off-board truck stop electrification is a commercially available system that can avoid the need for idling of the truck base engine while a truck is parked at a truck stop. This extern al system enables a truck driver to switch off the base engine by connecting the truck to a specially designed service module. This module provi des heating, air conditioning and electricity to the truck cab, and it is installed temporarily through a window of the truck. This system is reported to consumes less energy than the base engines and emits less CO 2 . 26-29 A commercially available example of this is the IdleAire system. 30 The estimated potential reduction in modal GHG emissions is 0.3%. The operation charge for this system is approximately $1.25~$1.50 per hour per truck. 5

Technology 1-2. Truck-Board Truck Stop Electrification Truck-board truck stop electrification, also called a shore power truck electrified parking system, is a comme rcially available system that can avoid the need for idling of the truck base engine while a truck is parked at a truck stop. In contrast to Best Practice 1-1, which involves an external service module, truck stop electrification can be as simple as connecting the truck to a shore-base d power supply via an electrical cable. This type of system is effec tive in situations where the heating, ventilation and air conditioning (HVAC) system of the sleeper cab is entirely electrically operated and, thus, is independent of the base engine. This system enables a truck driver to switch off the base engine by connecting the truck to the electrical grid. Thus, the energy use and emissions for this best practice are associated with those of the power grid. Compared to use of the base engine, this type of electrification is reported to consume less energy and emits less CO 2 . 28,29,31 The estimated potential reduction in modal GHG emissions is 0.4%. The operation charge for this system is $0.5~$1.00 per hour per truck. 5 Anti-Idling

Technology 1-3. Auxiliary Power Units Auxiliary power units (APUs) are commercially available systems that can avoid the need for idling of a tr uck’s base engine wherever a truck driver parks for rest. An APU is installed externally on a truck and consists of a small diesel engine that provides power for an HVAC system and electrical outlets that service the sleeper cab. APUs are advertised as consuming less fuel unde r typical load conditions than the base engine. There are some practical questions regarding whether APUs are sufficiently quiet for use wh ile a driver is sleeping, especially if they cycle on and off to meet intermittent A/C compressor demand, regarding their ability to rapidly cool-down the cab on very hot days, and their actual fuel efficiency relative to base engines. Based on available information, APUs are estimated to consume less diesel fuel than the base engine and emits less CO 2 . 27,32 The estimated potential reduction in modal GHG emissions is 2.1%. The estimated incremental capital cost is $8,279. 31 

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### Table 4-1. Continued
Subgroup Type of Strategies Description

Technology 1-4. Direct-Fired Heaters Direct-fired heaters are commercially available systems for heating a sleeper cab by burning diesel fuel. Heat from combustion gases passes through a heat exchanger that warms th e air inside the sleeper cab. In addition, these heater systems can be configured to provide heat for the base engine to maintain readiness for b ase engine restart in cold weather. Unlike the previous three best practi ces described above, this system is only applicable to heating in cold weather and does not provide cooling in hot weather. Furthermore, this system does not provide electrical power; instead, electrical power is drawn from the truck’s existing battery. Direct-fired heaters are reported to consume less diesel fuel than the base diesel engines and to emit less CO 2 . The estimated potential reduction in modal GHG emissions is 1.1%. 27

Anti-Idling

Technology 1-5. Direct-Fired Heaters with Thermal Storage Units Direct-fired heaters are used to heat both the sleeper cab and engine when a truck is idling. Thermal storage systems consist of a phase change material that can be heated or cooled from the truck cab air conditioning unit or heating system while the base engine is operating. These systems are demonstrated. The thermal storage system can be used as a means of providing warm or cool air via a heat exchanger and a blower unit to the sleeper cab for up to eight hours when the base engine is off. In order to supplement the heating capability, thermal storage systems can be coupled with direct-fi red heaters to store more thermal energy that is available for warmi ng interior cabin air even when the direct-fired heater is not operating. This system supplies heating and cooling, but no electrical power, to the sleeper compartment when the base engine is off. Furthermore, similar to Best Practice 1-4, this system does not provide electrical power; instead, electrical power is drawn from the truck’s existing battery. The combination of direct-fired heaters and thermal storage units is reported to consume less energy than the base engines and to reduce CO 2 emissions. The potential reduction in modal GHG emissions may be as large as 2.9%. 27

Air conditioning System Improvement Technology 1-6. Enhanced Air Conditioning System I - for Direct Emissions Direct GHG emissions of current HFC-134a mobile A/C systems are due to refrigerant leakage. Enhanced mobile A/C systems, which are undergoing testing, can reduce direct GHG emissions by reducing 

### the leakage rate of the commonly used HFC-134a refrigerant . The refrigerant leakage rates of these system may be decreased through the use of low permeable hoses, improved hose ends and connectors, and improved compressor shaft seals. 12,33-35 HFC-134a emission from mobile A/C system is reported to be approximately 8.5 g CO 2 eq. per mile, including 6 g CO 2 eq. per mile from direct leakage in normal operation conditions. Other emission is because of accidental release and dism antling emissions. Enhanced A/C systems are estimated to reduce di rect leakage in normal operation conditions by 50%, which is about 3 g CO 2 eq. per mile. The estimated potential reduction in modal GHG emissions is 0.9%. 33 

### Continued on next Page40 

### Table 4-1. Continued
Subgroup Type of Strategies Description 1-7. Enhanced Air Conditioning System II - for Indirect Emissions Indirect GHG emissions of mobile A/C systems are additional exhaust CO 2 emissions that result from the engine load due to operation of mobile A/C system. Mobile A/C systems operation time is about 34% of truck operation time. Based on the assessment results of a California government report that indirect emissions of running HFC-134a A/C systems are about 7.35 g CO 2 eq. per mile, average indirect emissions are about 2.5 g CO 2 eq. per mile in truck operation time. Enhanced A/C systems for reducing indirect GHG emissions are commercially available. These systems can decrease base engine load requirements from mobile A/C systems by replacing fixed displ acement compressors (FDCs) with externally controlled variable disp lacement compressors (VDC), using improved control systems, and using improved condensers and evaporators. By reducing the engine load requirements, exhaust CO 2 emissions for powering A/C system is reported to be reduced by 25%. 33,36-37 The estimated potential reduction in modal GHG emissions is 0.2%.

Technology 1-8. Alternative Refrigerants - CO 2 The GWP of leaking refrigerant can be reduced by using an alternative low GWP refrigerant. One of alternative low GWP refrigerant is CO 2 , which is called R744 while as a refrigerant. The current widely used refrigerant, HFC-134a, has GWP = 1,300, whereas CO 2 has GWP = 1. The abundance of CO 2 supply from many industries is also the advantage of this alternative refrigerant. Another advantage is that recovery and recycling of CO 2 is not difficult. Vehicle industry is developing CO 2 -based air conditioning systems, and engineers are working to improve the reliability and efficiency of systems that use CO 2 as refrigerant. 12,33-34,36 The estimated potential reduction in modal GHG emissions is 2.5%. 33 Air conditioning System Improvement

Technology 1-9. Alternative Refrigerants - HFC-152a 1,1-difluoroethane (C 2 H 4 F 2 ), I is known as HFC-152a, is another promising low GWP refrigerant. HFC-152a has a lower GWP (120) than that of HFC-134a (1,300). The transition from one HFC to another, such as from HFC-134a to HFC-152a, would be relatively easy (compared a transition to CO 2 ) since these two refrigerants have similar thermodynamic characteristics and A/C system components would need less modification. However, its flammability causes add itional safety considerations and the needs of risk mitigation approaches. For example, the evaporator may need to be located far from the passen ger compartment. The design of the secondary heat exchange loop can enhance the safety of this system. HFC-152a systems is expected to be widely available within 4
years. 12,33-34,36 The estimated potential reduction in modal GHG emissions is 2.4%. 33 

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### Table 4-1. Continued
Subgroup Type of Strategies Description

Air conditioning System Improvement Technology 1-10.Alternative Refrigerants - HC Propane has been proposed as an alte rnative refrigerant for vehicle air conditioners. Propane is called R290 as an alternative refrigerant and has a lower GWP (20) than that of HFC-134a (1,300). 38 This propane based refrigerant system has had more than 400,000 accumulated unit-years of operating experience in Australia. Ho wever, a propane based refrigerant system uses about 10% more energy for the operation of vehicle air conditioners and increases indirect GHG emissions, thus there is some tradeoff. 34 Furthermore, there is concern regarding its safety because of the flammability of propane and the risk mitigation approaches are needed. 36 The volatile organic compound properties of propane that increase tropospheric ozone formation is another concern. 34,36,38 If such systems are accepted for use in the U.S., the estimated potential reduction in modal GHG emissions is 2.5%. 33

Technology 1-11. Vehicle Profile Improvement I - Cab Top Deflector, Sloping Hood and Cab Side Flares Truck tractor aerodynamic drag reduction options, including cab top deflector, sloping hood, and cab side fl ares, have been introduced into the market. Cab deflectors are designed at the same height as the trailer. Flares or fairings on the side of cabs cover batteries, fuel tank and suspension. These add-on devices are estimated to reduce the aerodynamic drag of medium- and heav y- duty trucks and increase their fuel efficiency by 2.0%. Taking into account that these devices reduce only a fraction of aerodynamic drag, th e estimated potential reduction in modal GHG emissions is 1.4%. The estimated incremental capital cost is $750. 32

Aerodynamic Drag Reduction

Technology 1-12. Vehicle Profile Improvement II - Closing and Covering of Gap Between Tractor and Trailer, Ae rodynamic Bumper, Underside Air Baffles, and Wheel Well Covers Truck side and underside aerodynami c drag reduction options, including closing and covering the gap betwee n a tractor and trailer (or van), aerodynamic bumper, underside air b affles, and wheel well covers, are commercially available technologies for medium- and heavy-duty trucks. Aerodynamic drag that results from the tractor-trailer gap can be reduced by installing gap covering add-on de vices, such as cab extenders, trailer splitter plates, gap vortex stabilizer and gap seals. Drag underneath the vehicle can be reduced by insta lling lower bumper and underside air b affles. Wheel well covers enclo se the open space between the wheels and the truck body, which streamlines the side of the truck. From the results of field tests, combining these options are estimated to reduce energy use and decrease GHG emissions. 11,32 Taking into account that these devices reduce a fraction of aerodynamic drag, the estimated potential reduction in modal GHG emissions is 2.4%. The estimated incremental capital cost is approximately $1,500. 32 

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### Table 4-1. Continued
Subgroup Type of Strategies Description

Technology 1-13. Vehicle Profile Improvement III - Trailer Leading and Trailing Edge Curvatures Truck trailer (or van) aerodynamic drag reduction options, including the improvement of their leading and trailing edge curvatures, are commercially available strategies. Aerodynamic drag can be reduced by the redesign of leading edges and traili ng edges of trailers or vans, such as rounded front corners and rounded aft corners. 40 The estimated potential reduction in modal GHG emissions is 1.2%. The estimated incremental capital cost is $500. 32,40

Technology 1-14 Pneumatic Aerodynamic Drag Reduction Pneumatic blowing systems are being tested as testing add-on devices that reduces aft-end aerodynamic drag. This type of system blows air from slots at the rear of the trailers of heavy-duty vehicles in order to smooth air flow over the trailer surfaces and reduce aft-end aerodynamic drag. This results in reduction in vehicle fuel en ergy requirements. From the results of full-scaled tests, this system reduces energy use for an individual truck by 3.9% to 4.8%. 32,41-42 However, based on the results of field tests, some truck configurations, such as the dimens ions of the tractor-trailer gap, may inhibit the reduction of aerodynamic drag achievable via this system. 43 This best practice is suitable for combin ation trucks that have van trailers, which are a portion of the total truck fleet. Therefore, the estimated potential reduction in modal GHG emissions is 2.2%. This system is expected to be available in 2010 and the estimated incremental capital cost is $2,500, but could be as high as $5,250. 32,51

Technology 1-15 Planar Boat Tail Plates on a Tractor-Trailer Planar boat tail plates are being tested as add-on devices that reduce aft-end aerodynamic drag. These devices are four rectangular plates mounted to the after-end of a trailer in an attempt to reduce the wake of trucks. The formation of a wake re quires energy; thus, reducing the wake can energy consumption. To maintaining full-functional operation, rigid composite sides with a flexible top and bottom are designed, and these plates can be folded. From a full-scal ed test for a tractor-trailer, this practice was found to reduce average energy use by approximately 8.3% over a 10,000 mile trip. 44 This best practice is suitable for combination trucks that have van trailers, which are a portion of the total truck fleet. Therefore, the estimated potential reduction in modal GHG emissions is 3.8%. Aerodynamic Drag Reduction

Operation 1-16. Vehicle Load Profile Improvement Aerodynamic drag can be reduced by th e use of a streamlined load profile for a trailer, which is a low-tech op tion. This practice keeps the load profile of a trailer as low as possible and secures tarpaulins to smooth air flow. For example, a suggested method fo r flatbed trailers is to arrange as low as possible and cover with a tarpaulin. A 2.4% energy reduction was reported for properly secured tarpaulins. 11 Taking into account that it is suitable for combination trucks that have non-van trailers, the estimated potential reduction in modal GHG emissions is 0.4%. 

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### Table 4-1. Continued
Subgroup Type of Strategies Description

Technology 1-17. Automatic Tire Inflation Systems With properly inflated tires, tire rolling resistance is decreased and fuel use is reduced compared to under-inflatio n. Automatic tire inflation (ATI) systems are commercially available and are intended to keep vehicle tires properly inflated. These systems contin ually monitor and adjust the level of pressurized air in tires. Installing ATI systems on a combination truck was reported to reduce 97 to 100 gallons of fuel per year, which is about 1.1 tons GHG emissions reduction per truck per year. 11,45 The estimated potential reduction in modal GHG emissions is 0.6%. The estimated incremental capital cost is $900. 5

Technology 1-18. Wide-Base Tires Combination trucks usually have two set s of dual tires at each end of an axle. Dual tires are heavy and al so produce high rolling resistance. Single wide-base tires, which are commercially available products, can replace these dual tires on combination trucks. Wide- b ase tires that have lower weight (e.g., there are only two sidewalls for one tire, versus four sidewalls for two tires) and produce lower rolling resistance reduce energy use. From the results of field tests, wide- b ase tires increase fuel economy for a typical long-haul combination truck by 3.0% compared to equivalent dual tires. 11,32,46 This best practice is suitable for combination trucks that have van trailers, which are a portion of the total truck fleet. Therefore, the estimated potential reduction in modal GHG emissions is 2.0%. New trucks with wide- b ase tires are possibly cheaper than with dual tires, but retrofitting existing trucks have higher cost. Averagely, the estimated incremental capital cost is $700. 32 Increasing the frequency of monitoring tire pressure is probably needed for adopting wide-base tires. Tire Rollin Resistance Improvement

Technology 1-19. Low-Rolling-Resistance Tires Conventional tires have high rolling resistance that increases energy use. Low-rolling-resistance tires are commercially available from most tire companies. Trucks with low-rolling resistance tires are more fuel-efficient because of the reduction of tire rolling resistance by the use of new materials, such as the combination of silica and synthetic elastomer. 47 Based on the results of interstate field tests, using low-rolling-resistance tires can reduce rolling resistance that reduce energy use by 2.9%. 32 Such tires could be used on any truck. Therefore, the estimated potential reduction in modal GHG emissions is 2.8%. The estimated incremental capital cost is $550. The requirements for higher inflation pressure and high monitori ng frequency may limit the extent of their market penetration. 

### Continued on next Page44 

### Table 4-1. Continued
Subgroup Type of Strategies Description

Tire Rollin Resistance Improvement Technology 1-20 Pneumatic Blowing to Reducing Rolling Resistance Pneumatic blowing is a technology under development that can reduce aerodynamic drag, which is discussed in Best Practice 1-14: Pneumatic Aerodynamic Drag Reduction, and tire rolling resistance. The system for Best Practice 1-14 that is used for aerodynamic drag reduction, including compressor, piping, and blow control, can also be used to blow streams of air under trucks. Additional pipes, jets, valves, selective blowing, and control system may be needed to blow air under trucks. Since tire rolling resistance is directly proportional to loaded weight on the wheels times the tire friction coefficient, these air streams provide a slight lift that unloads the tires and reduces tire rolling resistance. 48 Based on the results of full-scaled tests, this technology redu ce energy use for a combination truck by 1.19% when accounting for the energy to compress and deliver pressurized air versus the benefits of reduced rolling resistance. 32,42 This b est practice is suitable for combination trucks that have van trailers, which are a portion of the total truck fleet. Therefore, the estimated potential reduction in modal GHG emissions is 0.5%. If the pneumatic blowing system for reducing aerodynamic drag has been installed on a combination truck, additional $500 capital cost for extra components would be needed. 32 This technology is estimated to be available in 2015 for combination trucks. 51

Hybrid Propulsion Technology 1-21. Hybrid Trucks Stop-and-go truck driving includes a significant fraction of idling conditions during which the truck b ase engine consumes fuel but produces no economically useful output (e.g., movement of goods, or repositioning of the truck to a new location). Hybrid propulsion systems, which are in the development stage for trucks, shut off the engine under idling conditions or situations of low engi ne power demand. They recover or recycle energy from braking or deceleration. Fuel use reduction potential of hybrid trucks is sensitive to their duty cycles. Trucks that have high fractions stop-and-go freight transport activities within their driving cycles, such as medium-duty package and beverage delivery trucks, are good candidates for hybridization. Most of heavy-duty trucks and a fraction of medium-duty trucks are long-haul tr ucks. Long-haul trucks are not considered as good candidates because these trucks have a lower proportion of short-term idling or lo w engine power demand in their duty cycles because of traffic conditions or frequency stops compared to medium-duty trucks in local services. Based on the results of hybridization effects modeling, medium-duty trucks in local service (e.g., delivery) can reduce en ergy use by 41.5%. 20,49 This best practice is considered to be more suitable fo r medium duty trucks because of the characteristics of their duty cycles. Therefore, t he estimated potential reduction in modal GHG emissions is 3.4%. Experts in a study estimated that this technology would be available in 2010. 51,65 The estimated 2005 incremental capital cost is approxi mately $7,100, and the estimated 2025 incremental capital cost is expect ed to drop to approximately $3,100. 49 

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Subgroup Type of Strategies Description

Weight Reduction Technology 1-22. Lightweight Materials The energy consumed by a truck depends on many factors, including the tare weight of the vehicle itself. Substitution of light-weight materials for conventional materials (e.g., steel) can reduce the total vehicle weight. High-strength, lightweight materials include aluminum, plastics, and others. Since fuel use is directly proportional to truck weight, trimming 3,000 pounds (about 4% of truck wei ght) from a heavy-duty truck by using lighter-weight components improves fuel economy by 3%, and every 10% reduction in truck weight is estimated to reduce fuel use by 5 to 10%. 50 In one study, mass reduction was estimated to reduce energy use by 4.6% or

more. 51 The estimated potential reductions in modal GHG emissions are 4.8% or more. The estimated incr emental capital cost is $2,000.

Technology 1-23. Advanced Transmission Advanced transmission technologies, such as the optimization of engine-wheel speed ratios and reduction of mechanical losses in a transmission system can reduce truck fuel consumption. A traditional transmission has a fixed number of metal gears to provide several discrete speed ratios that do not often achieve maximum efficiency and increase fuel use. A continuously variable transmission (CVT) has belt-connected pulleys that provide an uninterrupted range of engine-wheel speed ratios to optimize transmission speed-load conditions and reduce fuel use. Adopting CVT for heavy-duty trucks n eeds new materials to withstand the high torque loads. Mechanical lo sses in a transmission, such as gear contact friction, can be reduced by the reduction of gear surface roughness, the use of low-friction coatings, the u se of new gear materials, and the use of a lock-up torque converter (a m echanical clutch locking the torque converter impeller and turbine together to eliminate slip at cruising speed). In one study, advanced transmi ssion and improved lubricants were estimated to reduce energy use by 2%. 51 Since improved transmission lubricants, which is described in Section 4.7.2, is estimated to reduce energy use by 1%, 52 this practice is estimated to reduce fuel use by 1.0% on average for all conditions. The estimated potential reductions in modal GHG emissions are 1.0%. This practice is ready introduced into market and the estimated incremental capital cost is $1,000. 32

. Transmission Improvement

Technology 1-24.Transmission Friction Reduction through Low-Viscosity Transmission Lubricants Lubricants can reduce gear contact fric tion in transmission, but they also reduce fuel efficiency because of their viscosity. 53 Low-viscosity transmission fluid, made from synthetic or mineral oil blends, are reported to decrease transmission friction and also reduce fuel consumption. Assuming that all trucks can adopt low-viscosity transmission fluids, this practice is estimated to reduce energy use by 1% or more. 52 The estimated potential reductions in modal GHG emissions are 0.9%. This practice is commercially available and the estimated incremental capital cost is $500. 11,51 

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Subgroup Type of Strategies Description

Technology 1-25.Engine Friction Reduction through Low-Viscosity Engine Lubricants Some energy losses in an engine ar e because of mechanical friction. Reduction in internal engine frictio n can be achieved using improved lubricants. Low-viscosity engine lubricants are made from synthetic or mineral oil blends for the purpose of reducing internal engine friction. Low-viscosity engine lubricants can reduce energy use by 1.86% or

more. 32,52 The estimated potential reductions in modal GHG emissions are 1.8%. This practice has commerc ially available products and the estimated incremental capital cost is $500. 11,51

Technology 1-26. Increased Peak Cylinder Pressures Diesel engine thermal efficiency is proportion to the peak pressures that can be achieved in the engine cyli nders. However, the peak cylinder pressures are constrained by the st rength and durability of the engine materials over the design service life of the engine. Measures that result in better materials that enable highe r peak pressures can lead to higher engine efficiency. 53,54 The development of new materials and associated new engine designs is an emerging area of work. This practice is commercially available and it is estimated to reduce energy use for heavy-duty trucks by 3.9%. 51 Although this practice is likely to be applicable to all diesel engines in the long-run, its initial application is expected to focus on heavy-duty trucks Therefore, the estimated potential reductions in modal GHG emissions are 3.1%. The incremental capital cost is $1,000. Diesel Engine Improvement

Technology 1-27. Improved Fuel Injectors Incorrect fuel injection causes a reduction of combustion efficiency and an increase of emissions. The improvement of fuel injection, such as a better control of the fuel injection rate and injection timing, and the production of finer vaporization of the fuel spray, is expected to reduce truck fuel use. The developments of advanced fuel injection systems, such as electronic unit injectors, common rail injectors, electronic unit pump, and electronic distribution pump, can improve fuel injection and reduce fuel use. For example, common rail injectors with electronic control use high-pressure pump to compress fuel into high-pressure accumulation chamber (Rail), and the pressure of fuel inside remain s constant. Since high-pressure fuel is always available for injection, electronic injectors can easily optimize fuel injection rate and time, and improves fuel atomization and dispersal. Maximizing fuel injection pressure can also enhance fuel reduction by improving fuel vaporization and dispersal in the cylinder. 32,51,54-55 The estimated potential reductions in modal GHG emissions are 5.5%. The estimated incremental capital cost is $1,500. 

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Subgroup Type of Strategies Description

Technology 1-28. Turbocharged, Direct Injec tion to Improved Thermal Management Diesel engine power is proportional to air intake and fuel. 

### Turbocharging utilizes the exhaust air flow from engine to drive a turbine and then drive an air compressor to increase engine air intake. Advanced turbochargers that drive more air in the cylinder increase combustion efficiency and allow direct injectors to inject more fuel into cylinders. 

### Most heavy-duty trucks have turbochargers, but medium-duty trucks do not. In one study, turbocharged, direct injection diesel engines 

### was estimated to increase medium-duty truck fuel economy by 5 to 8%. 22,51 

### Taking account that this practice is suitable for medium-duty trucks, t he estimated potential reductions in modal GHG emissions are 0.8%. This practice is already commercially available, and the estimated incremental capital cost is $700-1,000. 51 Diesel Engine Improvement

Technology 1-29. Thermoelectric Technology to Recovery Waste Heat Overall engine thermal efficiency can be increased if new materials and technologies can be developed and implement for improved thermal management. An example is the conversion of engine waste heat to electrical energy. Such systems are not commercially available and are undergoing development. Laboratory tests indicate that a small-scaled 5.54 kW thermoelectric generator can increase fuel economy by 2.2 to 4.4%. Combining thermoelectric ma terials and heat exchangers may recovery waste heat in order to produce electricity. Based on the results of laboratory tests, a thermoelectric generator with a heat exchanger is projected to reduce energy use by 6.5%. 56 

### The intended application o f this best practice is for heavy duty trucks. 51 The estimated potential reductions in modal GHG emissions are 5.2%. Those studies estimated that this technology would be introduced in 2010 and the estimated incremental capital cost is $2,000. 51

Accessory Load Reduction Technology 1-30. Electric Auxiliaries Truck auxiliaries, such as air-conditioning compressor, air compressor, fans, hydraulic pump, and coolant pump, are gear- or belt-driven by truck b ase engine. Mechanical auxiliaries operate whenever base engines are running, which waste energy when th e auxiliaries are not needed. The replacement of mechanical auxiliaries by electrically driven systems can decouple mechanical loads from the b ase engine and reduce energy use. Since the average engine loads from mechanical auxiliaries are higher than those from a small generator that supplies electricity to electric auxiliaries, base engine fuel can be reduced. Based on a full-scaled test of a prototype truck that used a small generator to produce electricity, full electrification of auxiliaries reduces fuel use by 2%. 57 The estimated potential reductions in modal GHG emissions are 1.4%. 32,51 The estimated incremental capital cost is $500. The additional small generator can also supply electricity for trucks to avoid extended idling, which is discussed in Best Practices 1-3, “Auxiliary Power Units.” 

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### Table 4-1. Continued
Subgroup Type of Strategies Description

Accessory Load Reduction Technology 1-31. Fuel-Cell-Operated Auxiliaries Fuel cells are an emerging technology for converting chemical energy in a fuel directly to electricity. The advantage of fuel cells over conventional engine and alternator technology is th at they have substantially higher thermal efficiency. Among the b arriers to practical use of fuel cells are the cost of precious materials used for their internal components and the need for conversion of readily availabl e transportation fuels to a form that can be processed by the fuel cell. This best practice is based on the use of a small fuel cell sized to provide the requirements of all of the electrical auxiliaries, and is complementary to a base diesel engine used to supply the energy requirements of the power train. This best practice uses electrically-operated auxiliaries similar to those of Best Practice 1-30 (see Section 4.9.1). This system could be available in the market by 2012 with acceptable capital cost, according to some estimates. 32,49 The estimated potential reductions in modal GHG emissions are 5.5%. The estimated incremental capital cost is $500. 32,49

Modifications in Driver Operational

Practice Operation 1-32. Truck Driver Training Program The b ehavior of truck drivers can significan tly impact fuel efficiency. For example, 

### unnecessarily frequent shifting, rapid acceleration and stops and starts increase fuel use. 58 Drivers can be encouraged to modify behaviors that unnecessarily increase fuel use vi a training programs that aim to convey better skills and habits. For ex ample, drivers can learn to improve their operation skills, such as accelerat ion and shifting technique. These programs can also change driving behaviors, such as route choice and unnecessary idling time. Furthermore, driver performance can be monitored and incentives can be provided to reward preferred behaviors. In one study, driver training and monitoring were estimated to reduce energy use by 3.8%. 11 In several other studies in Europe and Canada, the effect of driver training, monitori ng and incentive programs was estimated to increase fuel economy by 5 to 20%. 11,58-59 For example, a truck fleet company has reduce energy use by 19% by supplying fuel-saving information, using a driver incentive program and regularly reviewing engine printouts. 59 Some other best practices, such as anti-idling practices, may inhibit the reduction of energy use for truck driver training program. Taking into account that only a fraction of truck companies are likely to adopt these programs, 11 the estimated potential reductions in modal GHG emissions are 3.1%. 

### Continued on next Page49 

### Table 4-1. Continued
Subgroup Type of Strategies Description

Alternative Fuel Technology 1-33. B20 Biodiesel Fuel for Trucks Biodiesel fuels are produced based on vegetable oils or animal fats that have been transesterized in order to ach ieve a viscosity similar to that of petroleum diesel. The potential market share of B20 biodiesel is estimated as 51.2% in 2025 based on the potential maximum production capacity of biodiesel, which is estimated as 7.8 billion gallons in 2025, and the distribution ratio among the truck, rail and water modes. 63-64 The estimated potential reductions in modal GHG emissions are 4.4%. 61-64 Based on life cycle inventories, the production of alternative fuels consumes more energy than the pr oduction of petroleum diesel. For example, processes for producing biodi esel, such as soybean crushing and soy oil conversion, are energy intensive. 66 The estimated potential modal increase in energy use is 4.3%. 61



### 0 1 2 3 4 5 6

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33

Best Practice Number for the Truck Mode (1 refers to Best Practice 1-1, 2 refe rs to Best Practice 1-2, and so on)

Figure 4- 1. Reductions in Modal GHG Emis sions for the Best Practices for the Truck
ModeModal GHG Emissions Reductions (%)50 

### practical barriers to their acceptan ce, as described previously.

4.14 Quantitative Cost Results for Selected Best Practices
Quantitative cost results for the best practic es for which sufficient information was available to perform such assessments are summa rized in standardized reporting tables, which are given in Appendix A. In c ontrast, assessment results for th e best practices which have a lack of sufficient information from which to quantify costs are summarized in simplified summary tables individually, which are also given in Appendix A. To date, there is sufficient information for five best practices upon which to make quantitative assessments. The other 29 best practices are assessed qualitatively. The best practices assessed qua ntitatively include off-board truck stop electrification, auxiliary power units, direct-fir ed heaters, hybrid trucks, and B20 biodiesel. Table 4-2 summarizes the quantitative assessment resu lts of modal GHG emissions reductions, modal energy use reductions, annualized cost, energy cost saving, net savings, net savings per unit of GHG emissions reductions, net savings per unit of energy use reduction, and simple pay-back periods for these five selected best practices. Four of these five best practices produce ne t cost savings. These savings are the net result of substantial costs offset by substantia l savings based on reduced energy usage. For one of the best practices, biodiesel, the net saving is negative, indicating that this practice do not pay for themselves. Its fuel cost is higher than th at for petroleum diesel (based on current typical experience) and thus there is a net increase in total costs. Overall, there is substantial variability in the cost-effectiveness of these best practices when net cost savings are normalized based on the GHG emissions reductions. Direct-fired heater appears to be the most cost-effective, wh ereas the use of B20 biodi esel appears to be the least cost effective. However, the APU, hybri d, and biodiesel practices have the potential to achieve substantially larger magnitudes of GHG emi ssions reductions than the other two options. Off-board truck-stop electrifi cation could only cont ribute small magnitude of GHG emissions reductions because 80% of truck idling is not at truck stops. Direct-fired heaters can be only used in cold weather; therefore, this rest riction limits their potential for GHG emissions reductions and energy reduction.51 

### Table 4- 2. Summary Table for the Comparis on of the Quantitative Cost Results for
Selected Best Practices for the Truck Mode a

Best Practice Number 1-1 1-3 1-4 1-21 1-34

Name Off-Board Truck Stop Electrification Auxiliary Power Units Direct-Fired Heaters Hybrid Trucks B20 Biodiesel

Subgroup Anti-idling Anti-idling Anti-idling Hybrid Propulsion Alternative Fuel

Responsible Parties 1, 2, 5, 13, 20, 21, 22 1, 2, 5, 6, 8, 11 1, 2, 5 1, 2, 4, 5, 6, 8, 9, 12, 16, 18, 19, 20,

21, 22 1, 2, 4, 5, 6, 12, 14, 16, 18, 19, 20,

21, 22 Target Parties 1, 2, 6, 8 1, 2, 4, 6 1, 2, 4, 6 1, 2, 4, 6, 7 1, 2, 4, 5, 6, 7 Target GHGs CO 2 CO 2 CO 2 CO 2 CO 2 Strategy Types Technology Technology Technology Techno logy Technology Developmental Status C C C N C Modal GHG Emission Reduction (10 6 ton CO 2 eq./year) 2.4 15.0 7.6 24.5 30.8

Modal Energy Use Reduction (10 12 BTU/year) 27 185 94 300 -370.0

Annualized Costs ($ 10 6 /year) 570 3,000 390 2430 3,300 Annual Energy Cost Saving ($ 10 6 /year) 900 3,400 1,740 5,600 0 Net Saving ($ 10 6 /year) 330 440 1,350 3,190 -3,300 Net Saving per Unit of GHG Emissions Reductions ($/ton CO 2 eq.) 138 29 178 130 -108

Net Saving per Unit of Energy Use Reduction ($/ton CO 2 eq.) 12 2.3 14 10.6 N/A b

Simple Pay-back Period (years) N/A c 3.2 0.6 2.1 N/A d

a These assessments are based on the assumptions th at these best practices reach their potential maximum market shares in 2025. Cost results ar e presented only for those best practices for which adequate data were available.
b This practice has no energy use reduction due to an increase in energy use, and it has no net saving due to high annualized cost and no energy cost saving.

c There is no pay-back period for this best practi ce because there is no initia l capital cost to uses.
d There is no pay-back period for this b est practice because there is no net saving.52 

### 5.0. BEST PRACTICES FOR THE RAIL MODE

This chapter identified and characterizes six po tential best practices applicable to the rail mode. These best practices are divided in to four subgroups, including anti-idling, weight reduction, rolling resistance improvement, and alte rnative fuel. Additional details regarding these best practices are in Appendix B. For four of these best practices, sufficient data were available to quantify costs.

5.1 Anti-Idling

Line-haul locomotives and switchers are often idled for long periods of time to heat or
cool the cab and to avoid the diff iculty of restarting the engine. Over half (55%) of long-haul locomotive operation time and approximately 75% of switcher operation time are at idle. 67 

### During idling, a typical locomotive consumes approximately 3 gallons of fuel per hour. 67-68 

### Anti-idling technology can reduce l ong-duration locomotive idling, wh ich in turn reduces fuel use and greenhouse gas emissions.

5.1.1 Best Practice 2-1: Combined Diesel Powered Heating and Auto Engine Start/Stop Systems A diesel powered heating system can keep the engine block temperature above 100 o 

### F. Such systems utilize waste heat from a small dies el engine to heat the main engine and to generate electricity using by an alternator. An auto engine start/stop system can shutdown and restart both long-haul and switching loco motive engines automatically, based on a preprogrammed set of values (e.g., water and cool ant temperature, batter y voltage, and air brake cylinder pressure). 69 

### For example, a driver can set the syst em to the restart engine and turn on heat when the ambient temperature falls below 65° F. 70 

### Both of these systems can be used simultaneously to shut down the engine when not needed while also keep the engine warm in preparation for a restart and while maintaining batte ries in a ready status. This practice, which includes both of these systems, can reduce loco motive energy use at idling by approximately
80%. 67 

### This practice has been demonstrated in terms of installation on a locomotive and realization of reduced idling. 68 

### Based on the results of field tests, this practice was found to reduce overall long-haul id ling time by 70% and overall switcher idling time by 80%. 67-68 

### The estimated potential reductions in modal GHG emissions and energy use are both 3.6%.53 

### 5.1.2 Best Practice 2-2: Battery-Die sel Hybrid Switching Locomotive Battery-diesel hybrid switchers are commercia lly available locomotives that can replace traditional switching locomotives. Traditional sw itchers typically have 2,000 hp diesel engines. Battery-diesel hybrid switchers include a small diesel engine (e.g., 125 to 300 hp) and large (60,000 lbs) lead-acid batteries. This small diesel engine is used to charge batteries that maintain batteries in a ready status during periods of locomo tive non-use. At full load, the batteries account for 95% of the horsepower and th e small diesel engine accounts for another 5%. This hybrid switcher also has an auto start/st op system that contains a microprocessor to automatically shut down the small diesel engine during periods of locomotive non-use or when the batteries are fully charged based on battery volta ge values. From the re sults of field tests, a battery-diesel hybrid switcher was found to reduce daily fuel use by 35 to 57%. 71 

### Since switching locomotives are responsib le for only a small portion (5%) of total rail fuel use, the estimated potential reductions in modal GHG emissions and energy use are both 1.8%. The drawback of this practice is that only yard switchers can apply this practice.

5.1.3 Best Practice 2-3: Plug-In Units Plug-in units are commercially available syst ems that can avoid the need for idling of switcher engines while switchers are parked in sw itching yards. These systems, which require both on-board and off-board components, enable locomotive drivers to switch off their diesel engines by plugging a locomotive into an external electrical power source. These systems can use electricity powered systems to supply heat, circulate and heat cool ant and oil, and keep batteries charged. The use of a plug-in unit with a switching locomotive is estimated to consume 14% less energy than without a plug-in unit, when taking into account avoided direct diesel fuel use for operating the locomotive and production of electricity for the external power supply. 72 

### Since switching locomotives are responsible for only a small portion (5%) of total rail fuel use, the estimated potential reductions in modal GHG emissions and energy use are 0.6% and 0.4%, respectively. The drawback of this pract ice is that only yard sw itchers can apply this practice at appropriate ly equipped locations.

5.2 Weight Reduction

― Best Practice 2-4: Lightweight Materials
The use of lighter-weight components to redu ce the weight of loco motives and railcars has the potential to reduce fuel use. High-stre ngth, lightweight components include aluminum, plastics, and others. Redesigns can also reduce railcar weight and reduce fuel use. For example, newly designed coil steel cars have light er tare weight and extra carrying capacity. Redesigned railcars for hauling stee l slabs, which are lighter than conventional rail cars, can carry54 

### more goods and also reduce energy use. Higher-capacity railcars that have bett er design and that use lightweight materials were introduced by Canadian Pacific Railway. 73-74 

### Based on a Canadian study, light-weight coal cars are esti mated to reduce energy use by 10 percent, and light-weight grain cars are estimated to reduce energy use by 5 percent. The estimated potential
reductions in modal GHG emissions and en ergy use are both 4.8%. However, current light-weight materials may be cos tly and may not have satisfactory material characteristics, such as strength. Further research and devel opment for advanced materials is needed.

5.3 Rolling Resistance Improvement

― Best Practice 2-5: Lubrication Improvement
Some energy expended by the locomotive is lost to wheel-to-rail fric tion. Reductions in
wheel-to-rail resistance can be made via improved lubricati on. Efficient lubrication systems, such as top-of-rail lubrication sy stems, reduce wheel and rail wear and reduce fuel consumption. These systems can avoid wheel slippage by distri buting a proper amount of lubricants on the rail,
so as to reduce wheel-to-rail resi stance without causing slippage. 75 

### Based on the results of field tests, this practice can reduce fuel consumption by 4% to 6%. 76-77 

### The estimated potential
reductions in modal GHG emissions and energy use are both 4.0%.

5.4 Alternative Fuel

― Best Practice 2-6: B20 Biodiesel Fuel for Locomotives
B20 biodiesel, which is descri bed in Section 4.11.2, is a po tential alternative fuel for diesel locomotives. Based on a life cycle analysis, the CO 2 

### emissions are estimated to decrease by 0.0069 tons CO 2 

### eq. per 10 6 

### BTU for B20 compared to petr oleum diesel. The estimated potential reduction in mo dal GHG emissions is 5.5%. 61,63-64,78-79 

### Based on life cycle inventories, the production of biodiesel cons umes more energy than the pr oduction of petroleum diesel. 66 

### The estimated potential modal increase in energy use is 5.3%. 61



### . 5.5 Summary of Potential Best Practices for the Rail Mode
The six potential best practices for the rail mode are summarized in Table 5-1. They are
in table format for the convenience of readers.

5.6 Comparisons of the Modal GHG Emissi ons Reductions for the Best Practices
Figure 5-1 illustrates the vari ability among the potential best practices with respect to
estimated reductions in modal GHG emissions. Some best practices are mutually exclusive or have interactions with others. Thus, these percentage reductions cannot be summed to obtain a total aggregated emission reduction.55 

### Table 5- 1. List and Description of Po tential Best Practices for the Rail Mode

Subgroup Type of Strategies Description

Technology 2-1. Combined Diesel Powered Heating System and Auto Engine Start/stop System A small diesel powered heating system can keep the engine block temperature above 100 o F. Such systems utilize waste heat from a small diesel engine to heat the main engine an d to generate electricity using by an alternator. An auto engine start/st op system can shutdown and restart both long-haul and switching locomotive engines automatically, based on a preprogrammed set of values (e.g., 

### throttle position, water and coolant temperature, battery voltage, and air brake cylinder pressure), by using a microprocessor. 69 For example, a driver can set the system to the restart engine and turn on heat when the ambient temperature falls below 65° F. 70 Both of these systems can be used simu ltaneously to shut down the engine when not needed while also keep th e engine warm in preparation for a restart and while maintaining batteries in a ready status. This practice, which includes both of these systems, ca n reduce locomotive energy use at idling by approximately 80%. 67 This practice has been demonstrated in terms of installation on a locomotive and realization of reduced idling. 16 Based on the results of field tests, this practice was found to reduce overall long-haul idling time by 70% and overall switcher idling time by 80%. 67-68 The estimated potential reduction in modal GHG emissions and energy use are both 3.6%. The estimated incremental capital cost is $28,000 for diesel powered heating system and $7,500 for auto engine start stop system. 68 Anti-Idling

Technology 2-2. Battery-Diesel Hybrid Switching Locomotive Battery-diesel hybrid switchers are commercially available locomotives that can replace traditional switching lo comotives. Traditional switchers typically have 2,000 hp diesel engines. Battery-diesel hybrid switchers include a small diesel engine (e.g., 1 25 to 300 hp) and la rge (60,000 lbs) lead-acid batteries. The lifetime of these Pb-acid batteries are expected to be 10–15 years. 69,72 The small diesel engine is used to charge batteries that maintain batteries in a ready status during periods of locomotive non-use. At full load, the batteries account for 95% of the horsepower and the small diesel engine accounts for another 5%. This hybrid switcher also has an auto start/stop system that contains a microprocessor to automatically shut down the small diesel engine during periods of locomotive non-use or when the batteri es are fully charged based on battery voltage values. 71 From the results of field tests, a battery-diesel hybrid switcher was found to reduce daily fuel use by 35 to 57%. 71 Since switching locomotives are responsible for only a small portion (5%) of total rail fuel use, the estimated potential reduction in modal GHG emissions is 1.8%. The estimated capital cost is $200,000. 

### Continued on next Page56 

### Table 5-1. Continued

Subgroup Type of Strategies Description

Anti-Idling Technology 2-3. Plug-In Units Plug-in units are commercially available rail yard electrification systems that can avoid the need for idling of switcher engines while switchers are parked in switching yards. These systems, which require both on- b oard and off-board components, enable locomotive drivers to switch off their diesel engines by plugging a locomoti ve into an external power source o f three-phase AC. These systems can u se electricity powered systems to supply heat, circulate and heat coolant and oil, and keep batteries charged. They are only available at specific lo cations, such as switching yard. The use of a plug-in unit with a switching locomotive is estimated to consume 14% less energy than without a plug-in unit, when taking into account avoided direct diesel fuel use for operating the locomotive and production of electricity for the external power supply. 72 Since switching locomotives are responsible for only a small portion (5%) of total rail fuel use, the estimated potential reduction in modal GHG emissions and energy use are 0.6% and 0.4%, respectively. The estimated capital cost is $8,000.

Weight Reduction Technology 2-4. Lightweight Materials The use of lighter-weight components to reduce the weight of locomotives and railcars has the potential to reduce fuel use. High-strength, lightweight components include aluminum, plastics, and others. Redesigns can also reduce railcar weight and reduce fuel use. For example, newly designed coil steel cars have lighter tare weight b y up to 55,200 pounds and extra carrying cap acity. Redesigned railcars for hauling steel slabs, which are lighter than conventional railcars by 20,000 pounds, can carry more goods and also reduce energy use. Higher-capacity railcars that have bett er design and that use lightweight materials were introduced by Canadian Pacific Railway. 73-74 Based on a Canadian study, light-weight coal car s are estimated to reduce energy use by 10 percent, and light-weight grain cars are estimated to reduce energy use by 5 percent. The estimated potential reduction in modal GHG emissions is 4.8% or more.

Rolling Resistance Improvement Technology 2-5. Lubrication Improvement Some energy 

### expended by the locomotive is lost to wheel-to-rail friction. Reductions in wheel-to-rail resistance can be made via improved lubrication. Efficient lubrication systems, such as top-of-rail lubrication systems, reduce wheel and rail wear and reduce fuel consumption. These systems can avoid wheel slippage by distributing a proper amount of lubricants on the rail, so as to re duce wheel-to-rail resistance without causing slippage. 75 Based on the results of field tests, this practice can reduce fuel consumption by 4% to 6%, depending on the grade and
curvature. 76-77 The estimated potential reduction in modal GHG emissions and energy use are both 4.0%. 

### Continued on next Page57 

### Table 5-1. Continued
Subgroup Type of Strategies Description

Alternative Fuel Technology 2-6. B20 Biodiesel Fuel for Locomotives 

### B20 biodiesel, which is described in Section 4.11.2, is a potential alternative fuel for diesel loco motives. Based on a life cycle analysis, the CO 2 emissions are estimated to decrease by 0.0069 tons CO 2 eq. per 10 6 BTU for B20 compared to petroleum diesel. 61 Although this alternative fuel has been a commercia lly available product for trucks, it is being tested for the suitability fo r the use as locomotive fuel. The potential market share of B20 biodiesel is estimated as 64% in 2025 based on the potential maximum production capacity of biodiesel, which is estimated as 7.8 billion gallons in 2025, and the distribution ratio among the truck, rail and water modes. 63-64 The estimated potential reduction in modal GHG emissions is 5.5%. 61,63-64,78-79 Based on life cycle inventories, the production of biodiesel consumes mo re energy than the production o f petroleum diesel. 66 The estimated potential modal increase in energy use is 5.3%. 61



### 0 1 2 3 4 5 6

2-1 2-2 2-3 2-4 2-5 2-6

Best Practice Number for the Rail Mode

Figure 5- 1. Reductions in Modal GHG Emis sions for the Best Practices for the Rail
ModeModal GHG Emissions Reductions (%)58 

### The percentage reductions in modal GHG em issions range from 0.6 to 5.5 percent when comparing individual best practices. Some be st practices are mutually exclusive or have interactions with others. Thus, these percentage reductions cannot be su mmed to obtain a total aggregated emission reduction.

5.7 Quantitative Cost Results fo r the Selected Best Practices
Quantitative cost results for the best practices with sufficient information are summarized
in individualized standard ized reporting tables, which are given in Appe ndix B. In contrast, assessment results for the best practices which have a lack of sufficient information from which to quantify costs are summarized in simplified su mmary tables individually , which are also given in Appendix B. To date, there is sufficient in formation for four best practices upon which to make quantitative assessments. The other thr ee best practices are assessed qualitatively. The best practices assessed quantitatively in clude combined diesel powered heating and start/stop system, battery-diesel hybrid switching locomotive, plug-in units, and B20 biodiesel. Table 5-2 summarizes the quantitative assessme nt results of modal GHG emissions reductions, modal energy use reductions, annualized cost, en ergy cost saving, net savings, net savings per unit of GHG emissions reductions, net savings per unit of energy use reduction, and simple pay-back periods for these four selected best practices. Three of these four best practices produce ne t cost savings. These savings are the net result of substantial costs offset by substantia l savings based on reduced energy usage. For one of the best practices, B20 biodies el, the net savings are negative, indicating that these practices do not pay for themselves. It is because that B20 biodiesel fuel cost is higher than that for petroleum diesel (based on current typical experien ce) and thus there is a net increase in total costs. When net cost savings are normalized based on the GHG emissions reductions, combined diesel powered heating and start/ stop system, battery-diesel hybrid switching locomotive, and plug-in units appear to be more cost-effective, whereas the use of B20 biodiesel appears to be less cost effective. However, combined diesel powered heating and start/stop system, battery-diesel hybrid sw itching locomotive, and biodiesel practices have the potential to achieve large magnitudes of GHG emissions reduc tions, but plug-in unit s could only contribute small magnitude of GHG emissions reductions b ecause this practice can be only used in switching yard; therefore, this restriction limits its potential for GHG emissions reductions and energy reduction.59 

### Table 5- 2. Summary Table for the Comparis on of the Quantitative Cost Results for
Selected Best Practices for the Rail Mode a

Best Practice Number 2-1 2-2 2-3 2-6

Name Combined Diesel Powered Heating System and Auto Engine Start/stop System Battery Diesel Hybrid Switching Locomotive Plug-In Unit B20 Biodiesel

Subgroup Anti-idling Anti-idling Anti-idling Alternative Fuel Responsible Parties 26, 27, 28, 35, 36, 37 26, 27 26, 27 23, 25, 26, 28, 29 Target Parties 11, 13 11 11 8, 10 Target GHGs CO 2 CO 2 CO 2 CO 2 Strategy Types Technology Tech nology Technology Technology Developmental Status P C P N Modal GHG Emission Reduction (10 6 ton CO 2 eq./year) 2.3 1.1 0.4 3.5

Modal Energy Use Reduction (10 12 BTU/year) 29 14 4 -42

Annualized Costs ($ 10 6 /year) 140 180 91 380 Annual Energy Cost Saving ($ 10 6 /year) 530 260 230 0 Net Saving ($ 10 6 /year) 390 70 135 -380 Net Saving per Unit of GHG Emissions Reductions ($/ton CO 2 eq.) 167 65 364 -109

Net Saving per Unit of Energy Use Reduction ($/ton CO 2 eq.) 13.5 5.2 38 N/A b

Simple Pay-back Period (years) 2.1 5.5 0.8 N/A c

a These assessments are based on the assumptions th at these best practices reach their potential maximum market shares in 2025. Cost results ar e presented only for those best practices for which adequate data were available.
b This practice has no energy use reduction due to an increase in energy use, and it has no net saving due to high annualized cost and no energy cost saving.

c There is no pay-back period for this b est practice because there is no net saving.60 

### 6.0. BEST PRACTICES FOR THE AIR MODE

This chapter identifies and characterizes 10 po tential best practices applicable to the air mode. These best practices are divided into 5 subgroups, in cluding: aerodynamic drag reduction; air traffic management; weight re duction; ground support equipment improvement; and engine improvement. Details regarding these best practices are in Appendix C. This chapter provides an overview of severa l potential best practices for greenhouse gas
emissions reductions for the aviati on freight transportation mode. Ho wever, this work is merely illustrative of possible best practices. Potential best practices were identified based on literature review. However, there may be other potential best practices that are not addressed here. Furthermore, in some cases, although potential best practices might be iden tified in the literature qualitatively, there is a lack of quantitative es timates of the possible impact of these potential best practices on emissions reductions. In general, there is a lack of reliable cost data for aviation potential best practices. Therefore, the information provided here is considered to be an initial but limited starting point for further identification and characterization of aviation freight potential best practices. For aviation freight, there are many means by which to achieve reductions in fuel use and greenhouse gas emissions. These include potent ial changes in operations, aircraft design, engine design, fuels, and ground support, among ot hers. For example, operations includes air traffic control, standard procedures for opera tion and movement of the aircraft on the ground, take-off and landing procedures, and so on. For ex ample, take-off procedures with derated or reduced thrust are estimated to reduce emissions of criteria air pollutants, such as NO x 

### , but may slightly increase the fuel consumption and GHG emissions. 80 

### In some cases, the potential best practices may be many years from realization, and thus there is limited information upon which to base an assessment at this time (e.g., IPCC, 1999). 81 

### In addition to technical options for potential best practices , there are policy options for strategies that potentia lly could reduce energy use and greenhouse gas emissions. For example, policy options for reduci ng the growth of emissions from the air mode may include more stringent regulations, reductions of subsidies and incentives that currently lead to negative environmental impacts, market-based mechan isms (e.g., carbon tax and emissions trading), voluntary agreements, research programs, and inte r-modal shifts. However, the efficacy and costs of such approaches are not adequately characterized for purposes of analysis here. 8161 

### 6.1 Aerodynamic Drag Reduction
Most of the fuel consumed by airplanes is needed to overcome aerodynamic drag, since they fly at very high speed. Reduction of aerodyna mic drag can significantly improve the fuel efficiency of airplanes. 82 

### Aerodynamic drag can be reduced by installing add-on devices, such as film surface grooves, hybrid laminar flow te chnology, blended winglets, and spiroid tips.

6.1.1 Best Practice 3-1: Surface Grooves Skin friction drag, also referred to as viscous drag, is caused by the c ontact of the air flow against the surface of the aircraft, and is impacted by the viscosity property of air. An approach that is undergoing testing is the use of an adhesi ve-backed film with micr o-grooves that is placed on the exterior surfaces of the wings and the fusela ge of the airplane. The series of microscopic grooves produces a drag-reducing surface. The re duction in skin friction drag results in a decrease in fuel use. Based upon results of wind tunnel and flight tests, this device is estimated to reduce total aerodynamic drag by up to 1.6%. 82 

### The estimated potential reduction in modal GHG emissions is 1.6%. The disadvantage of this practice is that the life time of the film with micro-grooves is only 2 to 3 years. Thus, resear ch is needed to improve the durability of the
materials for the film.

6.1.2 Best Practice 3-2: Hybrid Laminar Flow Technology Aerodynamic drag associated with skin fricti on can be reduced if tu rbulent air flow can be replaced by laminar airflow over the aircraft skin surface. Laminar flow is a smooth air flow moving across an airfoil without turbulence, bu t it is usually destroyed by turbulence induced because of interactions with wing surfaces, leading to skin friction. Furthermore, contamination on the aircraft surface, such as the accumulation of ice, in sects or other debris, degrades laminar flow. A newly developed concep t, hybrid laminar flow technology, integrates both passive and active approaches to maintain laminar flow. A passive device requires no energy for its operation. An active device re quires a source of ener gy for its operation.
Passive anti-contamination devices are used to prevent or minimize contamination. Examples of such devices include: design of the wing surface geometry to have favorable pressure gradient; insect sh ields, removable coverings, c ontinuous liquid dischargers and deflectors to prevent insect contamination; and anti-freeze agent dischargers and heat application techniques to avoid ice accumulation. 83 

### An example of a passive an ti-contamination device is a Krueger flap. This flap has hinged droop surfaces on the leading edge of the wings that can be
used for ice and insect-c ontamination prevention. 84 

### An active approach, a suction system, is comprised of a multi-layer panel on a wing62 

### surface. The multi-layer panel includes a thin out er layer with fine pores and a thicker inner layer. The space between these two layers is di vided into chambers. Air is sucked through the pores on the outer layer, then is vent ed through ducts out of the aircraft. 84 

### The ducts are located to avoid negative impact to the aerodynamic pe rformance of the aircra ft. The air suction process can reduce air flow turbulence to ma intain laminar flow on the surface of a wing. 82,84-85 

### Taking into account the power used for suc tion, the combination of these passive and active approaches can reduce fuel use by 6% to 10%. 82 

### The estimated potential reduction in
modal GHG emissions is 6.0%.

6.1.3 Best Practice 3-3: Blended Winglet Lift-induced drag is due to the tip vortices produced by a lifting wing. A blended winglet is a commercially av ailable wing-tip device that ca n reduce lift-induc ed drag. A winglet is an extension mounted at the tip of a wing. A blended winglet combines part of the wing tip with the winglet using a smooth blended sh ape that can decrease the tip vortex intensity. From the results of field tests, the weaken ed vortex intensity cause d by a blended winglet decreases lift-induced drag by 4% and reduces energy use by 2%. 82 

### The estimated potential reduction in modal GHG emissions and energy us e are both 2.0%. This practice incr eases the surface area of the wing of the aircraft, which c ould increase the viscous drag. The effect of additional viscous drag associated with the surf ace area increase is accounted for in the estimate given here.

6.1.4 Best Practice 3-4: Spiroid Tip An alternative type of wing-tip device is a spir oid tip. This device has been pilot tested and, like blended winglets, is intended to reduce li ft-induced drag. A spiroid tip is a spiral loop formed by joining vertical and horizontal wingle ts. This technique can decrease tip vortex intensity and, therefore, reduce lift-induced drag. From the results of model simulations, spiroid tip can reduced lift-induced drag by 3.3% and reduce energy use by 1.7%. 82 

### The estimated potential reduction in modal GHG em issions and energy use are both 1.7%. This practice increases the surface area of the wing of the aircraft, which could increase the viscous drag. The effect of additional viscous drag associated with the su rface area increase is accounted for in the estimate given here.

6.2 Air Traffic Management

― Best Practice 3-5
Optimized air traffic management systems are in the development stage. Compared to the current air traffic control system, there are opportunities to reduce congestion and improve63 

### aircraft routing in order to re duce fuel consumption. Advanced air traffic management systems can optimize air traffic flow, provide efficient r oute options, and increase situation awareness. These systems are expected to reduce aviation fuel use by 6 to 12 percent, depending on the implementation of international arrangements. 81 

### The estimated potential reduction in modal GHG emissions and energy use are both 6.0%. Air traffic management improvement is a poten tial best practice. An example of such an approach is the implementation of Communi cation, Navigation, Surveillance/Air Traffic Management (CNS/ATM). The concept of CNS/ATM, formerly known as the future air navigation systems (FANS) concept, was created by the International Civ il Aviation Organization (ICAO), in cooperation with the aviation civil co mmunity. This concept aims at improving traffic control and airline management by appl ying new technologies, su ch as satellites and advanced computers, data links, and advanced flight avionics, to e nhance capabilities of satellite-based navigation and di gital data link communication systems. With the enhanced capabilities, the combination of new CNS technol ogies and the next generation of ATM systems will reduce fuel use, emissions, noise, and airspace congestion. 86 

### In the US, the Federal inter-agency Joint Planning and Development Office (JPDO) has been established based on “Vision-100” legisl ation (Public Law 108-176) signed by the President in December 2003. JPDO is designing an advan ced air transportation system, the Next Generation Air Transportation System (NextG en), which is intended for deployment by 2025. 87 

### Many technologies are being developed for NextGen, such as the Automatic Dependent Surveillance Broadcast (ADS-B) and the Syst em Wide Information Management (SWIM). 88



### ADS-B is a satellite-based surveillance an d control systems intended to replace traditional ground-based surveillance and control systems. ADS-B includes aircraft on-board navigation systems and data-links. The former collects aircraft positi on and velocity data. The later automatically transmits data to air traf fic control radar systems. The application of ADS-B will enhance operational efficiency and redu ce fuel use by reducing visibility restrictions because pilots will be able to see what air traffic controllers see. 86,88 

### SWIM is a networking-based init iative that will link needed information, such as position, weather, and restricted airspace notices, and will deliver high-quality, timely data to users involved in the NextGen system. SWIM will re duce the number and t ypes of interfaces and systems, thereby enhancing operational effi ciency and expanding system capacity. 88 

### The implementation of CNS/ATM or the NextGen systems will provide new capabilities. 88,89 

### Three examples of new capabilities are: (1) Reduced Vertical Separation Minimum (RVSM): The RVSM is a procedure that allows air traffic controllers a nd pilots to reduce the standard required vertical separation from 2,000 feet to 1,000 feet between aircraft64 

### flying at altitudes between 29,000 and 41,000 f eet. The RVSM will enhance aircraft operating efficiency by increasing the number of more fuel and time efficient flight
altitudes. 90,91 

### (2) Continuous Descent Approach (CDA):
The conventional “dive-and-drive” aircra ft arrival and approach procedures requires the use of high thrust, the deploym ent of flaps and landing gear to slow the aircraft while it levels off at different stages , which results in additional fuel consumption, noise and pollution. The CDA is a procedure that optimizes the aircraft landing. CDA
involves a continuous descent of the aircraft on a constant sl ope without need to deploy flaps and landing gear. CDA flight tests in 2004 demonstrated reductions in fuel consumption of 900 lb to 1,500 lb comp ared to a conventional approach. 88,92 

### (3) Oceanic Trajectory-Based Operations: Aircraft currently use designated rout es to fly over oceanic airspace. Trajectory-based operati ons would enable pilots to tailor their individual flight paths based on four-dimensional trajectories, whic h include altitude, longitude, latitude, and time, of other aircraft. The advantages of trajectory-based operations are avoided congestion, more efficient use of ai rspace, and reduction in fuel use. 88



### 6.3 Weight Reduction
Reductions in the weight of aircraft through the use of light-weight materials and weight reduction of non-essential components could l ead to significant reductions in fuel use. 81



### 6.3.1 Best Practice 3-6: Airframe Weight Reduction The weight of an airframe is approximately 50% of an aircraft’s gross weight. Adoption of advanced lighter and stronger materials in the structural components of the airframe, such as aluminum alloy, titanium alloy, and composite materials for non-load-bearing structures, can reduce airframe weight, thereby le ading to a reduction in fuel use. 81 

### The International Civil Aviation Organization (ICAO) estimated that adop tion of such materials can reduce structural weight by 4%. 93 

### The estimated potential reduction in modal GHG emissions and energy use are both 2.0%. More research and development is n eeded to reach the proj ected structure weight reduction target.

6.3.2 Best Practice 3-7: Non-Essential Weight Reduction Trimming non-essential weight from aircraft can reduce fuel use. Adjustments to the amount of fuel, water, and emergency equi pment onboard with resp ect to anticipated65 

### requirements and a contingency allowance can reduce fuel use by no more than 1%. 81 

### The estimated potential reduction in m odal GHG emissions is 1.0%.

6.4 Ground Support Equipment Improvement
Ground support equipment can be designed an d deployed to help reduce energy use on-board aircraft, or can be redesi gned to be more fuel efficient. Potential best practices for ground support equipment include supplying en ergy for aircraft operation on the ground and substation of electric and hybrid delive ry trucks for conventional trucks. 81,94-97



### 6.4.1 Best Practice 3-8: Ground-Based Equipment as an Alternative to Auxiliary Power Units Aircraft auxiliary power units (APUs) are engine-driven ge nerators that s upply electricity for use aboard the plane while at a cargo load ing area. An alternative method for supplying electricity is to connect the aircraft to shore- based power or to use ground-based equipment to generate power for delivery to the aircraft. Su ch ground-based equipment has been pilot tested. Ground-based equipment can reduce AP U fuel use significantly while the aircraft is at the gate. 94 

### The reported estimates of fuel use and GHG emi ssions reductions for this best practice are
combined with those of Best Practice 3-9. The estimated combined reduction in modal fuel use
and GHG emissions for Best Practices 3-8 and 3-9 are 2.9%. 96-97



### 6.4.2 Best Practice 3-9: Electric or Hybrid Heavy Duty Delivery Trucks Off-road electric or hybrid vehicles fo r supporting airport operations have been pilot-tested. Such vehicles can replace existing, older ground support equipment. An off-road electric powered delivery vehicl e can operate for 100 miles after a single charge, carry 3,000 lbs of cargo, travel at a speed of up to 30 miles per hour, and climb grades up to 10%. These capabilities are suitable for ground equipment service. Other alte rnative ground support equipment propulsion systems can be based on LPG or gasoline powered hybrid vehicles. 94-95 

### As explained in Section 6.4.1, the reported estimat es of fuel use and GHG emissions reductions for this best practice are combined with those of Best Practice 3-8. The estimated combined
reduction in modal fuel use a nd GHG emissions for Best Pr actices 3-8 and 3-9 are 2.9%. 96-97 

### Reduction in cost is needed to expand the ma rket penetration potenti al of this practice.

6.5 Engine Improvement

― Best Practice 3-10: Improve d Engine Overall Efficiency
Current aircraft energy efficiency, the amount of energy used to transport one unit of payload over a distance, is about 10-13 MJ per ton-mile. 98 

### Aircraft fuel consumption can be66 

### reduced based on improving engine efficiency. Engine efficiency can be improved through increasing fan bypass ratio, increasing pressure rati o of compressor and better mixing of fuel and air prior to combustion. A new jet engine with several advanced tec hnologies is being developed and is scheduled to enter the market in 2008. One of the engine technologies features larger fan sizes to reach high engine bypass ratio by 9.5, 99 

### which is higher than 5 to 9 bypass ratios of today’s most advanced engines. 81 

### The increased fan weight caused by larger size is offset by a reduced number of fan blades and the use of composite ma terials. This engine is also equipped with a high-pressure compressor that produces a 23:1 pressure ratio. Engine efficiency can be improved further by better mixing of fuel and air, which leads to a more homogenous lean fuel/air mixture that burns more evenly, th ereby reducing local pockets of incomplete combustion. Moreover, a fuel-efficient tech nology that runs the high-pressure turbine clockwise and the low-pressure tu rbine counterclockwise has been demonstrated in tests and is also included in the new engine design. Ba sed on vendor information, this technology is estimated to reduce fuel use by 13.0%. 99-100 

### The estimated potential reduction in modal GHG emissions and energy use are both 13.0%.

6.6 Summary of Potential Best Practices for the Air Mode
All 10 potential best practices, sorted by 5 s ubgroups, for the air mode are summarized in Table 6-1. They are in table format for the convenience of readers.

6.7 Comparisons of the Modal GHG Emissi ons Reductions for the Best Practices
Figure 6-1 illustrates the vari ability among the potential best practices with respect to
estimated reductions in modal GHG emissions. The percentage reductions in modal GHG emissions range from 1.0 to 13.0 percent when comparing individual best practices. However, these percentage reductions cannot be summed
to obtain a total emission reduction. Some best practices are mutually exclusive or have
interactions with others. For all of the 10 identified best practices for the air mode, there is a lack of sufficient information to support quantitative assessments. For these strategies, qualitative assessments are summarized in simplified summary tables individually. If sufficient information becomes available in the future, best practices that ar e assessed here qualitativ ely could be reassessed quantitatively.67 

### Table 6- 1. List and Description of Po tential Best Practices for the Air Mode
Subgroup Type of Strategies Description

Technology 3-1. Surface Grooves Skin friction drag, also referred to as viscous drag, is caused by the contact of the air flow against the surface of the aircraft, and is impacted by the viscosity property of air. An approach that is undergoing testing is the use of an adhesive-backed film with micro-grooves, each a few thousandths o f an inch wide, that is placed on the ex terior surfaces of the wings and the fuselage of the airplane. These grooves are called V-groove riblets. Riblets produce a drag-reducing surf ace. The reduction in skin friction drag results in a decrease in fuel u se. Based upon results of wind tunnel and flight tests, this device is estimat ed to reduce total aerodynamic drag by up to 1.6%. 82 The estimated potential reduction in modal GHG emissions and energy use are both 1.6%. One disadvantage of the riblet is that its lifetime is only 2 to 3 years. 82

Aerodynamic Drag Reduction

Technology 3-2. Hybrid Laminar Flow Technology Aerodynamic drag associated with skin friction can be reduced if turbulent air flow can be replaced by laminar airflow over the aircraft skin surface. Laminar flow is a smooth air flow moving across an airfoil without turbulence, but it is usually destroyed by turbulence induced because of interactions with wing surfaces, leading to skin friction. Furthermore, contamination on the aircraft surf ace, such as the accumulation of ice, insects or other debris, degrades laminar flow. A newly developed concept, hybrid laminar flow technology, integrates both passive and active approaches to maintain laminar flow. A passive device requires no energy for its operation. An active device requires a source of energy for its operation. Passive anti-contamination devices are used to prevent or minimize contamination. Examples of such devices include: design of the wing surface geometry to have favorable pressure gradient; insect shields, removable coverings, continuous liquid dischargers and deflectors to prevent insect contamination; and an ti-freeze agent dischargers and heat application techniques to avoid ice accumulation. 83 An example of a passive anti-contamination device is a Krueger flap. This flap has hinged droop surfaces on the leading edge of the wings that can be used for ice and insect-contamination prevention. 84 An active approach, a suction system, is comprised of a multi-layer panel on a wing surface. The multi-layer pane l includes a thin outer layer with fine pores and a thicker inner layer. The space between these two layers is divided into chambers. Air is sucked through the pores on the outer layer, then is vented through ducts out of the aircraft. 84 The ducts are located to avoid negative impact to the aerodynamic performance of the aircraft. The air suction process can reduce air flow turbulence to maintain laminar flow on the surface of a wing. 82,84-85 Taking into account that the power used for suction is approximately 1% of aircraft fuel use, the combination of these passive and active approaches can reduce fuel use by 6% to 10%. 82 The estimated potential reduction in modal GHG emissions is 6.0%. 

### Continued on next Page68 

### Table 6-1. Continued
Subgroup Type of Strategies Description

Technology 3-3. Blended Winglet Lift-induced drag is due to the tip vortices produced by a lifting wing. A blended winglet is a commercially av ailable wing-tip device that can reduce lift-induced drag. A winglet is an extension mounted at the tip of a wing. A blended winglet combines part of the wing tip with the winglet using a smooth blended shape that can decrease the tip vortex intensity. From the results of field tests, the weakened vortex intensity caused by a blended winglet decreases lift-induced drag by 4% and reduces energy use by 2%. 82,101 This practice, however, incr eases surface area that increases the viscous drag. 82 The estimated potential reduction in modal GHG emissions and energy use are both 2.0%. Aerodynamic Drag Reduction

Technology 3-4. Spiroid Tip An alternative type of wing-tip device is a spiroid tip. This device has b een pilot tested and, like blended winglets, is intended to reduce lift-induced drag. A spiroid tip is a sp iral loop formed by joining vertical and horizontal winglets. This techni que can decrease tip vortex intensity and, therefore, reduce lift-induced drag. From the results of model simulations, spiroid tip can reduced lift-induced drag by 3.3% and reduce energy use by 1.7% or more. 82 This practice, however, increases surface area that increases the viscous drag. 82 The estimated potential reduction in modal GHG emissions and energy use are both 1.7%.

Air Traffic Management Operation 3-5. Air Traffic Management Improvement Air traffic management systems are designed for the guidance, separation, coordination, and control of aircraft movements. Today’s air traffic control systems have limitations which result in traffic congestion and inefficient routings. For example, aircraft operators in existing system need to follow established, inefficient airways. These limitations result in the increase of fuel use, air po llutants emissions, and GHG emissions. Optimized air traffic management systems are in the development stage. Compared to the current air traffic control system, there are opportunities to reduce congestion and improve aircra ft routing in order to reduce fuel consumption. Advanced air traffic management systems can optimize air traffic flow, provide efficient route options, and increase situation awareness. These systems are expected to reduce aviation fuel use by 6 to 12 percent, depending on th e implementation of international arrangements. 84 The estimated potential reduction in modal GHG emissions and energy use are both 6.0%. 

### Continued on next Page69 

### Table 5-1. Continued
Subgroup Type of Strategies Description

Technology 3-6. Airframe Weight Reduction The weight of an airframe is approximately 50% of an aircraft’s gross weight. Adoption of advanced light er and stronger materials in the structural components non-load- b earing structures of the airframe, such as aluminum alloy, titanium alloy, and composite materials for, can reduce airframe weight, thereby leading to a reduction in fuel use. Some design technologies, such as high-fidelity finite element models (FEMs), can be used for strength analysis to understand safety load-factor margins and reduce structural weight. 81 Historical trends demonstrated that airplane manufactures keep decreasing structural weight of airframes. For example, the Boeing 777, which is de veloped a decade ago, had an airframe with 10% composite structure by weight. The newly introduced Airbus 380 has an airframe with 25% composite structure by weight. The Boeing 787, scheduled for delivery beginning in 2008, will have an airframe with 50% composite structure by weight. 102 The International Civil Aviation Organization (ICAO) estimated that adoption of such materials can reduce structural weight by 4%. 93 However, improved techniques for investigating the airframe with compos ite material are needed to avoid structure failure. 102 The estimated potential reduction in modal GHG emissions and energy use are both 2.0%. Weight Reduction

Operation 3-7. Non-Essential Weight Reduction Trimming non-essential weight from aircraft can reduce fuel use. Additional non-essential weight has several sources, such as extra aviation fuel, potable water and emergency equi pments. Aviation fuel onboard is usually more than that required by the flight plan. Carrying extra fuel is because of several reasons, such as saf ety concern, fuel price difference among two places, fuel availability at some remote sites, fuel quality concern at some locations, or insuff icient time for refueling. Carrying extra potable water and emergency equipment also increase non-essential weight of aircrafts. Adjustments to the amount of fuel, water, and emergency equipment onboard with resp ect to anticipated requirements and a contingency allowance can reduce fuel use by no more than 1%. 81 The estimated potential reduction in modal GHG emissions and energy use are both 1.0%.

Ground Support Equipment Improvement Technology 3-8. Ground-Based Equipment as Alte rnative to Auxiliary Power Units Aircraft auxiliary power units are en gine-driven generators that supply electricity for use aboard the plane while at a cargo loading area. An alternative is to connect the aircraft to shore- b ased power or to use ground-based equipment to generate power for delivery to the aircraft. Such equipment has been pilot tested. Ground- b ased equipment can reduce APU fuel use significantly whil e the aircraft is at the gate. 81 The reported estimates of fuel use and GHG emissions reductions for this best practice are combined with those of Best Practice 3-9. The estimated combined reduction in modal fuel use and GHG emissions for Best Practices 3-8 and 3-9 are 2.9%. 96-97 

### Continued on next Page70 

### Table 5-1. Continued
Subgroup Type of Strategies Description

Ground Support Equipment Improvement Technology 3-9. Electric or Hybrid Heavy Duty Delivery Trucks Off-road electric or hybrid vehicles for supporting airpor t operations have been pilot-tested. Such vehicles can replace existing, older ground support equipment. An off-road electric powered delivery vehicle, equipped with a 320 volt AC drive train, can operate for 100 miles after a single charge, carry 3,000 lbs of cargo, travel at a speed of up to 30 miles per hour, and climb grades up to 10%. These capabilities are suitable for ground equipment service. Other a lternative ground support equipment propulsion systems can be based on LPG or gasoline powered hybrid vehicles. 94-95 As explained in Section 6.4.1, the reported estimates of fuel use and GHG emissions reductions for this best practice are combined with those of Best Practice 3-8. The estimated combined reduction in modal fuel use and GHG emissions for Best Practices 3-8 and 3-9 are 2.9%. 96-97

Engine Improvement Technology 3-10. Improved Engine Overall Efficiency Current aircraft energy efficiency, the amount of energy used to transport one unit of payload over a distance, is about 10-13 MJ per ton-mile. 98 Aircraft fuel consumption can be reduced based on improving engine efficiency. Engine efficiency can be improved through increasing fan bypass ratio, increasing pressure ratio of compressor and b etter mixing o f fuel and air prior to combustion. A new jet engine with several adva nced technologies is being developed and is scheduled to enter the market in 2008. One of the engine technologies features larger fan sizes to reach high engine bypass ratio by 9.5, 99 which is higher than 5 to 9 bypass ratios of today’s most advanced engines. 81 The increased fan weight caused by larger size is offset by a reduced number of fan blades and the u se of composite materials. This engine is also equipped with a high-pressure compressor that produces a 23:1 pressure ratio. Engine efficiency can be improved further by better mixing of fuel and air, which leads to a more homogenous lean fuel/air mixture that burns more evenly, thereby reducing local pockets o f incomplete combustion. Moreover, a fuel-efficient technology that runs the high-pressure turbine clockw ise and the low-pressure turbine counterclockwise has been demonstrated in tests and is also included in the new engine design. Based on vendor information, this technology is estimated to reduce fuel use by 13.0%. 99-100 The estimated potential reduction in modal GHG emissions and energy use are both 13.0%.71 

### 0 2 4 6 8 10 12 14

3-1 3-2 3-3 3-4 3-5 3-6 3-7 3-8 3-9 3-10

Best Practice Number for the Air Mode *The reduction in modal GHG emissions for Best Practice 3-9 represents the estimated combined

reduction in modal GHG emissions for Best Practices 3-8 and 3-9 

### Figure 6- 1. Reductions in Modal GHG Emissi ons for the Best Practices for the Air ModeModal GHG Emissions Reductions (%)



### * *72 

### 7.0 BEST PRACTICES FO R THE WATER MODE

This chapter identifies and characterizes five potential best practices applicable to the water mode. These best practices are di vided into three subgroups, including:

• improved propeller system;

• anti-idling; and

• alternative fuel. Additional details regarding all of these best practices are in Appendix D. For one of these best practices, sufficient data were available to quantify costs.

7.1 Propeller System Improvement
A ship uses a propeller to convert ship engine power into th rust for propulsion of the ship. As ships move through the water, they produc e energy-consuming turbulent vortices depending on speed, ship hull geometry, and propeller de sign. A number of modified propeller systems have been introduced in order to improve the overall energy efficiency of ship propulsion. These systems are designed based on attempts to recover energy from tur bulent vortices in the water, or to prevent the formati on of such vortices. This, in tur n, leads to reduction in ship fuel
use and exhaust CO 2 

### emissions. 103-105



### 7.1.1 Best Practice 4-1: Off-Center Propeller The movement of the ship through water produ ces vortices in the water. The formation of such vortices requires energy. Thus, a porti on of the energy expended to move the ship is
transferred to the creation of such vortices. For example, vortices that are formed along the rear part of the ship and that flow into the wake ar e the result of turbulence. Such vortices are referred to as “bilge vortices” and they effec tively increase the resist ance of water movement around the ship hull. An off-cente r propeller is a commercially av ailable device that attempts to capture some of the flow and energy contained w ithin the bilge vortices to enhance propulsion efficiency. An off-center propeller is part of a system that includes the rudder and properly shaft located away from the longitudinal centerline of the ship. From the result of tank tests, an off-center propeller was estimated to reduce ship propulsion ener gy use by 3% or more. This practice can be implemented for new ships but is di fficult or impractical to retrofit to existing ships. This practice was combined with a re fined hull shape and othe r energy-saving measures in a large ore carrier, which lead to a total estimated reduction in energy use of 14%. 103 

### The estimated potential reduction in modal GHG em issions is 1.5%, assuming that the off-center73 

### propeller alone contributed only pa rtially to the total estimated reduction in energy use of the ore carrier, as well as implementation on only a portion of freight ships. This practice can be implemented for new ships but it is difficult or impractical to retrofit to existing ships.

7.1.2 Best Practice 4-2: Propelle r Boss Cap with Fins (PBCF) Turbulent vortices are genera ted by propeller rotation. The formation of vortices requires energy. Thus, energy that could be used for propulsion is diverted to the formation of vortices, which reduces the overall energy effici ency of the propulsion system. A method for reducing the formation of vortices associated with the propeller ration is the use of a propeller boss cap with fins (PBCF). 104 

### PBCF is commercially avai lable, and approximately 1,000 ships have adopted th is practice as of 2006. 106 

### The PBCF includes small fins installed behind the propeller and that rotates in the same direction as the propeller. The purpose of these fins is
to avoid the formation of vortices. From the results of field tests, this de vice appears to be able to reduce propulsion fuel use by 4 to 5 percent. 104 

### The estimated potential reduction in modal GHG emissions is 2.0%, assuming either less effec tiveness in practice or implementation on only a portion of freight ships.

7.1.3 Best Practice 4-3: Auxiliary Free -Rotating Propulsion Device behind the Main Propeller As noted in the previous section, propell er rotation results in the formation of energy-consuming turbulent vortices unless mitigating measures are implemented. An alternative to PBCF is a grim vane wheel (GVW ). GVW is a commercially available device, and approximately 59 ships had a dopted this practice as of 2000. 107 

### It is an auxiliary free-rotating propulsion device that has vanes with larger diameter than that of propeller and is located immediately behind the main propeller. The rotation of GVW modi fies the accelerated flow of water that is leaving the propeller, r ecovers a portion of the energy embodied in the accelerated flow of water, and in so doing pr ovides extra propulsion. A newly designed GVW system can be mounted on the rudder horn inst ead of propeller shaft, which may improve reliability. From the results of field tests, GVW techniques may reduce propulsion fuel use by
6% or more. 105107 

### Taking into account that not all ships will adopt this technique, the estimated potential reduction in moda l GHG emissions is 3.0%.

7.2 Anti-Idling

― Best Practice 4-4: Shoreside Power for Marine Vessels at Ports
Shoreside power is being tested as ship anti -idling system that can avoid the need for running the ship auxiliary engine continuously while a ship is docked at a port. Shoreside74 

### power is a system that connects th e ship to an external electrica l power source, thereby avoiding
the need for use of the auxiliar y engine. Thus, this system can reduce ship fuel use and GHG emissions. Taking into account reduced shipboa rd energy use and emissions, and increased shoreside energy use and emissions to produce electricity, shoreside power can reduce overall GHG emissions compared to an auxiliary engine by 13%. 108-109 

### However, the fuel use for the auxiliary engine is only a small fraction of total marine fuel use. Assuming that only a fraction of all ships adopts this technique and that ship auxiliary e ngines only use a small fraction of marine fuel, the estimated potential reduc tion in modal GHG emissions is 0.2%.

7.3 Alternative Fuel

― Best Practice 4-5: B20 Biodiesel Fuel for Ships
Large ocean-going ships usually have multiple engines, including main engines and auxiliary engines. Since 1980, a ll marine engines have been di esel-powered engines. Main marine engines usually burn residual fuel or blends of residual and distillate fuels. 110 

### Auxiliary engines usually burn marine gas oil, a high sulfur diesel fuel that is usually the fuel for small and medium sized marine engines. Thus, ocean-goi ng ships often carry both residual fuel oil and marine gas oil. 111 

### For marine fuel consumption, residual fuel oil for freight ships is about 60%
of total marine fuel use. Distil late fuel for freight sh ips is about 11% of tota l marine fuel use. Distillate fuel for other ships (such as passenger ships, fish ships, military ships) accounts for
other 29% of marine fuel use. 112


### B20 biodiesel, which is descri bed in Section 4.11.2, is a po tential alternative fuel for marine gas oil powered diesel engines. 113 

### Based on a life cycle analysis, the CO 2 

### emissions are estimated to decrease by 0.0069 tons CO 2 

### eq. per 10 6 

### BTU for B20 biodiesel compared to
land-use diesel fuel. Land-use dies el fuel and marine gas oil are both distillate fu els but differ
in that land-use diesel fuel has a much lower sulfur level than the marine gas oil. Sulfur
concentrations in distillate fuels can be re duced by a refining process, hydro-treating, that consumes energy and emits CO 2


### . 111 

### Since marine gas oil is high sulfur diesel fuel and removal of sulfur emits more GHG, the production of ma rine gas oil emits less GHG than the production of land-use diesel fuel based on life cycle in ventories. The differ ence of life cycle GHG emission analysis results between B20 biodiesel and marine gas oil should be lower than the
difference between B20 biodiesel a nd land-use diesel fuel. Thus, the latter provides a useful upper bound of the former. Taking in to account that only a fraction of marine fuel is marine gas oil, the estimated potential reductions in modal GHG emissions are 1.2%. 13,63-64,112,114-115 

### The estimated potential modal en ergy use increases by 1.3%. 6175 

### 7.4 Summary of Potential Best Practices for the Water Mode
All five potential best pract ices, sorted by three subgroups, for the water mode are summarized in Table 7-1. They are in ta ble format for the convenience of readers.

7.6 Comparisons of the Modal GHG Emissi ons Reductions for the Best Practices
Figure 7-1 illustrates the vari ability among the potential best practices with respect to
estimated reductions in modal GHG emissions. These percentage reductions in modal GHG emissions range from 0.2 to 3.0 percent when comparing individual best practices. Ho wever, these percentage reductions cannot be
summed to obtain a total GHG emission reduction. So me best practices ar e mutually exclusive with others, as described later in Chapter 9.

7.7 Quantitative Cost Results for the Water Mode
Quantitative cost results for the best practic es for which sufficient information was available to perform such assessments are summa rized in standardized reporting tables, which are given in Appendix D. In c ontrast, assessment results for th e best practices which have a lack of sufficient information from which to quantify costs are summarized in simplified summary tables individually, which are also given in Appendix D. To date, there is sufficient information for one best practice upon which to make quantitative assessments. The other four best practices are assessed qualitatively. The best practice assessed quantitatively is B20 biodiesel for ships. Table 7-2 summarizes the quantitative assessment resu lts of modal GHG emissions reductions, modal energy use reductions, annualized cost, energy cost saving, net savings, net savings per unit of GHG emissions reductions, net savings per unit of energy use reduction, and simple pay-back periods for this selected best practice. For B20 biodiesel, the net savings are negative. B20 biodiesel fuel cost is higher than that for marine gas oil, and thus ther e is a net increase in total costs. The use of B20 has the potenti al to achieve a larger magn itude of total GHG emissions
reductions.76 

### Table 7- 1. List and Description of Pote ntial Best Practices for the Water Mode
Subgroup Type of Strategies Description

Propeller

System Improvement Technology 4-1. Off-Center Propeller The movement of the ship through water produces vortices in the water. The formation of such vortices require s energy. Thus, a portion of the energy expended to move the ship is transferred to the creation of such vortices. For example, vortices that are formed along the rear part of the ship and that flow into the wake are the result of turbulence. Such vortices are referred to as “bilge vortices” and they effectively increase the resistance of water movement around the ship hull. An off-center propeller is a commercially available device that attempts to capture some of the flow and energy contained within the bilge vortices to enhance propulsion efficiency. An off-center propeller is part of a system that includes the rudder an d properly shaft located away from the longitudinal centerline of the sh ip. For a ship with clockwise rotating propeller, the propeller is moved to starboard of the ship. For a ship with anti-clockwise rotating pr opeller, the propeller is moved to port of the ship. From the result of tank tests, an off-center propeller was estimated to reduce ship propulsion energy use by 3% or more. This practice can be implemented fo r new ships but is difficult or impractical to retrofit to existing sh ips. This practice was combined with a refined hull shape and other energy-saving measures in a large ore carrier, which lead to a total est imated reduction in energy use of 14%. 103 The estimated potential reduction in modal GHG emissions is 1.5%, assuming that the off-center propeller alone contributed only partially to the total estimated reduction in energy use of the ore carrier, as well as implementation on only a portion of freight ships. 

### Continued on next Page77 

### Table 7-1. Continued
Subgroup Type of Strategies Description

Propeller

System Improvement Technology 4-2. Propeller Boss Cap with Fins Turbulent vortices are generated by propeller rotation. The formation of vortices requires energy. Thus, energy that could be used for propulsion is diverted to the formation of vortices, which reduces the overall energy efficiency of the pr opulsion system. A ship propeller generates hub vortices behind it during operation. Water very close to the hub (e.g., 3 mm) flows along the direction of propeller rotation, but water that has a small distance from th e hub (e.g., 10 mm) flows in the opposite direction. These conflicting flows produce hub vortices that consume more energy. A method for reducing the formation of hub vortices associated with the propeller ration is the use of a propeller boss cap with fins (PBCF). 104 PBCF is commercially available, and approximately 1,000 ships have adopted this practice as of 2006. 106 The PBCF includes small fins that the number of fins is as the same as that of propeller blades. It is installed behind the propeller and that rotates in the same direction as the propeller. The purpose of these fins is to b lock water in hub vortices, move water along the direction o f propeller rotation, and produce a st raight slip stream behind the propeller. From the results of field t ests, this device appears to be able to reduce propulsion fuel use by 4 to 5 percent. 104 The estimated potential reduction in modal GHG emissions is 2.0%, assuming either less effectiveness in practice or implementation on only a portion o f freight ships. The estimated capital cost of PBCF ranges from $20,000 for 735 kW engine to $146,000 for 22,050 kW engine, which can be recovered within two years by fuel cost savings. 

### Continued on next Page78 

### Table 7-1. Continued
Subgroup Type of Strategies Description

Propeller

System Improvement Technology 4-3. Auxiliary Free-Rotating Propulsion Device b ehind the Main Propeller As noted in the previous section, propeller rotation results in the formation of energy-consuming turbulent vortices unless mitigating measures are implemented. Ship propeller produces accelerated flow in the propeller wake that consumes energy. An alternative to PBCF is a grim vane wheel (GVW). GVW is a commercially available device that transfers accel erated flow in the wake into extra propulsion and increases fuel efficiency. Approximately 59 ships had adopted this practice as of 2000. 107 It is an auxiliary free-rotating propulsion device that has vanes with larger diameter than that of propeller and is located immediately behind the main propeller. The rotation of GVW modifies the accelerated flow of water that is leaving the propeller, recovers a portion of the energy embodied in the accelerated flow of water, and in so doing provides extra propulsion. Older designs of GVW are mounted on the propeller shaft, but can have problems with mechanical failure. A newly designed GVW system can be mounted on the rudder horn instead of prop eller shaft, which may improve reliability. 105 From the results of field tests, GVW techniques may reduce propulsion fuel use by 6% or more. 107 Taking into account that not all ships will adopt this techni que, the estimated potential reduction in modal GHG emissions is 3.0%. The estimated capital cost of new-designed GVW is approximately $1.2 million dollars, which can be recovered in about three years based on fuel cost savings.

Anti-Idling Technology 4-4. Shoreside Power for Marine Vessels at Ports Shoreside power is being tested as ship anti-idling system that can avoid the need for running the ship auxiliary engine while a ship is docked at a port. A docked ship usually runs its on-board auxiliary engine continuously, which consumes energy and emits criteria air pollutants and GHGs at the port. Shoreside power at the port allows for shut down of the auxiliary engine and reduces fuel use and emissions. From the result of a report for European Commission, CO 2 emitted from the ship auxiliary engine ranges from 690 to 720 g/kWh, 109 Average CO 2 emissions from electricity production in the US are approximately 615 g/kWh. 108 Taking into account reduced shipboard energy use and emissions, and increased shoreside energy use and emissions to produce electricity, this system reduces overall GHG emissions compared to auxiliary engine by approximately 13%. European Commission report estimates that 60% of marine vessels are suitable for use of shore-side electricity. 109 Taking into account that only a fraction of all ships adopts this technique and the ship auxiliary engines only use a small fraction of marine fuel, the estimated potential reduction in modal GHG emissions is 0.2%. The installation o f shoreside power for marine vessels at ports is likely to be phased-in over 5 to 10 years. 116 

### Continued on next Page79 

### Table 7-1. Continued
Subgroup Type of Strategies Description

Alternative Fuel Technology 4-5. B20 Biodiesel Fuel for Ships Large ocean-going ships usually have multiple engines, including main engines and auxiliary engines. Si nce 1980, all marine engines have been diesel-powered engines. Main marine engines usually burn residual fuel or blends of residual and distillate fuels. 110 Auxiliary engines usually burn marine gas oil, a high sulfur diesel fuel that is usually the fuel for small and medium sized marine engines. Thus, ocean-going ships often carry both residual fuel oil and marine gas oil. 111 For marine fuel consumption, residual fuel oil for freight ships is about 60% of total marine fuel use. Marine gas oil for freight ships is about 11% of total marine fuel use. Marine gas oil for other ships (such as passenger ships, fish ships, military ships) accounts for other 29% of marine fuel use. Thus, marine gas oil accounts for 15% of marine fuel for freight ships. 112 B20 biodiesel, which is described in Section 4.11.2, is a potential alternative fuel for marine gas oil powered diesel engines. 113 Based on a life cycle analysis, the CO 2 emissions are estimated to decrease by 0.0069 tons CO 2 eq. per 10 6 BTU for B20 biodiesel compared to land-use diesel fuel. Land-use diesel fuel and marine gas oil belong to distillate fuel except that the land- use diesel fuel has a much lower sulfur level than the marine gas oil. Sulfur concentrations in distillate fuels can be reduced by a refining process, hydro-treating, that consumes energy and emits CO 2 . 111 Since marine gas oil is high sulfur diesel fuel and removal of sulfur emits more GHG, the production o f marine gas oil emits less GHG than the production of land-use diesel fuel based on life cycle inventories. The difference of life cycle GHG emission analysis results between B20 biodiesel and marine gas oil should be lower than the difference between B20 biodiesel and land-use diesel fuel. Thus, the latter provides a useful upper bound of the former. Taking into account that only a fraction of marine fuel is marine gas oil, the estimated potential reductions in modal GHG emissions are 1.2%. 13,63-64,114-115 The estimated potential modal energy use increases by 1.3%. 6180 

### 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

4-1 4-2 4-3 4-4 4-5

Best Practice Number for the Water Mode

Figure 7- 1. Reductions in Modal GHG Emis sions for the Best Practices for the Water
ModeModal GHG Emissions Reductions (%)81 

### Table 7- 2. Summary Table for the Comparison of the Quantitative Cost Results for A
Selected Best Practices for the Water Mode a

Best Practice Number 4-5

Name B20 Biodiesel Subgroup Alternative Fuel Responsible Parties 58, 61, Target Parties 23, 25 Target GHGs CO 2 Strategy Types Technology Developmental Status N Modal GHG Emissions Reductions (10 6 ton CO 2 eq./year) 1.5 Modal Energy Use Reduction (10 12 BTU/year) -18

Annualized Costs ($ 10 6 /year) 180 Annual Energy Cost Saving ($ 10 6 /year) 0 Net Saving ($ 10 6 /year) -180 Net Saving per Unit of GHG Emissions Reductions ($/ton CO 2 eq.) -120

Net Saving per Unit of Energy Use Reduction ($/ton CO 2 eq.) N/A b

Simple Pay-back Period (years) N/A c

a These assessments are based on the assumptions th at these best practices reach their potential maximum market shares in 2025. Cost results ar e presented only for this best practice for which adequate data were available.
b This practice has no energy use reduction due to an increase in energy use, and it has no net saving due to high annualized cost and no energy cost saving.

c 

### There is no pay-back period for this best practice because there is no net saving.82 

### 8.0 BEST PRACTICES FOR THE PIPELINE MODE

This chapter identifies and characterizes 5 potential best practices applicable to the pipeline mode. The pipeline mode best practices focus on techniques or stra tegies applicable to natural gas pipelines. The main source of GHG emissions from these pipelines is leakage of natural gas, which is comprised mostly of meth ane. These best practices are divided into 3 subgroups, including:

• Improved process control devices;

• connecting method; and

• maintenance. Additional details regarding all of these best practices are in Appendix E. For three of these best practices, sufficient data were available to quantify costs.

8.1 Process Control Device Improvement
Natural gas pneumatic controls are used fo r pipeline operations. These controls are a source of methane leakage. Conversion of these controls to compressed instrument air systems or replacement of high-bleed with low-bl eed devices, can reduce methane emissions significantly. 117-119



### 8.1.1 Best Practice 5-1: Convert Natural Gas Pneumatic Controls to
Instrument Air Pneumatic control systems for pipelines are cu rrently operated using pressurized natural gas. However, pneumatic controls based on compressed air could be used instead. Since natural gas is continuously bled from the current control devices, they are one of the largest methane emissions sources in the natural gas industry. 1,117 

### Conversion of pneumatic control systems from natural gas to compressed air would reduce methane emissions. 117 

### Taking into account the electricity energy n eeded for powering the compre ssed instrument air powered systems, the estimated potential reductions in modal GHG emissions and energy use are 0.5% and 0.1%, respectively. Since this practice needs electricity for it s operation, it can be applied only in locations near electricity grids or by installing engine-gener ator sets at remote sites. The estimates given here are based on use of electricity from the grid, not from an engine-generator set.83 

### 8.1.2 Best Practice 5-2: Replace High-B leed Natural Gas Pneumatic Devices
with Low-Bleed Pneumatic Devices Current high-bleed pneumatic control system s, which are approximately 26% of current installed pneumatic control systems for pipelines , are based on high-bleed compressed methane. An alternative designed is based on low-bleed. Replacing high-bleed with low-bleed devices is estimated to reduce methane emissions from the control system by 90%. 118-119 

### Taking into account that methane vented from high-bleed pneu matic control systems is a small fraction of total methane emissions from the pipeline mode, the estimated potential reductions in modal GHG emissions and energy use are 0.6% and 0.2%, respectively.

8.2 Connecting Method

― Best Practice 5-3: “Hot Tap” Pipeline Connecting Method
Methods for constructing new pipeline connections for an existing, operational pipeline usually result in significant venting of natural gas. In contrast, the “hot tap” pipeline connecting method is a commercially available technology that reduces GHG emissions. This method avoids the need for venting natural gas. It involves attaching a branch pipeline connection on the outside of an operating pipeline a nd cutting out the inside pipeline wall. This practice would reduce natural gas emission. 120-122 

### The estimated potential reductions in modal GHG emissions and energy use are 1.9% and 0.5%, respectively.

8.3 Maintenance
In the natural gas industry, fugitive emissions of methane are due to leaking pipelines, meters and regulating equipment. The improv ement of inspection and maintenance processes can be a cost-effective way to reduce methane emissions.

8.3.1 Best Practice 5-4: Transfer Compression During the pipeline maintenance process, a sec tion of pipe is often isolated and taken out for maintenance, and methane is vented from the isolated section. An a lternative to venting is to transfer the natural gas in the isolated sectio n to an operating section of the pipeline, thereby avoiding loss of methane. A system for doing this is a transfer compressor unit, which is commercially available. Several transfer co mpressors can be operated simultaneously to increase the methane recovery rate. 121-123 

### The estimated potential reductions in modal GHG emissions and energy use are 0.1 % and 0.02%, respectively.

8.3.2 Best Practice 5-5: Inline Inspection Pipeline flaws, especially stress corrosion cr acking (SCC), cause pipeli ne failure that are84 

### of safety concern and that lead to fugitive meth ane emissions. A pipeline inline inspection (ILI) tool, referred to as “smart pig,” was originally designed to inspect internal pipeline conditions, such as dents or metal loss, by using ultrasound. 124 

### A ultrasound inline inspection tool based on a newer design can detect not only dents or metal lo ss, but also SCC. This new tool is able to locate more pipeline flaws. By identifying an d correcting such flaws sooner, fugitive methane
emissions can be reduced. 121 

### The estimated potential reductions in modal GHG emissions and energy use are 1.3% and 0.4%, respectively.

8.4 Summary of Potential Best Pr actices for the Pipeline Mode
All five potential best practices for the pi peline mode, organized by three subgroups, are summarized in Table 8-1. They are in ta ble format for the convenience of readers.

8.5 Comparisons of the Modal GHG Emissi ons Reductions for the Best Practices
Figure 8-1 summarizes the variability among the potential best practi ces with respect to
estimated reductions in modal GHG emissions. These percentage reductions in modal GHG emissions range from 0.1 to 1.9 percent when comparing individual best practices.

8.6 Quantitative Cost Resu lts for the Pipeline Mode
Quantitative cost results for the best practic es for which sufficient information was available to perform such assessments are summa rized in standardized reporting tables, which are given in Appendix E. In contrast, qualitative assessment results for the best practices which
have a lack of sufficient information from wh ich to quantify costs are summarized in simplified summary tables individually, which are also given in Appendix E. To date, there is sufficient information for three best pract ices upon which to make quantita tive assessments. The other two best practices are assessed qualitatively. The best practices assessed quantitatively include: convert natural gas pneumatic controls to instrument air; replace high bleed natural gas pneumatic devices with low bleed pneumatic devices; and “hot tap” pipeline connecting method. Table 8-2 summarizes the quantitative assessment results of modal GHG emissions reductions, modal energy use reductions, annualized cost, energy cost savin g, net savings, net savings per unit of GHG emissions reductions, net savings per unit of ener gy use reduction, and simple pay-back periods for these three selected best practices.85 

### Table 8- 1. List and Description of Pote ntial Best Practices for the Pipeline Mode
Subgroup Type of Strategies Description

Technology 5-1. Convert Natural Gas Pneumatic Controls to Instrument Air Compressed air powered pneumatic control systems, which are the alternative to currently used natural gas powered systems, are commercially available devices that reduce GHG emissions. There are approximately 90,000 to 130,000 pneumatic control devices used in natural gas pipelines. They are used to actuate isolation va lves, control liquid level, and regulate gas flow and pressure at compressor stations, pipelines, and storage facilities. These systems are usually powered by readily available high-pressure natural gas, and natural gas is constantly bled from these devices. Thus, these devices contribute to GHG emissions. 117 EPA estimates that approximately 8.46×10 9 tons methane were emitted in 2003 for pipeline operation. 1 Conversion of natural gas-powered pneumatic control systems to compressed instrument air powered systems can reduce methane emissions. 117 Taking into account the electricity energy needed for powering the compressed instrument air powered systems, the estimated potential reductions in modal GHG emissions and energy use are 0.5% and 0.1%, respectively. However, to implement instrument air systems, utility or self-generated electrical power should be available on site. Process Control Device Improvement

Technology 5-2. Replace High-Bleed Natural Gas Pneumatic Devices with Low-Bleed Pneumatic Devices Low-bleed natural gas powered pneumatic control systems are commercially available. Of the existing natural gas powered control devices, 26% of them are high-bleed devices. Most high- b leed devices can be replaced or retrofitted with low-bleed devices, th ereby reducing the per-device methane emissions by 90%. 118-119 Taking into account that methane vented from high-bleed pneumatic control systems is a fraction of total methane emission from the pipeline mode, the estimated potential reductions in modal GHG emissions and energy use are 0.6% and 0.2%, respectively.

Connecting

Method Technology 5-3. “Hot Tap” Pipeline Connecting Method Methods for constructing new pipeline connections for an existing, operational pipeline usually result in significant venting of natural gas. In contrast, the “hot tap” pipeline connecting method is a commercially available technology that reduces GHG emissions. Traditional connecting methods usually vent a significant amount of natural gas into atmosphere during their operation. This method avoids the need for venting natural gas. It involves attaching a branch pi peline connection on the outside of an operating pipeline and cutting out the in side pipeline wall. This practice would reduce natural gas emission. 120-122 The estimated potential reductions in modal GHG emissions a nd energy use are 1.9% and 0.5%, respectively. Natural gas cost saving is generally sufficient to justify the costs for hot tap method instead of the costs for traditional connecting methods. The simple pay-back period for this practice is approximately 12 months. 

### Continued on next Page86 

### Table 8-1. Continued
Subgroup Type of Strategies Description

Technology 5-4. Transfer Compression During the pipeline maintenance process, a section of pipe is often isolated and taken out for maintenance, and a significant amount of methane is vented into the atmosphere. A transfer compressor is a commercial available system that reduces methane em issions in this process. It pumps natural gas from the isolated pipeline se ction to an operational section of the pipeline section, thereby decreasing the amount of vented methane. Several transfer compressors, which can be mounted on trucks, are operated at the same time. 121,123 The estimated potential reductions in modal GHG emissions and energy use are 0.1% and 0.02%, respectively.

Maintenance

Technology 5-5. Inline Inspection Pipeline flaws, especially stress corrosion cracking (SCC), cause pipeline failures that are of safety concern and that increase fugitive methane emissions. In order to ensure the integrity of the pipeline systems, these flaws must be detected and repaired. A pipeline inline inspection (ILI) tool, referred to as “smart pig,” is a commercially available device that helps in detection of pipeline flaws. 124 By correcting such flaws, fugitive methane emissions are avoided. A newer de sign for an ultrasound inline inspection tool has been developed. This new-designed tool can detect not only dents or metal loss, but also SCC. The ne w tool is more sensitive in detecting problems, thereby enabling identification of problems sooner. This upgraded tool can find more flaws in the pipeline system and, therefore, enable quickly corrective action lead to larger reductions in fugitive methane emissions. 121 The estimated potential reduc tions in modal GHG emissions and energy use are 1.3% and 0.4%, respectively.87 

### 0 0.5 1 1.5

2 2.5

5-1 5-2 5-3 5-4 5-5

Best Practice Number for the Pipeline Mode

Figure 8- 1. Reductions in Modal GHG Emis sions for Best Practices for the Pipeline
Mode

All three best practices produce net cost sa vings. These savings are the net result of substantial costs offset by substantial savings based on reduced energy usage. Although the hot tap method has the potential to achieve larger magnitudes of GHG emissions reductions and higher amount of net savings than those of the other two practices , all three practices appear to have a similar magnitude of cost-effectiveness when normalized by GHG emissions reductions.Modal GHG Emissions Reductions (%)88 

### Table 8- 2. Summary Table for the Comparis on of the Quantitative Cost Results for Selected Best Practices for the Pipeline Mode. a

Best Practice Number 5-1 5-2 5-3

Name Convert Natural Gas Pneumatic Controls to Instrument Air Replace High-Bleed Natural

Gas Pneumatic Devices with Low-Bleed Pneumatic Devices “ Hot Tap” Method

Subgroup Process Control Device Improvement Process Control Device Improvement Connecting Method Responsible Parties 70, 71, 72, 73 70, 71, 72, 73 70, 71, 72, 73 Target Parties 26, 27, 28 26, 27, 28 26, 27, 28, 29 Target GHGs CH 4 CH 4 CH 4 Strategy Types Technology Technology Technology Developmental Status C C C Modal GHG Emission Reduction (10 6 ton CO 2 eq./year) 0.7 0.8 2.5

Modal Energy Use Reduction (10 12 BTU/year) 1 2 5

Annualized Costs ($ 10 6 /year) 1.7 1.8 11 Annual Energy Cost Saving ($ 10 6 /year) 13 15 51 Net Saving ($ 10 6 /year) 12 13 40 Net Saving per Unit of GHG Emissions Reductions ($/ton CO 2 eq.) 18 18 16

Net Saving per Unit of Energy Use Reduction ($/ton CO 2 eq.) 9.6 8.8 7.8

Simple Pay-back Period (years) 0.3 0.9 0.2

a These assessments are based on the assumptions th at these best practices reach their potential maximum market shares in 2025. Cost results ar e presented only for those best practices for which adequate data were available.89 

### 9.0 SUMMARY AND COMPARISON OF GHG EMISSIONS REDUCTIONS FOR
ALL FREIGHT TRANSPORTATION MODES

A total of 59 strategies have been identified as best practices in fr eight transportation. There are 33, 6, 10, 5, and 5 best practices for th e truck, rail, air, water, and pipeline modes, respectively. Approximately half of the total nu mber of best practices are for the truck mode. The purpose of this Chapter is to:

z 

### summarize the potential for reductions in GHG emissions, Energy use or Refrigerant Use (GERU) for individual best practices and subgroups;

z 

### summarize and evaluate the variability in GERU reductions and cost-effectiveness of the best practices among different modes, based on quantitative assessment results; and

z 

### evaluate the potential impact of intermodal substitutions.

9.1 Truck Mode

Total GHG emissions reductions for all five mo des are mainly attributable to reductions in energy use. However, a small portion of emissions reductions for the truck mode are contributed by reductions in re frigerant use or leakage. Table 9-1 summarizes potential individual and aggregate reductions in GHG emi ssions and energy use for best practices for the
truck mode. These reductions are summarized in four ways: (1) The potential per-device reductions in GHG emissions and energy use for an individual best practice, which are the pe rcentage reductions compared to emissions and energy use of a device that does not use the practice. (2) The potential reductions in modal GHG emissions and energy use for an individual best practice, which are the percentage reduc tions for a practice when it is used on all applicable devices for a mode. These re ductions are compared to modal total emissions and energy use without use of this practice. (3) Percentage contributions of a subgroup to total reductions in modal GHG emissions and energy use if all best practices are implemented. (4) The magnitude of aggregate reductions in modal GHG emissions and energy use in 2025 if all best practices are used for each subgroup. The reductions in refrigerant use for best practices within the air conditioning improvement subgroup (I.D. No. 1-6 to 1-10) are not included in Table 9- 1. Four of the five best practices in this subgroup have the pot ential to reduce GHG emissions by reducing90 

### refrigerant leakage rate or use of low global-warming-potential refrigerants. Their potential modal GHG emissions reductions range from 0.9% to 2.5%. A small portion of the potential total GHG emissions reduction by 20 25 for all 33 best practices for the truck mode is attributed to reduced refrigerant leakage rate or use of low GWP refrigerants. Some subgroups include best practices wi th complex conditions, such as mutual exclusion, interaction, and technol ogical barriers. Some interactions exist not only among best practices within a subgroup, but also among best practices from different subgroups. (1) Anti-Idling (I.D. Nos. 1-1 to 1-5 in Table 9-1) Auxiliary power units are the basis for the estimated GHG emissions reductions for the anti-idling subgroup. Five best practices are mutually exclusive. The top two practices are auxiliary power units and direct-fired heater s with thermal storage units. The former is chosen here because operation of the later requires battery power and inhibits its acceptance by the market. (2) Air Conditioning System Improvement (I.D. Nos. 1-6 to 1-10 in Table 9-1)
The assessment results of the estimated GHG emissions reductions for this subgroup are based on the choice of CO 2 

### as a refrigerant. Three alternative refrigerants that could be used as best practices are mutually exclusive, since only one refrigerant can be used in an air conditioning system. CO 2 

### is chosen here because it has the lowest GWP compared to the other candidate refrigerants and its potential reductio ns in modal GHG emissions are the highest. There is interaction between enhanced air conditioning systems with respect to direct emissions and low-GWP refrigerants. At a given leakage rate, the systems using low-GWP refrigerant contribute less GHG emissions than those using CFC-152a. Thus, the potential GHG emissions for enhanc ed air conditioning systems for direct emission are reduced if CFC-152a refriger ant is replaced by any of the low-GWP refrigerants.
There is also interaction between enhan ced air conditioning systems for indirect emissions and low-GWP refrigerants. More energy may be needed to operate some low-GWP refrigerant systems. For example, a propane based refrigerant system uses about 10% more energy for the operation of vehicle air conditi oners and increases indirect GHG emissions The potential GHG emissions reduction for enhanced air conditioning systems for indirect emission ma y increase if alterna tive refrigerants are
used. (3) Aerodynamic Drag Reduction (I.D. Nos. 1-11 to 1-16 in Table 9-1) This subgroup includes two be st practices, pneumatic aerodynamic drag reduction (I.D. No. 1-14) and planar boat tail plates on tractor-trailers (I.D. No. 1-15), which are91 

### mutually exclusive. They are mutually ex clusive because both of these best practices
are installed on the tails of tr actor-trailer for aft-end drag reduction. They cannot both be implemented on the same truck. The fo rmer is chosen here because reductions by the former are estimated to be higher than the reductions by the latter. There is interaction between pneumatic aerodynamic drag reduction systems and some truck configurations. For example, the dimensions of the tractor-trailer gap may inhibit the reduction of aerodynamic drag ach ievable via this system. Thus, adopting another best practice that reduces the trac tor-trailer gap may enhance th e reduction potential of this practice. The available data for the eff ectiveness of aerodynamic drag reductions are
based on individual field tests that do not take into account these interacti ons, and thus there is not an empirical basis for quant itatively estimating the effect of such
interactions on reductions in vehicle fuel consumption. 43 

### (4) Tire Rolling Resistance Improvement (I.D. Nos. 1-17 to 1-20 in Table 9-1) This subgroup includes two best practices, low rolling- resistance tires (I.D. No. 1-19) and wide-base tires (I.D . No. 1-20), which are mutually exclusive. They are mutually exclusive, since th ey cannot both be implemented on the same truck. Both of them can reduce GHG emissions by the same magnitude, so the results of the assessment are not sensitive to the choice between these two approaches. The estimates for low rolling-resistance tires are used here. (5) Transmission Improvement (I.D. Nos. 1-23 to 1-24 in Table 9-1)
There is interaction between advanced transmissions (I.D. No. 1-23) and transmission friction reduction through low- viscosity transmission lubricants (I.D. No. 1-24). Advanced transmissions are designe d to reduce internal friction, such as by reduction of gear surface roughness and by the us e of low-friction coatings. Lubricants are also used to reduce gear contact fricti on. Thus, the total reduction may not be a simple linear combination of the reductions of these two practices. However, there is a
lack of data with which to quantify the impact of the interaction. Thus, a simple linear combination of the reductions is applied. (6) Diesel Engine Improvement (I.D. Nos. 1-25 to 1-29 in Table 9-1) For the diesel engine improvement subgroup, there is an interaction between two practices: improved fuel injectors (I.D. No. 1-27); and turbocharged, direct injection to improved thermal management (I.D. No. 1-28). The former improves the fuel injection systems for all trucks. The latte r improves the fuel injection systems for medium-duty trucks. Most heavy-duty trucks already have turbocharged systems. Since the former focuses on the improvement of fuel injection system and the latter also involves a change in the fuel injection sy stem, the combined reduction may not be a92 

### simple linear combination of the reductions of these two practices if implemented on the same. However, there is a lack of data with which to quantify the impact of the interaction. Thus, a simple linear combina tion of the reductions is applied for the former practice for heavy duty trucks and th e latter practice for medium duty trucks. (7) Accessory Load Reduction (I.D. Nos. 1-30 to 1-31 in Table 9-1) Accessory load reduction can be achieved by conversion of mechanical auxiliary loads to electrically-operated ones. Furtherm ore, the electric power for auxiliaries can be obtained from an source separate from the tr uck base engine, such as a small fuel cell system or a small diesel engine with an alte rnator. Thus, these tw o best practices have common technology with respect to auxiliary loads, but differ in terms of the electric power supply system for the auxiliaries. Therefore, although the same kinds of electrically-operated auxiliary components can be used for both best practices, they differ in a mutually exclusive way because they are a based on different energy conversion systems. For purpose of maki ng an upper bound estimate of the potential for auxiliary load reduction, the fuel cell-based energy conversion system with electrically operated auxiliarie s is chosen, since this practi ce has the potential to reduce GHG emissions more than the small diesel engine-based system. The two most important subgroups for GHG emissions reduction are diesel engine improvement (I.D. Nos. 1-25 to 1-29) and aerodyna mic drag reduction (I.D. Nos. 1-11 to 1-16). These two subgroups contribute 29 and 16 percent, respectively, to the estimated total modal
GHG emissions reductions.

9.2 Rail Mode
Table 9-2 summarizes potenti al individual and aggregate reductions in GHG emissions and energy use for best practic e for the rail mode. These reduc tions are summarized in four ways, which are the same as those for Table 9-1. A subgroup, anti-idling (I.D. Nos. 2-1 to 2-3) , includes best practices that are mutually exclusive. Rail companies usually use different types of locomotives for long-haul versus yard switching service. The latter locomotives typically have larg er engines (e.g., 5,000 hp) than the former (e.g., 2,000 hp). Assuming th at the national ratio of yard switchers to to tal locomotives is the same as the ratio for Union Pacific (U P), the largest railroad company in the U.S., approximately 71% of locomotives are long-haul. 125 

### The remainder are switchers. Best practice 2-1 is applicable to bo th long-haul locomotives and switc hers. Best practices 2-2 and 2-3 are applicable only to switchers. Although best practice 2-2 has the potential to reduce93Table 9- 1. Potential Best Practicesfor the Truck Mode and the Estimated Reductions in GHG Emissions and Energy UseSubgroupI.D.No.Brief Name of Best Practice Developmental Status
a Potential Per-device Reductions in GHG Emissions (%) b Potential Per-device Reductions in Energy Use (%) b Potential Reductions in Modal GHG Emissions (%)
c Potential Reductions in Modal Energy Use (%)
c Percentage Contribution of a Subgroup to Total Reductions in Modal GHG Emissions (%) d Percentage Contribution of a Subgroup to Total Reductions in Modal Energy Use (%) d Potential Aggregate GHG Emission Reduction in 2025 for Each Subgroup (10 6 Tons CO 2 eq.)
e Potential Aggregate Energy Use Reduction in 2025 for Each Subgroup (10 15 BTU)
e1-1Off-Board Truck StopElectrificationC 1.53 1.45 0.33 0.311-2Truck-Board Truck StopElectrificationC 1.83 1.88 0.39 0.411-3 Auxiliary Power Units C 9.62 9.87 2.08 2.131-4 Direct-Fired Heaters C 4.85 5.00 1.05 1.08Anti-Idling1-5Direct-Fired Heaters withThermal Storage UnitsP 13.33 13.74 2.88 2.973.64 4.50 15.00 0.191-6Enhanced Air ConditioningSystem I - for Direct EmissionsP 0.88 -f0.88 -f1-7Enhanced Air ConditioningSystem II - for IndirectEmissionsC 0.18 0.19 0.18 0.191-8 Alternative Refrigerants - CO2N 2.47 -f2.47 -f1-9Alternative Refrigerants -HFC-152aN 2.35 -f2.35 -fAir ConditioningSystem Improvement1-10 Alternative Refrigerants - HC N 2.46 -f2.46 -f4.65 0.40 19.15g0.02Continued on next page94Table 9-1. ContinuedSubgroupI.D.No.Brief Name of Best Practice Developmental Status
a Potential Per-device Reductions in GHG Emissions (%) b Potential Per-device Reductions in Energy Use (%) b Potential Reductions in Modal GHG Emissions (%)
c Potential Reductions in Modal Energy Use (%)
c Percentage Contribution of a Subgroup to Total Reductions in Modal GHG Emissions (%) d Percentage Contribution of a Subgroup to Total Reductions in Modal Energy Use (%) d Potential Aggregate GHG Emission Reduction in 2025 for Each Subgroup (10 6 Tons CO 2 eq.)
e Potential Aggregate Energy Use Reduction in 2025 for Each Subgroup (10 15 BTU)
e1-11Cab Top Deflector, SlopingHood and Cab Side FlaresC 1.90 1.96 1.43 1.471-12Closing and Covering of GapBetween Tractor and Trailer,Aerodynamic Bumper,Underside Air Baffles, andWheel Well CoversC 2.37 2.44 2.37 2.441-13Trailer or Van Leading andTrailing Edge CurvaturesC 1.24 1.28 1.24 1.281-14Pneumatic Aerodynamic DragReductionN 4.62 4.76 2.17 2.241-15Planar Boat Tail Plates on aTractor-TrailerN 8.01 8.26 3.76 3.88Aerodynamic DragReduction1-16Vehicle Load ProfileImprovementC 2.37 2.44 0.43 0.4416.17 19.98 66.56 0.831-17 Automatic Tire Inflation Systems C 0.78 0.80 0.56 0.581-18 Wide-Base Tires C 2.83 2.91 2.03 2.101-19 Low-Rolling-Resistance Tires C 2.83 2.91 2.83 2.91Tire RollingResistanceImprovement1-20Pneumatic Blowing to ReducingRolling ResistanceN 1.15 1.19 0.54 0.566.88 8.50 28.33 0.35Hybrid Propulsion 1-21 Hybrid trucksN 40.27 41.52 3.40 3.50 5.95 7.36 24.50 0.30Weight Reduction 1-22 Lightweight Materials P 4.62 4.76 4.62 4.76 8.10 10.00 33.32 0.411-23 Advanced Transmission P 0.97 1.00 0.97 1.00TransmissionImprovement1-24Transmission Friction Reductionthrough Low-ViscosityTransmission LubricantsC 0.97 1.00 0.92 0.953.31 4.10 13.64 0.17Continued on next page95Table 9-1. ContinuedSubgroupI.D.No.Brief Name of Best Practice Developmental Status
a Potential Per-device Reductions in GHG Emissions (%) b Potential Per-device Reductions in Energy Use (%) b Potential Reductions in Modal GHG Emissions (%)
c Potential Reductions in Modal Energy Use (%)
c Percentage Contribution of a Subgroup to Total Reductions in Modal GHG Emissions (%) d Percentage Contribution of a Subgroup to Total Reductions in Modal Energy Use (%) d Potential Aggregate GHG Emission Reduction in 2025 for Each Subgroup (10 6 Tons CO 2 eq.)
e Potential Aggregate Energy Use Reduction in 2025 for Each Subgroup (10 15 BTU)
e1-25Engine Friction Reductionthrough Low-Viscosity EngineLubricantsC 1.90 1.96 1.81 1.861-26Increased Peak CylinderPressuresC 3.73 3.85 3.07 3.161-27 Improved Fuel Injectors P 5.49 5.66 5.49 5.661-28Turbocharged, Direct Injection toImproved Thermal ManagementC 4.62 4.76 0.82 0.85Diesel EngineImprovement1-29Thermoelectric Technology toRecovery Waste HeatN 6.35 6.54 5.22 5.3828.75 35.52 118.31 1.471-30 Electric Auxiliaries C 1.43 1.48 1.43 1.48Accessory LoadReduction1-31 Fuel-Cell-Operated Auxiliaries N 5.49 5.66 5.49 5.669.62 11.89 39.60 0.49Modifications inDriver OperationalPractice1-32 Truck Driver Training ProgramC 3.69 3.80 3.10 3.195.43 6.70 22.33 0.281-33 B20 Biodiesel Fuel for Trucks C 8.34 -8.30 4.27 -4.257.49 -8.92 30.81 -0.37Total for the TruckMode--57.06h47.61h100.00100.00411.544.14aDevelopmental status: N = new concepts; P = pilot tests; C =commercially available systems. New concepts include basic research activities, applied research activities,and experiments at laboratory level. Pilot tests include testing prototype vehicles and demonstration projects. Commerciallyavailable systems can be purchased orimplemented now.bPotential per-device reductionsin GHG emissions or energy useare percentagereductions compared toGHG emissions (energy use) of a device withoutusing this practice.cPotential reductions in modal GHG emissionsor energy use are estimated based onthe difference in 2025 modal GHG emissions orenergy use with and without the selectedbest practice divided by the total modal GHG emissions or energy use ifno best practicesare implemented.dPercentage contribution of a subgroup to total reductions is defined by dividing the percentage reductions for a subgroup by total modal reductions for all best practices.eThese reductions are estimated based on the difference between 2025 modal GHG emissionsor energy use withand without implementation of the representative bestpractices of the subgroup..fThese best practices reduce refrigerant leakage rate or use low GWP refrigerants.gGHG emission reduction here are contributed by both energy use reduction and refrigerant leakagerate reduction or using low GWP refrigerants.hTotal potential reductions in GHGemissions and energy use exclude the reductionscontributed by the strategies that are not the highest one in the casesof mutual exclusion.96Table 9- 2. Potential Best Practicesfor the Rail Mode and the Estimated Reductions in GHG Emissions and Energy UseSubgroupI.D.No.Brief Name of Best Practice Developmental Status
a Potential Per-device Reductions in GHG Emissions (%) b Potential Per-device Reductions in Energy Use (%) b Potential Reductions in Modal GHG Emissions (%)
c Potential Reductions in Modal Energy Use (%)
c Percentage Contribution of a Subgroup to Total Reductions in Modal GHG Emissions (%) d Percentage Contribution of a Subgroup to Total Reductions in Modal Energy Use (%) d Potential Aggregate GHG Emission Reduction in 2025 for Each Subgroup ( 10 6 Tons CO 2 e q . )
e Potential Aggregate Energy Use Reduction in 2025 for Each Subgroup (10 15 BTU)
e2-1Combined Diesel PoweredHeating System and Auto EngineStart/stop SystemP 3.81 3.81 3.62 3.622-2Battery-Diesel Hybrid SwitchingLocomotiveC 35.00 35.00 1.75 1.75Anti-Idling2-3 Plug-In Units C 11.50 8.80 0.58 0.4427.34 60.90 3.43 0.042Weight Reduction 2-4 Light Weight Materials C 4.76 4.76 4.764.76 24.25 53.98 3.05 0.038Rolling ResistanceImprovement2-5 Lubrication Improvement P 4.00 4.00 4.00 4.00 20.38 45.36 2.56 0.032Alternative Fuel 2-6B20 Biodiesel Fuel forLocomotivesN 8.60 -8.30 5.50 -5.3128.04 -60.24 3.52 -0.042Total for the RailMode--19.63f8.82f100.00100.0012.560.070aDevelopmental status: N = new concepts; P = pilot tests; C =commercially available systems. New concepts include basic research activities, applied research activities,and experiments at laboratory level. Pilot tests include testing prototype vehicles and demonstration projects. Commerciallyavailable systems can be purchased orimplemented now.bPotential per-device reductionsin GHG emissions or energy useare percentagereductions compared toGHG emissions (energy use) of a device withoutusing this practice.cPotential reductions in modal GHG emissionsor energy use are estimated based onthe difference in 2025 modal GHG emissions orenergy use with and without the selectedbest practice divided by the total modal GHG emissions or energy use ifno best practicesare implemented.dPercentage contribution of a subgroup to total reductions is defined by dividing the percentage reductions for a subgroup by total modal reductions for all best practices.eThese reductions are estimated based on the difference between 2025 modal GHG emissionsor energy use withand without implementation of the representative bestpractices of the subgroup..fTotal potential reductions in GHGemissions and energy use for the rail mode exclude the reductions contributed by the strategies that are not the highest one in the cases ofmutual exclusion.97 

### per-vehicle GHG emissions more than the other tw o best practices, it is only applicable to switchers, which are estimated to account fo r only 5% of total locomotive fuel use. 117 

### Best practice 2-1 has a larger over-all impact even though the per locomo tive reduction is not as large, because it can be applied to all locomotives. The two most important subgroups for GHG emissi ons reduction are alternative fuel (I.D. No. 2-6) and anti-idling (I.D. Nos. 2-1 to 2- 3). These two subgroups both contribute 28 and 27 percent, respectively, to the estimated total reduction in modal GHG emissions.

9.3 Air Mode
Table 9-3 summarizes potenti al individual and aggregate reductions in GHG emissions and energy use for best practices for the air m ode. These reductions are summarized in four ways, which are the same as those for Table 9-1. A subgroup, aerodynamic drag reduction (I.D. No s. 3-1 to 3-4), includes two best practices that are mutually exclusive. Blended winglet (I.D. No. 3-3) and spiroid tip (I.D. No. 3-4) are mutually exclusive because both of these best practices are designed to reduce lift-induced drag and cannot both be implemented on the same airplane. The reductions by the former are estimated to be higher than the redu ctions by the latter. Therefore, the former is used as the basis for the analysis. The two most important subgroups for GHG emissions reduction are engine improvement (I.D. No. 3-10) and aerodynamic drag reduction (I.D. Nos. 3-1 to 3-4). These two subgroups contribute 38 and 28 percent, respect ively, to the estimated total modal GHG
emissions reductions.

9.4 Water Mode
Table 9-4 summarizes potenti al individual and aggregate reductions in GHG emissions and energy use for best practices for the water mode. These reductions are summarized in four ways, which are the same as those for Table 9-1. A subgroup, propeller system improvement (I.D. No s. 4-1 to 4-3), includes best practices that are mutually exclusive. Each of them are based on different propeller designs. They cannot be implemented simultaneously on the same ship. To provide an upper bound on the potential benefits of this subgr oup, the best practice that has the largest estimated reductions in
fuel use and GHG emissions is sele cted as the basis for the anal ysis of modal reductions. The selected best practice is an auxiliary free-ro tating propulsion device behind the main propeller.98Table 9- 3. Potential Best Practicesfor the Air Mode and the Estimated Reductions in GHG Emissions and Energy UseSubgroupI.D.No.Brief Name of Best Practice Developmental Status
a Potential Per-device Reductions in GHG Emissions (%) b Potential Per-device Reductions in Energy Use (%) b Potential Reductions in Modal GHG Emissions (%)
c Potential Reductions in Modal Energy Use (%)
c Percentage Contribution of a Subgroup to Total Reductions in Modal GHG Emissions (%) d Percentage Contribution of a Subgroup to Total Reductions in Modal Energy Use (%) d Potential Aggregate GHG Emission Reduction in 2025 for Each Subgroup (10 6 Tons CO 2 eq.)
e Potential Aggregate Energy Use Reduction in 2025 for Each Subgroup ( 10 15 BTU )
e3-1Surface GroovesP1.601.601.601.603-2Hybrid Laminar FlowTechnologyN 6.00 6.00 6.00 6.003-3 Blended WingletC 2.00 2.00 2.00 2.00Aerodynamic DragReduction3-4 Spiroid Tip P 1.65 1.65 1.65 1.6527.7927.795.660.059Air TrafficManagement3-5Air traffic ManagementImprovementN 6.00 6.00 6.00 6.0017.37 17.37 3.54 0.0373-6 Airframe Weight Reduction N 2.00 2.00 2.00 2.00Weight Reduction3-7 Non-Essential Weight Reduction N 1.00 1.00 1.00 1.008.69 8.69 1.77 0.0183-8Ground-Based Equipment as anAlternative to Auxiliary PowerUnitsPGround SupportEquipmentImprovement3-9Electric or Hybrid Heavy DutyDelivery TrucksP2.94 2.94 2.94 2.948.51 8.51 1.73 0.018Continued on next page99Table 9-3. ContinuedSubgroupI.D.No.Brief Name of Best Practice Developmental Status
a Potential Per-device Reductions in GHG Emissions (%) b Potential Per-device Reductions in Energy Use (%) b Potential Reductions in Modal GHG Emissions (%)
c Potential Reductions in Modal Energy Use (%)
c Percentage Contribution of a Subgroup to Total Reductions in Modal GHG Emissions (%) d Percentage Contribution of a Subgroup to Total Reductions in Modal Energy Use (%) d Potential Aggregate GHG Emission Reduction in 2025 for Each Subgroup (10 6 Tons CO 2 eq.)
e Potential Aggregate Energy Use Reduction in 2025 for Each Subgroup ( 10 15 BTU )
eEngine Improvement 3-10Improved Engine OverallEfficiencyC 13.00 13.00 13.00 13.0037.64 37.64 7.66 0.079Total for the AirMode--34.54f34.54f100.00100.0020.350.211aDevelopmental status: N = new concepts; P = pilot tests; C =commercially available systems. New concepts include basic research activities, applied research activities,and experiments at laboratory level. Pilot tests include testing prototype vehicles and demonstration projects. Commerciallyavailable systems can be purchased orimplemented now.bPotential per-device reductionsin GHG emissions or energy useare percentagereductions compared toGHG emissions (energy use) of a device withoutusing this practice.cPotential reductions in modal GHG emissionsor energy use are estimated based onthe difference in 2025 modal GHG emissions orenergy use with and without the selectedbest practice divided by the total modal GHG emissions or energy use ifno best practicesare implemented.dPercentage contribution of a subgroup to total reductions is defined by dividing the percentage reductions for a subgroup by total modal reductions for all best practices.eThese reductions are estimated based on the difference between 2025 modal GHG emissionsor energy use withand without implementation of the representative bestpractices of the subgroup..fTotal potential reductions in GHGemissions and energy use for the air mode exclude the reductions contributed by the strategies that are not the highest one in the cases ofmutual exclusion.100Table 9- 4. Potential Best Practices for the Water Modeand the Estimated Reductions inGHG Emissions and Energy UseSubgroupI.D.No.Brief Name of Best Practice Developmental Status
a Potential Per-device Reductions in GHG Emissions (%) b Potential Per-device Reductions in Energy Use (%) b Potential Reductions in Modal GHG Emissions (%)
c Potential Reductions in Modal Energy Use (%)
c Percentage Contribution of a Subgroup to Total Reductions in Modal GHG Emissions (%) d Percentage Contribution of a Subgroup to Total Reductions in Modal Energy Use (%) d Potential Aggregate GHG Emission Reduction in 2025 for Each Subgroup (10 6 Tons CO 2 eq.)
e Potential Aggregate Energy Use Reduction in 2025 for Each Subgroup (10 15 BTU)
e4-1 Off-Center Propeller C 3.00 3.00 1.50 1.504-2 Propeller Boss Cap withFins C 4.00 4.00 2.00 2.00Propeller SystemImprovement4-3Auxiliary Free-RotatingPropulsion Device behind theMain PropellerC 6.00 6.00 3.00 3.0068.44 174.93 3.65 0.043Anti-Idling 4-4Shoreside Power for MarineVessels at PortsP 13.00 -3.20 0.16 -0.043.71 -2.33 0.20 > -0.001Alternative Fuel 4-5 B20 Biodiesel Fuel for Ships N 8.14 -8.30 1.22 -1.25 27.85 -72.59 1.48 -0.018Total for the WaterMode--4.38f1.72f100.00100.005.330.025aDevelopmental status: N = new concepts; P = pilot tests; C =commercially available systems. New concepts include basic research activities, applied research activities,and experiments at laboratory level. Pilot tests include testing prototype vehicles and demonstration projects. Commerciallyavailable systems can be purchased orimplemented now.bPotential per-device reductionsin GHG emissions or energy useare percentagereductions compared toGHG emissions (energy use) of a device withoutusing this practice.cPotential reductions in modal GHG emissionsor energy use are estimated based onthe difference in 2025 modal GHG emissions orenergy use with and without the selectedbest practice divided by the total modal GHG emissions or energy use ifno best practicesare implemented.dPercentage contribution of a subgroup to total reductions is defined by dividing the percentage reductions for a subgroup by total modal reductions for all best practices.eThese reductions are estimated based on the difference between 2025 modal GHG emissionsor energy use withand without implementation of the representative bestpractices of the subgroup..fTotal potential reductions in GHGemissions and energy use for the water mode exclude the reductions contributed by the strategies that are not the highest one in the cases ofmutual exclusion.101 

### The two most important subgroups for GHG em issions reduction are propeller system improvement (I.D. Nos. 4-1 to 4-3) and alternative fuel (I.D . No. 4-5). These two subgroups contribute 68 and 28 percent, respectively, to the estimated total modal GHG emissions
reductions.

9.5 Pipeline Mode
GHG emissions reductions for the pipeline m ode are based upon en ergy use reductions, which include petroleum fuel use reductions a nd natural gas emission reductions. Table 9-5 summarizes potential individual and aggregate reductions in GHG emissions and energy use for best practices for the pipeline mode. These redu ctions are summarized in four ways, which are
the same as those for Table 9-1. The most important subgroup for GHG emissi ons reduction is connecting method (I.D. Nos. 5-3). This subgroup contributes 44 percen t to the estimated total modal GHG emissions
reductions.

9.6 Intermodal Comparisons
The purpose of this section is to summarize and discuss:

• comparisons of total reductions in relative and absolute modal GHG emissions in 2025 for multiple best practices for all modes;

• annual reductions in modal GHG emissions, energy use reduction, and cost-effectiveness of selected best practices for which there is sufficient information for quantitative analysis; and

• impacts of intermodal substitutes if intermodal shifts are available.

9.6.1 Total Modal GHG Emissions Reductions
Modal GHG emissions reductions in this section are estimated based on the difference
between 2025 modal emissions with or without implementation of the representative best practices. There is substantial variability among the best practices in terms of their potential percentage reductions in modal GHG emissions. The variations in reductions among individual practices range from 0.2 to 5.5 percent for the truck mode, 0.6 to 5.5 percent for the rail mode, 1.0 to 13.0 percent for the air mode, 0.2 to 3.0 percent for the water mode, and 0.1 to 1.9 percent for the pipeline mode. The average reductions for a best practice are 2.2, 3.4, 2.3, 1.6, and 0.9 percent for the truck, rail, air, wate r, and pipeline modes, respectively.102Table 9- 5. Potential Best Practices for the Pipeline Modeand the Estimated Reductions inGHG Emissions and Energy UseSubgroupI.D.No.Brief Name of Best Practice Developmental Status
a Potential Per-device Reductions in GHG Emissions (%) b Potential Per-device Reductions in Energy Use (%) b Potential Reductions in Modal GHG Emissions (%)
c Potential Reductions in Modal Energy Use (%)
c Percentage Contribution of a Subgroup to Total Reductions in Modal GHG Emissions (%) d Percentage Contribution of a Subgroup to Total Reductions in Modal Energy Use (%) d Potential Aggregate GHG Emission Reduction in 2025 for Each Subgroup (10 6 Tons CO 2 eq.)
e Potential Aggregate Energy Use Reduction in 2025 for Each Subgroup (10 15 BTU)
e5-1Convert Natural Gas PneumaticControls to Instrument AirC 10.00 9.02 0.50 0.13Process ControlDevice Improvement5-2Replace High-Bleed Natural GasPneumatic Devices withLow-Bleed Pneumatic DevicesC 90.00 90.00 0.57 0.1624.52 23.64 1.40 0.003Connecting Method 5-3“Hot Tap” MethodC 1.93 0.54 1.93 0.5443.83 44.35 2.50 0.0055-4 Transfer Compression C 0.11 0.02 0.07 0.02Maintenance5-5 Inline Inspection C 1.32 0.37 1.32 0.3731.65 32.01 1.81 0.004Total for the PipelineMode--4.401.22100.00100.005.700.011aDevelopmental status: N = new concepts; P = pilot tests; C =commercially available systems. New concepts include basic research activities, applied research activities,and experiments at laboratory level. Pilot tests include testing prototype vehicles and demonstration projects. Commerciallyavailable systems can be purchased orimplemented now.bPotential per-device reductionsin GHG emissions or energy useare percentagereductions compared toGHG emissions (energy use) of a device withoutusing this practice.cPotential reductions in modal GHG emissionsor energy use are estimated based onthe difference in 2025 modal GHG emissions orenergy use with and without the selectedbest practice divided by the total modal GHG emissions or energy use ifno best practicesare implemented.dPercentage contribution of a subgroup to total reductions is defined by dividing the percentage reductions for a subgroup by total modal reductions for all best practices.eThese reductions are estimated based on the difference between 2025 modal GHG emissionsor energy use withand without implementation of the representative bestpractices of the subgroup..103 

### Within each mode, multiple best practices can be applied simultaneously to achieve total 2025 modal GHG emissions reductions (compared to pr ojected emissions if no best practices are used) of 57, 19, 34, 4, and 4 percent for the tr uck, rail, air, water, and pipeline modes, respectively, depending on the mode, as summarized in Figure 9-1 (a) and (b), which illustrate modal percentage reductions categorized by devel opmental status and target GHGs, respectively.
N 2 

### O emission is not included because its contribution is less th an 0.4% of total GHG emissions. The truck mode is the biggest GHG emissions contributor, and it also has the highest GHG emissions reduction potential. The truck mode is estimated to contri bute 66 percent of freight transportation GHG emissions in 2025 if none of the best practices are adopted. The
total GHG emissions of this mode in 2025 are es timated to increase 67 percent over 2003 levels. If all identified best practi ces are implemented aggressive ly, 2025 GHG emissions could be
reduced by as much as 28 percent compared to 2003 levels. Furthermore, such reductions would amount to a 57 percent reduction compar ed to 2025 GHG emissions if none of the best practices are used.
Each of the other four modes is estimated to contribute 12 percent or less to total freight GHG emissions in 2025. If no best practices are implemented, modal GHG emissions in 2025 from the rail, air, water, and pipeline modes are estimated to increas e 49, 65, 28, and 15 percent, respectively, compared to 2003 levels. If a ll identified best practices are implemented aggressively, 2025 GHG emissions could increa se by 20, 8, 22, and 9 percent, respectively, compared to 2003 levels, which is a smaller incr ease. If all identifi ed best practices are implemented aggressively, 2025 GHG emissions could be reduced by 19, 34, 4, and 4 percent, respectively, compared to 2025 GHG emissions if none of the best practices are used. The magnitude of the estimated potential GHG emissions reductions for each mode in 2025 ranges from approximately 5 million to 412 million tons CO 2 

### eq., as summarized in Figure 9-2. The magnitude of the estim ated potential GHG emissions reduc tions for the truck mode in 2025 is significantly higher than fo r any of the other four modes.
Both the total relative and absolute m odal 2025 GHG emissions reductions possibilities for the truck mode are significantly higher than for the other four modes. The truck mode currently contri butes more than 60 percen t of total energy use an d GHG emissions in freight transportation. There are more research and development programs focusing on the truck mode. Furthermore, an individual strategy for this mode can achieve higher absolute reductions even if the percentage reduction is comparable to that of best practices in other modes. For example, anti-idling practices for the truck mode are es timated to reduce truck mode GHG emissions by 2.1%. Anti-idling practices for the rail mode are estimated to reduce rail mode emissions by 5.4%. However, the magnitude of the truck model GHG emissions reductions is several times of the magnitude of the rail mode reductions, ev en though the percentage reduction is smaller.104 0 10 20 30 40 50 60

Truck Rail Air Water Pipeline New Concepts

Pilot Tests
Commercially Available Systems



### (a) Categorized by Developmental Status

0 10 20 30 40 50 60

Truck Rail Air Water Pipeline HFC

CH4

CO2



### (b) Categorized by Target GHGs Figure 9- 1. Total Modal 2025 GHG Emissi ons Reductions Based on Simultaneous Implementation of Multiple Best Practices in Each ModeGHG Emissions Reductions (%)GHG Emissions Reductions (%)105 0 50 100 150 200 250 300 350 400 450

Truck Rail Air Water Pipeline New Concepts

Pilot Tests

Commercially Available Systems



### Figure 9- 2. Magnitudes of the Total Mo dal 2025 GHG Emissions Reductions Based on Simultaneous Implementation of Mult iple Best Practices for Each Mode

9.6.2 Comparisons of Best Practices Whos e Costs Are Assessed Quantitatively
Current available cost informa tion for best practices whose co sts are not sufficient to be assessed quantitatively is summarized in simplified summary tables in Appendices. It is critical to have cost data for quantitative assessments. Wh ile it is clear that many best practices will not be considered by potential adopters until adequate cost data is available upon which to estimate costs reliably, at this time insufficient data are av ailable to characterize costs reliably for most of the best practices identified here. Thus, there is a critical need for future work to better characterize these costs. To date, sufficient information has been obtained to assess 13 best practices quantitatively. Tabl e 9-6 provides quantitative estim ates of reductions in 2025 modal GHG emissions and energy use, as well as regarding costs.
There is substantial variab ility among these 13 best prac tices in terms of annual reductions in modal 2025 GHG emissions and energy use within their individual modes, which is compared to 2025 GHG emissions and energy use w ithout using these best practices. Three best practices for the truck mode, which includ e auxiliary power units, hybrid trucks, and B20 biodiesel, have the potential to achieve substantial GHG emissions reductions (15 × 10 6 

### ton CO 2 

### eq./year or more). Two best practices for the truck mode, auxiliary power units and hybrid trucks, also have the potential to reduce energy use substantially, by 185 × 10 12 

### BTU or more.GHG Emissions Reductions(Million Tons CO2eq.)106Table 9- 6. Quantitative Summary ofReductions in GHG Emissions, Energy Use,and Costs of Selected Best PracticesaMode Truck Rail Water PipelineI.D. No. 1-1 1-3 1-4 1-21 1-33 2-1 2-2 2-3 2-6 4-5 5-1 5-2 5-3Practice Name Off-Board Truck Stop Electrification Auxiliary Power Units Direct Fire Heaters Hybrid Trucks B20 Biodiesel Combined Diesel P owered Heating Syste m and Auto Engine Start/Stop System Battery Diesel Hybrid Switching Locomotive Plug-In Unit B20 Biodiesel B20 Biodiesel Convert Natural Gas Pneumatic Controls to Instrument Air Replace High Bleed Natural Gas Pneumatic Devices with Low Bleed Pneumatic Devices “Hot Tap” MethodAnnual GHG Emissions Reductions(106ton CO2eq./year)2.4 15.0 7.6 24.5 30.8 2.3 1.1 0.4 3.5 1.5 0.7 0.8 2.5Annual Energy Use Reduction(1012BTU /year)27 185 94 300 -370 29 14 4 -42 -18 1 2 5Unit GHG Emissions Reductions(10-3lb CO2eq./ton-mile)11 66 34 130 29 2.0 1.0 0.3 3.0 5.0 3.4 3.9 13Unit Energy Use Reduction(BTU /ton-mile)60 409 207 804 -176 12 6 2 -18 -31 3 4 13Annualized Cost ($106/year) 570 3000 390 2430 3300 140 180 91 380 180 1.7 1.8 11Annual Energy Cost Saving($106/year)900 3400 1740 5600 0 530 260 230 0 0 13 15 51Net Saving ($106/year) 330 440 1350 3190 -3300 390 70 135 -380 -180 12 13 40Net Savings per Unit of GHGEmissions Reductions($/ton CO2eq.)138 29 178 130 -108 167 65 364 -109 -120 18 18 16Net Savings per Unit of Energy UseReduction($/106BTU)12 2.3 14 10.6 N/Ab13.5 5.2 38 N/AbN/Ab9.6 8.8 7.8Simple Pay- back period (years) N/Ac3.2 0.6 2.1 N/Ad2.1 5.5 0.8 N/AdN/Ad0.3 0.9 0.2aThese assessments are based on the assumptions that these bestpractices reach their potential maximum market shares in 2025.bThis practice has no energy use reduction due to an increase in energy use, and it has no net saving due to high annualized cost and no energy cost saving.cThere is no pay-back period for this best practice because thereis no initial capital cost to uses.dThere is no pay-back period for this best practice because there is no net saving.107 

### There is substantial variability among these 13 best practices regarding their net cost savings. Ten best practices produce net cost savings. Many of these have very high capital costs, annual costs, or both but these are offset by even greater sa vings, typically for reduced fuel cost savings. For three of the best practices, th e net savings are negative . Thus, these practices do not pay for themselves. These three practices, based on the use of B20 biodiesel, have a net
increase in total costs because the fuel cost is higher than that for petroleum diesel, based on current typical experience. There is substantial variability among these 13 best practices regarding their cost-effectiveness. The top three most cost-effec tive best practices are: plug-in units for the rail mode; direct-fired heaters for the truck mo de; and combined diesel powered heating system and auto engine start/stop system for the rail m ode. The least cost-effective best practices are B20 biodiesel for the truck, rail an d water modes. The variability of fuel prices, capital costs and operation and maintenance costs stro ngly impacts the accuracy of th e cost-effectiveness results. Volatile fuel prices could cause the practices that do not correctly pay for themselves to produce net cost savings. For example, if diesel fu el price is reduced by 12%, the net savings of auxiliary power units for the truck mode would be negative. Changes in capital cost, such as an expected decrease ove r time in the capital cost for hybrid trucks, could cause practices that do not yet pay for themselves to produce a net cost saving. If petroleum o il prices continue to increase, it is possible that biodiesel fuel price might become lower than petroleum diesel fuel price, in which case the use of B20 Bi odiesel might produce a net cost saving.
There is substantial variabili ty among these 13 best practices regarding their simple pay-back periods. Eight best practices have simp le pay-back periods of less than 5 years, and five among these seven practices have simple pa yback periods of a year or less. One best practice produces a net savings but has no pay-back period because there is no initial capital cost. There is no pay-back period for the three best practices because they do not produce a net saving. From a national policy perspective, cons ideration of the potential magnitude of reductions is important. From an individual owner or operator perspective, consideration of cost savings and cost effectivene ss may tend to be more important.

9.6.3 Intermodal Substitutions Intermodal shifts, such as from modes with high emissions per unit of freight transport (e.g., airplanes and trucks), to lower-emission modes, such as rail and sea-going ships, are attractive options for GHG emissions reductions, if feasible. The typical unit GHG emissions per unit of freight activity of each of these modes range from 0.06 to 2.16 lb CO 2 

### per ton-mile, as illustrated in Figure 9-3. For example, the GHG emissions per ton-mile for rail are only 8 percent of those for trucks, implying a maximum GHG emissions reduction of 92 percent if rail108 

### 0.0 0.5 1.0 1.5 2.0 2.5

Truck Rail Air Water Pipeline

Figure 9- 3. Estimated GHG Emissions per Unit of Freight Transport of Each Mode

could substitute completely for trucking. Th e GHG emissions per ton-mile for ships are only 17 percent those of trucks, implying a maximum GHG emissions reduction of 83 percent if ships could substitute completely for trucking.
There have been some recent evaluations of th e effectiveness of inter-modal shifts as a GHG emissions reduction strategy. A Germa ny mail-order company reduced its annual CO 2 

### emissions by 40% from 1993 to 1999, based on substituting sea-going ships for truck and air transport. 126 

### For example, five percent of its consignments were transported by ship instead of truck in its Turkish market, and le d to a savings of 0.16 tonnes of CO 2 

### per tonne of merchandise. Furthermore, eight percent of air freight in the Hong Kong market was shifted to a combined sea-air transportation sequence, lead ing to reductions of 2.8 tonnes of CO 2 

### per tonne of merchandise. A Canadian study estimated that a sh ift of one-third of truck freight to rail could decrease emissions by 19% between 2000 and 2010 in Ontario. This analysis was based on both vehicle and fuel cycle emissions. 127 

### However, whether freight can be shifted from trucks to rail or ships may depend on a
number of factors. These fact ors include distance, availabili ty of infrastructure (e.g., port terminals, rail/truck intermodal facilities), size of the cargo, schedule, durability of the cargo, relative costs, 127 

### and the need for new logistics systems. 126 

### For example, some amount of truck activities, such as pick up and de livery, are likely to be needed even if most of the ton-miles involved rail,. According to one estimate, se ven percent of the freight ton-miles requireGHG Emissions per Unit of FreightTransport(lb CO2eq.per ton-mile)109 

### shipment by truck for pick up and deliv ery, with the balance shipped by rail. 128 

### For this scenario, the rail-truck inte r-modal shift would reduce GHG emissions by approximately 85 percent, instead of the maximum possible 92 percen t. Of course, the actu al reductions are also affected by implementation of best practices for GHG reduction in both the truck and rail modes, which can lead to a differing percentage difference for the inter-modal shift. Thus, whether one mode of shipping can be a substitute for another depends on site-specific characteristics, and system-lev el intermodal analysis will be needed.110 

### 10.0. CONCLUSIONS AND RECOMMENDATIONS

The purpose of the guidebook is to identify and characterize potential best practices for reducing energy use and refrigeran t use in freight transportation, which could lead to reductions in GHG emissions. Some best practices for wh ich sufficient information is available are assessed quantitatively based on several criteria. There is a lack of quantitative data for most of the identified best practices, and these best prac tices are assessed qualitatively. This research represents a “first step” in identifying best practices in the freight industry. Qualitative assessments are accompanied by preliminary estimates of overall reductions based on various assumptions that are detailed in the appendices. This Chapter presents key conclusions and
recommendations.

10.1 Conclusions
If current trends continue, the increase in modal GHG emi ssions could range from 15 to 67 percent from 2003 to 2025, depending on the mode . If best practices are aggressively implemented, it is possible to achieve a net decrease in total GHG emissions and energy use, even if intermodal substitutions (e.g., truck to ra il) do not occur. Even larger percentage reductions are possible if intermodal shifts are en couraged, particularly away from trucking and
air and toward rail and water-borne modes. Of course, as best practices are implemented that reduce GHG emissions from each mode, the relative reduction associat ed with inter-modal shifts will also change. Many best practices are in early stages of de velopment or commercialization. Therefore, there is limited cost data upon which to assess thes e best practices quantita tively. For thirteen best practices for which adequate cost data are available for qua ntitative assessment, the modal reductions in GHG emissions and energy use we re highly variable. The normalized cost savings per unit of GHG emissions reduction was also highly variab le. Ten of these practices offer net cost savings, while thre e of them have net cost increas es. There is also substantial variability regarding the simple pay-back periods of best prac tices that have net savings. However, five of them have simple payback periods of a year or less. Governments and individual owners or opera tors should carefully identify and compare their options. From a national policy perspective, some best practices, such as direct fired
heaters and B20 biodiesel for truc ks, offer greater potential for large magnitudes in reduction of total GHG emissions, but may not be as cost-effective. There may be targeted opportunities for the Federal government to promote research and de velopment of such options in order to reduce111 

### their costs or to provide other incentives for th eir adoption. Of course, consideration must be given to co-benefits or adverse consequences of any given policy option. From an individual owner or operator perspective, c onsideration of cost savings and cost effectiveness may tend to be more important. Some best practices may be a “no regrets” proposition, in that the owner or operator can realize a net cost savings. This guidebook makes no recommendations about the use of specific strategies as best practices. Typically information regarding ma ny best practices is incomplete and does not enable situation-specific assessm ent and comparison. While it is cl ear that many best practices will not be considered by potential adopters until adequate cost da ta is available upon which to estimate costs reliably, at this time insufficient data are available to characterize costs reliably for most of the best practices identified here. Pote ntial best practices assessed qualitatively can be assessed quantitatively after sufficient informa tion is available for quantitative assessment. Potential best practices assessed quantitatively can be further analyzed ta king into account the variability or uncertainty of ke y assumptions, such as market pe netration rates, fuel prices, discount rates, capital costs, and operation and maintenance costs.

10.2 Recommendations for Future Research Needs
To further inform decisions regarding adoptio n of suitable best pr actices, the following
work is recommended: (1) Update information Many technologies are currently in the developmental stage and there is not sufficient information available yet for quan titative assessments. There is a critical
need for future work to better characteriz e the costs data. Information given here may be updated as new information becomes available. (2) Revise or Develop Cost Estimates as New Data Become Available In this work, costs could be assessed for only 13 best practices. However, potential adopters of best pract ices need cost data for all of the possible best practices that could be applied to their situation. T hus, there is a critical need for more cost information. Ongoing work is recommended to obtain or develop cost estimates for best practices for which costs are not reported here, as well as to update cost estimates reported here as new data become available. (3) Evaluate key assumptions and other factors that influence the selection of best practices The impact of variations of key assumpti ons, such as market penetration rates, fuel prices, capital costs, and operation a nd maintenance costs, may be assessed via112 

### sensitivity analysis. It is also important to understand the impacts of other factors, such as: the applicability and practical barriers of new technologies; policies and regulations; governmental incentiv es, such as financial, data, and analytical support, and costs and benefits seen by operators versus overall national reductions. (4) Develop tools to support decision making regarding best practices i. Develop a web-based decision tree: A decision tree is helpful when faced with a complex multistage decision problem. Thus, a decision tree is a useful tool to help inform decision making regarding the choice of best practices. A decision tree involves a hierarchical cascade of questions to guide responsibl e and target parties toward promising best practices appropriate to their situ ations. Decision trees include choice nodes, uncertainty nodes, and valuati on. Choice nodes represent discrete actions that can be taken by a decision maker. Uncertainty nodes represent the range of possible outcomes associated with a particular decision option. Decisions can be made in a sequence, le ading to a complete design for vehicle or modal technology and operations. Th e value of each alternative strategy can be quantified in a multiple attribute framework, including monetized attributes (e.g., cost savings) and non-m onetized attributes (e.g., percentage reduction in energy use, emissions). Th e decision tree may be implemented in an interactive web-based format and could be publicly accessible.
ii. Develop a decision tool Conditions of a specific responsible or target party, such as local fuel
costs are critical considerations in choosing a best prac tice to adopt. Therefore, there is a critical need to develop a decision support that will allow such parties to compare multiple best practices on the basis of representative and relevant important assumptions. For such a tool, a user should be able to enter his or her own data and assumptions.113 

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### APPENDIX A. DETAILS OF INPUT DATA, ASSUMPTIONS, AND ESTIMATION
RESULTS FOR TRUCK MO DE BEST PRACTICES

This appendix is additional descriptive information for the best practices in Chapter 4, including the standardized reporting tables, if th eir corresponding best practices can be assessed quantitatively, or the simplified summary tabl es, if their correspondi ng best practices are assessed qualitatively. For those assessed quantit atively, the methods for the estimation of data in the standardized reporting tables are also described.

Appendix A.1 Best Practice 1-1: Of f-Board Truck Stop Electrification This best practice is assessed quantitativel y. Table A-1 summarizes the assessment results. This table is in the format of the standardized reporting table for quantitative results. The basis of the quantitative estimates is explained.

A. Estimate of total number of vehicles or devices:
(a) Assumption: i. Total number of trucks w ith sleeper cab is equal to the number of trucks having conventional cab wi th sleeper plus the number of trucks having cab over engine with sleeper.

ii. Total truck number in 2002 is equal to total truck number in

2003.
iii. Annual per-truck energy use in 2025 is the same as annual

per-truck energy use in 2003.
(b) Calculation: i. The 2002 Vehicle I nventory and Use Survey reported that 568,600 trucks had conventional cab with sleeper, and 109,000 trucks had cab over engine with sleeper. 18 

### Thus, there were 677,600 trucks with sleeper cab in 2003. 

# ( ) ( ) trucks trucks trucks 600
, 677 000
, 109 600
, 568 = +


### ii. Since per-truck energy use is the same and modal energy use are

estimated to grow by 67% from 2003 to 2025, 4 

### total truck number increases by 67% from 2003 to 2025.

trucks 500
, 131
, 1 %) 67 1 ( trucks 600
, 677 = + ×136 

### Table A-1. Standardized Reporting Table fo r Best Practice 1-1, Off-Board Truck Stop Electrification. a Characteristics of the Practice Description

Practice Name Off-Board Truck Stop Electrification Mode Type Truck Subgroup Anti-Idling Responsible Parties 1, 2, 5, 13, 20, 21, 22 Target Parties 1, 2, 6, 8 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all trucks with sleeper cabs participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.33% (2.4 ×10 6 tons of CO 2 eq.) and 0.31% (27.3 ×10 12 Btu), respectively. Developmental Status C Practice Summary This practice enables truck drivers to switch off their base engines by connecting to a service module, which includes heating, air conditioning and electricity, at a truck stop. Emissions, Energy Use, and Refrigerant Use Unit Value

Annual Transport Activity for the Mode (ATAM) 10 9 ton-miles/year 2,098 Annual Transport Activity to Which a Practice Is Applicable (ATAP) 10 9 ton-miles/year 453 Annual GHG Emissions Reductions(AGR) 10 6 ton CO 2 eq./year 2.4 Annual Energy Use Reduction (AER) 10 12 BTU /year 27.3 Annual Refrigerant Use Reduction (ARR) lbs/year N/A Unit GHG Emissions Reductions (UGER) 10 -3 lb CO 2 eq./ton-mile 11 Unit Energy Use Reduction (UER) BTU /ton-mile 60 Unit Refrigerant Use Reduction (URR) lbs/ton-mile N/A Practice Costs

Capital Cost ® 10 6 USD ($) N/A Discount Rate ® % 10% Technical Lifetime of Technology (L) years N/A Fixed Charge Factor (a) year -1 N/A Annual O & M Cost (AOM) $10 6 /year N/A Annualized Cost (AC) $10 6 /year 570 Annual Energy Cost Saving (AECS) $10 6 /year 900 Annual Refrigerant Cost Saving (ARCS) $10 6 /year N/A Net Savings (NS) $10 6 /year 330 Net Savings per Unit of GHG Emissions Reductions (NSGR) $/ton CO 2 eq. 140 Net Savings per Unit of Energy Use Reduction (NSER) $/10 6 BTU 12 Net Savings per Unit of Refrigerant Use Reduction (NSRR) $/lb N/A Simple Payback Period (SPP) years N/A b

a These assessments are based on the assumptions th at these best practices reach their potential137 maximum market shares in 2025.
b There is no pay-back period for this best practi ce because there is no initia l capital cost to uses.



### (d) Results: There will be 1,131,500 trucks with sleeper cab in 2025.

B. Estimate of annual trans port activity for the mode:
(a) Assumption: The growth rate of total tran sport activity is the same as the growth rate of energy use for the truck mode.
(b) 2003 Results: The estimated total transpor t activity for the truck mode in the U.S. in 2003 is 1,256 ×10 9 

### ton-miles. 3



### (c) 2025 Results: Since total energy use for th e truck mode is estimated to grow by 67% from 2003 to 2025, 4 

### the estimated total transport activity for the truck mode in the U.S. in 2025 will be 2,098 ×10 9 

### ton-miles.

C. Estimate of annual transport activity to which a practi ce is applicable:
(a) Assumption: The ratio of annual transpor t activity of trucks with sleeper cab to annual transport activity of all trucks is proportional to the ratio of energy use for trucks with sleeper cab to energy use for all trucks.
(b) Calculation: The ratio of energy use fo r trucks with sleeper cab to energy use for all trucks is 21.6% (1.125×10 15 

### BTU vs. 5.21×10 15 

### BTU). 3



### (c) Results: Since the ratio is 21.6%, the estimated to tal transport activity for
the truck mode in the U.S. in 2025 will be 453 ×10 9 

### ton-miles.

D. Estimate of annual GHG emissions reductions:
(a) Assumption: i. Total GHG emissions reductions are that GHG emissions reductions due to energy use reduction minus GHG emissions due to electricity use for operati ng this practice at truck stops.
ii. Approximately 20% of truc ks are idled at truck stops. 129



### iii. On an annual basis an average truck accumulates about 1,830138 

### hours of parking idle, 130 

### and one hour idle of a truck consumes 0.85 gallon of diesel fuel. 27



### (b) Calculation: i. Truck idle fuel us e is 0.85 gal/hr, which is equal to 117,887
BTU/hr because that the estima ted heating value of petroleum diesel is 138,690 BTU/gallon. 131-132



### ii. Total idle fuel use for truc ks with sleeper cab in 2003 is
estimated to be 1.46×10 8 

### (10 6 

### BTU) per year.



# ( ) BTU 10 10 46

. 1 gallon BTU 698
, 138
hr gallon 85

. 0
trucks

hrs 830
, 1 trucks 600
, 677

6 8 × =        

× × ×



### iii. GHG emissions coefficient for diesel fuel is 0.0808 tons CO 2 

### eq. per 10 6 

### BTU. 1



### iv. Total GHG emissions reductions due to fuel use reduction are
estimated to be 2.36×10 6 

### tons CO 2 

### eq. in 2003. 

# ( )

. eq CO tons 10 36

. 2 BTU 10 . eq CO tons 0808

. 0 % 20 BTU 10 10 46

. 1

2 6 6 2 6 8



### × = × × ×

v. Total energy output for IdleAi re is 18,000 BTU/hr because that A/C or heater energy output average is 17,500 BTU/hr and other accessory consumes approximately 500 BTU/hr of

energy.

vi. GHG emissions coefficient fo r electricity is 0.0007 tons CO 2 

### eq. per kWh. 108



### vii. Total GHG emissions due to elect ricity use are estimated to be
0.92×10 6 

### tons CO 2 

### eq. in 2003.

. eq CO tons 10 92

. 0 % 20 kWh . eq CO tons 0007

. 0
BTU 3412 kWh
hr BTU 18000
trucks

hrs 830
, 1 trucks 600
, 677

2 6 2

× = ×        

× × × ×



### viii. The estimated annual GHG emissions reductions are estimated
to be 1.44×10 6 

### tons CO 2 

### eq. in 2003.139 

## ( )

. eq CO tons 10 44

. 1

. eq CO tons 10 92

. 0 10 36

. 2 2 6 2 6 6 × = ×

− ×



### (c) Results: Since GHG emissions for the truck mode is estimated to grow by 67%, which is explained in Se ction 1.2, the estimated 2025 annual
GHG emissions reductions are 2.41×10 6 

### tons CO 2 

### eq.

E. Estimate of annual energy use reduction:
(a) Assumption: i. Total energy use reduction is that energy use reduction minuses energy for producing electricity for operating this practice.
ii. Approximately 20% of truc k idling is at truck stops. 129



### iii. On an annual basis an average truck accumulates about 1,830 hours of parking idle, 130 

### and one hour idle consume 0.85 gallon
of diesel fuel. 27



### (b) Calculation: i. Truck idle fuel us e is 0.85 gal/hr, which is equal to 117,887
BTU/hr because that the estima ted heating value of petroleum diesel is 138,690 BTU/gallon. 131-132



### ii. Hourly electricity needed for producing electricity in order to operate this practice is 18,000 BTU/hr, including 17,500 BTU/hr for the average for operating A/C or heater and 500 BTU/hr for operating other accessory.
iii. Since the ratio of primary ener gy input to electricity output is
estimated to be 2.89 based on total electricity generated and total primary energy consumed in the U.S. in 2005, 133 

### primary energy needed for producing electricity in order to operate this practice is 52,000 BTU/hr.
iii. Since only 20% of trucks idle at truck stops, the suitable locations for this practice, the pe rcentage of energy reduction for adopting this practice is estimated to be 11.2%.

% 2

. 11 % 20 117887 52000 117887

= ×      

−



### iv. Total energy use for trucks with sleeper cab at idle in 2003 is140 

### estimated to be 1.46×10 8 

### (10 6 

### BTU) per year.



## ( ) BTU 10 10 46

. 1 gallon BTU 698
, 138
hr gallon 85

. 0
trucks

hrs 830
, 1 trucks 600
, 677

6 8 × =        

× × ×



### v. The estimated annual energy use reduction in 2003 is 1.63×10 7 

### (10 6 

### BTU). 

## ( ) ( ) BTU 10 10 63

. 1 % 6

. 10 BTU 10 10 46

. 1 6 7 6 8 × = × ×


### (c) Results: Since total energy use for the truck mode is estimated to grow by 67%, 4 

### the estimated annual energy use reduction in 2025 is
2.73×10 7 

### (10 6 

### BTU).

F. Estimate of unit GHG emissions reductions:

mile ton . eq CO lb 011

. 0

ton lbs 000
, 2

. miles ton billion 453 eq CO tons million 41

. 2 2 2

− =        

×        

−



### G. Estimate of unit energy use reduction: 

## ( )

mile ton BTU 3

. 60

. miles ton billion 453 BTU 10 10 73

. 2 6 7

− =        

− ×



### H. Estimate of capital cost (Not available because of no initial cost for this practice)

I. Estimate of annual O & M cost 

### (Not available)

J. Estimate of annualized cost: (a) Assumption: The price for hourly service of this practice, which is provided by IdleAire, is the average of its individual driver’s price and its contract price.
(b) Calculation: i. The price for individual driver is $1.5/ hr and the contract price is $1.25/hr. Thus, the average price is estimated to be $1.375/hr. 5141 

### ii. The estimated annualized cost in 2003 is $341×10 6



### .

6 

### 10 341 $ hr

375

. 1 $ % 20 trucks

hrs 830
, 1 trucks 600
, 677 × =      

× × ×

(c) Results: Since total truck number is estimated to grow by 67%, which is explained in Appendix A.1.A, the estimated annualized cost in 2025 is $569 ×10 6



### .

K. Estimate of energy cost reduction: (a) Assumption: Diesel fuel price in 2025 is the same as the price of the second season of 2005, which is $2.56/gallon ( = $18.5/10 6 

### BTU). 114



### (b) Calculation: The estimated ener gy cost reduction in 2003 is $540 ×10 6



### . 

# ( ) 6 6 6 8 

### 10 540 $ BTU 10 5

. 18 $ % 20 BTU 10 10 46

. 1 × = × × ×

(c) Results: Since total energy use is es timated to grow by 67% from 2003 to 2025, which is explained in Append ix A.1.A, the estimated energy cost reduction in 2025 is $902 ×10 6



### .

L. Estimate of net savings:

6 6 6 

### 10 333 $ 10 569 $ 10 902 $ × = ×

− ×



### M. Estimate of net savings per unit of GHG emissions reductions:

. eq CO ton 2

. 138 $

. eq CO tons 10 41

. 2 10 333 $

2 2 6 6

= × ×



### N. Estimate of net savings per unit of energy use reduction:



### BTU 10 2

. 12 $
BTU 10 3

. 27 10 333 $

6 12 6



### = × ×

O. Estimate of simple payback period: (Not available because there is no in itial capital cost for this practice).142 

### Appendix A.2 Best Practice 1-2: Truc k-Board Truck Stop Electrification This best practice is assessed qualitatively. Table A-2 summarizes the assessment results in the standardized simp lified reporting table format.

Table A-2. Simplified Summary Table for Be st Practice 1-2, Truck-Board Truck Stop
Electrification Attribute Description

Practice Name Truck-board Truck Stop Electrification Mode Type Truck Subgroup Anti-Idling Responsible Parties 1, 2, 5, 6, 8, 11, 13, 20, 21, 22 Target Parties 1, 2,4, 6, 8 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all trucks with sleep er cabs participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.39% and 0.41%, respectively. Developmental Status C Practice Summary This system enables truck drivers to switch off their diesel engines by connecting parked trucks to electrical outlets (receptacles) for electric powered on-board HVAC systems at a truck stop. Potential Reductions in Modal GHG Emissions 0.39%

Potential Reduction in Modal Energy Use 0.41%

Potential Reduction in Modal HFC Use N/A

Cost Information The operation charge for th is system is $0.5~$1.00 per hour per truck Benefits and Drawbacks Using electricity consumes less energy and emits less GHG than using diesel fuel for truck base engine. Trucks cannot use this alternative unless they are parked at a truck stop with this type of electrification system.143 

### Appendix A.3 Best Practice 1-3: Auxiliary Power Units This best practice is assessed quantitativel y. Table A-3 summarizes the assessment results. This table is in the format of the standardized reporting table for quantitative results. The basis of the quantitative estimates is explained.

A. Estimate of total number of vehicles or devices:
Total number of vehicles is explained in Appendix A.1.A.

B. Estimate of annual trans port activity for the mode:
Annual transport ac tivity for the mode is explained in Appendix A.1.B.

C. Estimate of annual transport activity to which a practi ce is applicable:
Annual transport activity to wh ich this practice is applicable is explained in Appendix
A.1.C.

D. Estimate of annual GHG emissions reductions:
(a) Assumption: i. Total GHG emissions re ductions are due to energy use reduction.
ii. On an annual basis an average truck accumulates about 1,830 hours of parking idle, 130 

### and one hour idle of a truck consumes 0.85 gallon of diesel fuel. 27



### iii. The fuel rate for APU use is es timated to be 0.2 gallon of diesel fuel per hour. 134



### (b) Calculation: i. Idle fuel use is es timated to be 117,887 BTU/hr, explained in Appendix A.1.144 

### Table A-3. Standardized Reporting Table fo r Best Practice 1-3, Auxiliary Power Units. a Characteristics of the Practice Description

Practice Name Auxiliary Power Units Mode Type Truck Subgroup Anti-Idling Responsible Parties 1, 2, 5, 6, 8, 11 Target Parties 1, 2, 4, 6 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all trucks with sleeper cabs participate. The reductions in modal GHG emissions and energy use in 2025 would be 20.8% (15.0 ×10 6 tons of CO 2 eq.) and 2.13% (185 ×10 12 Btu), respectively. Developmental Status C Practice Summary APUs are mounted externally on the truck cabs or sleepers that provide heat and A/C for the sleeper, heat for engine, and power for auxiliaries. They can avoid the need for idling of the truck base engines Emissions, Energy Use, and Refrigerant Use Unit Value

Annual Transport Activity for the Mode (ATAM) 10 9 ton-miles/year 2,098 Annual Transport Activity to Which a Practice Is Applicable (ATAP) 10 9 ton-miles/year 453 Annual GHG Emissions Reductions(AGR) 10 6 ton CO 2 eq./year 15.0 Annual Energy Use Reduction (AER) 10 12 BTU /year 185.0 Annual Refrigerant Use Reduction (ARR) lbs/year N/A Unit GHG Emissions Reductions (UGER) 10 -3 lb CO 2 eq./ton-mile 66 Unit Energy Use Reduction (UER) BTU /ton-mile 409 Unit Refrigerant Use Reduction (URR) lbs/ton-mile N/A Practice Costs

Capital Cost (C) 10 6 USD ($) 9,400 Discount Rate (r) % 10% Technical Lifetime of Technology (L) years 5 Fixed Charge Factor (a) year -1 0.264 Annual O & M Cost (AOM) $10 6 /year 520 Annualized Cost (AC) $10 6 /year 2,990 Annual Energy Cost Saving (AECS) $10 6 /year 3,430 Annual Refrigerant Cost Saving (ARCS) $10 6 /year N/A Net Savings (NS) $10 6 /year 440 Net Savings per Unit of GHG Emissions Reductions (NSGR) $/ton CO 2 eq. 29 Net Savings per Unit of Energy Use Reduction (NSER) $/10 6 BTU 2.3 Net Savings per Unit of Refrigerant Use Reduction (NSRR) $/lb N/A Simple Payback Period (SPP) years 3.2

a These assessments are based on the assumptions th at these best practices reach their potential

maximum market shares in 2025.145 

### ii. Total fuel use reduction for th is practice in 2003 is estimated to
be 1.11×10 8 

### (10 6 

### BTU) per year.



# ( ) BTU 10 10 11

. 1 85

. 0 2

. 0 85

. 0 gallon BTU 698
, 138
hr gallon 85

. 0 trucks

hrs 830
, 1 trucks 600
, 677

6 8 × =      

− ×        

× × ×



### iii. GHG emissions coefficient for diesel fuel is 0.0808 tons CO 2 

### eq. per 10 6 

### BTU. 1



### iv. Total GHG emissions reductions due to fuel use reduction are
estimated to be 8.97×10 6 

### tons CO 2 

### eq. in 2002.


# ( )

. eq CO tons 10 97

. 8 BTU 10 . eq CO tons 0808

. 0 BTU 10 10 11

. 1

2 6 6 2 6 8

× = × ×



### (c) Results: Since GHG emissions for the truck mode is estimated to grow by 67%, which is explained in Se ction 1.2, the estimated 2025 GHG
emissions reductions are 14.98×10 6 

### tons CO 2 

### eq..

E. Estimate of annual energy use reduction:
i. Fuel use reduction for this practi ce in 2003 is estimated to be 1.11×10 8 

### (10 6 

### BTU), explained in Appendix A.3.D.
ii. Since energy use for the truck mode is estimated to grow by 67%, 4 

### the estimated annual energy use reduction in 2025 is 1.85×10 8 

### (10 6 

### BTU).

F. Estimate of unit GHG emissions reductions:

mile ton . eq CO lb 066

. 0

ton lbs 000
, 2

. miles ton billion 453 eq CO tons million 98

. 14 2 2

− =        

×        

−146 

### G. Estimate of unit energy use reduction: 

# ( )

mile ton BTU 96

. 408

. miles ton billion 453 BTU 10 10 85

. 1 6 8

− =        

− ×



### H. Estimate of capital cost i. The capital cost of an auxiliary power uni t, which includes factor y cost and installation cost, is estimated to be $8,279 per truck. 31 

### Total capital costs of auxiliary power units for all trucks with sleeper cab in 2003 is estimated to be $5.6 ×10 9



### .

9 9 10 6

. 5 $ 10 8

. 4 $ trucks 600
, 677 truck 279
, 8 $ × = × = ×



### ii. Since the truck mode is estimated to gr ow by 67%, total capital costs of auxiliary power units for all trucks with sleeper cab in 2025 is estimated to be $9.4 ×10 9



### .

I. Estimate of annual O & M cost


### i. Annual maintenance cost of an auxili ary power unit per is estimated to be $460. 51



### Total annual maintenance costs of auxiliary power units for all trucks with sleeper cab in 2003 is estimated to be $312 ×10 6



### .

6 8 10 312 $ 10 12

. 3 $ trucks 600
, 677 truck

460 $ × = × = ×



### ii. Since total truck number is estimated to grow by 67%, which is explained in Appendix A.1.A, annual O & M costs of auxiliary power units for all trucks with sleeper cab in 2025 is estimated to be $520 ×10 6



### .

J. Estimate of annualized cost: i. The life-time of auxiliary power units is estimated to be 5 years. 31



### ii. Fixed charge factor is estimated to be 0.264.


### ( )
( ) 264

. 0 79

. 3 1

1

. 0 1 1

1 arg 5

1 = =                

+ = 

## ∑

= i i a factor e ch Fixed



### iii. 

# ( ) ( ) 9 

### 10 99

. 2 $ million 520 $ 264

. 0 billion 4

. 9 $ × = + ×147 

### K. Estimate of energy cost reduction: (a) Assumption: Diesel fuel price in 2025 is the same as the price of the second season of 2005, which is $2.56/gallon ( = $18.5/10 6 

### BTU). 114



### (b) Calculation: The estimated ener gy cost reduction in 2003 is $2.05 ×10 9



### . 

# ( ) 9 6 6 8 10 05

. 2 $ BTU 10 5

. 18 $ BTU 10 10 11

. 1 × = × × ×



### (c) Results: Since total energy use for the truck mode is estimated to grow by 67% from 2003 to 2025, 4 

### the estimated energy cost reduction in 2025 is $3.43 ×10 9



### .

L. Estimate of net savings:

6 9 9 

### 10 438 $ 10 99

. 2 $ 10 43

. 3 $ × = ×

− ×



### M. M. Estimate of net savings pe r unit of GHG emissions reductions:

. eq CO ton 99

. 28 $

. eq CO tons 10 98

. 14 10 438 $

2 2 6 6

= × ×



### N. Estimate of net savings per unit of energy use reduction:



### BTU 10 34

. 2 $
BTU 10 185 10 438 $

6 12 6



### = × ×

O. Estimate of simple payback period:


# ( ) years 22

. 3 10 52

. 0 $ 10 43

. 3 $ 10 4

. 9 $

9 9 9



### = ×

− × ×148 

### Appendix A.4 Best Practice 1- 4: Direct-Fired Heaters This best practice is assessed quantitativel y. Table A-4 summarizes the assessment results. This table is in the format of the standardized reporting table for quantitative results. The basis of the quantitative estimates is explained.

A. Estimate of total number of vehicles or devices:
Total number of vehicles is explained in Appendix A.1.A.

B. Estimate of annual trans port activity for the mode:
Annual transport ac tivity for the mode is explained in Appendix A.1.B.

C. Estimate of annual transport activity to which a practi ce is applicable:
Annual transport activity to wh ich this practice is applicable is explained in Appendix
A.1.C.

D. Estimate of annual GHG emissions reductions:
(a) Assumption: i. Total GHG emissions re ductions are due to energy use reduction.
ii. This practice is estimated to reduce fuel use for trucks with sleeper cab by 5%. 135



### (b) Calculation: i. Total energy used for tr ucks with sleeper cab is estimated to be
1.125×10 15 

### BTU. 3



### ii. Total fuel use reduction for this practice in 2003 is estimated to
be 5.63×10 13 

### BTU per year.



### BTU 10 63

. 5 % 5 BTU 10 125

. 1 13 0 15 

### × = × ×

iii. GHG emissions coefficient for diesel fuel is 0.0808 tons CO 2 

### eq. per 10 6 

### BTU. 1149 

### Table A-4. Standardized Reporting Table fo r Best Practice 1-4, Direct-Fired Heaters. a Characteristics of the Practice Description

Practice Name 

### Direct-Fired Heaters Mode Type Truck Subgroup Anti-Idling Responsible Parties 1, 2, 5 Target Parties 1, 2, 4, 6 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all trucks with sleeper cabs participate. The reductions in modal GHG emissions and energy use in 2025 would be 1.05% (7.6 ×10 6 tons of CO 2 eq.) and 1.08% (94 ×10 12 Btu), respectively. Developmental Status C Practice Summary Direct-fired heaters can avoid the need for idling of truck base engines in cold weather. Heat is produced from diesel fuel combustion and transferred to a heat exchanger for sleeper cabs and engines. Emissions, Energy Use, and Refrigerant Use Unit Value

Annual Transport Activity for the Mode (ATAM) 10 9 ton-miles/year 2,098 Annual Transport Activity to Which a Practice Is Applicable (ATAP) 10 9 ton-miles/year 453 Annual GHG Emissions Reductions(AGR) 10 6 ton CO 2 eq./year 7.6 Annual Energy Use Reduction (AER) 10 12 BTU /year 93.9 Annual Refrigerant Use Reduction (ARR) lbs/year N/A Unit GHG Emissions Reductions (UGER) 10 -3 lb CO 2 eq./ton-mile 34 Unit Energy Use Reduction (UER) BTU /ton-mile 207 Unit Refrigerant Use Reduction (URR) lbs/ton-mile N/A Practice Costs

Capital Cost (C) 10 6 USD ($) 996 Discount Rate (r) % 10% Technical Lifetime of Technology (L) years 5 Fixed Charge Factor (a) year -1 0.264 Annual O & M Cost (AOM) $10 6 /year 125 Annualized Cost (AC) $10 6 /year 387 Annual Energy Cost Saving (AECS) $10 6 /year 1,740 Annual Refrigerant Cost Saving (ARCS) $10 6 /year N/A Net Savings (NS) $10 6 /year 1350 Net Savings per Unit of GHG Emissions Reductions (NSGR) $/ton CO 2 eq. 177.6 Net Savings per Unit of Energy Use Reduction (NSER) $/10 6 BTU 14.4 Net Savings per Unit of Refrigerant Use Reduction (NSRR) $/lb N/A Simple Payback Period (SPP) years 0.62

a These assessments are based on the assumptions th at these best practices reach their potential

maximum market shares in 2025.150 

### iv. Total GHG emissions reductions due to fuel use reduction are
estimated to be 4.55×10 6 

### tons CO 2 

### eq. in 2003.



## ( )

. eq CO tons 10 55

. 4 BTU 10 . eq CO tons 0808

. 0 BTU 10 10 63

. 5 2 6
6 2 6 7 × = × ×



### (c) Results: Since total GHG emissions for the truck mode is estimated to grow by 67%, which is explained in Section 1.2, the estimated 2025
annual GHG emissions reductions are 7.60×10 6 

### tons CO 2 

### eq.

E. Estimate of annual energy use reduction:
i. Fuel use reduction for this pract ice in 2003 is estimated to be 56.3×10 12 

### BTU, explained in Appendix A.4.D.
ii. Since total energy use for the truck mode is estimated to grow by 67%, 4 

### the estimated annual energy use reduction in 2025 is 93.9×10 12 

### BTU.

F. Estimate of unit GHG emissions reductions:

mile ton . eq CO lb 034

. 0

ton lbs 000
, 2

. miles ton 10 453 eq CO tons 10 60

. 7 2 9 2 6

− =        

×        

− × ×



### G. Estimate of unit energy use reduction: 

# ( )

mile ton BTU 3

. 207

. miles ton 10 453 BTU 10 10 39

. 9

9 6 7

− =        

− × ×



### H. Estimate of capital cost i. The capital cost of a direct-fired heater is estimated to be $3,200 in 1996, 27 

### but it has been re-estimated to be $880 per truck in 2006. 136 

### Total capital cost for all trucks with sleeper cab in 2003 is estimated to be $596.3 ×10 6



### .151 6 10 3

. 596 $ trucks 600
, 677 truck

880 $ × = ×



### ii. Since total truck number is estimated to grow by 67%, which is explained in Appendix A.1.A, total capital cost for all trucks w ith sleeper cab in 2025 is estimated to be $995.8 ×10 6



### .

I. Estimate of annual O & M cost


### i. The annual maintenance cost of a direct-f ired heater is estimated to be $110 per
truck. 128 

### Total O & M cost for all trucks with sleeper cab in 2003 is estimated to be $74.5 ×10 6



### .

6 10 54

. 74 $ trucks 600
, 677 truck

110 $ × = ×



### ii. Since total truck number is estimated to grow by 67%, which is explained in Appendix A.1.A, total O & M cost for a ll trucks with sleeper cab in 2025 is estimated to be $124.5 ×10 6



### .

J. Estimate of annualized cost: i. The life-time is estimated to be 5 years. 51



### ii. Fixed charge factor is estimated to be 0.264.


### ( )
( ) 264

. 0 79

. 3 1

1

. 0 1 1

1 arg 5

1 = =                

+ = 

## ∑

= i i a factor e ch Fixed



### iii. 

# ( ) 6 6 6 

### 10 4

. 387 $ 10 5

. 124 $ 264

. 0 10 8

. 995 $ × = × + × ×

iv. The estimated of annualized cost in 2025 is 387.4×10 6



### .

K. Estimate of energy cost reduction: (a) Assumption: Diesel fuel price in 2025 is the same as the price of the second season of 2005, which is $2.56/gallon ( = $18.5/10 6 

### BTU). 114



### (b) Calculation: 

# ( ) 9
6 6 7 10 74

. 1 $ BTU 10 5

. 18 $ BTU 10 10 39

. 9 × = × × ×152 

### (c) Results: The estimated energy cost reduction in 2025 is $1.74 × 10 9



### .

L. Estimate of net savings:

i. 6 9 9 

### 10 1350 $ 10 39

. 0 $ 10 74

. 1 $ × = ×

− ×
ii. The estimated net savings in 2025 is $1350 × 10 6



### .

M. Estimate of net savings per unit of GHG emissions reductions:

. eq CO ton 6

. 177 $

. eq CO tons 10 6

. 7 10 1350 $

2 2 6 6

= × ×



### N. Estimate of net savings per unit of energy use reduction:



### BTU 10 4

. 14 $
BTU 10 9

. 93 10 1350 $

6 12 6



### = × ×

O. Estimate of simple payback period:


# ( ) years 62

. 0 10 125

. 0 $ 10 74

. 1 $ 10 996

. 0 $

9 9 9



### = ×

− × ×153 

### Appendix A.5 Best Practice 1-5: Direct-f ired Heaters with Thermal Storage Units This best practice is assessed qualitatively. Table A-5 summarizes the assessment
results in the standardized si mplified reporting table format.

Table A-5. Simplified Summary Ta ble for Best Practice 1-5, Dire ct-Fired Heaters with Thermal Storage Units Attribute Description

Practice Name Direct-Fired Heaters with Thermal Storage Units Mode Type Truck Subgroup Anti-Idling Responsible Parties 1, 2, 5, 16, 18, 19 Target Parties 1, 2, 4, 6 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all trucks with sleep er cabs participate. The reductions in modal GHG emissions and energy use in 2025 would be 2.88% and 2.97%, respectively. Developmental Status P Practice Summary The combination of direct-fired heaters and thermal storage units, which consists of a phase change material fo r storing heating or cooling energy, supplies heating and cooling, but no electrical power, to the sleeper compartment when the base engine is off. Potential Reductions in Modal GHG Emissions 2.88%

Potential Reduction in Modal Energy Use 2.97%

Potential Reduction in Modal HFC Use N/A

Cost Information N/A Benefits and Drawbacks This system is probably the most energy-efficient anti-idling practice. The disadvantage of this practice is that it supplies no electricity, and requires power from the vehicle’s batteries.154 

### Appendix A.6 Best Practice 1-6: Enhanced Air Conditioning System I - for Direct
Emissions This best practice is assessed qualitatively. Table A-6 summarizes the assessment
results in the standardized si mplified reporting table format.

Table A-6. Simplified Summary Table for Best Practice 1-6, Enhanced Air Conditioning System I - for Direct Emissions Attribute Description

Practice Name Enhanced Air Conditioning System I - for Direct Emissions Mode Type Truck Subgroup Air Conditioning System Improvement Responsible Parties 1, 2, 4, 5, 6, 11, 18, 19 Target Parties 1, 2, 4, 6, 7 Target GHGs HFC Strategy Type Technology

Practice Goals Goal is to have all trucks partic ipate. The reductions in modal GHG emissions in 2025 would be 0.88%. Developmental Status P Practice Summary Enhanced air conditioning sy stems can reduce direct GHG emissions by reducing the leakage of HFC-134a. The refrigerant leakage rates can be decreased through the use of low permeable hoses, improved hose ends and connectors, and improved compressor shaft seals. Potential Reductions in Modal GHG Emissions 0.88%

Potential Reduction in Modal Energy Use N/A

Potential Reduction in Modal HFC Use 35.3%

Cost Information The incremental capital cost of this system is approximately $33 per truck. Benefits and Drawbacks This system can reduce a lot of refrigerant leakage for the truck mode, and save the cost for recharge the refrigerant. Safety characteristics of this system have no change because the same refrigerant is used. There is not as yet a standard method for testing and certifying the leakage rate of an enhanced system is in the developmental stage.155 

### Appendix A.7 Best Practice 1-7: Enhanced Air Conditioning System II - for Indirect
Emissions This best practice is assessed qualitatively. Table A-7 summarizes the assessment
results in the standardized si mplified reporting table format.

Table A-7. Simplified Summary Table for Best Practice 1-7, Enhanced Air Conditioning System II - for Indirect Emissions Attribute Description

Practice Name Enhanced Air Conditioning System II - for Indirect Emissions Mode Type Truck Subgroup Air Conditioning System Improvement Responsible Parties 1, 2, 4, 5, 6, 11, 18, 19 Target Parties 1, 2, 4, 6, 7 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all trucks partic ipate. The reductions in modal GHG emissions and energy use in 2025 would be 0.18% and 0.19%, respectively. Developmental Status C Practice Summary Enhanced air conditioning sy stems for reducing indirect GHG emissions can decrease base engine load require ments from mobile A/C systems. This system replaces fixed displacement compressors (FDCs) with externally controlled variable displacement compressors (VDC), and uses improved control systems, and improved condensers and evaporators. Potential Reductions in Modal GHG Emissions 0.18%

Potential Reduction in Modal Energy Use 0.19%

Potential Reduction in Modal HFC Use N/A

Cost Information The incremental capital cost of this system is approximately $7 per truck. Benefits and Drawbacks This system can reduce energy use for operating A/C, and save energy cost. The benefit of reducing engine load is only available in hot weather when the A/C system is used.156 

### Appendix A.8 Best Practice 1-8: Alternative Refrigerants - CO 2 

### This best practice is assessed qualitatively. Table A-8 summarizes the assessment results in the standardized simp lified reporting table format.

Table A-8. Simplified Summary Table for Best Practice 1-8, Alternative Refrigerants - CO 2 

### Attribute Description

Practice Name Alternative Refrigerants - CO 2 Mode Type Truck Subgroup Air Conditioning System Improvement Responsible Parties 1, 2, 4, 5, 6, 11, 16, 18, 19 Target Parties 1, 2, 4, 6, 7 Target GHGs HFC Strategy Type Technology

Practice Goals Goal is to have all trucks partic ipate. The reductions in modal GHG emissions in 2025 would be 2.47%. Developmental Status N Practice Summary The current widely used refrigerant, HFC-134a, has GWP = 1,300, whereas CO 2 has GWP = 1. Therefore, CO 2 is being investigated as an alternative refrigerant. Potential Reductions in Modal GHG Emissions 2.47%

Potential Reduction in Modal Energy Use N/A

Potential Reduction in Modal HFC Use 99.9%

Cost Information The incremental capital cost of CO 2 air conditioning system is $42.5 per truck, including $20 for upgr ading system hoses and components for higher pressure operating cond itions and $22.5 for additional safety equipment. Thus, the incremental capital cost of CO 2 may be increased to $70 per truck, including $20 for upgrading system and $50 for secondary loop designs. Benefits and Drawbacks This system uses alternat ive refrigerant with very low GWP. Safety assessment and potential risk mitig ation may be needed because of different safety characteristics of this alternative refrigerant compared to HFC-134a.157 

### Appendix A.9 Best Practice 1-9: Alternative Refrig erants - HFC-152a This best practice is assessed qualitatively. Table A-9 summarizes the assessment results in the standardized simplif ied reporting table format.

Table A-9. Simplified Summary Table for Best Practice 1-9, Alternative Refrigerants - HFC-152a Attribute Description

Practice Name Alternative Refrigerants - HFC-152a Mode Type Truck Subgroup Air Conditioning System Improvement Responsible Parties 1, 2, 4, 5, 6, 11, 16, 18, 19 Target Parties 1, 2, 4, 6, 7 Target GHGs HFC Strategy Type Technology

Practice Goals Goal is to have all trucks partic ipate. The reductions in modal GHG emissions in 2025 would be 2.35%. Developmental Status N Practice Summary The current widely used refrigerant, HFC-134a, has GWP = 1,300, whereas HFC-152a has GWP = 120. Therefore, HFC-152a is being investigated as an alternative refrigerant. Potential Reductions in Modal GHG Emissions 2.35%

Potential Reduction in Modal Energy Use N/A

Potential Reduction in Modal HFC Use 91%

Cost Information The incremental capital cost of HFC-152a air conditioning system is from $22.5 per truck for additional safety equipment, including in-cabin leak sensors and engine compartment evacuation valves, to $50 per truck for secondary loop designs. Benefits and Drawbacks This system uses al ternative refrigerant with low GWP. The transition from HFC-134a to HFC- 152a would be relatively easy (compared to a transition to CO 2 ) since these two refrigerants have similar thermodynamic properties and A/C system components need less modification. The flammability of this alternative refrigerant, although moderate, motivates the need for additional safety assessment and potential risk mitigation158 

### Appendix A.10 Best Practice 1-10: Alternative Refrigerants - HC This best practice is assessed qualitativel y. Table A-10 summarizes the assessment results in the standardized simp lified reporting table format.

Table A-10. Simplified Summary Table for Best Practice 1-10, Alternative Refrigerants - HC Attribute Description

Practice Name Alternative Refrigerants - HC Mode Type Truck Subgroup Air Conditioning System Improvement Responsible Parties 1, 2, 4, 5, 6, 11, 16, 18, 19 Target Parties 1, 2, 4, 6, 7 Target GHGs HFC Strategy Type Technology

Practice Goals Goal is to have all trucks partic ipate. The reductions in modal GHG emissions in 2025 would be 2.46%. Developmental Status N Practice Summary The current widely used refrigerant, HFC-134a, has GWP = 1,300, whereas propane has GWP = 20. Therefore, propane is being investigated as an alternative refrigerant. Potential Reductions in Modal GHG Emissions 2.46%

Potential Reduction in Modal Energy Use N/A

Potential Reduction in Modal HFC Use 98.5%

Cost Information The incremental capital cost of HC air conditioning system is from $22.5 per truck for additional safety equipment, including in-cabin leak sensors and engine compartm ent evacuation valves, to $50 per truck for secondary loop designs. Benefits and Drawbacks This system uses altern ative refrigerant with low GWP. However, this system may use 10% more energy for the operation of vehicle air conditioners and increases indirect GHG emissions. The flammability of this alternativ e refrigerant, a lthough moderate, motivates the need for additional safety assessment and potential risk mitigation. Release of propane to the atmosphere may also increase tropospheric ozone formation.159 

### Appendix A.11 Best Practice 1-11: Vehicle Profile Improvement I - Cab Top Deflector, Sloping Hood and Cab Side Flares This best practice is assessed qualitatively. Table A-11 summarizes the assessment results in the standardized simp lified reporting table format.

Table A-11. Simplified Summary Table for Best Practice 1-11, Vehicle Profile Improvement I - Cab Top Deflector, Sloping Hood and Cab Side Flares Attribute Description

Practice Name Vehicle Profile Improvement I - Cab Top Deflector, Sloping Hood and Cab Side Flares Mode Type Truck Subgroup Aerodynamic Drag Improvement Responsible Parties 1, 2, 5, 6 Target Parties 1, 2, 6 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all trucks partic ipate. The reductions in modal GHG emissions and energy use in 2025 would be 1.43% and 1.47%, respectively. Developmental Status C Practice Summary These add-on devices can reduce truck tractor aerodynamic drag, increase their fuel efficiency and reduce GHG emissions. Potential Reductions in Modal GHG Emissions 1.43%

Potential Reduction in Modal Energy Use 1.47%

Potential Reduction in Modal HFC Use N/A

Cost Information The incremental capital cost of this system is approximately $750 per truck. Benefits and Drawbacks These add-on devices that reduce aerodynamic drag can reduce energy use and GHG emissions. Although this best practice increases truck weight slightly, the estimated reduction in fuel use and GHG emissions takes this into account.160 

### Appendix A.12 Best Practice 1-12: Vehicl e Profile Improvement II - Closing and Covering of Gap between Tractor and Trailer, Aerodynamic Bumper, Underside Air Baffles, and Wheel Well Covers This best practice is assessed qualitativel y. Table A-12 summarizes the assessment results in the standardized simplif ied reporting table format.

Table A-12. Simplified Summary Table for Be st Practice 1-12, Vehicle Profile Improvement II - Closing and Covering of Gap Betw een Tractor and Trailer, Aerodynamic Bumper, Underside Air Baffles, and Wheel Well Covers Attribute Description

Practice Name Vehicle Profile Improvement II - Cl osing and Covering of Gap Between Tractor and Trailer, Aerodynamic Bumper, Underside Air Baffles, and Wheel Well Covers Mode Type Truck Subgroup Aerodynamic Drag Improvement Responsible Parties 1, 2, 5, 6 Target Parties 1, 2, 6 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all trucks partic ipate. The reductions in modal GHG emissions and energy use in 2025 would be 2.37% and 2.44%, respectively. Developmental Status C Practice Summary These add-on devices can reduce truck side and underside aerodynamic drag, increase their fuel efficiency and reduce GHG emissions. Potential Reductions in Modal GHG Emissions 2.37%

Potential Reduction in Modal Energy Use 2.44%

Potential Reduction in Modal HFC Use N/A

Cost Information The incremental capital cost of this system is approximately $1,500 per truck. Benefits and Drawbacks These add-on devices that reduce aerodynamic drag can reduce energy use and GHG emissions. Although this best practice increases truck weight slightly, the estimated reduction in fuel use and GHG emissions takes this into account.161 

### Appendix A.13 Best Practice 1-13: Vehicle Profile Improvement III - Trailer or Van Leading and Trailing Edge Curvatures This best practice is assessed qualitativel y. Table A-13 summarizes the assessment results in the standardized simplif ied reporting table format.

Table A-13. Simplified Summary Table for Best Practice 1-13, Vehicle Profile Improvement III - Trailer or Van Leading and Trailing Edge Curvatures Attribute Description

Practice Name Vehicle Profile Improvement III - Trailer or Van Leading and Trailing Edge Curvatures Mode Type Truck Subgroup Aerodynamic Drag Improvement Responsible Parties 1, 2, 5, 6 Target Parties 1, 2, 6 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all trucks partic ipate. The reductions in modal GHG emissions and energy use in 2025 would be 1.24% and 1.28%, respectively. Developmental Status C Practice Summary These add-on devices can reduce truck trailer (or van) aerodynamic drag, increase their fuel efficiency and reduce GHG emissions. Potential Reductions in Modal GHG Emissions 1.24%

Potential Reduction in Modal Energy Use 1.28%

Potential Reduction in Modal HFC Use N/A

Cost Information The incremental capital cost of this system is approximately $500 per truck. Benefits and Drawbacks These add-on devices that reduce aerodynamic drag can reduce energy use and GHG emissions.162 

### Appendix A.14 Best Practice 1-14: Pn eumatic Aerodynamic Drag Reduction This best practice is assessed qualitativel y. Table A-14 summarizes the assessment results in the standardized simplif ied reporting table format.

Table A-14. Simplified Summary Table for Be st Practice 1-14, Pneumatic Aerodynamic Drag Reduction Attribute Description

Practice Name Pneumatic Aerodynamic Drag Reduction Mode Type Truck Subgroup Aerodynamic Drag Improvement Responsible Parties 1, 2, 4, 5, 6, 7, 16, 18, 19 Target Parties 1, 2, 4, 6, 7 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all combination truc ks participate. The reductions in modal GHG emissions and energy use in 2025 would be 2.17% and 2.24%, respectively. Developmental Status N Practice Summary This system blows air from slots at the rear of the trailers of heavy-duty vehicles to reduce aft-end aerodynamic drag and reduce energy use and GHG emissions. Potential Reductions in Modal GHG Emissions 2.17%

Potential Reduction in Modal Energy Use 2.24%

Potential Reduction in Modal HFC Use N/A

Cost Information The estimated incremental cap ital cost is $2,500, but could be as high as $5,250. Benefits and Drawbacks This system that redu ces aerodynamic drag can reduce energy use and GHG emissions. If used in combination with another best practice, such as Best Practice 1-12, there may be a negative synergistic effect in that the total improvement in aer odynamics is less than the linear sum of improvements from individual practices.163 

### Appendix A.15 Best Practice 1-15: Planar Boat Tail Plates on a Tractor-Trailer This best practice is assessed qualitativel y. Table A-15 summarizes the assessment results in the standardized simp lified reporting table format.

Table A-15. Simplified Summary Table for Best Practice 1-15, Planar Boat Tail Plates on a Tractor-Trailer Attribute Description

Practice Name Planar Boat Tail Plates on a Tractor-Tailer Mode Type Truck Subgroup Aerodynamic Drag Improvement Responsible Parties 1, 2, 3, 4, 5, 6, 7, 12, 16, 18, 19 Target Parties 1, 2, 3, 4, 5, 6, 7 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all combination truc ks participate. The reductions in modal GHG emissions and energy use in 2025 would be 3.76% and 3.88%, respectively. Developmental Status N Practice Summary Planar boat tail plates are testing add-on devices that reduce aft-end aerodynamic drag. These devices are rectangular plates mounted to the after-end of a trailer that reduce the wake of trucks. Potential Reductions in Modal GHG Emissions 3.76%

Potential Reduction in Modal Energy Use 3.55%

Potential Reduction in Modal HFC Use N/A

Cost Information N/A Benefits and Drawbacks These add-on devices that reduce aerodynamic drag can reduce energy use and GHG emissions. The drawback of this practice is that it may interfere with loading and unloading operations, depending on the design.164 

### Appendix A.16 Best Practice 1-16: Vehicle Load Profile Improvement This best practice is assessed qualitativel y. Table A-16 summarizes the assessment results in the standardized simplif ied reporting table format.

Table A-16. Simplified Summary Table for Best Practice 1-16, Vehicle Load Profile Improvement Attribute Description

Practice Name Vehicle Load Profile Improvement Mode Type Truck Subgroup Aerodynamic Drag Improvement Responsible Parties 1, 2, 3, 5 Target Parties 1, 2, 3, 5, 6 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all non-van tra ilers within combination trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.43% and 0.44%, respectively. Developmental Status C Practice Summary Aerodynamic drag can be re duced by the use of a streamlined load profile for a trailer. This practice keeps the load profile of a trailer as low as possible and secures tarpaulin s to smooth air flow to reduce energy use and GHG emissions. Potential Reductions in Modal GHG Emissions 0.43%

Potential Reduction in Modal Energy Use 0.44%

Potential Reduction in Modal HFC Use N/A

Cost Information N/A Benefits and Drawbacks This low-tech optio n that reduces aerodynamic drag can reduce energy use and GHG emissions. The drawback of this practice is that extra work for loading and unloading operations may be required.165 

### Appendix A.17 Best Practice 1-17: Automatic Tire Inflation Systems This best practice is assessed qualitativel y. Table A-17 summarizes the assessment results in the standardized simplif ied reporting table format.

Table A-17. Simplified Summary Table for Be st Practice 1-17, Automatic Tire Inflation Systems Attribute Description

Practice Name Automatic Tire Inflation Systems Mode Type Truck Subgroup Tire Rolling Resistance Improvement Responsible Parties 1, 2, 4, 5, 6, 7, 8, 12 Target Parties 1, 2, 4, 6, 7 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all combination truc ks participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.56% and 0.58%, respectively. Developmental Status C Practice Summary These systems can keep tires to the right pressure by monitoring and continually adjusting the level of pr essurized air in tires. With properly vehicle tire inflation, tire rolling resistance is decreased and fuel use is reduced. Potential Reductions in Modal GHG Emissions 0.56%

Potential Reduction in Modal Energy Use 0.58%

Potential Reduction in Modal HFC Use N/A

Cost Information The estimated increm ental capital cost is $900. The tire maintenance cost saving is about $200 annually. Benefits and Drawbacks While these systems are in stalled, drivers do not need to check tire pressure manually and can pay less a ttention to their truck tires.166 

### Appendix A.18 Best Practice 1-18: Wide-Base Tires This best practice is assessed qualitativel y. Table A-18 summarizes the assessment results in the standardized simp lified reporting table format.

Table A-18. Simplified Summary Table for Best Practice 1-18, Wide-Base Tires Attribute Description

Practice Name Wide-Base Tires Mode Type Truck Subgroup Tire Rolling Resistance Improvement Responsible Parties 1, 2, 5, 6, 7 Target Parties 1, 2, 6 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all combination truc ks participate. The reductions in modal GHG emissions and energy use in 2025 would be 2.03% and 2.10%, respectively. Developmental Status C Practice Summary Dual tires that combination trucks usually have are heavy and also produce high rolling resistance. Single wide-base tires can replace these dual tires on combination trucks. Wide-base tires that have lower weight and produce lower rolling resistance reduce energy use. Potential Reductions in Modal GHG Emissions 2.03%

Potential Reduction in Modal Energy Use 2.10%

Potential Reduction in Modal HFC Use N/A

Cost Information The estimated incrementa l capital cost is $700 in average. New trucks with wide-base tires are possibly cheaper than with dual tires, but retrofitting existing trucks have higher cost. Benefits and Drawbacks This practice has lowe r weight and produces lowe r rolling resistance. Aerodynamic drag and pass-by noise may also be decreased slightly. By using single instead of dual tires, there is a need for increased attention to tire inflati on pressure for safety reasons167 

### Appendix A.19 Best Practice 1-19: Low-Rolling-Resistance Tires This best practice is assessed qualitativel y. Table A-19 summarizes the assessment results in the standardized simplif ied reporting table format.

Table A-19. Simplified Summary Table for Be st Practice 1-19, Low-Rolling-Resistance Tires Attribute Description

Practice Name Low-Rolling-Resistance Tires Mode Type Truck Subgroup Tire Rolling Resistance Improvement Responsible Parties 1, 2, 5, 6, 7 Target Parties 1, 2, 6 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all trucks partic ipate. The reductions in modal GHG emissions and energy use in 2025 would be 2.83% and 2.91%, respectively. Developmental Status P Practice Summary Trucks with low-rolling resist ance tires are fuel-efficient because of the reduction of tire rolling resistance. Potential Reductions in Modal GHG Emissions 2.83%

Potential Reduction in Modal Energy Use 2.91%

Potential Reduction in Modal HFC Use N/A

Cost Information The estimated in cremental capital cost is $550. Benefits and Drawbacks This practice produ ces lower rolling resistance. However, the requirements for higher inflation pressure and high monitoring frequency may limit the extent of their market penetration. The fuel saving advantage tends to be reduced when these low-resistance tires wear down.168 

### Appendix A.20 Best Practice 1-20: Pneumatic Blowing to Reducing Rolling Resistance This best practice is assessed qualitativel y. Table A-20 summarizes the assessment results in the standardized simplif ied reporting table format.

Table A-20. Simplified Summary Table for Best Practice 1-20, Pneumatic Blowing to Reducing Rolling Resistance Attribute Description

Practice Name Pneumatic Blowing to Reducing Rolling Resistance Mode Type Truck Subgroup Tire Rolling Resistance Improvement Responsible Parties 1, 2, 4, 5, 6, 7, 8, 12, 16, 18, 19 Target Parties 1, 2, 4, 6, 7 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all combination truc ks participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.54% and 0.56%, respectively. Developmental Status N Practice Summary This system for reducing aft-end aerodynamic drag blows air from slots at the rear of the trailers of heavy-duty vehicles. The installation of additional pipes, jets, valves, selectiv e blowing, and control system can blow air under trucks. These air streams provide a slight lift that reduces tire rolling resistance. Potential Reductions in Modal GHG Emissions 0.54%

Potential Reduction in Modal Energy Use 0.56%

Potential Reduction in Modal HFC Use N/A

Cost Information If the pneumatic blowing system for reducing aerodynamic drag has been installed on a combination truc k, additional $500 capital cost for extra components would be needed. Benefits and Drawbacks This practice can u tilize the air-blowing system to reduce rolling resistance and reduce tire wear. This practice may also assist conventional truck control and improve safety. However, this system may slightly increase dust po llution by dislodging particles on the road surface.169 

### Appendix A.21 Best Practice 1-21: Hybrid Trucks This best practice is assessed quantitatively. Table A-21 summarizes the assessment results. This table is in the format of the standardized reporting table for quantitative results. The basis of the quantitative estimates is explained.

A. Estimate of total number of vehicles or devices:
(a) Assumption: The growth rate of medium -duty trucks is the same as the growth
rate of total trucks for th e truck mode from 2003 to 2025.
(a) 2003 Results: It is estimated that there were 2,824,000 trucks as medium-duty
trucks in 2003. 18



### (b) 2025 Results: Since the growth rates of medium-duty trucks and total trucks are the same and the number of total trucks is estimated to grow by 67% from 2003 to 2025, which is explained in Appendix A.1.A, there will be 4,716,000 trucks as medium-duty trucks in 2025.

B. Estimate of annual trans port activity for the mode:
Annual transport ac tivity for the mode is explained in Appendix A.1.

C. Estimate of annual transport activity to which a practi ce is applicable:
(a) Assumption: The ratio of annual trans port activity of medium-duty trucks to annual transport activity of all trucks is proportional to the ratio of energy use for medium-duty trucks to energy sue for all trucks.
(b) Calculation: The ratio of energy use for medium-duty trucks to energy use for
all trucks is estimated to be 17.8%. 20



### (c) Results: Since the ratio is 17.8%, the estimated total ton-miles for medium-duty trucks in the U.S. in 2025 will be 373 ×10 9



### ton-miles.170 

### Table A-21. Standardized Reporting Tabl e for Best Practice 1-21, Hybrid Trucks a Characteristics of the Practice Description

Practice Name Hybrid Trucks Mode Type Truck Subgroup Hybrid Propulsion Responsible Parties 1, 2, 4, 5, 6, 8, 9, 12, 16, 18, 19, 20, 21, 22 Target Parties 1, 2, 4, 6, 7 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all local traveled medium-duty trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 3.4% (24.5 ×10 6 tons of CO 2 eq.) and 3.5% (300 ×10 12 Btu), respectively. Developmental Status N Practice Summary Hybrid propulsion systems recover or recycle energy for braking or deceleration to reduce truck fuel use. They help to shut off the engine under idling conditions within stop-and-go driving. Emissions, Energy Use, and Refrigerant Use Unit Value

Annual Transport Activity for the Mode (ATAM) 10 9 ton-miles/year 2,098 Annual Transport Activity to Which a Practice Is Applicable (ATAP) 10 9 ton-miles/year 373 Annual GHG Emissions Reductions(AGR) 10 6 ton CO 2 eq./year 24.5 Annual Energy Use Reduction (AER) 10 12 BTU /year 300 Annual Refrigerant Use Reduction (ARR) lbs/year N/A Unit GHG Emissions Reductions (UGER) 10 -3 lb CO 2 eq./ton-mile 130 Unit Energy Use Reduction (UER) BTU /ton-mile 804 Unit Refrigerant Use Reduction (URR) lbs/ton-mile N/A Practice Costs

Capital Cost I 10 6 USD ($) 9,210 Discount Rate I % 10% Technical Lifetime of Technology (L) years 15 Fixed Charge Factor (a) year -1 0.131 Annual O & M Cost (AOM) $10 6 /year 1,220 Annualized Cost (AC) $10 6 /year 2,430 Annual Energy Cost Saving (AECS) $10 6 /year 5,620 Annual Refrigerant Cost Saving (ARCS) $10 6 /year N/A Net Savings (NS) $10 6 /year 3,190 Net Savings per Unit of GHG Emissions Reductions (NSGR) $/ton CO 2 eq. 130 Net Savings per Unit of Energy Use Reduction (NSER) $/10 6 BTU 10.6 Net Savings per Unit of Refrigerant Use Reduction (NSRR) $/lb N/A Simple Payback Period (SPP) years 2.1

a These assessments are based on the assumptions th at these best practices reach their potential

maximum market shares in 2025.171 

### D. Estimate of annual GHG emissions reductions:
(a) Assumption: i. Total GHG emissions reductions are due to energy use.
ii. Approximately 47% of total tr avel distance for medium-duty
trucks is within local area. 49



### iii. Hybrid medium-duty trucks traveled locally are estimated to increase fuel economy by 71%, 49 

### which is equal to reduce energy use by 41.5%.
(b) Calculation: i. Adopting hybrid medium-duty trucks for local area purpose is estimated to reduce energy use for medium-duty trucks by
19.5%. 

## ( ) % 5

. 19 % 47 % 5

. 41 = ×


### ii. Since the ratio of energy use fo r medium-duty trucks to energy use for all trucks is 17.8%, adopting hybrid medium-duty trucks for local area use is estimated to reduce energy use for the whole truck mode by 3.49%. 

## ( ) %. 49

. 3 % 8

. 17 % 5

. 19 = ×



### iii. Total energy use reduction in 2003 is estimated to be 1.82×10 8 

### (10 6 

### BTU) per year. 

# ( )

. BTU 10 82

. 1 BTU 10 21

. 5 % 49

. 3 14 15 × = × ×



### iv. Since the truck mode is estimat ed to grow by 67% from 2003 to 2025, 4 

### the estimated annual energy use reduction in 2025 is
3.0×10 8 

### (10 6 

### BTU).

v. Total GHG emissions reductions due to fuel use reduction are
estimated to be 24.5×10 6 

### tons CO 2 

### eq. in 2025.

. eq CO tons 10 5

. 24 BTU 10 . eq CO tons 0808

. 0 BTU 10 0

. 3 2 6
6 2 14 × =        

× ×172 

### (c) Results: The annual GHG emissions reductions are estimated to be
24.5×10 6 

### tons CO 2 

### eq. in 2025.

E. Estimate of annual energy use reduction:
The estimated annual energy use reduction in 2025 is 300×10 12 

### BTU, estimated in Appendix A.21.D.

F. Estimate of unit GHG emissions reductions:

mile ton . eq CO lb 13

. 0

ton lbs 000
, 2

. miles ton 10 373 eq CO tons 10 5

. 24 2 9 2 6

− =        

×        

− × ×



### G. Estimate of unit energy use reduction: 

# ( )

mile ton BTU 6

. 803

. miles ton 10 373 BTU 10 10 0

. 3

9 6 8



### − =        

− × ×

H. Estimate of capital cost i. The estimated incremental capital cost for a hybrid truck is $3,100 in 2025. 49



### ii. Approximately 63% of medium -duty trucks are used locally. 49



### iii. Total incremental capital costs of medium-duty hybrid tr ucks in 2025 are estimated to be $9.21×10 9



### .

9 6 10 21

. 9 $ % 63 trucks 10 72

. 4 truck 100
, 3 $ × = × × ×



### I. Estimate of annual O & M cost 

### (a) Assumption: i. Battery cost is estimated to be 50% of incremental capital cost of a hybrid truck. 49



### ii. Lifetime of battery is estimated to be 5 years.173 

### iii. Discount rate is 10%.
(b) Calculation: i. Based on the estimated lifetime and discount rate, fixed charged
factor is estimated to be 0.264.
ii. Total annual cost for battery is estimated to be $1.22 ×10 9



### .

9 6 10 22

. 1 $ % 63 trucks 10 72

. 4 264

. 0 % 50 truck 100
, 3 $ × = × × × × ×



### (c) Results: The estimated annual O & M cost is estimated to be $1.22 ×10 9



### .

J. Estimate of annualized cost: (a) Assumption: i. The life-time of hybrid trucks is estimated to be 15 years.

ii. Discount rate is 10%.
(b) Calculation: i. Based on the estimated lifetime and discount rate, fixed charged
factor is estimated to be 0.131.

ii. 

# ( ) ( ) 9 9 9 10 43

. 2 $ 10 22

. 1 $ 131

. 0 10 21

. 9 $ × = × + × × 

### (c) Results: The estimated annualized cost is estimated to be $2.43 ×10 9



### .

K. Estimate of energy cost reduction: (a) Assumption: Diesel fuel price in 2025 is the same as the price of the second season of 2005, which is $2.56/gallon ( = $18.5/10 6 

### BTU). 114



### (b) Calculation: The estimated ener gy cost reduction in 2003 is $3.37 ×10 9



### . 

# ( ) 9
6 6 8 10 37

. 3 $ BTU 10 5

. 18 $ BTU 10 10 82

. 1 × = × ×



### (c) Results: Since total energy use for the truck mode is estimated to grow by 67% from 2003 to 2025, 4 

### the estimated energy cost reduction in 2025 is $5.62 ×10 9



### .

L. Estimate of net savings:

9 9 9 

### 10 19

. 3 $ 10 43

. 2 $ 10 62

. 5 $ × = ×

− ×174 

### M. Estimate of net savings per unit of GHG emissions reductions:

. eq CO ton 2

. 130 $

. eq CO tons 10 5

. 24 10 19

. 3 $

2 2 6 9

= × ×



### N. Estimate of net savings per unit of energy use reduction:

BTU 10 6

. 10 $
BTU 10 300 10 19

. 3 $

6 12 9

= × ×



### O. Estimate of simple payback period: 

# ( ) years 1

. 2 10 22

. 1 $ 10 62

. 5 $ 10 21

. 9 $

9 9 9

= ×

− × ×175 

### Appendix A.22 Best Practice 1-22: Lightweight Materials This best practice is assessed qualitativel y. Table A-22 summarizes the assessment results in the standardized simplif ied reporting table format.

Table A-22. Simplified Summary Table for Best Practice 1-22, Lightweight Materials Attribute Description

Practice Name Lightweight Materials Mode Type Truck Subgroup Weight Reduction Responsible Parties 1, 2, 5, 6, 7, 10, 16, 18, 19 Target Parties 1, 2, 6 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all trucks partic ipate. The reductions in modal GHG emissions and energy use in 2025 would be 4.62% and 4.76%, respectively. Developmental Status P Practice Summary Using high-strength, light-weight components, including aluminum, plastics, and others, reduces the weight of trucks that can significantly reduce fuel use and reduce GHG emissions. Potential Reductions in Modal GHG Emissions 4.62%

Potential Reduction in Modal Energy Use 4.76%

Potential Reduction in Modal HFC Use N/A

Cost Information The estimated incremental capital cost is $2,000. Benefits and Drawbacks Lightweight components can reduce truck fuel use, allow more cargo and increase productivity. However, current light-weight materials are costly and with no satisfied material characteristics. However, current light-weight materials are costly and with no satisfied material characteristics. Further researc h and development for advanced materials are needed.176 

### Appendix A.23 Best Practice 1-23: Advanced Transmission This best practice is assessed qualitativel y. Table A-23 summarizes the assessment results in the standardized simplif ied reporting table format.

Table A-23. Simplified Summary Table for Best Practice 1-23, Advanced Transmission Attribute Description

Practice Name Advanced Transmission Mode Type Truck Subgroup Transmission Improvement Responsible Parties 1, 2, 4, 5, 6, 9, 16, 18, 19 Target Parties 1, 2, 4, 6, 7 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all trucks partic ipate. The reductions in modal GHG emissions and energy use in 2025 would be 0.97% and 1.00%, respectively. Developmental Status P Practice Summary A continuously variable tr ansmission (CVT) has belt-connected pulleys that can optimize speed-load conditions and reduce fuel use. Mechanical losses in a transmission can be reduced by the reduction of gear surface roughness, the use of lo w-friction coatings, the use of new gear materials, and the use of the lock-up torque converter. Potential Reductions in Modal GHG Emissions 0.97%

Potential Reduction in Modal Energy Use 1.00%

Potential Reduction in Modal HFC Use N/A

Cost Information The estimated incremental capital cost is $1,000. Benefits and Drawbacks CVTs ha ve smoother operation and allow the engine speed to remain at the level of peak efficiency to reduce energy use and emissions. Driver training may be needed to avoid the confusion because the sound of the engine with traditional transmissions changes for acceleration operations but the sound of the engine with improved transmission does not change in the condition of acceleration.177 

### Appendix A.24 Best Practice 1-24: Tran smission Friction Reduction through Low-Viscosity Transmission Lubricants This best practice is assessed qualitativel y. Table A-24 summarizes the assessment results in the standardized simplif ied reporting table format.

Table A-24. Simplified Summary Table for Best Practice 1-24, Transmission Friction Reduction through Low-Viscosity Transmission Lubricants Attribute Description

Practice Name Transmission Friction Reduction through Low-Viscosity Transmission Lubricants Mode Type Truck Subgroup Transmission Improvement Responsible Parties 1, 2, 4, 5, 9, 15 Target Parties 1, 2, 4, 6, 7 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all trucks partic ipate. The reductions in modal GHG emissions and energy use in 2025 would be 0.92% and 0.95%, respectively. Developmental Status C Practice Summary Low-viscosity transmissi on fluids can be adopted to decrease transmission friction and also reduce fuel consumption. Potential Reductions in Modal GHG Emissions 0.92%

Potential Reduction in Modal Energy Use 0.95%

Potential Reduction in Modal HFC Use N/A

Cost Information The estimated incremental capital cost is $500. Benefits and Drawbacks Low-viscosity lubricants can reduce energy use, but it typically costs more than conventional lubricants.178 

### Appendix A.25 Best Practice 1-25: Engine Friction Reduction through Low-Viscosity Engine Lubricants This best practice is assessed qualitativel y. Table A-25 summarizes the assessment results in the standardized simplif ied reporting table format.

Table A-25. Simplified Summary Table for Be st Practice 1-25, Engine Friction Reduction through Low-Viscosity Engine Lubricants Attribute Description

Practice Name Engine Friction Reduction th rough Low-Viscosity Engine Lubricants Mode Type Truck Subgroup Diesel Engine Improvement Responsible Parties 1, 2, 4, 5, 9, 15 Target Parties 1, 2, 4, 6, 7 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all trucks partic ipate. The reductions in modal GHG emissions and energy use in 2025 would be 1.81% and 1.86%, respectively. Developmental Status C Practice Summary Low-viscosity engine lubrican ts are made from synthetic or mineral oil blends for the purpose of reducing internal engine friction. Potential Reductions in Modal GHG Emissions 1.81%

Potential Reduction in Modal Energy Use 1.86%

Potential Reduction in Modal HFC Use N/A

Cost Information The estimated incremental capital cost is $500. Benefits and Drawbacks Low-viscosity lubricants can reduce energy use, but it typically costs more than conventional lubricants.179 

### Appendix A.26 Best Practice 1-26: Increased Peak Cylinder Pressures This best practice is assessed qualitativel y. Table A-26 summarizes the assessment results in the standardized simp lified reporting table format.

Table A-26. Simplified Summary Table for Best Practice 1-26, Increased Peak Cylinder Pressures Attribute Description

Practice Name Increased Peak Cylinder Pressures Mode Type Truck Subgroup Diesel Engine Improvement Responsible Parties 1, 2, 4, 5, 6, 9 Target Parties 1, 2, 4, 6, 7 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all heavy-duty truc ks participate. The reductions in modal GHG emissions and energy use in 2025 would be 3.07% and 3.16%, respectively. Developmental Status C Practice Summary Diesel engine thermal efficien cy is proportion to the peak pressures that can be achieved in the engine cylinde rs. However, the peak cylinder pressures are constrained by the strength and durability of the engine materials over the design service life of the engine. Measures that result in better materials that enable higher peak pressures can lead to higher engine efficiency. Potential Reductions in Modal GHG Emissions 3.07%

Potential Reduction in Modal Energy Use 3.16%

Potential Reduction in Modal HFC Use N/A

Cost Information The estimated incremental capital cost is $1,000. Benefits and Drawbacks They can withstand higher peak cylinder pressures and increase thermal efficiency.180 

### Appendix A.27 Best Practice 1-27: Improved Fuel Injectors This best practice is assessed qualitativel y. Table A-27 summarizes the assessment results in the standardized simp lified reporting table format.

Table A-27. Simplified Summary Table for Best Practice 1-27, Improved Fuel Injectors Attribute Description

Practice Name Improved Fuel Injectors Mode Type Truck Subgroup Diesel Engine Improvement Responsible Parties 1, 2, 4, 5, 6, 9 Target Parties 1, 2, 4, 6, 7 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all trucks partic ipate. The reductions in modal GHG emissions and energy use in 2025 would be 5.49% and 5.66%, respectively. Developmental Status P Practice Summary Incorrect fuel injection causes a reduction of combustion efficiency and an increase of emissions. The improvement of fuel injection via better control is expected to reduce truck fuel use. For example, advanced fuel injection systems, such as electronic unit injectors or common rail injectors with increased fuel injection pressure, are estimate to result in better control of the fuel injection rate and injection timing, and to produce finer vaporization of the fuel spray. Potential Reductions in Modal GHG Emissions 5.49%

Potential Reduction in Modal Energy Use 5.66%

Potential Reduction in Modal HFC Use N/A

Cost Information The estimated incremental capital cost is $1,500. Benefits and Drawbacks These systems have better control of the fuel injection rate, injection timing, and finer fuel spray. However, a drawback of higher injection pressures is the need to have stronger fuel-injection system and other engine components that withstand the higher pressures. The improved high pressure injectors may have leakage problem after a period of operation time. Regular diagnosis is needed to identify and address this problem.181 

### Appendix A.28 Best Practice 1-28: Turboc harged, Direct Injection to Improved Thermal Management This best practice is assessed qualitativel y. Table A-28 summarizes the assessment results in the standardized simplif ied reporting table format.

Table A-28. Simplified Summary Table for Best Practice 1-28, Turbocharg ed, Direct Injection to Improved Thermal Management Attribute Description

Practice Name Turbocharged, Direct Inj ection to Improved Thermal Management Mode Type Truck Subgroup Diesel Engine Improvement Responsible Parties 1, 2, 4, 5, 6, 9 Target Parties 1, 2, 4, 6, 7 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all medium-duty truc ks participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.82% and 0.85%, respectively. Developmental Status C Practice Summary Turbocharger is a turbine that is driven by the exhaust air flow form the engine and increase air intake. Adva nced turbochargers that drive more air into the cylinder increase combustion efficiency and allow direct injectors to inject more fuel into cylinders. Potential Reductions in Modal GHG Emissions 0.82%

Potential Reduction in Modal Energy Use 0.85%

Potential Reduction in Modal HFC Use N/A

Cost Information The estimated incr emental capital cost is $700-1,000. Benefits and Drawbacks The combination of turboc harger and direct injector allow for precise control of the fuel/air mixture which produce more power and higher fuel efficiency.182 

### Appendix A.29 Best Practice 1-29: Thermoe lectric Technology to Recovery Waste
Heat This best practice is assessed qualitativel y. Table A-29 summarizes the assessment results in the standardized simp lified reporting table format.

Table A-29. Simplified Summary Table for Be st Practice 1-29, Thermoelectric Technology to Recovery Waste Heat Attribute Description

Practice Name Thermoelectric Technology to Recovery Waste Heat Mode Type Truck Subgroup Diesel Engine Improvement Responsible Parties 1, 2, 4, 5, 6, 9 Target Parties 1, 2, 4, 6, 7 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all heavy-duty truc ks participate. The reductions in modal GHG emissions and energy use in 2025 would be 5.22% and 5.38%, respectively. Developmental Status N Practice Summary Overall engine thermal efficiency can be increased if new materials and technologies can be developed and implement for improved thermal management. An example is the conversion of engine waste heat to electrical energy. Such systems are not commercially available and are undergoing development. Combining thermoelectric materials and advanced heat exchangers may recove r waste heat in order to produce electricity. Potential Reductions in Modal GHG Emissions 5.22%

Potential Reduction in Modal Energy Use 5.38%

Potential Reduction in Modal HFC Use N/A

Cost Information The estimated incremental capital cost is $2,000. Benefits and Drawbacks Thermoelectric convert er technology needs further research and development (R & D) to increase its currently low conversion efficiency. The estimates reported here presume that such R & D will be successful.183 

### Appendix A.30 Best Practice 1-30: Electric Auxiliaries This best practice is assessed qualitativel y. Table A-30 summarizes the assessment results in the standardized simp lified reporting table format.

Table A-30. Simplified Summary Table for Best Practice 1-30, El ectric Auxiliaries Attribute Description

Practice Name Electric Auxiliaries Mode Type Truck Subgroup Accessory Load Reduction Responsible Parties 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12 Target Parties 1, 2, 3, 4, 6, 7 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all trucks partic ipate. The reductions in modal GHG emissions and energy use in 2025 would be 1.43% and 1.48%, respectively. Developmental Status C Practice Summary Most mechanical auxiliaries operate whenever truck base engines are running, which waste energy when th e auxiliaries are not needed. The replacement of gear- or belt-driven auxiliaries by electrically driven systems can decouple mechanical loads from the base engine and reduce energy use. An electric truck can use a generator to produce electricity as power source for electric auxiliaries. Potential Reductions in Modal GHG Emissions 1.43%

Potential Reduction in Modal Energy Use 1.48%

Potential Reduction in Modal HFC Use N/A

Cost Information The estimated incremental capital cost is $500. Benefits and Drawbacks More electric trucks can reduce fuel use rate and reduce GHG emissions. The smaller generator for this practice may need pollution control devices in order to comply with future emissions standards.184 

### Appendix A.31 Best Practice 1-31: Fuel-Cell-Operated Auxiliaries This best practice is assessed qualitativel y. Table A-31 summarizes the assessment results in the standardized simp lified reporting table format.

Table A-31. Simplified Summary Table for Best Practice 1-31, Fuel-Cell- Operated Auxiliaries Attribute Description

Practice Name Fuel-Cell-Operated Auxiliaries Mode Type Truck Subgroup Accessory Load Reduction Responsible Parties 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12 Target Parties 1, 2, 3, 4, 6, 7 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all trucks partic ipate. The reductions in modal GHG emissions and energy use in 2025 would be 5.49% and 5.66%, respectively. Developmental Status N Practice Summary Fuel cells are an emerging technology for converting chemical energy in a fuel directly to electricity. The advantage of fuel cells over conventional engine and alternator technology is that they have substantially higher thermal efficiency. Among the barriers to practical use of fuel cells are the cost of preci ous materials used for their internal components and the need for conversion of readily available transportation fuels to a form that can be processed by the fuel cell. The use of fuel cells coupled with electrically operated auxiliaries could be available in the market by 2012. Potential Reductions in Modal GHG Emissions 5.49%

Potential Reduction in Modal Energy Use 5.66%

Potential Reduction in Modal HFC Use N/A

Cost Information The estimated incremental capital cost is $1,500. Benefits and Drawbacks This practice has high th ermal efficiency, but further R & D is needed in order to reduce cost.185 

### Appendix A.32 Best Practice 1-32: Truck Driver Training Program This best practice is assessed qualitativel y. Table A-32 summarizes the assessment results in the standardized simp lified reporting table format.

Table A-32. Simplified Summary Table for Best Practice 1-32, Truck Driver Training Program Attribute Description

Practice Name Truck Driver Training Program Mode Type Truck Subgroup Modifications in Driver Operational Practice Responsible Parties 1, 2, 5 Target Parties 1, 2, 5, 6 Target GHGs CO 2 Strategy Type Operation

Practice Goals Goal is to have all trucks partic ipate. The reductions in modal GHG emissions and energy use in 2025 would be 3.10% and 3.19%, respectively. Developmental Status C Practice Summary The behavior of truck driver s can significantly impact fuel efficiency. Drivers can be encouraged to modify behaviors that unnecessarily increase fuel use via training programs that aim to convey better skills and habits. Furthermore, driver performance can be monitored and incentives can be provided to reward preferred behaviors. Potential Reductions in Modal GHG Emissions 3.10%

Potential Reduction in Modal Energy Use 3.19%

Potential Reduction in Modal HFC Use N/A

Cost Information N/A Benefits and Drawbacks Driver training can reduce fuel consumption significantly.186 

### Appendix A.33 Best Practice 1-33: B20 Biodiesel Fuel for Trucks This best practice is assessed quantitatively. Table A-33 summarizes the assessment results. This table is in the format of the standardized reporting table for quantitative results. The basis of the quantitative estimates is explained.

A. Estimate of total number of vehicles or devices:
(a) 2003 Results: It is estimated that there were 7.9 million trucks in 2003. 3



### (b) 2025 Results: Since total truck number is estimated to grow by 67% from 2003 to 2025, which is explained in Appe ndix A.1.A, there will be 13.2
million trucks in 2025.

B. Estimate of annual trans port activity for the mode:
Annual transport ac tivity for the mode is explained in Appendix A.1.B.

C. Estimate of annual transport activity to which a practi ce is applicable:
Annual transport activ ity to which this practice is appli cable is the same as the transport activity for the whole mode, which is explained in Appendix A.1.B.

D. Estimate of annual GHG emissions reductions:
(a) Assumption: i. The net life-cycle CO 2 

### emissions reduction of B20 biodiesel is
about 0.0069 tons CO 2 

### eq. per 10 6 

### BTU, which is estimated in Appendix F.2.3. 61



### ii. Biodiesel industry was estimated that it has the potential to produce 1.7 billion gallo ns of B100 biodiesel in 2003, 3.5 billion gallons of B100 biodiesel in 2015, and 10 billion gallons of
B100 biodiesel in 2030. 63,64 

### Thus, the estimated production of B100 biodiesel in 2025 is 7.8 billion gallons.187 

### Table A-33. Standardized Reporting Table fo r Best Practice 1-33, B20 Biodiesel Fuel for Trucks a Characteristics of the Practice Description

Practice Name B20 Biodiesel Fuel for Trucks Mode Type Truck Subgroup Alternative Fuels Responsible Parties 1, 2, 4, 5, 6, 12, 14, 16, 18, 19, 20, 21, 22 Target Parties 1, 2, 4, 5, 6, 7 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all trucks participate. The reductions in modal GHG emissions and energy use in 2025 would 4.27% (30.8 ×10 6 tons of CO 2 eq.) and -4.25% (-370 ×10 12 Btu), respectively. Developmental Status C Practice Summary The life-cycle CO 2 emissions coefficient of B20 biodiesel decreases by 0.0069 tons CO 2 eq. per 10 6 BTU compared to that of petroleum diesel. Emissions, Energy Use, and Refrigerant Use Unit Value

Annual Transport Activity for the Mode (ATAM) 10 9 ton-miles/year 2,098 Annual Transport Activity to Which a Practice Is Applicable (ATAP) 10 9 ton-miles/year 2,098 Annual GHG Emissions Reductions(AGR) 10 6 ton CO 2 eq./year 30.8 Annual Energy Use Reduction (AER) 10 12 BTU /year -370 Annual Refrigerant Use Reduction (ARR) lbs/year N/A Unit GHG Emissions Reductions (UGER) 10 -3 lb CO 2 eq./ton-mile 29 Unit Energy Use Reduction (UER) BTU /ton-mile -176 Unit Refrigerant Use Reduction (URR) lbs/ton-mile N/A Practice Costs

Capital Cost I 10 6 USD ($) N/A Discount Rate I % 10% Technical Lifetime of Technology (L) years N/A Fixed Charge Factor (a) year -1 N/A Annual O & M Cost (AOM) $10 6 /year N/A Annualized Cost (AC) $10 6 /year 3,340 Annual Energy Cost Saving (AECS) $10 6 /year 0 Annual Refrigerant Cost Saving (ARCS) $10 6 /year N/A Net Savings (NS) $10 6 /year -3,340 Net Savings per Unit of GHG Emissions Reductions (NSGR) $/ton CO 2 eq. -108 Net Savings per Unit of Energy Use Reduction (NSER) $/10 6 BTU N/A b Net Savings per Unit of Refrigerant Use Reduction (NSRR) $/lb N/A Simple Payback Period (SPP) years N/A c

a These assessments are based on the assumptions th at these best practices reach their potential maximum market shares in 2025. b This practice has no energy use reduction due to an increase in energy use, and it has no net saving due to high annualized cost and no energy cost saving.188 c There is no pay-back period for this best practice because there is no net saving



### .

iii. The estimated heating value of B100 biodiesel is 126,789 BTU/gallon, and the estimated heati ng value of petroleum diesel is 138,690 BTU/gallon. 131-132 

### Thus, the estimated heating value of B20 biodiesel is 136,310 BTU/gallon.

iv. The truck mode consumed 4.6×10 15 

### BTU of diesel fuel in
2003. 2,3 

### The rail mode consumed 0.531×10 15 

### BTU diesel in
2003. 3 

### The water mode consumed 0.385×10 15 

### BTU distillate fuel
oil in 2003. 1,3



### v. The potential market share of B20 biodiesel for the truck mode is estimated to be 51.2% in 2025 based on the potential maximum production capacity of biodiesel, wh ich is estimated as 7.8 billion gallons in 2025, and the distribu tion ratio among the truck, rail and
water modes.
(b) Calculation: i. Energy use for the truck mode in 2025 is estimated to be
8.7×10 15 

### BTU.
ii. Maximum B20 biodiesel product ion capacity for the truck mode
in 2003 is estimated to be 0.97×10 15 

### BTU.
iii. Maximum B20 biodiesel production capacity for the truck
mode in 2025 is estimated to be 4.45×10 15 

### BTU.

BTU 10 45

. 4 % 2

. 51 BTU 10 7

. 8 15 15 × = × ×



### iii. The annual GHG emissions reduc tions are estimated to be
30.8×10 6 

### tons CO 2 

### eq. in 2025.



### . eq CO tons 10 8

. 30 BTU 10 . eq CO 0069

. 0 BTU 10 45

. 4 2 6
6 2 15 

### × = × ×

(c) Results: The annual GHG emissions reductions are estimated to be
30.8×10 6 

### tons CO 2 

### eq. in 2025.189 

### E. Estimate of annual energy use reduction:
i.. Energy use reduction based on life cycl e inventory is estimated to be -8.3%. 61



### ii. Energy use reduction based on life cycle inventory in 2025 is estimated to be -3.7×10 14



### BTU

BTU 10 7

. 3 BTU 10 45

. 4 %. 3

. 8 14 15 ×

− = × ×

−



### F. Estimate of unit GHG emissions reductions:

mile ton . eq CO lb 029

. 0

ton lbs 000
, 2

. miles ton 10 2097 eq CO tons 10 8

. 30 2 9 2 6

− =        

×        

− × ×



### G. Estimate of unit energy use reduction: 

# ( )

mile ton BTU 4

. 176

. miles ton 10 2097 BTU 10 10 7

. 3

9 6 8

− −
=        

− × ×

−



### H. Estimate of capital cost (Not available)

I. Estimate of annual O & M cost 

### (Not available)

J. Estimate of annualized cost: i. The average fuel cost of B100 Biodiese l in April 2005 is estimated to be $22.2 per 10 6



### BTU. 137



### ii. Diesel fuel price in 2025 is the same as the price of the second season of 2005, which is $18.5/10 6 

### BTU. 114



### iii. Thus, B20 biodiesel fuel price is estimated to be $19.21/10 6 

### BTU, which is $0.75/10 6 

### BTU higher than the price of diesel fuel.

iv. Annualized cost is estimated to be $3.34 ×10 9



### .190 9 15
6 10 34

. 3 $ BTU 10 45

. 4 BTU 10 75

. 0 $
× = × ×



### K. Estimate of energy cost reduction: (No energy cost reduction)

L. Estimate of net savings:

9 9 

### 10 34

. 3 $ 10 34

. 3 $ 0 $ ×

− = ×

−

M. Estimate of net savings per unit of GHG emissions reductions:

. eq CO ton 4

. 108 $

. eq CO tons 10 8

. 30 10 34

. 3 $

2 2 6 9

−

= × ×

−



### N. Estimate of net savings per unit of energy use reduction: (Not available: This practice has no en ergy use reduction due to an increase in energy use, and it has no net saving due to high a nnualized cost and no energy cost saving).

O. Estimate of simple payback period: (Not available: there is no pay-back peri od for this practice because there is no net saving).191 

### APPENDIX B. DETAILS OF INPUT DATA, ASSUMPTIONS, AND ESTIMATION
RESULTS FOR RAIL MODE BEST PRACTICES

This appendix is additional descriptive information for the best practices in Chapter 5, including the standardized reporting tables, if th eir corresponding best practices can be assessed quantitatively, or the simplified summary tabl es, if their correspondi ng best practices are assessed qualitatively. For those assessed quantit atively, the methods for the estimation of data in the standardized reporting tables are also described.

Appendix B.1 Best Practice 2-1: Combined Diesel Powered Heating System and Auto Engine Start/Stop System This best practice is assessed quantitativel y. Table B-1 summarizes the assessment results. This table is in the format of the standardized reporting table for quantitative results. The basis of the quantitative estimates is explained.

A. Estimate of total number of vehicles or devices:
(a) Assumption: Annual per-locomotive energy use in 2025 is the same as annual per-locomotive energy use in 2003.
(b) Calculation: i. It is estimated that there were 20,774 Class I locomotives in
2003. 3



### ii. Since per-locomotive energy use is the same and modal energy

use is estimated to grow by 49% from 2003 to 2025, 4 

### locomotive number increases by 49% from 2003 to 2025.

965
, 30 %) 49 1 ( 774
, 20 = + ×


### (c) Results: There will be 30,965 Class I locomotives in 2025.

B. Estimate of annual trans port activity for the mode:
(a) Assumption: The growth rate of total tran sport activity is the same as the growth rate of energy use for the rail mode.
(b) 2003 Results: It is estima ted that there were 1,551 ×10 9 

### ton-miles in 2003. 3192 

### Table B-1. Standardized Reporting Table for Best Practice 2-1, Combined Diesel Powered Heating System and Auto Engine Start/Stop System a
Characteristics of the Practice Description

Practice Name Combined Diesel Powered Heating System and Auto Engine Start/Stop System Mode Type Rail Subgroup Anti-idling Responsible Parties 26, 27, 28, 35, 36, 37 Target Parties 11, 13 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all long-haul and switching locomotives participate. The reductions in modal GHG emissions and energy use in 2025 would both be 3.62% (2.32 ×10 6 tons of CO 2 eq. and 28.7 ×10 12 Btu, respectively). Developmental Status P Practice Summary Diesel powered heating systems keep the engine block temperature above 100 o F. Such systems utilize waste heat from a small diesel engine to heat the main engine and to generate electricity using by an alternator. An auto engine start/stop system can shutdown and restart both long-haul and switching locomotive engines automatically, based on a preprogrammed set of values. Both of these systems can be used simultaneously to shut down the engine when not needed while also keep the engine warm in preparation for a restart and while maintaining batteries in a ready status. Emissions, Energy Use, and Refrigerant Use Unit Value

Annual Transport Activity for the Mode (ATAM) 10 9 ton-miles/year 2,312 Annual Transport Activity to Which a Practice Is Applicable (ATAP) 10 9 ton-miles/year 2,312 Annual GHG Emissions Reductions(AGR) 10 6 ton CO 2 eq./year 2.32 Annual Energy Use Reduction (AER) 10 12 BTU /year 28.7 Annual Refrigerant Use Reduction (ARR) lbs/year N/A Unit GHG Emissions Reductions (UGER) 10 -3 lb CO 2 eq./ton-mile 2.0 Unit Energy Use Reduction (UER) BTU /ton-mile 12.4 Unit Refrigerant Use Reduction (URR) lbs/ton-mile N/A Practice Costs

Capital Cost (C) 10 6 USD ($) 1,100 Discount Rate (r) % 10% Technical Lifetime of Technology (L) years 15 Fixed Charge Factor (a) year -1 0.131193 Annual O & M Cost (AOM) $10 6 /year N/A Annualized Cost (AC) $10 6 /year 144.0 Annual Energy Cost Saving (AECS) $10 6 /year 531.4 Annual Refrigerant Cost Saving (ARCS) $10 6 /year N/A Net Savings (NS) $10 6 /year 387.4 Net Savings per Unit of GHG Emissions Reductions (NSGR) $/ton CO 2 eq. 167 Net Savings per Unit of Energy Use Reduction (NSER) $/10 6 BTU 13.5 Net Savings per Unit of Refrigerant Use Reduction (NSRR) $/lb N/A Simple Payback Period (SPP) years 2.1

a These assessments are based on the assumptions th at these best practices reach their potential maximum market shares in 2025.



### (c) 2025 Results: Since total energy use for the rail mode is estimated to grow by 49% from 2003 to 2025, 4 

### there will be 2,312 ×10 9 

### ton-miles in
2025.

C. Estimate of annual transport activity to which a practi ce is applicable:
Annual transport activ ity to which this practice is appl icable is the same as the total ton-miles of this mode, which is explained in Appendix B.1.B.

D. Estimate of annual GHG emissions reductions:

(a) Assumption: i. Total GHG emissions reduc tions are due to energy use reduction.
ii. Long-haul Class I locomotives work 330 days per year and 55%
of time is at idle. 67 

### Switchers work 330 days per year 72 

### and
75% of time of switchers is at idle. 67 

### 55% of idle time is used for all locomotive for the estimation in order to simplify the
calculation.

iii. Idle fuel use for a Class I loco motive is estimated to be 3 gallon per hour. 138



### iv. This best practice is applicab le to both long-haul locomotives
and switchers.
ix. This practice can reduce idle ti me by 64% if 55% of time is at idle, 68 

### and reduce fuel use at idle by 80%. 67194 

### (b) Calculation: i. Class I locomotives cons ume fuel at idle in 2025 is estimated to
be 5.61×10 13 

### BTU.



### BTU 10 61

. 5 gallon BTU 138690 % 55 days 330 hrs 24 hr gallon 3 30965

13 

### × =        

× × × × ×

ii. Energy use reduction for adop ting this pract ice in 2025 is
estimated to be 2.87×10 13 

### BTU.

BTU 10 87

. 2 % 80 % 64 BTU 10 61

. 5 13 13 × = × × ×



### iii. Total GHG emissions reductions in 2025 due to fuel use
reduction are estimated to be 2.32×10 6 

### tons CO 2 

### eq.

. eq CO tons 10 32

. 2 BTU 10 . eq CO tons 0808

. 0 BTU 10 87

. 2 2 6
6 2 13 × =        

× ×



### (c) Results: The annual GHG emissions reductions are estimated to be 2.32×10 6



### tons CO 2 

### eq. in 2025.

E. Estimate of annual energy use reduction:
The estimated annual energy us e reduction in 2025 is 2.87×10 7 

### (10 6 

### BTU), which is estimated in Appendix B.1.D.

F. Estimate of unit GHG emissions reductions:

mile ton . eq CO lb 002

. 0

ton lbs 000
, 2

. miles ton 10 2312 eq CO tons 10 32

. 2 2 9 2 6

− =        

×        

− × ×



### G. Estimate of unit energy use reduction: 

# ( )

mile ton BTU 4

. 12

. miles ton 10 2312 BTU 10 10 87

. 2

9 6 7

− =        

− × ×195 

### H. Estimate of capital cost The estimated capital cost for th is practice is $35,500 per locomotive. 68 

### Total capital costs for all locomotives in 2025 is estimated to be $1.1 ×10 9



### .

9 9 10 1

. 1 $ 10 1

. 1 $ s locomotive 965
, 30 truck 500
, 35 $ × = × = ×



### I. Estimate of annual O & M cost 

### (Not available)

J. Estimate of annualized cost: i. The life-time of this practice is estimated to be 15 years.
ii. Fixed charge factor is estimated to be 0.131. 

## ( )
( ) 131

. 0

1

. 0 1 1

1 a factor e arg ch Fixed

15

1 i i =                

+ = 

## ∑

=


### iii. Annualized cost is estimated to be $144.0 ×10 6



### . 

# ( ) 6 9 10 0

. 144 $ 131

. 0 10 12

. 1 $ × = × ×



### K. Estimate of energy cost reduction: (a) Assumption: Diesel fuel price in 2025 is the same as the price of the second season of 2005, which is $2.56/gallon ( = $18.5/10 6 

### BTU). 114



### (b) Calculation: The estimated ener gy cost reduction in 2025 is $531.4 ×10 6



### . 

# ( ) 6
6 6 7 10 4

. 531 $ BTU 10 5

. 18 $ BTU 10 10 87

. 2 × = × × ×



### (c) Results: The estimated energy cost reduction in 2025 is $531.4 ×10 6



### .

L. Estimate of net savings:

6 6 6 

### 10 4

. 387 $ 10 0

. 144 $ 10 4

. 531 $ × = ×

− ×

M. Estimate of net savings per unit of GHG emissions reductions:196 . eq CO ton 0

. 167 $

. eq CO tons 10 32

. 2 10 387

. 0 $

2 2 6 9

= × ×



### N. Estimate of net savings per unit of energy use reduction:

BTU 10 5

. 13 $
BTU 10 7

. 28 10 387

. 0 $

6 12 9

= × ×



### O. Estimate of simple payback period: 

# ( ) years 1

. 2 10 531

. 0 $ 10 1

. 1 $

9 9

= × ×197 

### Appendix B.2 Best Practice 2-2: Battery -Diesel Hybrid Switching Locomotive This best practice is assessed quantitativel y. Table B-2 summarizes the assessment results. This table is in the format of the standardized reporting table for quantitative results. The basis of the quantitative estimates is explained.

A. Estimate of total number of vehicles or devices:
(a) Assumptions: i. Assuming that the na tional ratio of yard switchers to total locomotives is the same as the ratio for Union Pacific (UP), the largest railroad company in th e U.S., approximately 71% of locomotives are long-haul. 125



### ii. The remainder (29% of locomotives) are switchers.
iii. The growth rate of total switcher number is the same as the growth rate of total locomotive number for the rail mode.
(b) Calculations: i. It is estimated that there were 20,774 Class I locomotives in
2003. 3



### ii. It is estimated that there were 6,000 switching locomotives in
2003.



### ( ) 000
, 6 % 29 774
, 20 = ×



### (c) Results Since total locomotive number for this mode is estimated to grow by 49% from 2003 to 2025, which is explained in Appendix B.1.A, there will be 8,860 switchers in 2025.

B. Estimate of annual trans port activity for the mode:
Annual transport activity fo r the rail mode is expl ained in Appendix B.1.B.

C. Estimate of annual transport activity to which a practi ce is applicable:
Annual transport activ ity to which this practice is appl icable is the same as the total ton-miles of this mode, which is explained in Appendix B.1.C.198 

### Table B-2. Standardized Reporting Table for Best Practice 2-2, Battery-Diesel Hybrid Switching Locomotive a
Characteristics of the Practice Description

Practice Name Battery-Diesel Hybrid Switching Locomotive Mode Type Rail Subgroup Anti-Idling Responsible Parties 26, 27 Target Parties 11 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all switching locomotives participate. The reductions in modal GHG emissions and energy use in 2025 would both be 1.75% (1.12 ×10 6 tons of CO 2 eq. and 13.8 ×10 12 Btu, respectively). Developmental Status C Practice Summary Battery-diesel hybrid switchers are commercially available locomotives that can replace traditional switching locomotives. Traditional switchers typically have 2,000 hp diesel engines. Battery-diesel hybrid switchers include a small diesel engine (e.g., 125 to 300 hp) and large (60,000 lbs) lead-acid batteries. This small diesel engine is used to charge batteries that maintain batteries in a ready status during periods of locomotive non-use. At full load, the batteries account for 95% of the horsepower and the small diesel engine accounts for another 5%. This hybrid switcher also has an auto start/stop system that contains a microprocessor to automatically shut down the small diesel engine during periods of locomotive non-use or when the batteries are fully charged based on battery voltage values. Emissions, Energy Use, and Refrigerant Use Unit Value

Annual Transport Activity for the Mode (ATAM) 10 9 ton-miles/year 2,312 Annual Transport Activity to Which a Practice Is Applicable (ATAP) 10 9 ton-miles/year 2,312 Annual GHG Emissions Reductions(AGR) 10 6 ton CO 2 eq./year 1.12 Annual Energy Use Reduction (AER) 10 12 BTU /year 13.8 Annual Refrigerant Use Reduction (ARR) lbs/year N/A Unit GHG Emissions Reductions (UGER) 10 -3 lb CO 2 eq./ton-mile 1.0 Unit Energy Use Reduction (UER) BTU /ton-mile 6.0 Unit Refrigerant Use Reduction (URR) lbs/ton-mile N/A Practice Costs199 Capital Cost (C) 10 6 USD ($) 1401.4 Discount Rate (r) % 10% Technical Lifetime of Technology (L) years 15 Fixed Charge Factor (a) year -1 0.131 Annual O & M Cost (AOM) $10 6 /year N/A Annualized Cost (AC) $10 6 /year 183.6 Annual Energy Cost Saving (AECS) $10 6 /year 255.8 Annual Refrigerant Cost Saving (ARCS) $10 6 /year N/A Net Savings (NS) $10 6 /year 72.2 Net Savings per Unit of GHG Emissions Reductions (NSGR) $/ton CO 2 eq. 64.5 Net Savings per Unit of Energy Use Reduction (NSER) $/10 6 BTU 5.2 Net Savings per Unit of Refrigerant Use Reduction (NSRR) $/lb N/A Simple Payback Period (SPP) years 5.5

a These assessments are based on the assumptions th at these best practices reach their potential

maximum market shares in 2025.



### D. Estimate of annual GHG emissions reductions:

(a) Assumption: i. Total GHG emissions reduc tions are due to energy use reduction.
ii. Switchers work 330 days per year 72 

### and 75% of time of switchers
is at idle. 67



### iii. Assuming that the national ratio of yard switchers to total locomotives is the same as the ratio for Union Pacific (UP), the largest railroad company in th e U.S., approximately 71% of locomotives are long-haul. 125 

### The remainder are switchers.
iv. This practice is applicable to switchers only.
v. Assuming that the national ra tio of yard switchers to total
locomotives is the same as the ra tio for Union Pacific (UP), it is
estimated that switchers account for only 5% of total locomotive
fuel use. 117



### vi. Total fuel use for this mode in 2003 is 3.826 × 10 9 

### gallons. 3



### vii. This practice can reduce energy use for switchers by 35%. 71



### viii. Total GHG emissions for the rail mode is estimated to grow by 49% from 2003 to 2025, which is explained in Section 1.2.
(b) Calculation: i. Energy use for switche rs in 2025 is estimated to be 3.95×10 13200 

### BTU.



## ( ) BTU 10 95

. 3 % 49 1 % 5 gallon BTU 138690 10 826

. 3 13 9 

### × =        
+ × × × ×

ii. Energy use reduction in 2025 for adopting this practice is
estimated to be 1.38×10 13 

### BTU.



### BTU 10 38

. 1 % 35 BTU 10 95

. 3 13 13 

### × = × ×

iii. Total GHG emissions reductions due to energy use reduction are
estimated to be 1.12×10 6 

### tons CO 2 

### eq. in 2025.

. eq CO tons 10 12

. 1 BTU 10 . eq CO tons 0808

. 0 BTU 10 38

. 1 2 6
6 2 13 × =        

× ×



### (c) Results: The annual GHG emissions reductions are estimated to be 1.12×10 6



### tons CO 2 

### eq. in 2025.

E. Estimate of annual energy use reduction:
The estimated annual energy use reduction in 2025 is 1.38×10 7 

### (10 6 

### BTU) while it is estimated in Appendix B.2.D.

F. Estimate of unit GHG emissions reductions:

mile ton . eq CO lb 001

. 0

ton lbs 000
, 2

. miles ton 10 2312 eq CO tons 10 12

. 1 2 9 2 6

− =        

×        

− × ×



### G. Estimate of unit energy use reduction: 

# ( )

mile ton BTU 0

. 6
miles ton 10 2312 BTU 10 10 38

. 1

9 6 7

− =        

− × ×



### H. Estimate of capital cost201 

### (a) Assumptions: i. A switcher consumes 348 gallons of fuel per day. 72



### ii. A switcher works 330 days per day. 72



### iii. The working loads of switchers are 50%. 72



### iv. Only a fraction of switchers are in use.
v. The capital cost of a battery-diesel hybrid switcher is estimated to be $283,000. 71



### (b) Calculations: i. Energy use for switc hers in 2025 is estimated to be 3.95×10 13 

### BTU, which is estimated in Appendix B.2.D.

ii. It is estimated that there were 4,950 switching locomotives in
use in 2025. 

# ( ) 950
, 4

gallon BTU 138690 % 50 days 330 gallons 348 BTU 10 95

. 3 13



### =        

× × × ×

iii. For this estimation, 4,950 is the number of switchers used for estimating total capital cost b ecause the switchers that are considered to be replaced by hybr id switchers are the switchers in use, not total switchers (total switchers are estimated to be 8,860, which is estimated in Appendix B.2.A.).
iv. Total capital cost in 2025 is estimated to be $1.401 × 10 9



### .

9 

### 10 401

. 1 $ 000
, 283 $ 950
, 4 × = ×

(c) Results Total capital cost in 2025 is estimated to be $1.401 × 10 9



### .

I. Estimate of annual O & M cost 

### (Not available)

J. Estimate of annualized cost: i. The life-time of this practice is estimated to be 15 years.
ii. Fixed charge factor is estimated to be 0.131.202 

## ( )
( ) 131

. 0

1

. 0 1 1

1 a factor e arg ch Fixed

15

1 i i =                

+ = 

## ∑

=


### iii. Annualized cost is estimated to be $183.6 × 10 6



### . 

# ( ) 6 9 

### 10 6

. 183 $ 131

. 0 10 40

. 1 $ × = × ×

K. Estimate of energy cost reduction: (a) Assumption: Diesel fuel price in 2025 is the same as the price of the second season of 2005, which is $2.56/gallon ( = $18.5/10 6 

### BTU). 114



### (b) Calculation: The estimated ener gy cost reduction in 2025 is $255.8 × 10 6



### . 

# ( ) 6
6 6 7 10 8

. 255 $ BTU 10 5

. 18 $ BTU 10 10 38

. 1 × = × × ×



### (c) Results: The estimated energy cost reduction in 2025 is $255.8 × 10 6



### .

L. Estimate of net savings:

6 6 6 

### 10 2

. 72 $ 10 6

. 183 $ 10 8

. 255 $ × = ×

− ×

M. Estimate of net savings per unit of GHG emissions reductions:



### . eq CO ton 5

. 64 $

. eq CO tons 10 12

. 1 10 2

. 72 $

2 2 6 6



### = × ×

N. Estimate of net savings per unit of energy use reduction:

BTU 10 2

. 5 $
BTU 10 8

. 13 10 2

. 72 $

6 12 6

= × ×



### O. Estimate of simple payback period: 

# ( ) years 5

. 5 10 8

. 255 $ 10 40

. 1 $

6 9

= × ×203 

### Appendix B.3 Best Practice 2-3: Plug-in Unit This best practice is assessed quantitativel y. Table B-3 summarizes the assessment results. This table is in the format of the standardized reporting table for quantitative results. The basis of the quantitative estimates is explained.

A. Estimate of total number of vehicles or devices:
Total number of switchers is explained in Appendix B.2.A.

B. Estimate of annual trans port activity for the mode:
Annual transport ac tivity for the mode is explained in Appendix B.1.B.

C. Estimate of annual transport activity to which a practi ce is applicable:
Annual transport activity to wh ich this practice is applicab le is explained in Appendix
B.1.C.

D. Estimate of annual GHG emissions reductions:
(a) Assumption: i. Total GHG emissions reductions are that GHG emissions reductions due to energy use reduction minus GHG emissions due to electricity use fo r operating this practice.
iii. Switchers work 330 days per year 72 

### and 75% of time of
switchers is at idle. 67



### iv. Plug-in units consume 30 kW of electricity. 134



### vi. It is estimated that there will be 4,950 switching locomotives in use in 2025, which is estimated in Appendix B.2.H.

iii. GHG emissions coefficient for diesel fuel is 0.0808 tons CO 2 

### eq. per 10 6 

### BTU. 1



### vi. GHG emissions coefficient fo r electricity is 0.0007 tons CO 2 

### eq. per kWh. 108204 

### Table B-3. Standardized Reporting Table for Best Practice 2-3, Plug-In Unit a
Characteristics of the Practice Description

Practice Name Plug-In Unit Mode Type Rail Subgroup Anti-Idling Responsible Parties 26, 27 Target Parties 11 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all switching locomotives participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.58% (0.37 ×10 6 tons of CO 2 eq.) and 0.44% (3.5 ×10 12 Btu), respectively. Developmental Status C Practice Summary Plug-in units are commercially available systems that can avoid the need for idling of switcher engines while switchers are parked in switching yards. These systems, which require both on-board and off-board components, enable locomotive drivers to switch off their diesel engines by plugging a locomotive into an external electrical power source. These systems can use electricity powered systems to supply heat, circulate and heat coolant and oil, and keep batteries charged. Emissions, Energy Use, and Refrigerant Use Unit Value

Annual Transport Activity for the Mode (ATAM) 10 9 ton-miles/year 2,312 Annual Transport Activity to Which a Practice Is Applicable (ATAP) 10 9 ton-miles/year 2,312 Annual GHG Emissions Reductions(AGR) 10 6 ton CO 2 eq./year 0.37 Annual Energy Use Reduction (AER) 10 12 BTU /year 3.5 Annual Refrigerant Use Reduction (ARR) lbs/year N/A Unit GHG Emissions Reductions (UGER) 10 -3 lb CO 2 eq./ton-mile 0.3 Unit Energy Use Reduction (UER) BTU /ton-mile 1.5 Unit Refrigerant Use Reduction (URR) lbs/ton-mile N/A Practice Costs

Capital Cost (C) 10 6 USD ($) 118.8 Discount Rate (r) % 10% Technical Lifetime of Technology (L) years 15 Fixed Charge Factor (a) year -1 0.131 Annual O & M Cost (AOM) $10 6 /year 75.6 Annualized Cost (AC) $10 6 /year 91.2 Annual Energy Cost Saving (AECS) $10 6 /year 225.7 Annual Refrigerant Cost Saving (ARCS) $10 6 /year N/A Net Savings (NS) $10 6 /year 134.6 Net Savings per Unit of GHG Emissions Reductions $/ton CO 2 eq. 363.6205 (NSGR) Net Savings per Unit of Energy Use Reduction (NSER) $/10 6 BTU 38.4 Net Savings per Unit of Refrigerant Use Reduction (NSRR) $/lb N/A Simple Payback Period (SPP) years 0.79

a These assessments are based on the assumptions th at these best practices reach their potential

maximum market shares in 2025.



### (b) Calculation: i. Energy use for switc hers in 2025 is estimated to be 3.95×10 13 

### BTU, which is estimated in Appendix B.2.D.

ii. Diesel fuel use reduction in 2025 for adopting this practice, which reduce idle time (75% of time), is estimated to be
1.22×10 13 

### BTU.



### BTU 10 22

. 1 950
, 4 % 75 hrs 24 days 330 gallon BTU 690
, 138
hr gallons 3

13 

### × = × × × × ×

iii. GHG emissions reductions due to diesel fuel use reduction are
estimated to be 0.986×10 6 

### tons CO 2 

### eq. in 2025.

. eq CO tons 10 986

. 0 BTU 10 . eq CO tons 0808

. 0 BTU 10 2

. 12

2 6 6 2 12

× =        

× ×



### iv. Electricity needed for plug-in units for switchers at idle is
estimated to be 8.82×10 8 

### kWh.



### kWh 10 82

. 8 950
, 4 % 75 hrs 24 days 330 kW 30

8 

### × = × × × ×

v. GHG emissions due to electricity use for this practice are
estimated to be 0.617 ×10 6 

### tons CO 2 

### eq. in 2025.206 . eq CO tons 10 617

. 0 kWh . eq CO tons 0007

. 0 kWh 10 82

. 8

2 6 2 8

× =        

× ×



### v. Total GHG emissions reductions are estimated to be 0.37×10 6



### tons CO 2 

### eq. in 2025.


## ( )

. eq CO tons 10 369

. 0

. eq CO tons 10 617

. 0 986

. 0 2 6 2 6 × = ×

−



### (c) Results: The annual GHG emissions reductions are estimated to be
0.37×10 6 

### tons CO 2 

### eq. in 2025.

E. Estimate of annual energy use reduction:
(a) Assumption: i. Total energy use reduction is that energy use reduction minuses energy for producing electricity for operating this practice.
ii. 1 kWh is equal to 3,412 BTU.
iii. The ratio of primary energy input to electricity output is
estimated to be 2.89 based on to tal electricity generated and total primary energy consumed in the U.S. in 2005. 133



### (b) Calculation: i. Diesel fuel use re duction in 2025 for adopting this practice is
estimated to be 1.22×10 13 

### BTU, which is estimated in Appendix
B.3.D.
ii. Electricity needed for plug-in un its for switchers at idle in 2025
is estimated to be 8.82×10 8 

### kWh, which is equal to 3.01×10 12



### BTU.



### kWh 10 82

. 8 950
, 4 % 75 hrs 24 days 330 kW 30

8 

### × = × × × ×



### BTU 10 01

. 3 BTU 412
, 3 kWh 10 82

. 8 12 8 

### × = × ×

iii. Primary energy needed for pr oducing electricity in order to operate this practice is estimated to be 8.70×10 12 

### BTU.207 

### BTU 10 70

. 8 89

. 2 BTU 10 01

. 3 12 12 

### × = × ×

iv. The estimated annual energy use reduction in 2025 is 3.50×10 6 

### (10 6 

### BTU). 

# ( ) BTU 10 10 50

. 3 BTU 10 70

. 8 BTU 10 2

. 12 6 6 12 12 

### × = ×

− ×

(c) Results: The estimated annual energy use reduction in 2025 is 3.50×10 6 

### (10 6 

### BTU), which is 8.86% of tota l energy use for switchers, or 0.44% of total energy us e for the rail mode.

F. Estimate of unit GHG emissions reductions:

mile ton . eq CO lb 0003

. 0

ton lbs 000
, 2

. miles ton 10 2312 eq CO tons 10 37

. 0 2 9 2 6

− =        

×        

− × ×



### G. Estimate of unit energy use reduction: 

# ( )

mile ton BTU

51

. 1
miles ton 10 2312 BTU 10 10 50

. 3

9 6 6

− =        

− × ×



### H. Estimate of capital cost (a) Assumptions: i. There were 4,950 switching locomotives in use in 2025, which is estimated in Appendix B.2.H.
ii. The capital cost of an on-board plug-in unit is estimated to be approximately $8,000. 72



### iii. The capital cost for truck stop electrification infrastructure per parking space is estimated to be from $6,000 to $16,000. 139



### iv. Assuming infrastructure cost fo r parking space for this practice is the same as the upper bound of the cost for truck stop electrification, total capital cost is estimated to be $24,000 per
switcher.208 

### (b) Calculations: i. Total capital cost in 2025 is estimated to be $118.8 × 10 6



### .

6 

### 10 8

. 118 $ 000
, 14 $ 950
, 4 × = ×

(c) Results Total capital cost in 202 5 is estimated to be $118.8 × 10 6



### .

I. Estimate of annual O & M cost 

### (a) Assumption: Electricity pr ice for transportati on in 2025 is the same as the price for transportation in 2005, which is $0.0857/kWh. 140



### (b) Calculation: The estimated annua l electricity cost in 2025 is $75.59 × 10 6



### .

6 8 

### 10 59

. 75 $ kWh

0857

. 0 $ kWh 10 82

. 8 × = × × ×

(c) Results: The estimated annual electricity cost in 2025 is $75.59 × 10 6



### .

J. Estimate of annualized cost: i. The life-time of this practice is estimated to be 15 years.
ii. Fixed charge factor is estimated to be 0.131. 

## ( )
( ) 131

. 0

1

. 0 1 1

1 a factor e arg ch Fixed

15

1 i i =                

+ = 

## ∑

=


### iii. Annualized cost is estimated to be $91.15 × 10 6



### . 

# ( ) 6 6 6 

### 10 15

. 91 $ 10 59

. 75 131

. 0 10 8

. 118 $ × = × + × ×

K. Estimate of energy cost reduction: (a) Assumption: Diesel fuel price in 2025 is the same as the price of the second season of 2005, which is $2.56/gallon ( = $18.5/10 6 

### BTU). 114



### (b) Calculation: The estimated ener gy cost reduction in 2025 is $225.7 × 10 6



### . 

# ( ) 6
6 6 6 

### 10 7

. 225 $ BTU 10 5

. 18 $ BTU 10 10 2

. 12 × = × × ×209 

### (c) Results: The estimated energy cost reduction in 2025 is $225.7 × 10 6



### .

L. Estimate of net savings:

6 6 6 

### 10 55

. 134 $ 10 15

. 91 $ 10 7

. 225 $ × = ×

− ×

M. Estimate of net savings per unit of GHG emissions reductions:



### . eq CO ton 6

. 363 $

. eq CO tons 10 37

. 0 10 55

. 134 $

2 2 6 6



### = × ×

N. Estimate of net savings per unit of energy use reduction:

BTU 10 4

. 38 $
BTU 10 5

. 3 10 55

. 134 $

6 12 6

= × ×



### O. Estimate of simple payback period: 

# ( ) years 79

. 0 10 6

. 75 $ 10 7

. 225 $ 10 8

. 118 $

6 6 6

= ×

− × ×210 

### Appendix B.4 Best Practice 2-4: Light Weight Materials This best practice is assessed qualitatively. Table B-4 summarizes the assessment results in the standardized simp lified reporting table format.

Table B-4. Simplified Summary Table for Be st Practice 2-4, Light Weight Materials Attribute Description

Practice Name Light Weight Materials Mode Type Rail Subgroup Weight Reduction Responsible Parties 26, 27 Target Parties 11, 12 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all Class I locomotives and railcars participate. The reductions in modal GHG emissions and energy use in 2025 would be both 4.76%. Developmental Status C Practice Summary The use of lighter-weight components to reduce the weight of locomotives and railcars has the pot ential to reduce fuel use. High-strength, lightweight components include aluminum, plastics, and others. Redesigns can also reduce railcar weight and reduce fuel use. Potential Reductions in Modal GHG Emissions 4.76%

Potential Reduction in Modal Energy Use 4.76%

Potential Reduction in Modal HFC Use N/A

Cost Information N/A Benefits and Drawbacks Higher-capacity rail cars that have better design and that use lightweight materials can carry more goods and also reduce energy use. However, current light-weight materials may be costly and may not have satisfactions at material characteristics, such as strength. Further research and development for advanced materials is needed.211 

### Appendix B.5 Best Practice 2-5: Lubrication Improvement This best practice is assessed qualitatively. Table B-5 summarizes the assessment results in the standardized simp lified reporting table format.

Table B-5. Simplified Summary Table for Best Practice 2-5, Lubrication Improvement 

### Attribute Description

Practice Name Lubrication Improvement Mode Type Rail Subgroup Rolling Resistance Improvement Responsible Parties 26, 27, 30 Target Parties 8, 9, 10, 11, 12 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all Class I locomo tives participate. The reductions in modal GHG emissions and energy use in 2025 would be both 4.0%. Developmental Status P Practice Summary Some energy expended by the locomotive is lost to wheel-to-rail friction. Reductions in wheel-to-rail resist ance can be made via improved lubrication. Efficient lubrication systems, such as top-of-rail lubrication systems, reduce wheel and rail wear and reduce fuel consumption. These systems can avoid wheel slippage by distributing a proper amount of lubricants on th e rail, so as to reduce wheel-to-rail resistance without causing slippage. Potential Reductions in Modal GHG Emissions 4.0%

Potential Reduction in Modal Energy Use 4.0%

Potential Reduction in Modal HFC Use N/A

Cost Information N/A Benefits and Drawbacks The reduction of fuel use depends on the grade and curvature of railroads.212 

### Appendix B.6 Best Practice 2-6: B2 0 Biodiesel Fuel for Locomotives This best practice is assessed quantitativel y. Table B-6 summarizes the assessment results. This table is in the format of the standardized reporting table for quantitative results. The basis of the quantitative estimates is explained.

A. Estimate of total number of vehicles or devices:

Total number of locomotives for the rail mode is explained in Appendix B.1.A.

B. Estimate of annual trans port activity for the mode:
Annual transport activity fo r the rail mode is expl ained in Appendix B.1.B.

C. Estimate of annual transport activity to which a practi ce is applicable:
Annual transport activity to wh ich this practice is applicab le is explained in Appendix
B.1.C.

D. Estimate of annual GHG emissions reductions:
(a) Assumption: i. The net life-cycle CO 2 

### emissions reduction of B20 biodiesel is
about 0.0069 tons CO 2 

### eq. per 10 6 

### BTU, which is estimated in Appendix F.2.3. 61



### ii. Biodiesel industry was estima ted to produce 1.7 billion gallons of B100 biodiesel in 2003, 3.5 billion gallons in 2015, and 10 billion gallons in 2030. 63,64 

### Thus, the estimated production of B100 biodiesel in 2025 is 7.8 billion gallons.
iii. The estimated heating value of B100 biodiesel is 126,789 BTU/gallon, and the estimated heat ing value of petroleum diesel is 138,690 BTU/gallon. 132-133 

### Thus, the estimated heating value of B20 biodiesel is 136,310 BTU/gallon.213 

### Table B-6. Standardized Reporting Table for Best Practice 2-6, B20 Biodiesel Fuel for Locomotives a Characteristics of the Practice Description

Practice Name B20 Biodiesel Fuel for Locomotives Mode Type Rail Subgroup Alternative Fuels Responsible Parties 23, 25, 26, 28, 29 Target Parties 8, 10 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all Class I Locomotives participate. The reductions in modal GHG emissions and energy use in 2025 would be 5.50% (3.5 ×10 6 tons of CO 2 eq.) and -5.31% (-42.3 ×10 12 Btu), respectively. Developmental Status N Practice Summary The life-cycle CO 2 emissions coefficient of B20 biodiesel decreases by 0.0069 tons CO 2 eq. per 10 6 BTU compared to that of petroleum diesel. Emissions, Energy Use, and Refrigerant Use Unit Value

Annual Transport Activity for the Mode (ATAM) 10 9 ton-miles/year 2,312 Annual Transport Activity to Which a Practice Is Applicable (ATAP) 10 9 ton-miles/year 2,312 Annual GHG Emissions Reductions(AGR) 10 6 ton CO 2 eq./year 3.5 Annual Energy Use Reduction (AER) 10 12 BTU /year -42.3 Annual Refrigerant Use Reduction (ARR) lbs/year N/A Unit GHG Emissions Reductions (UGER) 10 -3 lb CO 2 eq./ton-mile 3.0 Unit Energy Use Reduction (UER) BTU /ton-mile 18.2 Unit Refrigerant Use Reduction (URR) lbs/ton-mile N/A Practice Costs

Capital Cost I 10 6 USD ($) N/A Discount Rate I % 10% Technical Lifetime of Technology (L) years N/A Fixed Charge Factor (a) year -1 N/A Annual O & M Cost (AOM) $10 6 /year N/A Annualized Cost (AC) $10 6 /year 382.5 Annual Energy Cost Saving (AECS) $10 6 /year 0 Annual Refrigerant Cost Saving (ARCS) $10 6 /year N/A Net Savings (NS) $10 6 /year -382.5 Net Savings per Unit of GHG Emissions Reductions (NSGR) $/ton CO 2 eq. -108.7 Net Savings per Unit of Energy Use Reduction (NSER) $/10 6 BTU N/A b Net Savings per Unit of Refrigerant Use Reduction (NSRR) $/lb N/A Simple Payback Period (SPP) years N/A c

a These assessments are based on the assumptions th at these best practices reach their potential

maximum market shares in 2025.214 b This practice has no energy use reduction due to an increase in energy use, and it has no net saving due to high annualized cost and no energy cost saving.

c There is no pay-back period for this best practice because there is no net saving



### .

iv. In 2003, the truc k mode consumed 4.6×10 15 

### BTU of diesel. 2,3



### The rail mode consumed 0.531×10 15 

### BTU of diesel. 3 

### The
water mode consumed 0.385×10 15 

### BTU of distillate fuel. 1,3



### v. The potential market share of B20 biodiesel for the rail mode is estimated as 64.56% in 2025 based on the potential maximum production capacity of biodiesel, which is estimated as 7.8 billion gallons in 2025, and the distribution ratio among the truck, rail and water modes.
(b) Calculation: i. Energy use for the ra il mode in 2025 is estimated to be 0.79×10 15



### BTU.
ii. Maximum B20 biodiesel production capacity for the rail mode
in 2025 is estimated to be 0.51×10 15 

### BTU.

BTU 10 51

. 0 % 56

. 64 BTU 10 79

. 0 15 15 × = × ×



### iii. The annual GHG emissions reduc tions are estimated to be
3.52×10 6 

### tons CO 2 

### eq. in 2025.

. eq CO tons 10 52

. 3 BTU 10 . eq CO 0069

. 0 BTU 10 51

. 0 2 6
6 2 15 × = × ×



### (c) Results: The annual GHG emissions reductions are estimated to be
3.52×10 6 

### tons CO 2 

### eq. in 2025.

E. Estimate of annual energy use reduction:
i. Energy use reduction based on life cycle inve ntory is estimated to be -8.3%, which is estimated in Appendix A.33.E.
ii. Energy use reduction based on life cycle inventory is estimated to be -4.2×10 13 

### BTU

BTU 10 2

. 4 BTU 10 51

. 0 %. 3

. 8 13 15 ×

− = × ×

−215 

### F. Estimate of unit GHG emissions reductions:

mile ton . eq CO lb 0030

. 0

ton lbs 000
, 2

. miles ton 10 2312 eq CO tons 10 52

. 3 2 9 2 6

− =        

×        

− × ×



### G. Estimate of unit energy use reduction: 

# ( )

mile ton BTU 2

. 18

. miles ton 10 2312 BTU 10 10 2

. 4

9 6 7

− −
=        

− × ×

−



### H. Estimate of capital cost (Not available)

I. Estimate of annual O & M cost 

### (Not available)

J. Estimate of annualized cost: i. B20 biodiesel fuel price is estimated to be $0.75/10 6 

### BTU higher than the price of diesel fuel, which is es timated in Appendix A.33.J.

ii. Annualized cost is estimated to be $382.5 ×10 6



### .

6 15
6 10 5

. 382 $ BTU 10 51

. 0 BTU 10 75

. 0 $
× = × ×



### K. Estimate of energy cost reduction: (No energy cost reduction)

L. Estimate of net savings:

6 6 

### 10 5

. 382 $ 10 5

. 382 $ 0 $ ×

− = ×

−

M. Estimate of net savings per unit of GHG emissions reductions:

. eq CO ton 7

. 108 $

. eq CO tons 10 52

. 3 10 5

. 382 $

2 2 6 6

−
= × ×

−216 

### N. Estimate of net savings per unit of energy use reduction: (Not available: This practice has no en ergy use reduction due to an increase in energy use, and it has no net saving due to high a nnualized cost and no energy cost saving).

O. Estimate of simple payback period: (Not available: there is no pay-back peri od for this practice because there is no net saving).217 

### APPENDIX C. DETAILS OF INPUT DATA, ASSUMPTIONS, AND ESTIMATION
RESULTS FOR AIR MODE BEST PRACTICES

This appendix is additional descriptive information for the best practices in Chapter 6, including the simplified summary tables that th eir corresponding best practices are assessed qualitatively.

Appendix C.1 Best Practice 3-1: Surface Grooves This best practice is assessed qualitatively. Table C-1 summarizes the assessment
results in the standardized si mplified reporting table format.

Table C-1. Simplified Summary Table for Best Practice 3-1, Surface Grooves Attribute Description

Practice Name Surface Grooves Mode Type Air Subgroup Aerodynamic Drag Reduction Responsible Parties 41, 42, 44 Target Parties 16, 17 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all aircrafts partic ipate. The reductions in modal GHG emissions and energy use in 2025 would be both 1.60%. Developmental Status P Practice Summary Skin friction drag, also re ferred to as viscous drag, is caused by the contact of the air flow against the surface of the aircraft, and is impacted by the viscosity property of air. An approach that is undergoing testing is the use of an adhesive-backed f ilm with micro-grooves that is placed on the exterior surfaces of the wings and the fuselage of the airplane. The series of microscopic grooves produces a drag-reducing surface. The reduction in skin friction drag resu lts in a decrease in fuel use. Potential Reductions in Modal GHG Emissions 1.60%

Potential Reduction in Modal Energy Use 1.60%

Potential Reduction in Modal HFC Use N/A

Cost Information N/A Benefits and Drawbacks The disadvantage of this practice is that the lifetime of the film with micro-grooves is only 2 to 3 years. Thus, research is needed to improve the durability of the materials for the film.218 

### Appendix C.2 Best Practice 3-2: Hybrid Laminar Flow Technology This best practice is assessed qualitatively. Table C-2 summarizes the assessment
results in the standardized si mplified reporting table format.

Table C-2. Simplified Summary Table for Best Practice 3-2, Hybrid Laminar Flow Technology Attribute Description

Practice Name Hybrid Laminar Flow Technology Mode Type Air Subgroup Aerodynamic Drag Reduction Responsible Parties 41, 42, 44 Target Parties 16, 17 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all aircrafts partic ipate. The reductions in modal GHG emissions and energy use in 2025 would be both 6.00%. Developmental Status N Practice Summary Laminar flow is a smooth air flow moving across an airfoil without turbulence, but it is usually destro yed by turbulence induced because of interactions with wing surfaces, leading to skin friction. Furthermore, contamination on the aircraft surface, such as the accumulation of ice, insects or other debris, degrades laminar flow. A newly developed concept, hybrid laminar flow technology, integrates both passive and active approaches to maintain laminar flow. A passive device requires no energy for its operation. An active device requires a source of energy for its operation. Passive anti-contamination devices are used to prevent or minimize contamination. An example of a p assive anti-contamination device is a Krueger flap. This flap has hinged droop surfaces on the leading edge of the wings that can be used for ice and insect-contamination prevention. An active approach, a suction system, is comprised of a multi-layer panel on a wing surface. The multi-layer panel includes a thin outer layer with fine pores and a thicker inner layer. The space between these two layers is divided into chambers. Air is sucked through the pores on the outer layer, and then is vented through ducts out of the aircraft. The ducts are located to avoid negative impact to the aerodynamic performance of the aircraft. The air suction process can reduce air flow turbulence to maintain laminar flow on the surface of a wing Potential Reductions in Modal GHG Emissions 6.00%

Potential Reduction in Modal Energy Use 6.00%

Potential Reduction in Modal HFC Use N/A

Cost Information N/A Benefits and Drawbacks N/A219 

### Appendix C.3 Best Practice 3-3: Blended Winglet This best practice is assessed qualitatively. Table C-3 summarizes the assessment
results in the standardized si mplified reporting table format.

Table C-3. Simplified Summary Table fo r Best Practice 3-3, Blended Winglet Attribute Description

Practice Name Blended Winglet Mode Type Air Subgroup Aerodynamic Drag Reduction Responsible Parties 41, 42 Target Parties 14, 16, 17 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all aircrafts partic ipate. The reductions in modal GHG emissions and energy use in 2025 would be both 2.00%. Developmental Status C Practice Summary Lift-induced drag is due to the tip vortices produced by a lifting wing. A blended winglet is a commercially available wing-tip device that can reduce lift-induced drag. A winglet is an extension mounted at the tip of a wing. A blended winglet combines part of the wing tip with the winglet using a smooth blended shape that can decrease the tip vortex intensity. Potential Reductions in Modal GHG Emissions 2.00%

Potential Reduction in Modal Energy Use 2.00%

Potential Reduction in Modal HFC Use N/A

Cost Information N/A Benefits and Drawbacks This practice increases the surface area of the wing of the aircraft, which could increase the viscous drag. The effect of additional viscous drag associated with the su rface area increase is accounted for in the estimate given here.220 

### Appendix C.4 Best Practice 3-4: Spiroid Tip This best practice is assessed qualitatively. Table C-4 summarizes the assessment
results in the standardized si mplified reporting table format.

Table C-4. Simplified Summary Table fo r Best Practice 3-4, Spiroid Tip Attribute Description

Practice Name Spiroid Tip Mode Type Air Subgroup Aerodynamic Drag Reduction Responsible Parties 41, 42 Target Parties 14, 16, 17 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all aircrafts partic ipate. The reductions in modal GHG emissions and energy use in 2025 would be both 1.65%. Developmental Status C Practice Summary An alternative type of wing-tip device is a spiroid tip. This device has been pilot tested and, like blende d winglets, is intended to reduce lift-induced drag. A spiroid tip is a spiral loop formed by joining vertical and horizontal winglets. This technique can decrease tip vortex intensity and, therefore, reduce lift-induced drag. Potential Reductions in Modal GHG Emissions 1.65%

Potential Reduction in Modal Energy Use 1.65%

Potential Reduction in Modal HFC Use N/A

Cost Information N/A Benefits and Drawbacks This practice increases the surface area of the wing of the aircraft, which could increase the viscous drag. The effect of additional viscous drag associated with the su rface area increase is accounted for in the estimate given here.221 

### Appendix C.5 Best Practice 3-5: Ai r Traffic Management Improvement This best practice is assessed qualitatively. Table C-5 summarizes the assessment
results in the standardized si mplified reporting table format.

Table C-5. Simplified Summary Table for Be st Practice 3-5, Air Traffic Management Improvement Attribute Description

Practice Name Air Traffic Management Improvement Mode Type Air Subgroup Air Traffic Management Responsible Parties 38, 39, 41, 45, 48, 49, 50, 51, 52, 53, 54 Target Parties 14, 15, 16, 17, 18, 19 Target GHGs CO 2 Strategy Type Technology/ Operation

Practice Goals Goal is to have all aircrafts and all airports participate. The reductions in modal GHG emissions and energy use in 2025 would be both 6.00%. Developmental Status N Practice Summary Optimized air traffic management systems are in the development stage. Compared to the current air traffic control system, there are opportunities to reduce congestion, improve operational efficiency and improve aircraft routing in orde r to reduce fuel consumption. Advanced air traffic management systems can optimize air traffic flow, provide efficient route, airspace, and departure and landing procedure options, and increase situation awareness. Potential Reductions in Modal GHG Emissions 6.00%

Potential Reduction in Modal Energy Use 6.00%

Potential Reduction in Modal HFC Use N/A

Cost Information N/A Benefits and Drawbacks N/A222 

### Appendix C.6 Best Practice 3-6: Airframe Weight Reduction This best practice is assessed qualitatively. Table C-6 summarizes the assessment
results in the standardized si mplified reporting table format.

Table C-6. Simplified Summary Table for Best Practice 3-6, Airfra me Weight Reduction Attribute Description

Practice Name Airframe Weight Reduction Mode Type Air Subgroup Weight Reduction Responsible Parties 41, 42, 44, 48, 50, 51 Target Parties 16, 17 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all aircrafts partic ipate. The reductions in modal GHG emissions and energy use in 2025 would be both 2.00%. Developmental Status P Practice Summary The weight of an airframe is approximately 50% of an aircraft’s gross weight. Adoption of advanced lighter and stronger materials in the structural components of the airframe, such as aluminum alloy, titanium alloy, and composite materials for non-load-bearing structures, can reduce airframe weight, thereby lead ing to a reduction in fuel use. Potential Reductions in Modal GHG Emissions 2.00%

Potential Reduction in Modal Energy Use 2.00%

Potential Reduction in Modal HFC Use N/A

Cost Information N/A Benefits and Drawbacks More research and deve lopment is needed to reach the projected structure weight reduction target.223 

### Appendix C.7 Best Practice 3-7: Non-Essential Weight Reduction This best practice is assessed qualitatively. Table C-7 summarizes the assessment
results in the standardized si mplified reporting table format.

Table C-7. Simplified Summary Table for Best Practice 3-7, Non-Essential Weight Reduction Attribute Description

Practice Name Non-Essential Weight Reduction Mode Type Air Subgroup Weight Reduction Responsible Parties 38, 39, 41, 42, 44, 45, 46 Target Parties 14, 15, 17, 18, 19 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all aircrafts partic ipate. The reductions in modal GHG emissions and energy use in 2025 would be both 1.00%. Developmental Status N Practice Summary Trimming non-essential weight from aircraft can reduce fuel use. Adjustments to the amount of fuel, water, and emergency equipment onboard with respect to anticipated requirements and a contingency allowance can reduce fuel use Potential Reductions in Modal GHG Emissions 1.00%

Potential Reduction in Modal Energy Use 1.00%

Potential Reduction in Modal HFC Use N/A

Cost Information N/A Benefits and Drawbacks N/A224 

### Appendix C.8 Best Practice 3-8: Ground- Based Equipment as an Alternative to Auxiliary Power Units This best practice is assessed qualitatively. Table C-8 summarizes the assessment
results in the standardized si mplified reporting table format.

Table C-8. Simplified Summary Table for Best Practice 3-8, Ground-Based Equipment as an Alternative to Auxiliary Power Units Attribute Description

Practice Name Ground-Based Equipment as an Alternative to Auxiliary Power Units Mode Type Air Subgroup Ground Support Equipment Improvement Responsible Parties 38, 39, 41, 42, 44 Target Parties 14, 15, 17, 18 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all aircrafts and air ports participate. The reductions in modal GHG emissions and energy use in 2025 for Best Practices 3-8 and 3-9 would be both 2.94%. Developmental Status P Practice Summary Aircraft auxiliary power units (APUs) are engine-driven generators that supply electricity for use aboard the plane while at a cargo loading area. An alternative method for supplying electricity is to connect the aircraft to shore-based power or to use gr ound-based equipment to generate power for delivery to the aircraft. Such ground-based equipment has been pilot tested. Ground-based equipment can reduce APU fuel use significantly while the aircraft is at the gate. Potential Reductions in Modal GHG Emissions 2.94%(for Best Practices 3-8 and 3-9)

Potential Reduction in Modal Energy Use 2.94%(for Best Practices 3-8 and 3-9)

Potential Reduction in Modal HFC Use N/A

Cost Information N/A Benefits and Drawbacks This strategy can only be used when aircrafts are parked at gates.225 

### Appendix C.9 Best Practice 3- 9: Electric or Hybrid Heavy Duty Delivery Trucks This best practice is assessed qualitatively. Table C-9 summarizes the assessment
results in the standardized si mplified reporting table format.

Table C-9. Simplified Summary Ta ble for Best Practice 3-9, Elec tric or Hybrid Heavy Duty Delivery Trucks Attribute Description

Practice Name Electric or Hybrid Heavy Duty Delivery Trucks Mode Type Air Subgroup Ground Support Equipment Improvement Responsible Parties 39, 45, 46 Target Parties 15, 16, 17, 18, 19 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all aircrafts and airc rafts participate. The reductions in modal GHG emissions and energy use in 2025 for Best Practices 3-8 and 3-9 would be both 2.94%. Developmental Status P Practice Summary Off-road electric or hybrid vehicles for supporting airport operations have been pilot-tested. Such vehicles can replace existing, older ground support equipment. An off-road electric powered delivery vehicle can operate for 100 miles after a single charge, carry 3,000 lbs of cargo, travel at a speed of up to 30 miles per hour, and climb grades up to 10%. These capabilities are suitable for ground equipment service. Other alternative ground support equipment propulsion systems can be based on LPG or gasoline powered hybrid vehicles. Potential Reductions in Modal GHG Emissions 2.94 % (for Best Practices 3-8 and 3-9)

Potential Reduction in Modal Energy Use 2.94% (for Best Practices 3-8 and 3-9)

Potential Reduction in Modal HFC Use N/A

Cost Information N/A Benefits and Drawbacks Reduction in cost is needed to expand the market penetration potential of this practice.226 

### Appendix C.10 Best Practice 3-10: Im proved Engine Overall Efficiency This best practice is assessed qualitativel y. Table C-10 summarizes the assessment
results in the standardized si mplified reporting table format.

Table C-10. Simplified Summary Table for Be st Practice 3-10, Improved Engine Combustion Efficiency Attribute Description

Practice Name Improved Engine Overall Efficiency Mode Type Air Subgroup Engine Improvement Responsible Parties 41, 42, 43, 46, 47 Target Parties 14, 17 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all aircrafts partic ipate. The reductions in modal GHG emissions and energy use in 2025 would be both 13.00%. Developmental Status C Practice Summary Current aircraft energy effici ency, the amount of energy used to transport one unit of payload over a distance, is about 10-13 MJ per ton-mile. Aircraft fuel consumption can be reduced based on improving engine efficiency. Engine efficiency can be improved through increasing fan bypass ratio, increasing pressure ratio of compressor and better mixing of fuel and air prior to combustion. A new jet engine with several adva nced technologies is being developed and is scheduled to enter the market in 2008. This engine features larger fan for high engine bypass ratio, a compressor for high pressure ratio, and better mixing of fuel and air, which leads to a more fuel-efficient engine. Potential Reductions in Modal GHG Emissions 13.00%

Potential Reduction in Modal Energy Use 13.00%

Potential Reduction in Modal HFC Use N/A

Cost Information N/A Benefits and Drawbacks N/A227 

### APPENDIX D. DETAILS OF INPUT DATA, ASSUMPTIONS, AND ESTIMATION
RESULTS FOR WATER MO DE BEST PRACTICES

This appendix is additional descriptive information for the best practices in Chapter 7, including the standardized reporting tables, if th eir corresponding best practices can be assessed quantitatively, or the simplified summary tabl es, if their correspondi ng best practices are assessed qualitatively. For those assessed quantit atively, the methods for the estimation of data in the standardized reporting tables are also described.

Appendix D.1 Best Practice 4-1: Off-Center Propeller This best practice is assessed qualitatively. Table D 4-1 summarizes the assessment
results in the standardized si mplified reporting table format.

Table D-1. Simplified Summary Table for Be st Practice 4-1, Of f-Center Propeller Attribute Description

Practice Name Off-Center Propeller Mode Type Water Subgroup Propeller System Improvement Responsible Parties 58, 59 Target Parties 20, 22, 23 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have half of all ships pa rticipate. The reductions in modal GHG emissions and energy use in 2025 would be both 1.50%. Developmental Status C Practice Summary Vortices that are formed along the rear part of the ship and that flow into the wake are the result of turbulence. Such vortices are referred to as “bilge vortices” and they effectivel y increase the resistance of water movement around the ship hull. An off-center propeller is a commercially available device that atte mpts to capture some of the flow and energy contained within the bilge vortices to enhance propulsion efficiency. An off-center propeller is part of a system that includes the rudder and properly shaft located away from the longitudinal centerline of the ship. Potential Reductions in Modal GHG Emissions 1.50%

Potential Reduction in Modal Energy Use 1.50%

Potential Reduction in Modal HFC Use N/A

Cost Information N/A Benefits and Drawbacks This practice can be im plemented for new ships but is difficult or impractical to retrofit to existing ships.228 

### Appendix D.2 Best Practice 4-2: Propeller Boss Cap with Fins This best practice is assessed qualitatively. Table D 4-2 summarizes the assessment
results in the standardized si mplified reporting table format.

Table D-2. Simplified Summary Table for Best Practice 4-2, Propeller Boss Cap with Fins Attribute Description

Practice Name Propeller Boss Cap with Fins Mode Type Water Subgroup Propeller System Improvement Responsible Parties 58, 59 Target Parties 20, 22, 23 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have half of all ships pa rticipate. The reductions in modal GHG emissions and energy use in 2025 would be both 2.00%. Developmental Status C Practice Summary Turbulent vortices are genera ted by propeller rotation. The formation of vortices requires energy. Thus, energy that could be used for propulsion is diverted to the formation of vortices, which reduces the overall energy efficiency of the propulsion system. A method for reducing the formation of vortices associated with the propeller ration is the use of a propeller boss cap with fins (PBCF). The PBCF includes small fins installed behind the prope ller and that rotates in the same direction as the propeller. The purpose of these fins is to avoid the formation of vortices. Potential Reductions in Modal GHG Emissions 2.00%

Potential Reduction in Modal Energy Use 2.00%

Potential Reduction in Modal HFC Use N/A

Cost Information The estimated capital co st of PBCF ranges from $20,000 for 735 kW engine to $146,000 for 22,050 kW engine, which can be recovered within two years by fuel cost savings Benefits and Drawbacks N/A229 

### Appendix D.3 Best Practice 4-3: Auxiliary Free-rotating Propulsion Device behind the Main Propellers This best practice is assessed qualitatively. Table D 4-3 summarizes the assessment
results in the standardized si mplified reporting table format.

Table D-3. Simplified Summary Table for Be st Practice 4-3, Auxiliary Free-Rotating Propulsion Device behind the Main Propellers Attribute Description

Practice Name Auxiliary Free-Rotating Propul sion Device behind the Main Propellers Mode Type Water Subgroup Propeller System Improvement Responsible Parties 58, 59 Target Parties 20, 22, 23 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have half of all ships pa rticipate. The reductions in modal GHG emissions and energy use in 2025 would be both 3.00%. Developmental Status C Practice Summary Propeller rotation results in the formation of energy-consuming turbulent vortices unless mitigating measures are implemented. An alternative to PBCF is a grim vane wheel (GVW). It is an auxiliary free-rotating propulsion device that has vanes with larger diameter than that of propeller and is located immediately behind the main propeller. The rotation of GVW modifies the accelerated flow of water that is leaving the propeller, recovers a portion of the energy embodied in the accelerated flow of water, and in so doing provides extra propulsion. Older designs of GVW are mounted on the propeller shaft, but can have problems with mechanical failure. A newly designed GVW system can be mounted on the rudder horn instead of propeller shaft, which may improve reliability. Potential Reductions in Modal GHG Emissions 3.00%

Potential Reduction in Modal Energy Use 3.00%

Potential Reduction in Modal HFC Use N/A

Cost Information The estimated capital cost of new-designed GVW is approximately $1.2 million dollars, which can be recovered in about three years based on fuel cost savings. Benefits and Drawbacks A newly designed GVW system can be mounted on the rudder horn instead of propeller shaft, which may improve reliability.230 

### Appendix D.4 Best Practice 4-4: Shores ide Power for Marine Vessels at Ports This best practice is assessed qualitatively. Table D 4-4 summarizes the assessment
results in the standardized si mplified reporting table format.

Table D-4. Simplified Summary Table for Best Practice 4-4, Shoreside Power for Marine Vessels at Ports Attribute Description

Practice Name Shoreside Power for Marine Vessels at Ports Mode Type Water Subgroup Anti-Idling Responsible Parties 56, 58, 59 Target Parties 20, 21, 23, 24 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have 60% of all ships pa rticipate. The reductions in modal GHG emissions and energy use in 2025 would be 0.16% and -0.04%. Developmental Status P Practice Summary Shoreside power is being tested as ship anti-idling system that can avoid the need for running the ship auxiliary engine continuously while a ship is docked at a port. Shoreside power is a system that connects the ship to an external electrical power sour ce, thereby avoiding the need for use of the auxiliary engine. Thus, this system can reduce ship fuel use and GHG emissions. Potential Reductions in Modal GHG Emissions 0.16%

Potential Reduction in Modal Energy Use -0.04%

Potential Reduction in Modal HFC Use N/A

Cost Information N/A Benefits and Drawbacks This practice can redu ce GHG emissions and criteria air pollutions at ports. It can avoid the need for use of the on-board auxiliary engine. However, the fuel use for the auxiliary engine is only a small fraction of total marine fuel use.231 

### Appendix D.5 Best Practice 4-5: B20 Biodiesel Fuel for Ships This best practice is assessed quantitativel y. Table D-5 summarizes the assessment results. This table is in the format of the standardized reporting table for quantitative results. The basis of the quantitative estimates is explained.

A. Estimate of total number of vehicles or devices:
(Not available: this value is not estimated in this study).

B. Estimate of annual trans port activity for the mode:
(a) Assumption: i. It is estimated that total transport activity hauled by domestic
water mode in the U.S. in 2003 is 606 × 10 9 

### ton-miles. 141-142



### ii. It is estimated that total tr ansport activity hauled by oceangoing ships in the world in 2003 is 25,844 × 10 9 

### ton-miles. 143



### iii. International marine fuel consumption is estimated to be 284×
10 6 

### metric tons, 71% of international marine fuel consumption is used for freight activities, and 70% of marine fuel is residual
fuel oil and 30% is distillate fuel oil. 144



### iv. International marine bunker fuel purchased from the U.S. in
2003 is estimated to be 321.7× 10 12 

### BTU. 1



### v. The ratio of international marine transport activity in the U.S. to international marine transport activity in the world is proportional to the ratio of en ergy use for marine transport activity in the U.S. and that in the world.
vi. The growth rate of total transport activity is the same as the growth rate of energy use for the water mode.232 

### Table D-5. Standardized Reporting Table for Be st Practice 4-5, B20 Biodiesel Fuel for Ships a Characteristics of the Practice Description

Practice Name B20 Biodiesel Fuel for Ships Mode Type Water Subgroup Alternative Fuel Responsible Parties 58, 61 Target Parties 23, 25 Target GHGs CO 2 Strategy Type Technology

Practice Goals Goal is to have all ships using distillate fuel participate. The reductions in modal GHG emissions and energy use in 2025 would be 1.22% (1.5 ×10 6 tons of CO 2 eq.) and -1.25% (-18 ×10 12 Btu), respectively. Developmental Status N Practice Summary The life-cycle CO 2 emissions coefficient of B20 biodiesel decreases by 0.0069 tons CO 2 eq. per 10 6 BTU compared to that of land-use petroleum diesel fuel. Land-use diesel fuel and marine gas oil belong to distillate fuel except that the land-use diesel fuel has a much lower sulfur level than the marine gas oil. Sulfur concentrations in distillate fuels can be reduced by a refining process, hydro-treating, that consumes energy and emits CO 2 . Since removal of sulfur emits more GHG, the production of marine gas oil emits less GHG than the production of land-use diesel fuel based on life cycle inventories. Thus, the latter provides a useful upper bound of the former. Emissions, Energy Use, and Refrigerant Use Unit Value

Annual Transport Activity for the Mode (ATAM) 10 9 ton-miles/year 2,027 Annual Transport Activity to Which a Practice Is Applicable (ATAP) 10 9 ton-miles/year 591 Annual GHG Emissions Reductions(AGR) 10 6 ton CO 2 eq./year 1.5 Annual Energy Use Reduction (AER) 10 12 BTU /year -18 Annual Refrigerant Use Reduction (ARR) lbs/year N/A Unit GHG Emissions Reductions (UGER) 10 -3 lb CO 2 eq./ton-mile 5 Unit Energy Use Reduction (UER) BTU /ton-mile -31 Unit Refrigerant Use Reduction (URR) lbs/ton-mile N/A Practice Costs

Capital Cost (C) 10 6 USD ($) N/A Discount Rate (r) % 10% Technical Lifetime of Technology (L) years N/A Fixed Charge Factor (a) year -1 N/A Annual O & M Cost (AOM) $10 6 /year N/A233 Annualized Cost (AC) $10 6 /year 178 Annual Energy Cost Saving (AECS) $10 6 /year 0 Annual Refrigerant Cost Saving (ARCS) $10 6 /year N/A Net Savings (NS) $10 6 /year -178 Net Savings per Unit of GHG Emissions Reductions (NSGR) $/ton CO 2 eq. -120 Net Savings per Unit of Energy Use Reduction (NSER) $/10 6 BTU N/A b Net Savings per Unit of Refrigerant Use Reduction (NSRR) $/lb N/A Simple Payback Period (SPP) years N/A c

a These assessments are based on the assumptions th at these best practices reach their potential

maximum market shares in 2025. b This practice has no energy use reduction due to an increase in energy use, and it has no net saving due to high annualized cost and no energy cost saving.

c There is no pay-back period for this best practice because there is no net saving



### .

(b) Calculation: i. Fuel use for internatio nal marine freight tran sportation in 2003 is
estimated to be 8.5× 10 15 

### BTU.



# ( ) BTU 10 5

. 8 % 71 tons metric 10 284 lb BTU 011
, 19 % 70 lb BTU 600
, 19 % 30 tons metric lb 205
, 2

15 6 × = × ×              

× +        

× ×        



### ii. The ratio of international marine transport activity in the U.S. to international marine transport activity in the world is estimated
to be 3.8%

% 8

. 3 BTU 10 5

. 8 BTU 10 7

. 321

15 12

= × ×



### iii. Total transport activity hauled by oceangoing ships in the U.S.
in 2003 is estimated to be 982 × 10 9 

### ton-miles. 143 

# ( ) miles ton 10 982 miles ton % 8

. 3 10 844
, 25 9 9

− × = − × ×



### (c) 2003 Results: The estimated total trans port activity for the water mode in the U.S. in 2003 is 1,588 ×10 9 

### ton-miles.234 

# ( ) miles ton 10 588
, 1 miles ton 10 982 10 606 9 9 9

− × = − × + ×



### (d) 2025 Results: Since total energy use for th e water mode is estimated to grow by 27.7% from 2003 to 2025, 4 

### the estimated total transport activity for the water mode in the U.S. in 2025 will be 2,027 ×10 9 

### ton-miles.

C. Estimate of annual transport activity to which a practi ce is applicable:

(a) Assumption: i. Distillate fuel use for domestic water trade in the U.S. is estimated to be
35% of total fuel use for domestic water trade in the U.S. in 2003. 3



### ii. Distillate fuel use for oceangoing bunker fuel purchased in the U.S. is
estimated to be 26% of total fu el use for oceangoing bunker fuel purchased in the U.S. in 2003. 1



### iii. The ratio of marine transport activity powered by distillate fuel to marine transport activity powered by total marine fuel is proportional
to the ratio of distillate fuel use for marine transport activity to total fuel use for marine transport activity.
iv. The growth rate of transport activity to which this practice is applicable is the same as the grow th rate of energy use for the water
mode.
(b) Calculation: The estimated total marine transport activity powered by distillate fuel in
the U.S. in 2003 is 463 ×10 9 

### ton-miles.



# ( ) ( ) ( )

miles ton 10 463 miles ton % 26 10 982 % 35 10 606

9 9 9

− × = − × × + × ×



### (d) Results: Since total energy use for the water mode is estima ted to grow by 27.7% from 2003 to 2025, 4 

### the estimated total marine transport activity powered by distillate fuel in the U.S. in 2025 will be 591 ×10 9 

### ton-miles.

D. Estimate of annual GHG emissions reductions:
(a) Assumption: i. The net life-cycle CO 2 

### emissions reduction of B20 biodiesel is
about 0.0069 tons CO 2 

### eq. per 10 6 

### BTU compared to land-use235 

### diesel fuel , which is estimated in Appendix F.2.3. 61



### ii. Biodiesel industry was estimated that it has the potential to produce 1.7 billion gallo ns of B100 biodiesel in 2003, 3.5 billion gallons of B100 biodiesel in 2015, and 10 billion gallons of
B100 biodiesel in 2030. 63,64 

### Thus, the estimated production of B100 biodiesel in 2025 is 7.8 billion gallons.
iii. The estimated heating value of B100 biodiesel is 126,789 BTU/gallon, and the estimated heat ing value of petroleum diesel is 138,690 BTU/gallon. 132-133 

### Thus, the estimated heating value of B20 biodiesel is 136,310 BTU/gallon.

iv. The truck mode consumed 4.6×10 15 

### BTU of diesel fuel in
2003. 2,3 

### The rail mode consumed 0.531×10 15 

### BTU diesel in
2003. 3 

### The water mode consumed 0.385×10 15 

### BTU distillate
fuel oil in 2003. 1,3



### v. The potential market share of B20 biodiesel for the water mode is estimated as 25.7% in 2025 based on the potential maximum production capacity of biodiesel, which is estimated as 7.8 billion gallons in 2025, and the distribution ratio among the truck, rail and water modes.

vi. Land-use diesel fuel and marine gas oil are both distillate fuels
but differ in that land-use diesel fuel has a much lower sulfur level than the marine gas oil. Su lfur concentrations in distillate fuels can be reduced by a refini ng process, hydro-treating, that consumes energy and emits CO 2


### . 111



### vii. Since marine gas oil is high sulfur diesel fuel and removal of sulfur emits more GHG, the production of marine gas oil emits less GHG than the production of land-use diesel fuel based on life cycle inventories. The difference of life cycle GHG emission analysis results between B20 biodiesel and marine gas
oil should be lower than the difference between B20 biodiesel
and land-use diesel fuel. Thus , the latter provides a useful upper bound of the former.
viii. Energy use for the water mode in 2025 is estimated to be236 

### 1.43×10 15 

### BTU. 1,3



### ix. For marine fuel consumption, re sidual fuel oil for freight ships
is about 60% of total marine fuel use. Distillate fuel for freight ships is about 11% of total marine fuel use. Distillate fuel for other ships (such as passenger ships, fish ships, military ships)
accounts for other 29% of marine fuel use. 112 

### Thus, distillate fuel for freight ships is estimated to be 15% of total fuel for freight ships.
(b) Calculation: i. Even though maximum B2 0 biodiesel production capacity for the water mode in 2025 may reach 25 .7% of total fuel for freight ships, but only 15% of total fuel for freight ships are distillate
fuel.

ii. Maximum B20 biodiesel for the water mode in 2025 is
estimated to be 0.215×10 15 

### BTU.

BTU 10 215

. 0 % 15 BTU 10 43

. 1 15 15 × = × ×



### iii. The annual GHG emissions reduc tions are estimated to be
1.48×10 6 

### tons CO 2 

### eq. in 2025.

. eq CO tons 10 48

. 1 BTU 10 . eq CO 0069

. 0 BTU 10 215

. 0 2 6
6 2 15 × = × ×



### (c) Results: The annual GHG emissions reductions are estimated to be
1.48×10 6 

### tons CO 2 

### eq. in 2025.

E. Estimate of annual energy use reduction:
i. Energy use reduction based on life cycle inve ntory is estimated to be -8.3%, which is estimated in Appendix A.33.E.
ii. Energy use reduction based on life cycle inventory is estimated to be -1.8×10 13 

### BTU

BTU 10 8

. 1 BTU 10 215

. 0 %. 3

. 8 13 15 ×

− = × ×

−



### F. Estimate of unit GHG emissions reductions:237 mile ton . eq CO lb 0050

. 0

ton lbs 000
, 2

. miles ton 10 591 eq CO tons 10 48

. 1 2 9 2 6

− =        

×        

− × ×



### G. Estimate of unit energy use reduction: 

# ( )

mile ton BTU 5

. 30

. miles ton 10 591 BTU 10 10 8

. 1

9 6 7

− −
=        

− × ×

−



### H. Estimate of capital cost (Not available)

I. Estimate of annual O & M cost 

### (Not available)

J. Estimate of annualized cost: i. The average fuel cost of B100 Biodiese l in April 2005 is estimated to be $22.2 per 10 6



### BTU. 137



### ii. High sulfur diesel fuel price in 2025 is the same as the price of the second season of 2005, which is $18.03/10 6 

### BTU. 115



### iii. Thus, B20 biodiesel fuel price is estimated to be $18.86/10 6 

### BTU, which is $0.83/10 6 

### BTU higher than the price of high sulfur diesel fuel.

iv. Annualized cost is estimated to be $178 ×10 6



### .

6 15
6 10 178 $ BTU 10 215

. 0 BTU 10 83

. 0 $
× = × ×



### K. Estimate of energy cost reduction: (No energy cost reduction)

L. Estimate of net savings:

6 6 

### 10 178 $ 10 178 $ 0 $ ×

− = ×

−238 

### M. Estimate of net savings per unit of GHG emissions reductions:

. eq CO ton 4

. 120 $

. eq CO tons 10 48

. 1 10 178 $

2 2 6 6

−
= × ×

−



### N. Estimate of net savings per unit of energy use reduction: (Not available: This practice has no en ergy use reduction due to an increase in energy use, and it has no net saving due to high a nnualized cost and no energy cost saving).

O. Estimate of simple payback period: (Not available: there is no pay-back peri od for this practice because there is no net saving).239 

### APPENDIX E. DETAILS OF INPUT DATA, ASSUMPTIONS, AND ESTIMATION
RESULTS FOR PIPELINE MODE BEST PRACTICES

This appendix is additional descriptive information for the best practices in Chapter 8, including the standardized reporting tables, if th eir corresponding best practices can be assessed quantitatively, or the simplified summary tabl es, if their correspondi ng best practices are assessed qualitatively. For those assessed quantit atively, the methods for the estimation of data in the standardized reporting tables are also described.

Appendix E.1 Best Practice 5-1: Convert Natural Gas Pneumatic Controls to
Instrument Air This best practice is assessed quantitativel y. Table E-1 summarizes the assessment results. This table is in the format of the standardized reporting table for quantitative results. The basis of the quantitative estimates is explained.

A. Estimate of total number of vehicles or devices:
(a) Assumption: The growth rate of pneuma tic control devices is the same as the growth rate of total GHG emissions for the pipeline mode.
(b) 2003 Results: It is estimated that th ere were 110,000 pneumatic control devices in the pipeline mode in 2003. 117



### (c) 2025 Results: Since total GHG emissions fo r the pipeline mode is estimated to grow by 14.6% from 2003 to 2025, wh ich is explained in Section 1.2, there will be 126,100 pneumatic control devices in 2025.

B. Estimate of annual trans port activity for the mode:
(a) Assumption: The growth rate of total tran sport activity is the same as the growth rate of total GHG emissions for the pipeline mode.
(b) 2003 Results: It is esti mated that there were 335×10 9 

### ton-miles in 2003. 3



### (c) 2025 Results: Since total GHG emissions th e pipeline mode is estimated to grow by 14.6% from 2003 to 2025, which is explained in Section 1.2,
there will be 384 ×10 9 

### ton-miles in 2025.240 

### Table E-1. Standardized Reporting Table for Be st Practice 5-1, Convert Natural Gas Pneumatic Controls to Instrument Air a Characteristics of the Practice Description

Practice Name Convert Natural Gas Pneumatic Controls to Instrument Air Mode Type Pipeline Subgroup Process Control Device Improvement Responsible Parties 70, 71, 72, 73 Target Parties 26, 27, 28 Target GHGs CH 4 Strategy Type Technology

Practice Goals Goal is to have 10% of natural gas-powered pneumatic control systems participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.50% (0.65 ×10 6 tons of CO 2 eq.) and 0.13% (1.20 ×10 12 Btu), respectively. Developmental Status C Practice Summary Pneumatic control systems for pipelines are currently operated using pressurized natural gas. However, pneumatic controls based on compressed air could be used instead. Since natural gas is continuously bled from the current control devices, they are one of the largest methane emissions sources in the natural gas industry. Conversion of pneumatic control systems from natural gas to compressed air would reduce methane emissions Emissions, Energy Use, and Refrigerant Use Unit Value

Annual Transport Activity for the Mode (ATAM) 10 9 ton-miles/year 384 Annual Transport Activity to Which a Practice Is Applicable (ATAP) 10 9 ton-miles/year 384 Annual GHG Emissions Reductions(AGR) 10 6 ton CO 2 eq./year 0.65 Annual Energy Use Reduction (AER) 10 12 BTU /year 1.20 Annual Refrigerant Use Reduction (ARR) lbs/year N/A Unit GHG Emissions Reductions (UGER) 10 -3 lb CO 2 eq./ton-mile 3.4 Unit Energy Use Reduction (UER) BTU /ton-mile 3.1 Unit Refrigerant Use Reduction (URR) lbs/ton-mile N/A Practice Costs

Capital Cost (C) 10 6 USD ($) 3.7 Discount Rate (r) % 10% Technical Lifetime of Technology (L) years 15 Fixed Charge Factor (a) year -1 0.131 Annual O & M Cost (AOM) $10 6 /year 1.2 Annualized Cost (AC) $10 6 /year 1.7 Annual Energy Cost Saving (AECS) $10 6 /year 13.2241 Annual Refrigerant Cost Saving (ARCS) $10 6 /year N/A Net Savings (NS) $10 6 /year 11.5 Net Savings per Unit of GHG Emissions Reductions (NSGR) $/ton CO 2 eq. 17.6 Net Savings per Unit of Energy Use Reduction (NSER) $/10 6 BTU 9.6 Net Savings per Unit of Refrigerant Use Reduction (NSRR) $/lb N/A Simple Payback Period (SPP) years 0.31

a These assessments are based on the assumptions th at these best practices reach their potential

maximum market shares in 2025.



### C. Estimate of annual transport activity to which a practi ce is applicable:
Annual transport activ ity to which this practice is appl icable is the same as the total ton-miles of this mode, which is explained in Appendix E.1.B.

D. Estimate of annual GHG emissions reductions:
(a) Assumption: i. Total GHG emissions reductions are due to methane emission
reduction.
ii. The natural gas pipe line mode emits 38.3 ×10 6 

### tons CO 2 

### by using energy and emits 74.9 ×10 6 

### tons CO 2 

### eq. of methane in 2003 because of the leakage of natural gas. 1 

### Thus, the pipeline
mode emits 113.2×10 6 

### tons CO 2 

### eq. of GHG in 2003. Since the pipeline mode is estimated to grow by 15% from 2003 to 2025, there will be 129.6 ×10 6 

### tons CO 2 

### eq. of GHG for the pipeline mode in 2025.
iii. Pneumatic control devices in the natural gas industry is estimated to emit 949 Gg of methane in 2003. 1



### iv. The pipeline mode in the natura l gas industry is its transmission sector, which emit 26% of methane. 117



### v. Approximately 10% of pneumatic control systems powered by natural gas are assumed to be replaced by pneumatic control systems powered by compressed instrument air. Thus, 12,610 of pneumatic control devices are estimated to be replaced in
2025.242 

### vi. Since pneumatic control systems powered by compressed instrument air consume electricity,12,610 of pneumatic control
devices are estimated to consume 11×10 6 

### kWh of electricity. 117



### vii. The estimated emission factor for electricity is 0.0007 tons CO 2 

### eq. per kWh. 108



### (b) Calculation: i. Pneumatic control devices for the pipeline mode are estimated to
emit 5.71×10 6 

### tons CO 2 

### eq. of GHG in 2003.



### . eq CO Tons 10 71

. 5 lb 000
, 2 Ton

g 6

. 453 lb Gg g 10
CH . eq CO 21 % 26 CH Gg 949

2 6 9

4 2
4



### × =      

× × × × ×

ii. Since the pipeline mode is es timated to grow by 15% from 2003 to 2025, there will be 6.55 ×10 6 

### tons CO 2 

### eq. of GHG emitted from the pneumatic control devices in 2025.



### . eq CO Tons 10 55

. 6 % 15

. eq CO Tons 10 71

. 5 2 6 2 6 

### × = × ×

iii. Total methane emissions reductions in 2025 due to the replacement of 10% of pneumatic control devices are estimated
to be 0.655×10 6 

### tons CO 2 

### eq.

. eq CO tons 10 655

. 0 % 10

. eq CO tons 10 55

. 6 2 6 2 6 × = × ×



### iv. Total GHG emissions due to using electricity to power 12,610 of pneumatic control devices are estimated to be 0.008 ×10 6 

### tons
CO 2 

### eq.
v. Thus, total GHG emissions re ductions are estimated to be
0.65×10 6 

### tons CO 2 

### eq. in 2025.



### . eq CO Tons 10 5

. 6 . eq CO Tons 10 008

. 0

. eq CO Tons 10 655

. 0

2 6 2 6 2 6



### × = ×

− ×

(c) Results: The annual GHG emissions reductions are estimated to be243 

### 0.65×10 6 

### tons CO 2 

### eq. in 2025.

E. Estimate of annual energy use reduction:
(a) Assumption: i. Total energy use reduc tion is that natural gas emission reduction minuses energy for producing electric ity for operating this practice.
ii. 1 lb of natural gas contains 21,300 BTU of energy, which is explained in Appendix F.1.6.
iii. 1 kWh is equal to 3,412 BTU.
iv. The ratio of primary energy input to electricity output is estimated to be 2.89 based on total electricity generated and total primary energy consumed in the U.S. in 2005. 133



### (b) Calculation: i. Natural gas emission re duction in 2025 for adopting this practice is
estimated to be 1.33×10 12 

### BTU.



### . BTU 10 33

. 1 % 115 lb BTU 300
, 21

g 6

. 453 lb Gg g 10 % 10 % 26 CH Gg 949

12 9

4



### × = ×        

× × × × ×

ii. Primary energy needed for produci ng electricity in order to operate this practice in 2025 is estimated to be 0.11×10 12 

### BTU.



### BTU 10 11

. 0 89

. 2 kW h BTU 3412 kWh 10 11 12 6 

### × = × × ×

iii. The estimated annual energy use reduction in 2025 is 1.2×10 6 

### (10 6 

### BTU). 

# ( ) BTU 10 10 2

. 1 BTU 10 11

. 0 BTU 10 33

. 1 6 6 12 12 

### × = ×

− ×

(c) Results: The estimated annual en ergy use reduction in 2025 is 1.2 ×10 6 

### (10 6 

### BTU).

F. Estimate of unit GHG emissions reductions:244 mile ton . eq CO lb 0034

. 0

ton lbs 000
, 2

. miles ton 10 384 eq CO tons 10 65

. 0 2 9 2 6

− =        

×        

− × ×



### G. Estimate of unit energy use reduction: 

# ( )

mile ton BTU 1

. 3

. miles ton 10 384 BTU 10 10 2

. 1

9 6 6

− =        

− × ×



### H. Estimate of capital cost i. The capital cost for this practice for a facility is estimated to be $50,000, and this practice in this facility re duces natural gas emissions by 0.02 billion cubic feet (BcF). 117



### ii. Natural gas emission reduction from adoptin g this practice for the pipeline mode is

estimated to be 1.5 BcF in 2025.



### . BcF 5

. 1 % 115 lb lbs 04246

. 0

g 6

. 453 lb Gg g 10 % 10 % 26 CH Gg 949 9

4



### = ×        

× × × × ×

iii. Total capital costs for adopting this pr actice in 2025 are estimated to be $3.7 ×10 6



### .

6 10 7

. 3 $ BcF 02

. 0 BcF 5

. 1 000
, 50 $ × = ×



### I. Estimate of annual O & M cost 

### i. The annual O & M cost for this practice for a facility is estimated to be $3,200, and this

practice in this facility re duces natural gas emissions by 0.02 billion cubic feet (BcF). 117



### ii. The annual electric ity cost for this pract ice for a facility is estimated to be $13,140, and

this practice in this facility reduces natu ral gas emissions by 0. 02 billion cubic feet (BcF). 117



### iii. Natural gas emission reduction from adoptin g this practice for the pipeline mode is

estimated to be 1.5 BcF in 2025, which is estimated in Appendix F.1.H.

iv. The annual O & M costs, which include the electricity cost, for adopting this practice245 

### in 2025 are estimated to be $1.2 ×10 6



### .


## ( ) 6 10 2

. 1 $ BcF 02

. 0 BcF 5

. 1 200
, 3 $ 140
, 13 $ × = × +



### J. Estimate of annualized cost: i. The life-time of this practice is estimated to be 15 years.
ii. Fixed charge factor is estimated to be 0.131. 

## ( )
( ) 131

. 0

1

. 0 1 1

1 a factor e arg ch Fixed

15

1 i i =                

+ = 

## ∑

=


### iii. Annualized cost is estimated to be $1.7 ×10 6 

### in 2025. 

# ( ) 6 6 6 10 7

. 1 $ 10 2

. 1 $$ 131

. 0 10 7

. 3 $ × = × + × ×



### K. Estimate of energy cost reduction: (a) Assumption: i. Natural gas price in 2 025 is the same as the price of September 2005, which is $10.26 per thousand cubic feet. 114



### ii. Heating value of natural gas is estimated to be 1,031 BTU per
cubic feet. 145



### ii. Thus, natural gas price in 2025 is estimated to be $9.95/10 6



### BTU.
(b) Calculation: i. Natural gas reduction is estimated to be 1.33×10 12 

### BTU, which is estimated in Appendix E.1.E.
ii. The estimated energy cost reduction in 2025 is $13.2 ×10 6



### . 

# ( ) 6
6 6 6 10 2

. 13 $ BTU 10 95

. 9 $ BTU 10 10 33

. 1 × = × ×



### (c) Results: The estimated energy cost reduction in 2025 is $13.2 ×10 6



### .

L. Estimate of net savings:

6 6 6 

### 10 5

. 11 $ 10 7

. 1 $ 10 2

. 13 $ × = ×

− ×246 

### M. Estimate of net savings per unit of GHG emissions reductions:



### . eq CO ton 6

. 17 $

. eq CO tons 10 65

. 0 10 5

. 11 $

2 2 6 6



### = × ×

N. Estimate of net savings per unit of energy use reduction:

BTU 10 6

. 9 $
BTU 10 2

. 1 10 5

. 11 $

6 12 6

= × ×



### O. Estimate of simple payback period: 

# ( ) years 31

. 0 10 2

. 1 $ 10 2

. 13 $ 10 7

. 3 $

6 6 6

= ×

− × ×247 

### Appendix E.2 Best Practice 5-2: Replace High-Bleed Natural Gas Pneumatic Devices
with Low-Bleed Pneumatic Devices This best practice is assessed quantitativel y. Table E-2 summarizes the assessment results. This table is in the format of the standardized reporting table for quantitative results. The basis of the quantitative estimates is explained.

A. Estimate of total number of vehicles or devices:
(a) Assumption: Annual per-device GHG em issions in 2025 are the same as annual per-device GHG emissions in 2003 for the pipeline mode.
(b) 2003 Results: i. It is estimated that there were 110,000 pneumatic control devices in the pipeline mode in 2003. 117



### ii. Approximately 26% of pneumatic control devices are high-bleed
devices.

iii. Thus, it is estimated th at there were 28,600 high-bleed pneumatic control devices in the pipeline mode in 2003.
(c) 2025 Results: Since total GHG emissions fo r the pipeline mode is estimated to grow by 14.6% from 2003 to 2025, wh ich is explained in Section 1.2, there will be 32,800 high-bleed pneumatic control devices in
2025.

B. Estimate of annual trans port activity for the mode:
Annual transport ac tivity for this mode is ex plained in Appendix E.1.B.

C. Estimate of annual transport activity to which a practi ce is applicable:
Annual transport activ ity to which this practice is appl icable is the same as the total ton-miles of this mode, which is explained in Appendix E.1.B.248 

### Table E-2. Standardized Reporting Table for Best Practice 5-2, Replace High-Bleed Natural Gas Pneumatic Devices with Low-Bleed Pneumatic Devices a Characteristics of the Practice Description

Practice Name Replace High-Bleed Natural Gas Pneumatic Devices with Low-Bleed Pneumatic Devices Mode Type Pipeline Subgroup Process Control Device Improvement Responsible Parties 70, 71, 72, 73 Target Parties 26, 27, 28 Target GHGs CH 4 Strategy Type Technology

Practice Goals Goal is to have 26% of natural gas-powered pneumatic control systems participate. The reductions in modal GHG emissions in 2025 would be 0.57% (0.75 ×10 6 tons of CO 2 eq.) and 0.16% (1.5 ×10 12 Btu), respectively. Developmental Status C Practice Summary High-bleed pneumatic control systems are based on high- b leed compressed methane. An alternative designed is based on low-bleed compressed methane that reduces methane emission. Emissions, Energy Use, and Refrigerant Use Unit Value

Annual Transport Activity for the Mode (ATAM) 10 9 ton-miles/year 384 Annual Transport Activity to Which a Practice Is Applicable (ATAP) 10 9 ton-miles/year 384 Annual GHG Emissions Reductions(AGR) 10 6 ton CO 2 eq./year 0.75 Annual Energy Use Reduction (AER) 10 12 BTU /year 1.5 Annual Refrigerant Use Reduction (ARR) lbs/year N/A Unit GHG Emissions Reductions (UGER) 10 -3 lb CO 2 eq./ton-mile 3.9 Unit Energy Use Reduction (UER) BTU /ton-mile 3.9 Unit Refrigerant Use Reduction (URR) lbs/ton-mile N/A Practice Costs

Capital Cost (C) 10 6 USD ($) 13.6 Discount Rate (r) % 10% Technical Lifetime of Technology (L) years 15 Fixed Charge Factor (a) year -1 0.131 Annual O & M Cost (AOM) $10 6 /year N/A Annualized Cost (AC) $10 6 /year 1.8 Annual Energy Cost Saving (AECS) $10 6 /year 15.0 Annual Refrigerant Cost Saving (ARCS) $10 6 /year N/A Net Savings (NS) $10 6 /year 13.2 Net Savings per Unit of GHG Emissions Reductions (NSGR) $/ton CO 2 eq. 17.8 Net Savings per Unit of Energy Use Reduction (NSER) $/10 6 BTU 8.8 Net Savings per Unit of Refrigerant Use Reduction (NSRR) $/lb N/A249 Simple Payback Period (SPP) years 0.91

a These assessments are based on the assumptions th at these best practices reach their potential

maximum market shares in 2025.



### D. Estimate of annual GHG emissions reductions:
(a) Assumption: i. Total GHG emissions re ductions are due to methane emission
reduction.
ii. Approximately 86% of high-bleed pneumatic control devices are level controllers, and a level controller is estimated to averagely
emit 66.6×10 3 

### cubic feet of methane per year. 118



### iii. Approximately 14% of high-bleed pneumatic control devices are pressure controllers, and a pressu re controller is estimated to averagely emit 91.2×10 3 

### cubic feet of methane per year. 118



### iv. The replacement of high-bleed pneumatic control devices by low-bleed pneumatic control devices reduce methane emissions by
90%. 119



### v. Approximately 80% of high-bleed pneumatic control systems can be replaced by low-bleed pneumatic control systems. 118



### (b) Calculation: i. Total methane emission reduction is estimated to be 1.67 BcF in
2003. 

# ( ) ( ) 

# [ ] ( )

BcF 67

. 1 % 80 800
, 32 % 90 % 14 ft 10 2

. 91 % 86 ft 10 6

. 66 3 3 3 3



### = × × × × × + × ×

ii. Total methane emission reductio n is estimated to be 0.745×10 6



### tons CO 2 

### eq. in 2003.



### . eq CO Tons 10 745

. 0 lb 000
, 2 Ton
CH . eq CO 21
ft lbs 04246

. 0 BcF 67

. 1

2 6 4 2
3



### × =        

× × ×

(c) Results: The annual GHG emissions re ductions are estima ted to be 0.745×10 6



### tons CO 2 

### eq. in 2025.250 

### E. Estimate of annual energy use reduction:
The estimated annual energy use reduction in 2025 is 1.5 ×10 12 

### BTU.



### BTU 10 5

. 1 lb BTU 300
, 21
ft lbs 04246

. 0 BcF 67

. 1 12
3 

### × =        

× ×

F. Estimate of unit GHG emissions reductions:

mile ton . eq CO lb 0039

. 0

ton lbs 000
, 2

. miles ton 10 384 eq CO tons 10 745

. 0 2 9 2 6

− =        

×        

− × ×



### G. Estimate of unit energy use reduction: 

# ( )

mile ton BTU 9

. 3

. miles ton 10 384 BTU 10 10 5

. 1

9 6 6

− =        

− × ×



### H. Estimate of capital cost i. The capital cost for a level controller is es timated to be $380, and the capital cost for a

pressure controller is estimated to be $1,340. 118



### ii. Total capital costs for adopting this practice in 2025 are estimated to be $13.6 ×10 6



### . 

## ( )( ) 

## [ ] ( ) 6 10 6

. 13 $ % 80 800
, 32 % 14 340
, 1 $ % 86 380 $ × = × × × + ×



### I. Estimate of annual O & M cost


### The O & M cost of a low-bleed device is estima ted to be the same as the O & M cost of a high-bleed device. Thus, the change of the O & M cost for this practice is zero.

J. Estimate of annualized cost: i. The life-time of this practice is estimated to be 15 years.
ii. Fixed charge factor is estimated to be 0.131.251 

## ( )
( ) 131

. 0

1

. 0 1 1

1 a factor e arg ch Fixed

15

1 i i =                

+ = 

## ∑

=


### iii. Annualized cost is estimated to be $1.78 ×10 6 

### in 2025. 

# ( ) 6 6 10 78

. 1 $ 131

. 0 10 6

. 13 $ × = × ×



### K. Estimate of energy cost reduction: (a) Assumption: Natural gas price in 2025 is estimated to be $9.95/10 6 

### BTU, which is estimated in Appendix E.1.K.
(b) Calculation: i. Natural gas reduction is estimated to be 1.5×10 12 

### BTU, which is estimated in Appendix E.2.E.
ii. The estimated energy cost reduction in 2025 is $15.0 ×10 6



### . 

# ( ) 6
6 6 6 10 0

. 15 $ BTU 10 95

. 9 $ BTU 10 10 5

. 1 × = × ×



### (c) Results: The estimated energy cost reduction in 2025 is $15.0 ×10 6



### .

L. Estimate of net savings:

6 6 6 

### 10 24

. 13 $ 10 78

. 1 $ 10 0

. 15 $ × = ×

− ×

M. Estimate of net savings per unit of GHG emissions reductions:



### . eq CO ton 8

. 17 $

. eq CO tons 10 745

. 0 10 24

. 13 $

2 2 6 6



### = × ×

N. Estimate of net savings per unit of energy use reduction:

BTU 10 8

. 8 $
BTU 10 5

. 1 10 24

. 13 $

6 12 6

= × ×



### O. Estimate of simple payback period: 

# ( ) years 91

. 0 10 0

. 15 $ 10 6

. 13 $

6 6

= × ×252 

### Appendix E.3 Best Practice 5-3: “Hot Tap” Method This best practice is assessed quantitativel y. Table E-3 summarizes the assessment results. This table is in the format of the standardized reporting table for quantitative results. The basis of the quantitative estimates is explained.

A. Estimate of total number of vehicles or devices:
(a) Assumption: The growth rate of total pi peline length is the same as the growth rate of total GHG emissions for the pipeline mode.
(b) 2003 Results: It is estimated that there were 285,165 miles of pipelines for the pipeline mode in 2003. 1



### (c) 2025 Results: Since total GHG emissions fo r the pipeline mode is estimated to grow by 14.6% from 2003 to 2025, wh ich is explained in Section 1.2, there will be 326,900 mile s of pipelines in 2025.

B. Estimate of annual trans port activity for the mode:
Annual transport ac tivity for this mode is ex plained in Appendix E.1.B.

C. Estimate of annual transport activity to which a practi ce is applicable:
Annual transport activ ity to which this practice is appl icable is the same as the total ton-miles of this mode, which is explained in Appendix E.1.B.

D. Estimate of annual GHG emissions reductions:
(a) Assumption: i. Total GHG emissions reductions are due to methane emission
reduction.
ii. A Canadian natural gas company, which own 23,000 miles of pipelines, adopted this practice and reduce methane by 8.4×10 3


### tons per year. 121253 

### Table E-3. Standardized Reporting Table fo r Best Practice 5-3, “Hot Tap” Method a Characteristics of the Practice Description

Practice Name “Hot Tap” Method Mode Type Pipeline Subgroup Connecting Method Responsible Parties 70, 71, 72, 73 Target Parties 26, 27, 28, 29 Target GHGs CH 4 Strategy Type Technology

Practice Goals Goal is to have all pipeline systems participate. The reductions in modal GHG emissions in 2025 would be 1.93% (2.5 ×10 6 tons of CO 2 eq.) and 0.54% (5.1 ×10 12 Btu), respectively. Developmental Status C Practice Summary Methods for constructing new pipeline connections for an existing, operational pipeline usually result in significant venting of natural gas. In contrast, the “hot tap” pipeline connecting method is a commercially available technology that reduces GHG emissions. This method avoids the need for venting natural gas. It involves attaching a branch pipeline connection on the outside of an operating pipeline and cutting out the inside pipeline wall. Emissions, Energy Use, and Refrigerant Use Unit Value

Annual Transport Activity for the Mode (ATAM) 10 9 ton-miles/year 384 Annual Transport Activity to Which a Practice Is Applicable (ATAP) 10 9 ton-miles/year 384 Annual GHG Emissions Reductions(AGR) 10 6 ton CO 2 eq./year 2.5 Annual Energy Use Reduction (AER) 10 12 BTU /year 5.1 Annual Refrigerant Use Reduction (ARR) lbs/year N/A Unit GHG Emissions Reductions (UGER) 10 -3 lb CO 2 eq./ton-mile 13 Unit Energy Use Reduction (UER) BTU /ton-mile 13 Unit Refrigerant Use Reduction (URR) lbs/ton-mile N/A Practice Costs

Capital Cost (C) 10 6 USD ($) 8.3 Discount Rate (r) % 10% Technical Lifetime of Technology (L) years 15 Fixed Charge Factor (a) year -1 0.131 Annual O & M Cost (AOM) $10 6 /year 9.9 Annualized Cost (AC) $10 6 /year 11.0 Annual Energy Cost Saving (AECS) $10 6 /year 50.6 Annual Refrigerant Cost Saving (ARCS) $10 6 /year N/A Net Savings (NS) $10 6 /year 39.6 Net Savings per Unit of GHG Emissions Reductions (NSGR) $/ton CO 2 eq. 15.8254 Net Savings per Unit of Energy Use Reduction (NSER) $/10 6 BTU 7.8 Net Savings per Unit of Refrigerant Use Reduction (NSRR) $/lb N/A Simple Payback Period (SPP) years 0.2

a These assessments are based on the assumptions th at these best practices reach their potential maximum market shares in 2025.



### (b) Calculation: Total methane emissi on reduction is estimated to be 2.5×10 6 

### tons
CO 2 

### eq. in 2025.



### . eq CO Tons 10 5

. 2 miles 000
, 23 miles 900
, 326
CH . eq CO 21 CH tons 10 4

. 8

2 6 4 2
4 3



### × =        

× × ×

(c) Results: The annual GHG emissions re ductions are estimat ed to be 2.5×10 6



### tons CO 2 

### eq. in 2025.

E. Estimate of annual energy use reduction:
The estimated annual energy use reduction in 2025 is 5.1 ×10 12 

### BTU.



### BTU 10 1

. 5 miles 000
, 23 miles 900
, 326
lb BTU 300
, 21

ton lbs 000
, 2 CH tons 10 4

. 8 12 4 3 

### × = ×        

× × ×

F. Estimate of unit GHG emissions reductions:

mile ton . eq CO lb 013

. 0

ton lbs 000
, 2

. miles ton 10 384 eq CO tons 10 5

. 2 2 9 2 6

− =        

×        

− × ×



### G. Estimate of unit energy use reduction: 

# ( )

mile ton BTU 2

. 13

. miles ton 10 384 BTU 10 10 1

. 5

9 6 6

− =        

− × ×255 

### H. Estimate of capital cost i. The capital cost for this practice for a company is estimated to be $36,200, and this

practice reduces methane emissions by 0.0244 BcF for this company. 122



### ii. Methane emission reduction from adopting this practice for the pipeline mode is

estimated to be 5.61 BcF in 2025.



### BcF 61

. 5 miles 000
, 23 miles 900
, 326
lbs 04246

. 0 ft

ton lbs 000
, 2 CH tons 10 4

. 8 3

4 3 

### = ×        

× × ×

iii. Total capital costs for adopting this pr actice in 2025 are estimated to be $8.32 ×10 6



### .

6 10 32

. 8 $ BcF 0244

. 0 BcF 61

. 5 200
, 36 $ × = ×



### I. Estimate of annual O & M cost 

### i. The annual O & M cost for this practice for a company is estimated to be $43,000, and

this practice reduces methane emissions by 0.0244 BcF for this company. 122



### ii. The annual O & M costs for adopting this practice in 2025 are es timated to be $9.89
×10 6



### .


## ( ) 6 10 89

. 9 $ BcF 0244

. 0 BcF 61

. 5 000
, 43 $ × = ×



### J. Estimate of annualized cost: i. The life-time of this practice is estimated to be 15 years.
ii. Fixed charge factor is estimated to be 0.131. 

## ( )
( ) 131

. 0

1

. 0 1 1

1 a factor e arg ch Fixed

15

1 i i =                

+ = 

## ∑

=


### iii. Annualized cost is estimated to be $11.0 ×10 6 

### in 2025. 

# ( ) 6 6 6 10 0

. 11 $ 10 89

. 9 $ 131

. 0 10 32

. 8 $ × = × + × ×256 

### K. Estimate of energy cost reduction: (a) Assumption: Natural gas price in 2025 is estimated to be $9.95/10 6 

### BTU, which is estimated in Appendix E.1.K.
(b) Calculation: i. Natural gas reduction is estimated to be 5.1×10 12 

### BTU, which is estimated in Appendix E.3.E.
ii. The estimated energy cost reduction in 2025 is $50.6 ×10 6



### . 

# ( ) 6
6 6 6 10 6

. 50 $ BTU 10 95

. 9 $ BTU 10 10 1

. 5 × = × ×



### (c) Results: The estimated energy cost reduction in 2025 is $50.6 ×10 6



### .

L. Estimate of net savings:

6 6 6 

### 10 6

. 39 $ 10 0

. 11 $ 10 6

. 50 $ × = ×

− ×

M. Estimate of net savings per unit of GHG emissions reductions:



### . eq CO ton 8

. 15 $

. eq CO tons 10 5

. 2 10 6

. 39 $

2 2 6 6



### = × ×

N. Estimate of net savings per unit of energy use reduction:

BTU 10 8

. 7 $
BTU 10 1

. 5 10 6

. 39 $

6 12 6

= × ×



### O. Estimate of simple payback period: 

# ( ) years 20

. 0 10 89

. 9 $ 10 6

. 50 $ 10 32

. 8 $

6 6 6

= ×

− × ×257 

### Appendix E.4 Best Practice 5-4: Transfer Compression

This best practice is assessed qualitatively. Table E-4 summarizes the assessment results in the standardized simplified reporting table format.

Table E-4. Simplified Summary Table for Best Practice 5-4, Transfer Compression Attribute Description

Practice Name Transfer Compression Mode Type Pipeline Subgroup Maintenance Responsible Parties 70, 71, 72 Target Parties 26, 27, 28 Target GHGs CH 4 Strategy Type Technology

Practice Goals Goal is to have all pipeline systems participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.07% and 0.02%, respectively. Developmental Status C Practice Summary During the pipeline maintena nce process, a section of pipe is often isolated and taken out for maintenan ce, and methane is vented from the isolated section. An alternative to ve nting is to transfer the natural gas in the isolated section to an operating section of the pipeline, thereby avoiding loss of methane. A system for doing this is a transfer compressor unit, which is commercially available. Several transfer compressors can be operated simultaneously to increase the methane recovery rate. Potential Reductions in Modal GHG Emissions 0.07%

Potential Reduction in Modal Energy Use 0.02%

Potential Reduction in Modal HFC Use N/A

Cost Information N/A Benefits and Drawbacks N/A258 

### Appendix E.5 Best Practice 5-5: Inline Inspection

This best practice is assessed qualitatively. Table E-5 summarizes the assessment results in the standardized simplified reporting table format.

Table E-5. Simplified Summary Table fo r Best Practice 5-5, Inline Inspection Attribute Description

Practice Name Inline Inspection Mode Type Pipeline Subgroup Maintenance Responsible Parties 70, 71, 72, 73 Target Parties 26, 27, 28 Target GHGs CH 4 Strategy Type Technology

Practice Goals Goal is to have all pipeline systems participate. The reductions in modal GHG emissions and energy use in 2025 would be 1.32% and 0.37%, respectively. Developmental Status C Practice Summary Pipeline flaws, especia lly stress corrosion cracking (SCC), cause pipeline failure that are of safety concern and that lead to fugitive methane emissions. A pipeline inline inspection (ILI) tool, referred to as “smart pig,” was originally desi gned to inspect internal pipeline conditions, such as dents or meta l loss, by using ultrasound. A ultrasound inline inspection tool based on a newer design can detect not only dents or metal loss, but also SCC. This new tool is able to locate more pipeline flaws. By identifying and correcting such flaws sooner, fugitive methane emissions can be reduced. Potential Reductions in Modal GHG Emissions 1.32%

Potential Reduction in Modal Energy Use 0.37%

Potential Reduction in Modal HFC Use N/A

Cost Information N/A Benefits and Drawbacks This upgraded tool can find more flaws in the pipeline system and, therefore, enable quickly corrective action lead to larger reductions in fugitive methane emissions.259 

### APPENDIX F. FUEL PROPERTIES, CO 2 

### EMISSIONS COEFFICIENTS FOR FULES,
AND AVERAGE UNIT FUEL COSTS FOR GUIDEBOOK

APPENDIX F.1 Properties of Different Fuels
Many of the GHG emissions from freight transpor tation sector are related to fuel use, and are influenced by the types of fuels and the properti es of fuels. Major fuels used in the freight transportation sector include diesel fuel, jet fuel, residual fuel oil, biodiesel, and natural gas. For these fuels, there are usually a number of pa rameters that are used to measure chemical and physical properties. These fuel properties im pact the performance of vehicle operation and influence the fuel usage and the GHG emissions from freight transportation. For example, the energy density of the fuel will have an affect on the apparent fuel economy. 131 

### This section describes the important parameters for measur ing fuel properties, and discusses the fuel properties of diesel fuel, jet fuel, residua l fuel oil, biodiesel , and natural gas.

F.1.1 Definitions of Fuel Properties The following subsections describe several fu el properties, includi ng specific gravity, cetane number, distillation range, aromatic content, heating value, and viscosity, which influence the performance of vehicle operation and w ould impact greenhouse gas emissions from the freight transportation.

F.1.1.1 Specific Gravit y The specific gravity is defined as the ratio of the density of the fu el to the density of
water at 60°F. 131



### F.1.1.2 Cetane Number One key property of diesel fuel is the ease w ith which it ignites, quantified by the cetane number, with higher numbers indicating greater i gnitability. The cetane number is the standard measure of fuel ignition characteristics when inject ed into a diesel engine. It relates to the delay between when fuel is injected into the cylin der and when ignition occurs. Higher cetane number indicates shorter times between injecti on of the fuel and its ignition. Good ignition from a high cetane number assists in easy starti ng, starting at low temperature, low ignition pressures, and smooth operation wi th lower knocking characteristics. 131 

### Large, slower speed engines, as used in locomotive and marine a pplications, are more tolerant of poor-quality260 

### fuels. 146



### F.1.1.3 Distillation Range Distillation range refers to th e range of boiling points of di fferent liquid fractions of the fuel, which are observed when sepa rating the fuel into its component s. The distillation range is generally expressed in terms of the temperatures at whic h 10 percent (T10), 50 percent (T50), and 90 percent (T90) of the fuel will be evapor ated. The highest temperature recorded during distillation is called the end point . However, because a fuel’s end point is difficult to measure with good repeatability, 90 pe rcent distillation point of fuel is commonly used. 131



### F.1.1.4 Aromatic Content Aromatic content is characterized by the pres ence of the benzene family in hydrocarbon compounds in the fuel. Aromatic compounds in clude heavier compounds such as toluene, xylene, and naphthalene. 131



### F.1.1.5 Heating Value The heating value of a fuel is the enthalpy of reaction for combustion of the fuel. Thus, the heating value is the amount of energy released when the fuel is completely burned in a steady flow process. The magnitude of the h eating value depends on the fate of H 2 

### O in the combustion products. In most real systems, the H 2 

### O leaves the engine or com bustor in the vapor phase. For this situation, the Lower Heating Value (LHV) is used. However, in principle, one could condense the water vapor and recove r the latent heat of vaporizati on associated with this phase change. If this could be done, then the total heating value woul d be the sum of the LHV and the latent heat of condensation, which is referred to as th e Higher Heating Value (HHV). 131



### F.1.1.6 Viscosity Viscosity is a measure of the resistance of a fu el to shear or flow, and is a measure of the
fuel's adhesive/cohesive or frictional properties. 131



### F.1.2 Diesel Fuel
Distillate fuel oil is a classification for one of the distillation fraction of petroleum. It
includes diesel fuels and fuel oils. Diesel fuel is a complex mixture of many different hydrocarbons with a distilla tion range of 350 to 640 °F, 131 

### with carbon numbers in the range of C3 to C25, and with an average molecular weight of about 200. 132 

### Current commercial diesel
fuels in the United States include No. 1 diesel fuel, No. 2 diesel fuel, No. 4 diesel fuel, and marine gas oil. 111,146 

### Marine gas oil is one kind of bunker fuel that is used for small and261 

### medium sized marine engines. 111 

### No. 1 diesel fuel is usually us ed in city buses. No. 2 diesel fuel is used in high-speed diesel engines that are operated under load conditions, such as those in
trucks and railroad locomotives. No. 4 diesel fu el is usually used in industrial plants and in commercial burner installions, but is also used for low- and medium-speed diesel engines. 147 

### These fuels can differ with respect to cetane numb er, aromatic content, su lfur level, levels of contaminants (e.g., metals), and viscosity. 146 

### The major fuels related to freight transportation
are No. 2 diesel fuel and marine gas oil. Major properties of No. 2 diesel fuel, the fuel used in trucks and locomotives, are listed in Table F-1. The important differences between No. 2 diesel fuels and marine gas oil are sulfur content and visc osity. The sulfur content of marine gas oil is generally about 1.5-2.0% mass, but the sulfur content of No. 2 diesel fuel is generally about
0.05% mass or lower because sulfur content of No. 2 diesel fuel is restricted by state and federal regulations. The maximum viscosity of marine gas oil is about 6.0-11.0 at 104°F, and the density of marine gas oil is about 0.89-0.90 at 60°F. 148



### Table F-1. Major Properties of No. 2 Diesel Fuel. 131,132,149
Property Value Chemical formula C 3 to C 25

Physical state Liquid Molecular weight ≈ 200 Carbon 84–87 (86.4) Hydrogen 13–16 (13.4) Composition (weight %) Oxygen 0 Specific gravity @ 60  ̊ F 0.81–0.89 (0.84) Cetane Number 40-55 (44) 10% point, °F 410 to 430 50% point, °F 490 to 520 Distillation
range 90% point, °F 585 to 620 Aromatics, vol% 30 Higher (liquid fuel-liquid water) BTU/lb 19,200-20,000 Lower (liquid fuel-water vapor) BTU/lb 18,000-19,000
Higher (liquid fuel-liquid water) BTU/gallon , 138,690-138,700 (138,690) Heating value
Lower (liquid fuel-water vapor) BTU/gallon @ 60  ̊ F 128,400 Viscosity, Centipoise @ 60  ̊ F 2.6-4.1 Freezing point, F  ̊ -40–30 Reid vapor pressure, psi 0.2 BTU/lb @ 60  ̊ F ≈ 100 Latent heat of vaporization BTU/gallon @ 60  ̊ F ≈ 700262 

### F.1.3 Jet Fuel Jet fuel is a refined petroleum pr oduct used in jet aircraft engines. 111 

### Jet fuel includes kerosene-type jet fuel a nd naphtha-type jet fuel. 150 

### Kerosene-type jet fuel, including Grades JP-5 and JP-8, is a kerosene-b ased product that has a distilla tion temperature of 400 degrees Fahrenheit at the 10-percent recovery point a nd a final boiling point of 572 degrees Fahrenheit and meeting ASTM Specification D 1655 and Military Specifications MIL-T-5624P and
MIL-T-83133D. 147 

### MIL-T-5624P is for JP-5 and MIL-T-83133D is for JP-8. 151 

### Naphtha-type jet fuel, usually being Grade JP -4, is a fuel used primarily for military turbojet and turboprop aircraft engines because it has a lower freeze point than other aviation fuels and meets engine requireme nts at high altitudes and speed s. It has 20 to 90 percent distillation temperatures of 290 degrees to 470 degrees Fahr enheit, and meeting Military Specification MIL-T-5624L. It is 147,151 

### From a chemistry standpoint, the composition of jet fuels is quite similar to that of diesel fuel, kerosene or light distilla tes including home heating oil. Jet fuels are relatively safe to transport, store and handle when compared with gasoline. All of these jet fuels have about the similar heating values (around 18,40 0 BTU/lb), but JP-4 is more flammable than JP-8 and both
JP-4 and JP-8 are more flammable than JP-5. The Navy uses JP-5 since shipboard use requires a greater degree of safety. JP-8+100 is a new product that contains an additive package designed to increases the temperature range over which the fuels remains thermally stable by 100 °F. While commercial aircraft still use JP-4, the Navy now uses JP-5, and the Air Force uses
JP-8+100. 152 

### Major properties of jet fu el are listed in Table F-2.

Table F-2. Major Properties of Jet Fuel 151,153
Property JP-4 JP-5 JP-8 Carbon - - - Hydrogen 13.5 13.4 13.4 Composition (weight %) Oxygen - - - Density (kg/L) @ 15  ̊ C 0.751-0.802 0.788-0.845 0.775-0.840 Cetane Number - - 10% point, °C - 205 205 20% point, °C 145 - - 50% point, °C 190 - - 90% point, °C 245 - - Distillation
range End point, °C 270 300 300 Aromatics, vol% 25.0 25.0 25.0 Heating value* Lower (liquid fuel-water vapor) BTU/lb 18,400 18,300 18,400 Viscosity, Centipoise @ 20  ̊ C - 8.5 8.0 Freezing point, F  ̊ -72 -61 -53 Vapor pressure (psi) @ 100  ̊ F 2.0-3.0 - -263 

### F.1.4 Biodiesel
Biodiesel is defined as the mono alkyl esters of long-chai n fatty acids derived from vegetable oils or animal fats, and was develo ped for use in compression-ignition engines. 154 

### Major properties of 100% soybean-based biodiesel are listed in Table F-3.

Table F-3. Major Properties of B100 Biodiesel Blend Stock. 131,154
Property Value Chemical formula C 12 to C 22

Physical state Liquid Carbon 76.9-77.3 Hydrogen 11.8-12.1 Composition (weight %) Oxygen 11.0 Specific gravity @ 60  ̊ F 0.886 - 0.89 (average 0.888) Cetane Number 47.5 10% point, °F 631.4 50% point, °F 636.8 Distillation range 90% point, °F 645.8 Aromatics, vol% 0 Higher (liquid fuel-liquid water) BTU/lb 17,111 Higher (liquid fuel-liquid water) BTU/gallon 126,789 Heating value*
Lower (liquid fuel-water vapor) BTU/lb 15,993 Viscosity, Centipoise @ 104  ̊ F 4.1 Boiling temperature, F  ̊ 573 

### * Higher heating value of biodiesel is about 17,111 BTU/lb, or 126,789 BTU/gallon.

gallon BTU 789
, 126 gallon L 785

. 3
L g 888

g 6

. 453 lb lb BTU 111
, 17 = × × ×



### F.1.5 Residual Fuel Oil Residual fuel oil is a general classification for the heavier oils that remain after the distillate fractions are distilled away in refinery operations. It includes N o. 5 and No. 6 fuel oils and is used for large steam boilers and, with fu el preheating, for very large compression ignition engines, such as ocean-going ships. 111,147 

### No. 5 fuel oil is a residual fuel oil of medium viscosity, and is used in steam -powered vessels in government se rvice and inshore power plants.
No. 6 fuel oil includes marine re sidual fuel oil, another kind of bunker fuel (called Bunker C fuel oil), and is used for electric power plants, space heaters, marine vessels, and various industrial

purposes. 147 

### Major properties of marine residu al fuel oil are listed in Table F-4.264 

### Table F-4. Major Properties of Marine Residual Fuel Oil. 147,148,155
Property Value Specific gravity @ 60  ̊ F 0.991 Sulfur content, % mass 5 Higher heating value, BTU/gallon 149,700

Higher heating value, BTU/lb 19,011 Viscosity, Centipoise @ 122  ̊ F 340 Flash point, F  ̊ 140



### F.1.6 Natural Gas Natural gas is a naturally occurring mixture of hydr ocarbon and non-hydrocarbon gases found in porous geologic formations beneath th e earth's surface, often in association with petroleum. Natural gas is a fossil fuel composed almost entirely of methane, but does contain small amounts of other gases, such as ethane, propane, butane and pentane. 156 

### Major properties of natural ga s are listed in Table F-5. 157



### Table F-5. Major Properties of Natural Gas. 132,145,156,157
Property Value Methane concentration, % Volume 80 - 99

Ethane concentration, % Volume 2.7 - 4.6 Nitrogen concentration, % Volume 0.1 - 15 Carbon dioxide concentration, % Volume] 1 - 5 Sulphur concentration, ppm, mass <5 Physical state Gas Average Molecular weight 17-20 Carbon 73.3 Hydrogen 23.9 Composition (weight %) Oxygen 0.4 Specific gravity @ 59  ̊ F (15  ̊ F) 0.72-0.81 Lower heating value, MJ/kg 38-50 Lower heating value, BTU/lb 16,335-21,493 (21,300) Heating value
Lower heating value, BTU/ft 3 1,031 Freezing point, F  ̊ -296 Reid vapor pressure, psi 2400



### APPENDIX F.2 CO 2 

### Emissions Coefficients for Different Fuels

The total CO 2 

### emissions on a per energy basis depend on the weight percent of carbon in265 

### the fuel, the combustion efficiency, and the heating vale of the fuel. 131



### F.2.1 Diesel Fuel The carbon coefficient of distillate fuel oil, in cluding diesel fuel, is estimated to be 19.95 million metric tons carbon per quadrillion BTU. 13 

### Based on the transformation shown below,
the CO 2 

### emissions coefficient of diesel fu el is estimated to be 0.0808 tons CO 2 

### eq. per 10 6 

### BTU.

BTU CO tons
BTU BTU n quadrillio
carbon

CO

tons metric tons
BTU n quadrillio carbon tons metric

6 2
15 2 6 10 0808

. 0
10 12

44 105

. 1 10 95

. 19 = × × × ×



### F.2.2 Jet Fuel The carbon coefficient of jet fuel is estimated to be 19.33 million metric tons carbon per quadrillion BTU. 13 

### Based on the transformation shown below, CO 2 

### emissions coefficient of jet
fuel is estimated to be 0.0783 tons CO 2 

### eq. per 10 6 

### BTU.

BTU CO tons BTU BTU n quadrillio
carbon

CO

tons metric tons BTU n quadrillio carbon tons metric

6 2 15 2 6 10 0783

. 0
10 12

44 105

. 1 10 33

. 19 = × × × ×



### F.2.3 Biodiesel The net life-cycle CO 2 

### emissions of petroleum di esel are about 0.0938 tons CO 2 

### eq. per 10 6 

### BTU. The net life-cycle CO 2 

### emissions of B20 biodies el is about 0.0869 tons CO 2 

### eq. per 10 6 

### BTU. 61 

### The net life-cycle CO 2 

### emissions reduction is about 0.0069 tons CO 2 

### eq. per 10 6



### BTU.

F.2.4 Residual Fuel Oil
The carbon coefficient of residual fuel oil is estimated to be 21.49 million metric tons carbon per quadrillion BTU. 13 

### Based on the transformation shown below, CO 2 

### emissions
coefficient of residual fuel oil is estimated to be 0.087 tons CO 2 

### eq. per 10 6 

### BTU.

BTU CO tons
BTU BTU n quadrillio
carbon

CO

tons metric tons
BTU n quadrillio carbon tons metric

6 2
15 2 6 10 0870

. 0
10 12

44 105

. 1 10 49

. 21 = × × × ×



### F.2.5 Natural Gas The carbon coefficient of natural gas is esti mated to be 14.47 million metric tons carbon per quadrillion BTU. 13 

### Based on the transformation shown below, CO 2 

### emissions coefficient of natural gas is estimated to be 0.0586 tons CO 2 

### eq. per 10 6 

### BTU.

BTU CO tons
BTU BTU n quadrillio
carbon

CO

tons metric tons
BTU n quadrillio carbon tons metric

6 2
15 2 6 10 0586

. 0
10 12

44 105

. 1 10 47

. 14 = × × × ×266 

### F.2.6 Comparison of CO 2 

### Emissions Coefficients of Different Fuels
The CO 2 

### emissions coefficients of differ ent fuels are listed in Table F-6.

Table F-7. CO 2 

### Emissions Coefficients of Different Fuels
Fuel Name Diesel Fuel Jet Fuel Residual Fuel Oil Natural Gas
CO 2 

### Emissions

Coefficient (tons CO 2 

### eq./
10 6 

### BTU) 0.0808 0.0783 0.0870 0.0586

APPENDIX F.3 Average Unit Costs for Different Fuels
For calculating the average energy unit cost estimate and energy co st reduction in the standardized reporting tables, aver age unit costs of different fuels should be estimated first, and
these unit costs are desc ribed in this section.

F.3.1 Diesel Fuel Diesel price is 2.56 US Dollars per gallon, wh ich was estimated by U.S. Department of Energy for the diesel prices of the second season (Apr il to June) of 2005. 114 

### Also, heating value of diesel is 138,690 BTU per gallon. 13 

### Therefore, the average fuel cost estimate is $18.46/10 6



### BTU.

BTU BTU gallon gallon 6 10 46

. 18 $
690
, 138 56

. 2 $

=        

×        



### F.3.2 Jet Fuel Average market price of jet fuel is about 2.10 US Dollars per gallon, which was estimated by U.S. Energy Information Administration for the jet fuel prices of September 2005. 158 

### Also, heating value of jet fuel is estimated to be 134,000 BTU/gallon. Therefore, the average fuel cost estimate is $15.70/10 6 

### BTU.

BTU BTU gallon gallon 6 10 70

. 15 $
000
, 134 10

. 2 $

=        

×        



### F.3.3 Biodiesel Wholesale B100 biodiesel price around Ap ril 2005 was 2.82 US Dollars per gallon. 137 

### Also, heating value of B100 biodiesel is estim ated to be 126,789 BTU/ga llon. Therefore, the267 

### average fuel cost of B100 Biodiesel is estimated to be $22.2/10 6 

### BTU.

BTU BTU gallon gallon 6 10 2

. 22 $
789
, 126 82

. 2 $

=        

×        



### F.3.4 Residual Fuel Oil Average residual fuel oil price with sulfur greater than 1% is about 1.168 US Dollars per gallon, which was estimated by U.S. Energy Inform ation Administration for the residual fuel oil prices of September 2005. 159 

### Also, heating value of residual fuel oil is estimated to be 149,700 BTU/gallon. Therefore, the aver age fuel cost estimate is $7.80/10 6 

### BTU.

BTU BTU gallon gallon 6 10 80

. 7 $
700
, 149 168

. 1 $

=        

×        



### F.3.5 Natural Gas Average natural gas price for c ity gate is about 10.26 US Do llars per thousand cubic feet, estimated by U.S. Energy Information Administra tion for the natural gas prices of September
2005. 159 

### Also, heating value of natural gas is estimated to be 1,031 BTU per cubic feet. 145 

### Therefore, the average fuel cost estimate is $9.95/10 6 

### BTU.

F.3.6 Comparison of Average Un it Cost of Different Fuels The average unit cost of different fuels is listed in Table F-8.

Table F-8. Average Unit Cost of Different Fuels
Fuel Name Diesel Fuel Jet Fuel Biodiesel Residual Fuel Oil Natural Gas Average Unit Cost ($/10 6 

### BTU) 18.46 15.70 22.2 7.8 9.95