NATIONAL ENERGY TECHNOLOGY LABORATORY

Opportunities to Improve  

the Efficiency of Existing  

Coal‐fired Power Plants

WORKSHOP REPORT

July 15‐16, 2009

Hyatt Regency O’Hare

Rosemont, Illinois

Sponsored by:

National Energy Technology Laboratory

   

Prepared by:

Jack Eisenhauer

Richard Scheer
 

Improving Power Plant Efficiency ii Technical Workshop: July 15-16, 2009 

CONTENTS

Executive Summary ............................................................................................1

Technical Workshop for Improving Power Plant Efficiency..................................1

Major Findings....................................................................................................2

Next Steps  ..........................................................................................................4

Exhibit 1.  Ways to Enhance the NETL Analysis....................................................5

Exhibit 2.  Factors Affecting CFPP Efficiency ........................................................5

Exhibit 3.  Barriers to Achieving Higher Efficiencies in CFPPs...............................6

Exhibit 4.  Solutions For Overcoming Barriers......................................................8

Exhibit 5.  Stakeholder Roles...............................................................................9

Exhibit 6.  Technical Opportunities to Improve Efficiency in for Coal‐Fired Power

Plants...............................................................................................10

Participants.......................................................................................................12
 

Improving Power Plant Efficiency 1 Technical Workshop: July 15-16, 2009 

Opportunities to Improve the Efficiency of  

Existing Coal‐fired Power Plants

Executive Summary

Reducing the carbon footprint of energy production activities has emerged as one of the

defining environmental issues of the 21st century. The U.S. energy infrastructure encompasses

an enormous investment in capital assets and systems to produce fuels and electric power for

businesses, transportation, and homes. While the long‐term opportunity to reshape this

infrastructure to have a low‐carbon profile is promising, near‐term opportunities to reduce

carbon emissions are very limited. Because coal‐fired power plants account for over 80 percent

of carbon emissions from the power sector, improving the efficiency of the existing coal‐fired

power plant fleet presents one of the most promising, low‐cost options for reducing near‐term

carbon emissions.

Increasing the thermal efficiency of the existing U.S. fleet of coal‐fired power plants by 10

percent within five years would save 150 million metric tons of carbon equivalent emissions per

year and reduce the amount of coal required to produce the current level of electric power

generation from these plants. A 10 percent increase in the thermal efficiency would raise the

overall efficiency of the coal‐fired power plant fleet from 32.5% to 35.8% – about three

percentage points of efficiency gain – and likely reduce other environmental emissions. Data

analysis conducted by the National Energy Technology Laboratory (NETL) and the consensus of

selected industry experts indicate that this opportunity is technically and economically

achievable but will require leadership from power plant owners and operators and

commitments from regulators, vendors, federal agencies, and the public. Although some

technical issues exist, most barriers to improving thermal efficiency are based on regulatory

uncertainty, lack of economic incentives, business practices, plant operating practices, and

inadequate training and knowledge.  

Technical Workshop for Improving Power Plant Efficiency  

The U.S. Department of Energy National Energy Technology Laboratory hosted an industry

workshop on July 15‐16, 2009 in Chicago, IL to explore opportunities to improve the thermal

efficiency of existing and future coal‐fired power plants (CFPP). The workshop grew out of a

study conducted by NETL that analyzed the efficiency of the CFPP fleet and suggested that

improvements could be made, largely through better operating and maintenance practices. The

workshop brought together 18 leading industry experts, representing utility owners and

operators, equipment vendors, energy consultants, and power industry associations, to analyze

technical and non‐technical issues affecting plant efficiency and determine how they can be

addressed.  

Through facilitated discussions, workshop participants  
 

Improving Power Plant Efficiency 2 Technical Workshop: July 15-16, 2009 

 Recommended ways to enhance the NETL data analysis

 Identified barriers to achieving efficiency higher efficiencies in coal‐fired power plants

 Identified solutions to overcome these barriers

 Outlined the respective roles of stakeholders in implementing the solutions

 Identified the most important technical improvements that could be implemented

 Framed an overall opportunity to improve the CFPP fleet

The full workshop results are presented in Exhibits 1 through 6.

Major Findings

• The analysis of U.S. fleet of coal‐fired power plants shows a wide variation in efficiency

levels but the basic message is that these levels have been largely stagnant for decades

and that there is “headroom” for efficiency improvements among all plants including

those that currently operate at below average, average, and above average efficiency

levels. However, the analysis and supporting data can be improved to provide better

information about the magnitude of the potential efficiency gains. For example:

o If available, data from plant operators on design heat rates could enable analysis

of actual heat rates versus design heat rates on a plant‐by‐plant basis to

estimate the magnitude of potential efficiency improvements.

o Data on which plants have done recent testing and the length of time since

major turbine overhauls could be helpful in explaining the wide variation in plant

efficiency levels.

o Market segmentation analysis could also help explain variation, a.g., those plants

greater than 200 MW, or those that have on‐site performance engineers/heat

rate monitors.

o Additional in‐depth case studies of specific plants could be helpful in replicating

best practices from above average efficiency plants to average and below

average efficiency plants.

• To boost efficiency levels, a number of technical, regulatory, and institutional barriers

must overcome. For example:

o Making changes in plants to improve efficiency is hampered by the New Source

Review provisions of the Clean Air Act, which can trigger potentially lengthy and

costly regulatory proceedings when capital improvements and other changes in

the plant are made.  

o The lack of economic incentives to address efficiency improvements due to the

presence of fuel adjustment clauses in approved electricity rates that enable

power companies to “pass‐through” changes in fuel costs directly to customers.

o Concerns about regulatory proceedings, combined with the lack of economic

incentives, make it difficult to get management commitment for power plant

efficiency programs that must compete for scarce corporate capital and labor

resources. At the same time, the primary aim for power plant operators is to

optimize the profitability of the units and ensure they are available to serve load.
 

Improving Power Plant Efficiency 3 Technical Workshop: July 15-16, 2009 

While heat rates and efficiency are important, fuel cost savings represent only a

small portion of total costs and are typically of secondary concern when

compared to needs for maintaining system reliability.

o In order to control and improve efficiency levels, power plant operators need to

know about power plant performance across a variety of systems and

subsystems including turbines, boilers, fuel handling, and air management.

Unfortunately, there is a widespread lack of measurement and instrumentation

systems in power plants across the fleet and operators lack the real time data

they need to make operational adjustments even if they had the mandate for

doing so.

o Even if power plant operators were getting the data they need to improve

efficiency levels, there is a widespread lack of on‐site performance engineers

who are dedicated to heat rate improvement.

• Addressing these and other barriers is essential for power plant efficiency

improvements to be made across the entire fleet. Some plants operators have the data,

personnel, and management support they need to address efficiency improvements and

are addressing the issue.  In these cases the magnitude of the “headroom” for efficiency

gains will be limited. One of the key challenges will be implementing these best

practices with those operators who for a variety of reasons are not currently able to

mount efficiency program efforts. This will require regulatory agencies and power

industry executives to approve a renewed focus and efficiency and the changes in

practices, new equipment and systems, new personnel, and capital investments that will

be needed.  

• There are a number of specific improvements in power plants that can be investigated

relatively quickly. These include, for example:

o Cleaning tubes and boilers

o maintaining instrumentation

o restoring seals

o removing deposits on turbine blades

o condenser maintenance programs

o decreasing excess oxygen to the boiler

o Installing variable speed drives for motors

o Pursuing opportunities for waste heat utilization for coal drying and using solar

energy for feed water heating

• While the precise magnitude of the opportunity for power plant efficiency

improvements in the existing fleet is unknown, the need for such improvements to

address global climate change and reductions in the emission of greenhouse gases is an

important national priority.  
 

Improving Power Plant Efficiency 4 Technical Workshop: July 15-16, 2009 

Next Steps

• The NETL data analysis of the CFPP fleet to estimate the potential efficiency

improvement can be strengthened by obtaining additional data and conducting

additional studies to fine tune the estimates of the potential magnitude of carbon

savings and the costs of achieving those savings.

• The results of that analysis needs to be shared with a wider group of plant owners and

operators to help determine how NETL can assist in addressing the barriers to efficiency

gains and in building a public‐private partnership to leverage the resources of federal

and state government agencies, power plant owners and operators, and vendors and

suppliers.  

• A plan should be developed for public outreach and stakeholder engagement to educate

key audiences about the magnitude of the opportunity for reductions in greenhouse gas

emissions to facilitate inclusion of power plant efficiency efforts in national programs to

address carbon emissions and global climate change.  
Improving Power Plant Efficiency 5 Technical Wo

Exhibit 1. Ways to Enhance the NETL Analysis

CONSTRUCT AN ANALYSIS FRAMEWORK FOR INVESTMENT DECISIONS

EXHIBIT 2. FACTORS AFFECTING CFPP EFFICIENCY

• Study year-to-year variation in the heat rate achieved at each plant 

• Obtain more robust data about equipment at each plant • Estimate improvements above the performance above the current top 10% of power plants 

• Construct an analysis framework for investment decisions • Analysis of the unexplained efficiency data variation • Case studies of specific units • Normalized dollars spend for O&M • Focus on plants that have done recent testing • Years since last major turbine overhaul • Estimate best potential for each segment • Analysis the turbine cycle • Existence of a performance engineer/heat rate monitor • Examine data quality • Analysis of CFPPs above 200MW • Corporate focus on efficiency • Operating and maintenance practices • No dedicated performance engineer 

ANALYSIS VARIABLES ADDITIONAL FACTORS

• Nameplate capacity • SCR SO2 control equipment • Coal Btu content • Investor owned utility • Steam pressure • Load factor • Number of starts • Recirculated cooling 

• Current fuel vs. design fuel 

• Reheat temperature • Design heat rate (∆ from design) 

• Excess air - data available • Corporate culture • Whether plant has been given its “death sentence” or no• Fuel cost pass through • IPP [ownership] vs. regulated utility • Are co-ops and munis different • AGC and LGC are these installed • Regulatory policies affect utility actions and interest in O• SO2 control equipment retrofits not optimal 

• SCR control equipment • Plant footprint is a constraining factor • If you don’t measure it you can’t control it • Type of air heater 
Improving Power Plant Efficiency 6 Technical Wo

EXHIBIT 3. BARRIERS TO ACHIEVING HIGHER EFFICIENCIES IN CFPPS

(IN ORDER OF IMPORTANCE)

CFPP FLEET DIVERSITY QUANTIFYING AND ANALYZING ISSUES AND BENEFITS TECHNICAL ISSUES PUB

• Variation in power plant 

design

• Wide fuel range • “No one size fits all 

solution” - different steam tubine 

• models and 

configurations that require R&D 

• Identify and quantify issues in plant

– Measuring small incremental 

improvements is problematic 

• Difficulty in monetizing benefits • No accepted optimization equation 

– Cost-value trade-off analysis, CO2

dollars, efficiency, fuels, etc. 

– New metrics for evaluating PP 

performance 

• Obtaining “valid” process data needed 

for efficiency calculations 

• Ability to identify cost-effective 

improvements we have not already made 

• Making use of models and analysis to 

make improvements 

• Better instrumentation for measuring 

changes 

• Knowledge of fuel chemistry and 

HHV in real-time 

• Tail end fouling acid dewpoint • Technical: global excess O2 kept 

higher than “optimum” to avoid fouling, corrosion 

• Need low temperature heat 

sink/utilization and or reduce infiltration XR 

• Condenser performance monitoring 

(largest heat sink) 

• Waste heat utilization • Improvement longevity - turbine 

seals, tower repairs 

• Best available technology does not 

meet to the ideal requirement of objective 

• Coal pricing based on HHV not LHV • Difficulty of testing/developing new 

technologies at scale 

• Pub

fav

• Env

is a 

• Res

ren
Improving Power Plant Efficiency 7 Technical Wo

EXHIBIT 3. BARRIERS TO ACHIEVING HIGHER EFFICIENCIES IN CFPPS (CONT’D)

(IN ORDER OF IMPORTANCE)

BUSINESS

PRACTICES COST AND BUDGETING REGULA

STRUC

• Management support for performance 

improvements 

• Dedicated resources for action • Lack of experienced performance engineers 

dedicated to heat rate improvement 

• Plant focus on heat rate vs. availability • Its cost effectiveness not efficiency 

effectiveness 

• Justification - competition for funds 

– Management decision making 

processes 

• Lack of experienced plant managers 

• “Utility” culture - “been doing it this way for 

years”, “already optimized” 

• Less sharing of information among utilities 

and vendors 

• Ownership - some plants no Btu gain, no 

maintenance 

• Payback uncertainty - investing in dying plants 

• Budget limits - efficiency vs. availability, outage 

cycles 

• Payback period cost of fix vs. recovery time 

cost/benefit ratio 

• Decrease in frequency of planned outages • ROI/PB - small units continue to justify full 

turbine upgrade 

• Ability to borrow money at a reasonable rate - 

getting better 

• Overall utility budget - fight for share of tight 

budget 

• No economic incen

through, low fuel co

• Contradictory EPA 

requirements 

• Ability to pass throu• Cannot measure an

change 

• Uncertain CO2 price 

• Pass through of CO
Improving Power Plant Efficiency 8 Technical Wo

EXHIBIT 4. SOLUTIONS FOR OVERCOMING BARRIERS

CONTRADICTORY EPA AIR EMISSION 

REQUIREMENTS

LACK OF EXPERIENCED PERFORMANCE 

ENGINEERS DEDICATED TO HEAT RATE 

IMPROVEMENTS AND SYSTEMS 

LACK OF MANAGEMENT S

RATE IMPROV

• Take a proactive approach to articulate 

the contradictions 

• Mandate the existence of a performance 

engineer in plants above xMW 

– Need the proper infrastructure 

• Create a “heat rate champion” 

– Tie to incentive compensation 

• Ensure instrument and tools exist 

• Initiate training program on heat rate 

performance 

– Tie with academic institutions 

• Corporate sharing of lessons learned • Build performance engineering as 

a green job 

• Create incentives for pla

leaders 

• Make it a priority for cor

education needed 

• Leverage efficiency and 

image 

– Educate out of the se

• Federal tax incentive for 

improvement 

• Create a federal “prize” • Its cost effectiveness no

effectiveness 

Plant focus on heat rate 

NEED TO IDENTIFY/QUANTIFY 

ISSUES IN PLANTS

LACK OF KNOWLEDGE OF FUEL 

CHEMISTRY AND HHV IN REALTIME PAYBACK UNCERTAINTY - INVESTING IN DYING PLANTS LACK OF EC

DUE TO F

T

• Testing analytics monitoring 

instrumentation 

• Develop/install advanced 

instrumentation 

– Heat rate monitor 

• More precise measuring protocol 

– Better practices – Good tools/scorecard 

• Mandate the instrumentation and 

measurements 

• Prioritization guidance 

• Install advanced 

instrumentation - nuclear scare 

• Need to focus on bigger 

issues before the real-time HH 

• Focus on whole system 

boiler and turbine 

• Reduce legislative uncertainty 

– Tied to NSR 

• Mandate efficiency ala 

renewables - drive dollars into older plants 

• Retire them and remove the 

uncertainty 

– Cash for clunkers 

(government cost support) 

– New license contingent on 

retirement 

• Approach P

passing thr

• Convince P

CFPP effic

• Bypass PU

taught for pimprovemeinvestment 

• Change the 

national po

• Thermal pe

rate making 
Improving Power Plant Efficiency 9 Technical Wo

EXHIBIT 5. STAKEHOLDER ROLES

OWNERS AND 

OPERATORS

STATES AND 

REGULATORS FEDERAL AGENCIES VENDORS AND SUPPLIERS 

• Manage risk • Develop innovative 

strategies 

• Commit to the solution • Educate public • Training • Advocacy 

• Solve fuel cost pass 

through 

• Create the incentives • Champion efficiency • Understand the issues 

and the trade-offs 

• Mandates 

• Financial incentives • Fund research • Integrated strategies • Tax incentives • Enable/facilitate industry 

learning - training, information exchange 

• Educate public 

• New technology 

development and commercialization 

• BU (with right framework)• Shoot straight • Search for best available 

technology 

• Training 

• Und

liste

• Inve• Sac

cha
Improving Power Plant Efficiency 10 Technical Wo

EXHIBIT 6. TECHNICAL OPPORTUNITIES TO IMPROVE EFFICIENCY IN FOR COAL‐FIRED POWER PLANTS

SCOPE

• Within the power plant • Technical actions • Operations, maintenance • Capital projects 

ASSUMPTIONS

• “Typical” CFPP • Expectation of reasonable 

funding 

• Management support • Regulatory support • Public support 

TEAM 1 TEA

1. Perform equipment assessment 

– Generate heat balance, (design) as is – Perform cycle isolation alignment check – Determine deviations 

2. Improve heat exchange at back end of boiler 

– Duplex seals, repair casing leak, intelligent soot 

blowing 

3. Improve heat exchange at condenser and CT 

– Re-tube, clean tubes, maintain instruments, 

optimize condenser arrangement 

– Replace CT, fill adjust distribution of flow (L/g) – CFD tube bundle water box 

4. Improve heat exchange in feed water heaters 

– Re-tube, optimize levels of heater drain pumps 

5. Restore seals, remove deposits on turbine, improve 

turbine steam path 

– Install diffusers/vanes on turbine exhaust/hood 

6. Improve control 7. Install sliding pressure control at low load 8. Install boiler optimization neural network control 9. Install equipment to measure and control PC flow to 

each burner 

10. Variable speed drive for motors

1. Turbine seal repla2. Boiler leak seals 3. Turbine vale maint4. Mill maintenance 5. Water chemistry - 

continued monitor

6. Sliding pressure 7. Heat rate training 8. Optimization - tran9. Add performance e10. Real-time heat rate 11. Boiler cleaning - o12. Upgrade air heate13. Better air pre-heat

Game Changer Game C

• Waste heat utilization coal drying • High temperature O2 probe at the furnace exit 

• Coal pile umbrella • Some device to measure in situ flame temperature at 

each burner +/- 50°F 

• Condensing air heater, capture condensate and sulfur 

• Low grade waste hea

Rankine Cycle 

• Solar feed water hea• Biomass co-firing 
Improving Power Plant Efficiency 11 Technical Wo

EXHIBIT 6. TECHNICAL OPPORTUNITIES TO IMPROVE EFFICIENCY IN FOR COAL‐FIRED POWER PLANTS (CONT’D)

TEAM 3 TEAM 4 

1. Operator training/performance engineers 2. Improve steam seals 3. Increased frequency of maintenance 4. Condenser maintenance program 5. Cooling tower performance 6. Dense pack steam turbines 7. Tramp air management 8. Decrease global excess O2

9. Improved heat transfer surface cleaning 10. Hardened variable drive fans 11. Mill air management/bypass 12. Extra Regenerative air-heater 13. Reduce air-heater fouling 14. Replace feedwater pump drive 

1. Need a performance en2. Incentive program 3. Assess and determine 4. Gap analyses 5. Instrument and control 6. Educational training 7. Performance monitorin8. Monitoring by skilled st

9. Formal mechanic to ge

efficiency 

10. Cycle optimization 

Game Changer Game Chan

• Acid proof heat exchanger and ductwork • Cost benefit and analys

• Implement turbine upgra

resurfacing, new instrumwater chemistry

• Maintenance outage: pr

activities and assure it g

COMMON THEMES

• Assess • Measure and monitor • Improve controls • Plug leaks • Clean and maintain • Replace/upgrade 

components 

• Increase expertise • Provide incentives 
Improving Power Plant Efficiency 12 Technical Workshop: July 15-16, 2009 

Participants

Name Company E-mail Address 

Scott Affelt Zolo Technologies, Inc. saffelt@zolotech.com 

Paul Albert GE Energy Services paul.albert@ge.com 

Mike Booth GE Energy mike.booth@ge.com 

Thamarai Chelvan Siemens Energy, Inc. tham.chelvan@siemens.com 

Wayne Counterman Howden Buffalo, Inc. wcounterman@howdenbuffalo.com 

Phil DiPietro U.S. Department of Energy joseph.dipietro@netl.doe.gov 

Jeffrey Eppink Enegis, LLC jeppink@energis.com 

Robert Frank C-Lock Technology, Inc. rfrank@c-locktech.com 

John Holt Nat. Rural Electric Cooperative Assoc. john.holt@nreca.coop 

Sikander Khan U.S. Department of Energy sikander.khan@hq.doe.gov 

Jordan Kislear U.S. Department of Energy jordan.kislear@hq.doe.gov 

Sam Korellis Electric Power Research Institute skorellis@epri.com 

Fred Lang Exergetic Systems, Inc. lang@exergeticsystems.com 

James Laughner Allegheny Energy jlaugh1@alleghenyenergy.com 

George Mues Ameren Corporation gmues@ameren.com 

Joseph Nasal General Physics Corporation jnasal@gpworldwide.com 

Chris Nichols U.S. Department of Energy christopher.nichols@netl.doe.gov 

Charles Olsen American Electric Power cdolsen@aep.com

Paul Roediger Encotech proediger@encotech.com 

Michael Smiarowski Siemens Energy, Inc. michael.smiarowski@siemens.com 

G. Scott Stallard Black & Veatch stallardgs@bv.com 

Joseph Taura GE Energy Services joseph.taura@ge.com

 

Facilitators 

Richard Scheer Energetics Incorporated rscheer@energetics.com

Jack Eisenhauer Energetics Incorporated jeisenhauer@energetics.com