ES-i 

EXECUTIVE SUMMARY

TABLE OF CONTENTS

ES.1 OVERVIEW OF PRELIMINARY ANALYSIS ACTIVITIES ...................................... 1

ES.2 KEY RESULTS OF THE ANALYSIS ........................................................................... 3

ES.2.1 Determination of Scope ................................................................................................... 3

ES.2.2 Market and Technology Assessment ............................................................................... 5

ES.2.3 Screening Analysis .......................................................................................................... 6

ES.2.4 Engineering Analysis ....................................................................................................... 6

ES.2.5 Markups Analysis .......................................................................................................... 12

ES.2.6 Energy Use Characterization ......................................................................................... 12

ES.2.7 Life-Cycle Cost and Payback Period Analyses ............................................................. 13

ES.2.7.1 Life-Cycle Cost and Payback Period Analysis Results ............................... 15

ES.2.8 Shipments Analysis........................................................................................................ 16

ES.2.9 National Impact Analysis............................................................................................... 17

ES.2.9.1 National Energy Savings Analysis .............................................................. 18

ES.2.9.2 Net Present Value Analysis ......................................................................... 18

ES.2.10 Preliminary Manufacturer Impact Analysis ................................................................... 19

ES.2.11 Other Analyses ............................................................................................................... 19

ES.3 ISSUES ON WHICH THE U.S. DEPARTMENT OF ENERGY SEEKS PUBLIC 

COMMENT ................................................................................................................... 20

ES.3.1 Efficiency Requirements for Dual/Multiple-Voltage Secondaries ................................ 20

ES.3.2 Dual/Multiple-Voltage Transformers with Varying Basic Impulse Levels................... 20

ES.3.3 Weighted-Average Losses from Multiple Loading Points ............................................ 21

ES.3.4 Current DOE Test Procedure ......................................................................................... 21

ES.3.5 Symmetric Core Designs ............................................................................................... 21

ES.3.6 Core Deactivation Technology ...................................................................................... 21

ES.3.6.1 Nanotechnology Composites ....................................................................... 21

ES.3.7 Representative Units for Single-Phase, Liquid-Immersed Design Lines ...................... 22

ES.3.8 Representative Unit for Design Line 5 .......................................................................... 22

ES.3.9 Representative Unit for Design Line 13 ........................................................................ 22

ES.3.10 Additional Representative Units .................................................................................... 22

ES.3.11 Scaling Methodology ..................................................................................................... 22

ES.3.12 Design Option Combinations ........................................................................................ 22

ES.3.13 Materials Prices.............................................................................................................. 23

ES.3.14 Factory Overhead Markup for Designs Using a Prefabricated Amorphous Core ......... 23

ES.3.15 Shipping Costs ............................................................................................................... 23

ES.3.16 Additional Costs for Amorphous Designs in Large, Dry-Type Design Lines............... 23

ES.3.17 Trial Standard Levels ..................................................................................................... 24

ES.3.18 Impact on Manufacturers ............................................................................................... 24

ES.3.19 Supply of Core Steels .................................................................................................... 24

ES.3.20 Valuing Air-Borne Emission Reductions ...................................................................... 24

ES.3.21 Hourly Load Data .......................................................................................................... 25

ES.3.22 Installation Practices ...................................................................................................... 25

ES.3.23 Distributer Markups ....................................................................................................... 25
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ES.3.24 Evaluation of Energy Efficiency in the Basecase .......................................................... 25

ES.3.25 Replacement and Maintenance Practices ....................................................................... 25

ES.3.26 Sizing Practices .............................................................................................................. 26

ES.3.27 Efficiency Trends ........................................................................................................... 26

LIST OF TABLES

Table ES.2.1 Equipment Classes for Distribution Transformers .....................................................5

Table ES.2.2 Engineering Design Lines and Representative Units for Analysis ...........................7

Table ES.2.3 Summary of Baselines and Candidate Standard Levels for Distribution 

Transformer Representative Units ...........................................................................9

Table ES.2.4 Summary of Incremental Manufacturer Selling Prices over the Baseline for 

Distribution Transformer Representative Units .....................................................10

Table ES.2.5 Markups for Distribution Transformers ..................................................................12

Table ES.2.6 Summary of Life-Cycle Cost Savings (2010$) .......................................................15

Table ES.2.7 Summary of Payback Period Results (Years) .........................................................16

Table ES.2.8 Cumulative Shipments of Transformers by Candidate Standard Level 

(Billion kVA), 2015 - 2044 ....................................................................................17

Table ES.2.9 Mapping of Design Line (DL) to Equipment Class (EC) .......................................18

Table ES.2.10 Summary of Cumulative National Energy Savings and Net Present Value 

Impact ....................................................................................................................19

LIST OF FIGURES

Figure ES.1.1 Flow Diagram of Analyses for the Distribution Transformer Rulemaking 

Process .....................................................................................................................2

Figure ES.2.1 Cost-Efficiency Outputs of Engineering Analysis for Design Line 7 ...................11
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EXECUTIVE SUMMARY

ES.1 OVERVIEW OF PRELIMINARY ANALYSIS ACTIVITIES

 Section 6295(o)(3)(B) of 42 U.S.C. requires the U.S. Department of Energy (DOE or 

Department) to establish energy conservation standards that are technologically feasible and 

economically justified, and that would achieve the maximum improvement in energy efficiency. 

This executive summary highlights the activities associated with this preliminary analysis that 

DOE conducted when considering amended energy conservation standards for distribution 

transformers. The executive summary also describes key results from DOE’s preliminary 

analysis and delineates issues on which DOE seeks comment. These issues are highlighted in the 

public meeting presentation and are further discussed in chapter 2 of the preliminary technical 

support document (TSD). 

Figure ES.1.1 presents a summary of the analytical components of the standards-setting 

process and illustrates how key results are generated. The focal point of the figure is the center 

column, labeled “Analyses.” The columns labeled “Key Inputs” and “Key Outputs” show how 

the analyses fit into the process and relate to each other. Key inputs are the types of data and 

other information required by the analyses. DOE obtains some key information from public 

databases and collects other inputs from interested parties or persons having special knowledge 

and expertise. Key outputs are analytical results that feed directly into the standards-setting 

process. The issues on which DOE seeks comment from interested parties derive from the key 

results that are generated by the preliminary analyses. Arrows connecting analyses show the 

types of information that feed from one analysis to another. 
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Figure ES.1.1 Flow Diagram of Analyses for the Distribution Transformer Rulemaking 

Process
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ES.2 KEY RESULTS OF THE ANALYSIS 

 The following sections describe in detail the key analyses DOE performed. 

ES.2.1 Determination of Scope 

 Amendments to the Energy Policy and Conservation Act of 1975 (EPCA) direct DOE to

determine whether to amend energy conservation standards for distribution transformers. (42 

U.S.C. 6295(o)(2)(A)) DOE published a final rule in October 2007 that prescribed energy 

conservation standards for liquid-immersed and medium-voltage dry-type (MVDT) distribution 

transformers. 72 FR 58190 (Oct. 12, 2007); see 10 CFR 431.196(b)-(c). During the course of 

that rulemaking, the Energy Policy Act of 2005 (EPACT), Pub. L. 109-58, set standards for lowvoltage dry-type distribution (LVDT) transformers. (EPACT 2005, Section 135(c); codified at 

42 U.S.C. 6295(y)) Therefore, DOE had removed these transformers from the scope of the 

rulemaking. 72 FR 58191 

 After the publication of the final rule, certain parties filed petitions challenging the final 

rule. They alleged that, in developing its energy conservation standards for distribution 

transformers, DOE did not comply with certain applicable provisions of EPCA and the National 

Environmental Policy Act of 1969 (NEPA), 42 U.S.C. 4321 et seq. On July 10, 2009, DOE and 

the petitioners subsequently entered into a settlement agreement to resolve the appeals. The 

settlement agreement outlined an expedited timeline for DOE to determine whether to amend the 

energy conservation standards for liquid-immersed and medium-voltage dry-type distribution 

transformers. Under the terms of the settlement agreement, DOE must publish, no later than 

October 1, 2011, either a determination that the standards for these distribution transformers do 

not need to be amended or a notice of proposed rulemaking (NOPR) that includes any new 

proposed standards and that meets all applicable requirements of EPCA and NEPA. If DOE finds 

that amended standards are warranted, DOE must publish a final rule containing such amended 

standards no later than October 1, 2012. This document is DOE’s first step in satisfying the 

requirements of the settlement agreement. 

DOE is initiating this rulemaking at the preliminary analysis stage rather than the 

framework document stage. In considering new or amended standards for a given product or 

type of equipment, DOE’s current practice generally is to publish a framework document as the 

first step in the rulemaking process, and to subsequently issue a TSD that contains the 

Department’s preliminary analyses as to potential standards. The framework document generally 

advises interested parties of the analytical methods, data sources, and key assumptions DOE 
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plans to use in considering the adoption of standards for the product or equipment type. 

Typically, the document does not contain any analysis of the data. However, because the 

previous rulemaking to develop standards for distribution transformers was completed relatively 

recently, DOE has a set of methodologies, data sources and assumptions that have been vetted 

recently and revised according to public comments that DOE can use to perform the analyses 

needed for this rulemaking. Therefore, DOE is not issuing a framework document for this 

rulemaking. DOE will conduct the analyses referenced by the petitioners’ complaint and 

required by EPCA and NEPA according to standard practices for energy conservation standard 

rulemakings. Hence, DOE is initiating this rulemaking at the preliminary analysis stage and has 

prepared a preliminary TSD on which it is requesting comment.

 At present, DOE plans to examine in this rulemaking amended standards for LVDT

distribution transformers, as well as revised standards for liquid-immersed and MVDT

transformers. DOE is not required to consider LVDT distribution transformers as part of the 

settlement agreement. As such, DOE may subsequently opt to conduct a separate rulemaking for 

LVDT transformers with a different timeline. However, the preliminary analysis considers lowvoltage dry-type distribution transformers along with liquid-immersed and MVDT distribution 

transformers.

 The definition of a distribution transformer was presented in EPACT, and then further 

refined by DOE when it was codified into Title 10 of the Code of Federal Regulations, Part 431 

(10 CFR Part 431) on April 27, 2006. 71 FR 24972. 

As set forth in 10 CFR 431.192, Distribution transformer

(1) Has an input voltage of 34.5 kV or less; 

means a transformer that - 

(2) Has an output voltage of 600 V or less; 

(3) Is rated for operation at a frequency of 60 Hz; and 

(4) Has a capacity of 10 kVA [kilo-volt ampere] to 2500 kVA for liquid-immersed units 

and 15 kVA to 2500 kVA for dry-type units; but 

(5) The term “distribution transformer” does not include a transformer that is an– 

(i) Autotransformer;

(ii) Drive (isolation) transformer;

(iii) Grounding transformer; 

(iv) Machine-tool (control) transformer;

(v) Nonventilated transformer;
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(vi) Rectifier transformer;

(vii) Regulating transformer;

(viii) Sealed transformer;

(ix) Special-impedance transformer;

(x) Testing transformer;

(xi) Transformer with tap range of 20 percent or more; 

(xii) Uninterruptible power supply transformer; or

(xiii) Welding transformer.

ES.2.2 Market and Technology Assessment 

A market and technology assessment characterizes the relevant equipment markets and 

technology options, including prototype designs. See chapter 3 of the preliminary TSD for 

details.

 DOE generally divides covered equipment into equipment classes by the type of energy 

used, capacity, or other performance-related features that affect customer utility or efficiency. 

Different energy conservation standards may apply to different equipment classes. (42 U.S.C. 

6295(q)) Table ES.2.1 describes all of the equipment classes DOE is considering in this 

rulemaking. 

Table ES.2.1 Equipment Classes for Distribution Transformers

Equipment

Classes

Insulation Voltage Phase

Basic Impulse 

Level (BIL) Rating

kVA Range

1 Liquid-Immersed Medium Single - 10-833 kVA

2 Liquid-Immersed Medium Three - 15-2500 kVA

3 Dry-Type Low Single - 15-333 kVA

4 Dry-Type Low Three - 15-1000 kVA

5 Dry-Type Medium Single 20-45kV BIL 15-833 kVA

6 Dry-Type Medium Three 20-45kV BIL 15-2500 kVA

7 Dry-Type Medium Single 46-95kV BIL 15-833 kVA

8 Dry-Type Medium Three 46-95kV BIL 15-2500 kVA

9 Dry-Type Medium Single ≥ 96kV BIL 75-833 kVA

10 Dry-Type Medium Three ≥ 96kV BIL 225-2500 kVA
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DOE addresses (1) manufacturer market share and characteristics, (2) existing regulatory 

and non-regulatory initiatives for improving equipment efficiency, and (3) trends in equipment 

characteristics and retail markets. This information provides data and resource material 

throughout the analysis. 

DOE reviews literature and interviews manufacturers to develop an overall understanding 

of the distribution transformer industry. Industry publications including trade journals and

literature from manufacturers, government agencies, and trade organizations provide the bulk of 

the information, which includes: (1) manufacturers and their market share, (2) shipments by 

equipment type, (3) equipment information, and (4) industry trends. 

 DOE typically uses information about existing and past technology options and prototype 

designs to determine which technologies and combinations of technologies manufacturers use to 

attain higher performance levels. In consultation with interested parties, DOE develops a list of 

technologies to be considered. The technologies initially identified include all those DOE 

believes are technologically feasible. 

ES.2.3 Screening Analysis

 DOE develops an initial list of options for enhancing efficiency from the technologies 

that the technology assessment identified as feasible. In consultation with interested parties, DOE 

reviews the list to assess whether the technologies are practicable to manufacture, install, and 

service; would adversely affect equipment utility or availability; or would have adverse impacts 

on health and safety. In the subsequent engineering analysis, DOE further examines the 

technology options that it did not remove from consideration in the screening analysis. See 

chapter 4 of the preliminary TSD for details.

ES.2.4 Engineering Analysis 

The engineering analysis develops cost-efficiency relationships that show a 

manufacturer’s cost of achieving increased efficiency. DOE uses manufacturer markups to 

determine the manufacturer production cost (MPC) and then to convert the MPC to manufacturer 

selling price (MSP) for each unit. See chapter 5 of the preliminary TSD for details.

The engineering analysis analyzed 13 key design lines that cover the range of equipment 

classes within the distribution transformer market. Within each design line, DOE selected a 
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representative unit to analyze in the engineering analysis. Table ES.2.2 outlines the design lines 

and representative units selected for each equipment class.

Table ES.2.2 Engineering Design Lines and Representative Units for Analysis 

EC* DL* Type of Distribution 

Transformer

kVA 

Range

Representative Unit for this

Engineering Design Line

1 

1 Liquid-immersed, single-phase, 

rectangular tank 10–167 50 kVA, 65°C, single-phase, 60Hz, 14400V primary, 

240/120V secondary, rectangular tank

2 Liquid-immersed, single-phase, 

round tank 10–167 25 kVA, 65°C, single-phase, 60Hz, 14400V primary, 

120/240V secondary, round tank

3 Liquid-immersed, single-phase 250–833 500 kVA, 65°C, single-phase, 60Hz, 14400V primary, 

277V secondary

2 

4 Liquid-immersed, three-phase 15–500 150 kVA, 65°C, three-phase, 60Hz, 12470Y/7200V 

primary, 208Y/120V secondary

5 Liquid-immersed, three-phase 750–2500 1500 kVA, 65°C, three-phase, 60Hz, 

24940GrdY/14400V primary, 480Y/277V secondary

3 6 Dry-type, low-voltage, singlephase 15–333 25 kVA, 150°C, single-phase, 60Hz, 480V primary, 

120/240V secondary, 10kV BIL

4 

7 Dry-type, low-voltage, threephase 15–150 75 kVA, 150°C, three-phase, 60Hz, 480V primary, 

208Y/120V secondary, 10kV BIL

8 Dry-type, low-voltage, threephase 225–1000 300 kVA, 150°C, three-phase, 60Hz, 480V Delta 

primary, 208Y/120V secondary, 10kV BIL

6 

9 Dry-type, medium-voltage, 

three-phase, 20-45kV BIL 15–500 300 kVA, 150°C, three-phase, 60Hz, 4160V Delta 

primary, 480Y/277V secondary, 45kV BIL

10 Dry-type, medium-voltage, 

three-phase, 20-45kV BIL 750–2500 1500 kVA, 150°C, three-phase, 60Hz, 4160V primary, 

480Y/277V secondary, 45kV BIL

8 

11 Dry-type, medium-voltage, 

three-phase, 46-95kV BIL 15–500 300 kVA, 150°C, three-phase, 60Hz, 12470V primary, 

480Y/277V secondary, 95kV BIL

12 Dry-type, medium-voltage, 

three-phase, 46-95kV BIL 750–2500 1500 kVA, 150°C, three-phase, 60Hz, 12470V 

primary, 480Y/277V secondary, 95kV BIL

10 13 Dry-type, medium-voltage, 

three-phase, 96-150kV BIL 225–2500 2000 kVA, 150°C, three-phase, 60Hz, 12470V 

primary, 480Y/277V secondary, 125kV BIL

* EC = Equipment Class. DL = Design Line.

For each representative unit, DOE identified several design option combinations to 

characterize the range of possible efficiencies. For each design, DOE calculated the MSP and

efficiency to generate cost-efficiency curves for each representative unit. To calculate MSP, 

DOE used a commercially available software program to generate a bill of materials containing 

information on the transformer core, conductors, enclosure, and other components. DOE then 

applied additional cost estimates for labor and other manufacturer markups that are specific to 

the distribution transformer industry to arrive at the final MSP. DOE then extrapolated the 

results of its analysis from the unit studied to the other equipment with different kVA ratings 

within that same engineering design line. The technique DOE used to extrapolate the findings on 

the representative unit to the other kVA ratings within a design line is referred to as “the 0.75 
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scaling rule.” This rule states that, for similarly designed transformers, costs of construction and 

losses scale to the ratio of kVA ratings raised to the 0.75 power. See chapter 5 of the preliminary 

TSD for details.

Table ES.2.3 presents the efficiency identified for each baseline and candidate standard 

level (CSL) in the engineering analysis. The baseline CSL is the minimum efficiency rating 

evaluated in DOE’s analysis, determined by the current minimum efficiency standards. Table 

ES.2.4 presents the incremental MSP for each of the least-costly design options at each CSL. 
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Table ES.2.3 Summary of Baselines and Candidate Standard Levels for Distribution 

Transformer Representative Units

Design 

Line

Representative Unit

Baseline CSL1 CSL2 CSL3 CSL4 CSL5 CSL6 CSL7 

Eff.

[%]

Eff.

[%]

Eff.

[%]

Eff.

[%]

Eff.

[%]

Eff.

[%]

Eff.

[%]

Eff.

[%]

1 

50 kVA, 65°C, single-phase, 

60Hz, 14400V primary, 

240/120V secondary, rectangular 

tank

99.08 99.17 99.27 99.36 99.46 99.55 99.60 N/A

2 

25 kVA, 65°C, single-phase, 

60Hz, 14400V primary, 

120/240V secondary, round tank

98.91 99.02 99.13 99.24 99.35 99.46 N/A N/A

3 

500 kVA, 65°C, single-phase, 

60Hz, 14400V primary, 277V 

secondary

99.42 99.48 99.54 99.57 99.61 99.67 99.73 99.76

4 

150 kVA, 65°C, three-phase, 

60Hz, 12470Y/7200V primary, 

208Y/120V secondary

99.08 99.17 99.27 99.36 99.46 99.55 99.60 N/A

5 

1500 kVA, 65°C, three-phase, 

60Hz, 24940GrdY/14400V 

primary, 480Y/277V secondary

99.42 99.48 99.54 99.57 99.61 99.67 99.73 N/A

6 

25 kVA, 150°C, single-phase, 

60Hz, 480V primary, 120/240V 

secondary, 10kV BIL

98.00 98.23 98.47 98.60 98.70 98.93 99.17 99.40

7 

75 kVA, 150°C, three-phase, 

60Hz, 480V primary, 208Y/120V 

secondary, 10kV BIL

98.00 98.23 98.47 98.60 98.70 98.93 99.17 99.40

8 

300 kVA, 150°C, three-phase, 

60Hz, 480V Delta primary, 

208Y/120V secondary, 10kV BIL

98.60 98.80 99.02 99.19 99.41 99.59 N/A N/A

9 

300 kVA, 150°C, three-phase, 

60Hz, 4160V Delta primary, 

480Y/277V secondary, 45kV BIL

98.82 98.97 99.12 99.28 99.43 99.58 N/A N/A

10

1500 kVA, 150°C, three-phase, 

60Hz, 4160V primary, 

480Y/277V secondary, 45kV BIL

99.22 99.31 99.40 99.50 99.59 99.68 N/A N/A

11

300 kVA, 150°C, three-phase, 

60Hz, 12470V primary, 

480Y/277V secondary, 95kV BIL

98.67 98.84 99.00 99.17 99.33 99.50 N/A N/A

12

1500 kVA, 150°C, three-phase, 

60Hz, 12470V primary, 

480Y/277V secondary, 95kV BIL

99.12 99.21 99.30 99.39 99.48 99.57 99.66 N/A

13

2000 kVA, 150°C, three-phase,

60Hz, 12470V primary, 

480Y/277V secondary, 125kV 

BIL

99.15 99.25 99.35 99.46 99.56 99.66 N/A N/A
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Table ES.2.4 Summary of Incremental Manufacturer Selling Prices over the Baseline for 

Distribution Transformer Representative Units

Design 

Line

Representative Unit

Baseline CSL1 CSL2 CSL3 CSL4 CSL5 CSL6 CSL7 

$ $ $ $ $ $ $ $ 

1 

50 kVA, 65°C, single-phase, 60Hz, 

14400V primary, 240/120V 

secondary, rectangular tank

- 234 501 578 854 1,406 2,109 N/A

2 

25 kVA, 65°C, single-phase, 60Hz, 

14400V primary, 120/240V 

secondary, round tank

- 235 416 605 751 1,312 N/A N/A

3 

500 kVA, 65°C, single-phase, 

60Hz, 14400V primary, 277V 

secondary

- 675 2,386 2,246 3,005 4,544 7,140 11,922

4 

150 kVA, 65°C, three-phase,

60Hz, 12470Y/7200V primary, 

208Y/120V secondary

- 364 331 764 1,313 2,730 4,286 N/A

5 

1500 kVA, 65°C, three-phase, 

60Hz, 24940GrdY/14400V 

primary, 480Y/277V secondary

- 1,663 5,509 6,040 6,694 10,613 43,740 N/A

6 

25 kVA, 150°C, single-phase, 

60Hz, 480V primary, 120/240V 

secondary, 10kV BIL

- (2) 146 264 303 452 591 1,219

7 

75 kVA, 150°C, three-phase, 

60Hz, 480V primary, 208Y/120V 

secondary, 10kV BIL

- 18 117 288 565 1,171 1,234 2,703

8 

300 kVA, 150°C, three-phase, 

60Hz, 480V Delta primary, 

208Y/120V secondary, 10kV BIL

- 520 1,037 2,734 3,730 7,334 N/A N/A

9 

300 kVA, 150°C, three-phase, 

60Hz, 4160V Delta primary, 

480Y/277V secondary, 45kV BIL

- 828 2,780 4,189 5,443 9,715 N/A N/A

10

1500 kVA, 150°C, three-phase, 

60Hz, 4160V primary, 480Y/277V 

secondary, 45kV BIL

- 5,561 9,469 12,907 14,341 31,275 N/A N/A

11

300 kVA, 150°C, three-phase, 

60Hz, 12470V primary, 

480Y/277V secondary, 95kV BIL

- 460 2,079 3,861 5,617 10,715 N/A N/A

12

1500 kVA, 150°C, three-phase, 

60Hz, 12470V primary, 

480Y/277V secondary, 95kV BIL

- 2,567 5,170 11,072 12,556 19,192 33,255 N/A

13

2000 kVA, 150°C, three-phase, 

60Hz, 12470V primary, 

480Y/277V secondary, 125kV BIL

- 3,929 10,513 18,017 24,196 44,046 N/A N/A

DOE uses a software model to generate thousands of potential design options for each 

representative unit analyzed in the engineering analysis. DOE considers five to eight different 

design option combinations for each representative unit, and generates over 500 unique designs 

for each combination of design options. The output of the engineering analysis is this set of 
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thousands of unique designs for each representative unit. Figure ES.2.1 illustrates the costefficiency relationship of these designs for design line 7, a 75 kVA, three-phase, LVDT

distribution transformer. DOE generates a similar set of designs for each of the 13 representative 

units identified in Table ES.2.4. 

Figure ES.2.1 Cost-Efficiency Outputs of Engineering Analysis for Design Line 7

 DOE considered an advanced technology scenario that examines the cost-efficiency 

relationship of symmetric core designs. Symmetric core designs use a continuously wound core 

with 120 degree radial symmetry, resulting in a triangularly shaped core when viewed from 

above. This type of design has several benefits over traditional core designs, including reduced

weight, volume, no-load losses, noise, vibration, stray magnetic fields, inrush current, and power 

in the third harmonic. DOE simulated symmetric core designs for each three-phase design line 

by adjusting the traditional core designs. After the adjustments, symmetric core designs were 

typically less costly and more efficient than traditional core designs. DOE examined an 

additional CSL for each of these design lines to analyze the maximum possible efficiency, which 

is not attainable for traditional core designs. 

$1,500 

$2,500 

$3,500 

$4,500 

$5,500 

$6,500 

$7,500 

97.80% 98.00% 98.20% 98.40% 98.60% 98.80% 99.00% 99.20% 99.40% 99.60%

Manufacturer Selling Price ($)

Efficiency at 35% Load, Temperature Corrected

M12AlAl_bl_3leg

M12CuAl_bl_3leg

M6AlAl_bl_3leg

M6AlAl_fm_3leg

M4CuAl_fm_3leg

M3AlAl_fm_3leg

H0CuCu_fm_3leg

SA1CuCu_5leg

CSLs

CSL 0 CSL 1

CSL 2

CSL 3 CSL 4 CSL 5 CSL 6 CSL 7
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DOE also considered core deactivation technology, which uses a system of smaller 

transformers to replace a single, larger transformer. These smaller transformers can then be 

powered on and off in response to shifts in loading demand, which results in energy savings at 

lower load factors when some of the component transformers can be deactivated. Core 

deactivation technology presents energy savings potential at lower load factors, but may not 

demonstrate an efficiency benefit at the current test procedure load factor. In the preliminary 

analysis, DOE seeks comment on a potential revision to the test procedure that will examine a 

weighted-average loading for core deactivation technology. 

ES.2.5 Markups Analysis

The markups analysis (see chapter 6 of the preliminary TSD) develops appropriate 

markups in the distribution chain to convert the estimates of manufacturer cost derived in the 

engineering analysis to installed transformer prices. Transformers are specialty items, often 

custom-built with unlisted prices. The engineering analysis (see chapter 5 of the preliminary 

TSD) provided the manufacturer selling prices, including shipping costs, for each of the 

transformer designs analyzed by the LCC. DOE derived a set of prices for each transformer 

design produced by the engineering analysis by applying markups to the manufacturer selling 

price. These markups represent all the costs associated with bringing a manufactured 

transformer into service as an installed piece of electrical equipment at a customer’s site.

 For both liquid-immersed and dry-type transformers, DOE estimated national averages 

for sales tax, an installation labor and equipment markup, and weight-dependent installation 

costs. Table ES.2.5 summarizes the markup rates.

Table ES.2.5 Markups for Distribution Transformers

Markups Markup Rate

Liquid-Immersed Dry-Type

Distributor 1.07 1.15 

Installation/Contractor Materials 1.10 1.10

Installation/Contractor Labor/Equip. (LE) 1.43 1.52 

Sales Tax Markup 1.05 1.05

ES.2.6 Energy Use Characterization

The energy use characterization, which assesses the potential energy savings resulting 

from new or amended efficiency standards, provides the basis for developing energy savings 
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used in the life-cycle cost (LCC) and subsequent analyses. The energy use and end-use load 

characterization analysis (see Chapter 7 of the preliminary TSD) produced energy use estimates 

and end-use load shapesa for distribution transformers. The energy use estimates enable DOE to 

evaluate the energy savings from the operation of distribution transformer equipment at various 

efficiency levels, while the end-use load characterization allowed evaluation of the impact on 

monthly and peak demand for electricity from the operation of transformers. 

 The energy used by distribution transformers is characterized by two types of losses. The 

first are no-load losses, which are also known as core losses. No-load losses are roughly constant 

and exist whenever the transformer is energized (i.e., connected to live power lines). The second 

are load losses, which are also known as resistance or I2R losses. Load losses are proportional to 

the square of the instantaneous load being served by the transformer. Because the application of 

distribution transformers varies significantly by type of transformer (liquid-immersed or drytype) and ownership (electric utilities own approximately 95 percent of liquid-immersed 

transformers, while commercial/industrial entities use mainly dry-type), DOE performed two 

separate end-use load analyses to evaluate distribution transformer efficiency. The analysis for 

liquid-immersed transformers assumes that these are owned by utilities, and uses hourly load and 

price data to estimate the energy, peak demand and cost impacts of improved efficiency. For drytype transformers, the analysis assumes that these are owned by commercial and industrial 

customers, so the energy and cost savings estimates are based on monthly building-level demand 

and energy consumption data and marginal electricity prices. In both cases, the energy and cost 

savings are estimated for individual transformers, and aggregated to the national level using 

weights derived from either utility or commercial/industrial building data. 

 Chapter 7 provides greater detail on the methods, data, and assumptions used for the 

Energy Use and End-Use Load Characterization analyses.

ES.2.7 Life-Cycle Cost and Payback Period Analyses 

Stipulating new or amended energy conservation standards for equipment results in 

changes in consumer operating expenses (usually a decrease) and changes in consumer price 

(usually an increase). DOE analyzed the net effect of amended standards on consumers by 

evaluating the LCC using the cost-efficiency relationship derived in the engineering analysis, as 

well as the energy costs derived from the energy use characterization. Inputs to the LCC 

 

a End-use load shape is an expression used to describe the quantity of electricity used by a distribution transformer, 

measured over a period of time, usually one year.
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calculation included the installed cost to the consumer (purchase price plus installation cost), 

operating costs (primarily energy expenses), the expected lifetime of the equipment, and a 

discount rate. 

Because the installed cost of equipment typically increases while operating cost typically 

decreases in response to new or amended standards, there is a point when the equipment has 

higher-than-baseline efficiency while the net operating-cost benefit (in dollars) since the time of 

purchase is equal to the incremental first cost of purchasing the higher efficiency equipment. The 

length of time required for equipment to reach this cost-equivalence point is known as the 

payback period (PBP). 

 DOE conducted the LCC and PBP analyses using values that reflect utilization of the 

equipment in the field. DOE identified several input values for estimating the LCC, including 

retail equipment prices, energy prices, equipment lifetimes, and discount rates. 

 For dry-type distribution transformers, DOE used utility tariff data to develop monthly 

marginal electricity prices for each transformer in the LCC sample. The marginal prices are 

calculated by taking account of the difference between the transformer’s losses in the base-case 

and for a candidate standard level, in combination with the associated change in energy use. The 

price used is based on commercial and industrial tariffs. DOE then applied the calculated 

monthly prices to the estimated electricity use by the transformer in each corresponding month. 

For liquid-immersed distribution transformers, DOE used hourly system lambda data, as a proxy 

for system price data, from the Federal Energy Regulatory Commission (FERC) (for regions 

without wholesale markets) and day-ahead market clearing price data (for regions with wholesale 

markets) to determine average hourly prices of electricity. To estimate the future trends in energy 

prices, DOE used projections from the U.S. Energy Information Administration’s (EIA’s) 

Annual Energy Outlook 2010 (AEO 2010).b 

Because the basis for the lifetime estimates in the literature for distribution transformers 

is uncertain, and in view of the Oak Ridge National Laboratory (ORNL) Determination Analysis 

of Energy Conservation Standards for Distribution Transformers, ORNL-6847 that estimated a 

national average lifetime for utility owned transformers at 31.95 years, DOE assumed that the 

average life of distribution transformers is 32 years. This lifetime assumption includes a constant 

 

b AEO 2010 presents long-term projections of energy supply, demand, and prices through 2035, based on results 

from EIA’s National Energy Modeling System (NEMS). 
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failure rate of 0.5 percent/year due to lightning and other random failures unrelated to 

transformer age, and an additional corrosive failure rate of 0.5 percent/year starting at year 15. 

DOE adjusted the retirement distribution to maintain an average life of 32 years. 

 Using the projected distribution of equipment efficiencies for each design line, DOE 

assigned a specific equipment efficiency to each sample transformer. If a transformer was 

assigned an equipment efficiency that is greater than or equal to the efficiency of the standard 

level under consideration, the LCC calculation would show that this transformer is not impacted 

by that standard level. 

ES.2.7.1 Life-Cycle Cost and Payback Period Analysis Results 

Table ES.2.6 show summary LCC Savings results and Table ES.2.7 show summary PBP

results analyses for all design lines at each considered candidate standard level (CSL). 

Table ES.2.6 Summary of Life-Cycle Cost Savings (2010$) 

Design 

Line

Rated 

Capacity 

(kVA)

Candidate Standard Level

1 2 3 4 5 6 7 

1 50 221.1 1,138.9 1,271.8 1,347.7 944.8 172.7 N/A

2 25 83.9 507.8 490.2 362.9 -130.4 N/A N/A

3 500 935.8 5,705.0 7,179.7 7,662.4 8,067.0 6,559.5 4,087.1 

4 150 2,309.6 2,592.4 2,974.4 3,203.3 2,776.7 1,309.4 N/A

5 1500 7,827.9 19,260.0 19,625.1 20,091.7 18,797.7 -10,105.4 N/A

6 25 86.4 100.9 56.8 136.4 157.1 29.4 -820.3 

7 75 243.5 532.7 625.8 657.9 816.8 913.5 -782.8 

8 300 1,375.9 2,625.6 2,395.9 3,760.7 226.7 N/A N/A

9 300 1,382.7 1,455.0 2,312.5 2,556.8 -1,572.0 N/A N/A

10 1500 2,417.0 7,604.3 12,276.5 12,988.2 -7,203.8 N/A N/A

11 300 562.9 1,942.5 1,317.5 197.1 -7,054.2 N/A N/A

12 1500 -167.6 2,643.9 7,473.9 9,063.2 4,961.7 -18,429.1 N/A

13 2000 3,050.3 4,076.1 10,600.3 11,919.2 -9,580.7 N/A N/A
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Table ES.2.7 Summary of Payback Period Results (Years)

Design 

Line

Rated 

Capacity 

(kVA)

Candidate Standard Level

1 2 3 4 5 6 7 

1 50 26.8 8.4 10.4 12.5 22.6 31.2 N/A

2 25 26.5 13.7 16.7 20.6 30.4 N/A N/A

3 500 18.3 12.2 8.1 9.1 11.1 17.3 22.7 

4 150 5.8 4.8 9.4 11.8 23.7 33.5 N/A

5 1500 16.5 6.5 7.5 8.3 17.8 39.9 N/A

6 25 12.5 19.2 19.7 15.0 15.6 18.8 33.0 

7 75 0.3 7.8 9.8 11.2 12.3 12.7 24.0 

8 300 6.9 6.9 11.9 10.7 18.6 N/A N/A

9 300 13.6 13.6 13.0 14.1 21.7 N/A N/A

10 1500 18.5 13.3 10.4 11.1 22.5 N/A N/A

11 300 17.5 13.2 15.3 18.5 34.4 N/A N/A

12 1500 23.1 15.6 13.8 13.0 16.0 27.6 N/A

13 2000 14.4 17.4 13.7 13.8 21.8 N/A N/A

 Chapter 8 of the preliminary TSD provides more details on the methods, data, and 

assumptions used for the LCC and PBP analyses 

ES.2.8 Shipments Analysis

Shipment forecasts are needed to calculate the national impacts of new or amended 

standards on energy use, net present value (NPV) of consumer costs and savings, and future 

manufacturer cash flows for each representative equipment class under consideration. DOE 

obtained forecasts of shipments for the base case and each potential standards case as inputs to 

the National Energy Savings (NES) model that is used to estimate the total national energy 

savings as a function of shipments. For the distribution transformer rulemaking, DOE developed

an accounting framework to prepare shipment scenarios for the base case and each of the CSLs. 

The model keeps track of the aging and replacement of transformer capacity given a projection 

of future transformer sales based on electricity sales obtained from EIA’s Annual Electric Power 

Industry Database, 2008. The framework uses annual transformer sales and the age distribution 

of the in-service stock to calculate equipment costs for the NPV and energy use for the NES, 

respectively. New transformer capacity demand is created by growth in electrical demand. 

Transformer shipments, a retirement function, and the initial number of transformers in service 

influence how transformers in service and supply of transformer capacity change over time.

Table ES.2.8 shows the total shipments for all candidate standard levels for liquid-
ES-17

immersed and dry-type distribution transformers over the analysis period from 2015 to 2044. 

Table ES.2.8 Cumulative Shipments of Transformers by Candidate Standard Level 

(Billion kVA), 2015 - 2044 

Candidate Standard Level

Basecase

1 2 3 4 5 6 7 

Liquid-Immersed 1.96 1.96 1.95 1.95 1.94 1.93 1.93 1.93 

Low-Voltage Dry-Type 0.63 0.63 0.63 0.62 0.62 0.62 0.62 0.62 

Medium-Voltage Dry-Type 0.23 0.23 0.23 0.23 0.22 0.22 0.22 0.22 

 Chapter 9 of the preliminary TSD provides more details on the methods, data, and 

assumptions used for the Shipments analyses. 

ES.2.9 National Impact Analysis 

The national impact analysis (NIA) estimates the following national impacts from 

possible candidate standard levels: (1) NES, (2) monetary value of the energy savings due to new 

or amended standards, (3) increased total installed costs of the considered equipment due to new 

or amended standards, and (4) NPV of energy savings (difference between value of energy 

savings and increased total installed costs). DOE prepared a spreadsheet model to forecast 

energy savings and national consumer economic costs and savings resulting from new standards. 

 The NES and NPV calculations use the LCC calculations as the source of most input 

data. The LCC calculations are performed by design line, whereas any eventual standards would 

be promulgated by equipment class. As a first step, therefore, the NES calculation aggregates the 

LCC design line data to calculate data relevant to equipment classes. Design-line-to-equipmentclass aggregation is the process by which the Department took the results from the economic 

analysis of engineering design lines and combined them to provide estimates of economic impact 

by equipment class. To represent the variety of designs in some equipment classes, the 

Department analyzed up to three different design lines per equipment class. Specifically, 

equipment class 1 (single-phase, medium-voltage, liquid-immersed transformers) is represented 

by three design lines and equipment class 2 (three-phase, medium-voltage, liquid-immersed

transformers) is represented by two design lines. For single-phase equipment classes 5, 7, and 9, 

there are no directly corresponding dry-type single-phase design lines (DLs), the Department 

used the appropriate three-phase design lines of similar BIL rating, and divided by 3. Table 

ES.2.9 presents the mapping of design line to equipment class.
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Table ES.2.9 Mapping of Design Line (DL) to Equipment Class (EC)

Equipment Class BIL* 

(kV)

Capacity 

(kVA) Mapping

EC 1, Liquid-Immersed, MV,** Single-Phase Any 10-833 DL 1 + DL 2 + DL 3

EC 2, Liquid-Immersed, MV, Three-Phase Any 15-2500 DL 4 + DL 5

EC 3, Dry-Type, LV,† Single-Phase ≤ 10 15-333 DL 6

EC 4, Dry-Type, LV, Three-Phase ≤ 10 15-1000 DL 7 + D L8

EC 5, Dry-Type, MV, Single-Phase 20-45 15-833 (DL 9 ÷ 3) +(DL 10 ÷ 3) 

EC 6, Dry-Type, MV, Three-Phase 20-45 15-2500 DL 9 + DL 10

EC 7, Dry-Type, MV, Single-Phase 46-95 15-833 (DL 11 ÷ 3) +(DL 12 ÷ 3) 

EC 8, Dry-Type, MV, Three-Phase 46-95 15-2500 DL 11 + DL 12 

EC 9, Dry-Type, MV, Single-Phase ≥ 95 75-833 DL 13 ÷ 3 

EC 10, Dry-Type, MV, Three-Phase ≥ 95 225-2500 DL 13

* BIL = Basic Impulse Insulation Levels

** MV = Medium Voltage

† LV = Low Voltage

ES.2.9.1 National Energy Savings Analysis 

DOE calculated annual NES as the difference between national energy consumption in 

the base case (without new energy conservation standards) and under each CSL. DOE estimated 

energy consumption and savings based on site energy, and converted the site energy values to 

primary (source) energy using factors that account for losses in transmission and distribution and 

in electricity generation. Cumulative energy savings are the sum of the annual NES, which DOE 

determined over the analysis period from 2015 to 2044. 

Table ES.2.10 shows summary results of both the NES and NPV for liquid-immersed and 

dry-type transformers.

ES.2.9.2 Net Present Value Analysis

DOE calculated net monetary savings each year as the difference between total savings in 

operating costs and increases in total equipment costs in the base case and amended standards 

cases. DOE calculated savings over the life of the equipment purchased in the forecast period. 

The NPV is the difference between the present value of operating cost savings and the present 

value of increased total installed costs. DOE used discount rates of 7 percent and 3 percent to 

discount future costs and savings to the present. 

Table ES.2.10 shows summary results of both the NES and NPV for liquid-immersed and 

dry-type transformers.
ES-19

Table ES.2.10 Summary of Cumulative National Energy Savings and Net Present Value 

Impact

Analysis Discount 

Rate (%)

Candidate Standard Level

1 2 3 4 5 6 7 

Liquid-Immersed

Cumulative Source Savings 

2044 (Quads) 0.62 1.38 1.69 1.93 2.27 2.50 2.50 

Net Present Value (B 2010$) 3 5.21 13.84 15.08 14.98 8.67 -3.67 -3.74 

7 0.44 2.37 1.75 0.70 -4.12 -11.65 -11.69 

Dry-Type

Cumulative Source Savings 

2044 (Quads) 0.27 0.64 1.01 1.32 1.83 2.09 2.38 

Net Present Value (B 2010$) 3 2.14 4.85 6.51 7.99 8.43 8.08 2.75 

7 0.55 1.12 1.17 1.30 0.44 -0.34 -3.86 

 Chapter 10 of the preliminary TSD provides more details on the methods, data, and 

assumptions used for the NIA analyses. 

ES.2.10 Preliminary Manufacturer Impact Analysis

A preliminary manufacturer impact analysis (MIA) assesses the potential impacts of new 

or amended energy conservation standards on manufacturers, such as effects on expenditures for 

capital conversion, marketing costs, shipments, and research and development costs. Potential 

impacts might lead to changes in manufacturing practices for distribution transformers. DOE 

identified potential impacts through interviews with manufacturers and other interested parties. 

As a result of preliminary interviews, DOE identified three key issues relevant to 

distribution transformers: core steel availability, equipment conversion costs, and intellectual 

property. Chapter 12 of the preliminary TSD provides additional detail on the preliminary 

manufacturer impact analysis.

ES.2.11 Other Analyses

The remaining chapters of the preliminary TSD address the analyses to be performed for 

the NOPR:

• The LCC analysis for subgroups evaluates the effects of amended energy conservation 

standards on various national subgroups (chapter 11). 
ES-20

• The utility impact analysis examines impacts of amended energy conservation standards 

on the generation capacity of electric utilities (chapter 13).

• The employment impact analysis examines the effects of amended energy conservation 

standards on national employment (chapter 14).

• The environmental assessment examines the effects of amended energy conservation 

standards on various airborne emissions (chapter .15) 

• The regulatory impact analysis examines the national impacts of non-regulatory 

alternatives to mandatory energy conservation standards (chapter 16). 

ES.3 ISSUES ON WHICH THE U.S. DEPARTMENT OF ENERGY SEEKS PUBLIC 

COMMENT 

DOE is interested in receiving comments on all aspects of this preliminary analysis. DOE 

especially invites comments or data to improve DOE’s analysis, including information that will 

respond to the following questions and concerns that were raised during DOE’s preliminary 

interviews with manufacturers and in the preparation of the preliminary TSD. 

ES.3.1 Efficiency Requirements for Dual/Multiple-Voltage Secondaries

 DOE understands that dual-voltage and multiple-voltage distribution transformers with

reconfigurable secondaries typically exhibit small differences in efficiency between series and 

parallel connections. Additionally, the less-efficient (parallel) connection is rarely used in 

service of the distribution transformer. DOE seeks comment on its proposal to change the testing 

requirement to permit compliance testing in any secondary configuration. Additionally, DOE 

seeks comment on whether the proposed revision should apply to all covered distribution 

transformers or a subset of transformers. DOE welcomes the submission of any data that would 

support a conclusion. 

ES.3.2 Dual/Multiple-Voltage Transformers with Varying Basic Impulse Levels 

DOE welcomes comment on its proposal to require compliance at the lowest basic 

impulse level (BIL) that a dual/multiple-voltage distribution transformer is rated for operation. 
ES-21

ES.3.3 Weighted-Average Losses from Multiple Loading Points 

 Certain technology options, such as core deactivation technology, enable energy savings 

at lower loading points when compared to traditional transformer design options. DOE seeks 

comment on its proposal to designate a weighted-average loss calculation using various loadings 

to capture the energy savings potential of technologies that do not follow the standard “loading 

vs. losses” relationship evident in traditional transformer designs. DOE welcomes comment on 

the appropriate weightings to use for the different load factors. 

ES.3.4 Current DOE Test Procedure

DOE welcomes comment on all aspects of the current test procedure for distribution 

transformers.

ES.3.5 Symmetric Core Designs

DOE seeks comment on symmetric core designs, their practicability to manufacture and 

install, and whether or not they offer potential for efficiency improvement. In particular, DOE 

seeks comment on any application types for which using a symmetric core design may be 

infeasible. DOE requests comment on the adjustments it used to estimate symmetric core costefficiency relationships, and welcomes any performance data generated from simulation or 

testing that demonstrate the performance of symmetric core designs.

ES.3.6 Core Deactivation Technology 

 DOE seeks comment on core deactivation technology. DOE requests input on any 

considerations necessary for analyzing core deactivation systems composed of different 

component transformers, or core deactivation systems for medium-voltage distribution 

transformers. DOE also seeks comment on the types of applications that might benefit from the 

technology, and any other considerations related to the incorporation of the technology in the 

current test procedure. Finally, DOE seeks input on any intellectual property concerns related to 

employing core deactivation technology. 

ES.3.6.1 Nanotechnology Composites

 DOE knows of no current commercial efforts or prototype designs that employ 

nanotechnology composites in distribution transformers, but welcomes comment on such 

technology and its implications for the future of the industry. 
ES-22

ES.3.7 Representative Units for Single-Phase, Liquid-Immersed Design Lines

DOE welcomes comment on the representative units selected for the single-phase, liquidimmersed units in design line 1 through design line 3. Specifically, DOE seeks comment on its 

decision to use a 14400V primary voltage for design line 1 through design line 3. 

ES.3.8 Representative Unit for Design Line 5

DOE welcomes comment on the representative unit selected for design line 5, a 1500 

kVA, three-phase, liquid-immersed transformer. Specifically, DOE asks for comment on the 

appropriate primary voltage for analyzing this selected representative unit.

ES.3.9 Representative Unit for Design Line 13

DOE seeks comment on the representative unit selected for design line 13, a 2000 kVA, 

three-phase, medium-voltage dry-type transformer. DOE specifically would like comments on 

the most appropriate primary voltage for analyzing this representative unit. 

ES.3.10 Additional Representative Units

 DOE welcomes comment on additional representative units or design lines that should be 

considered in its analysis. DOE welcomes comment on all aspects of its selected representative 

units and design lines. 

ES.3.11 Scaling Methodology 

 DOE uses “the 0.75 scaling rule” to scale results from analyzed representative units to 

other units with kVA ratings within the same engineering design line. During preliminary 

manufacturer interviews, DOE heard that the application of this scaling rule during the previous 

rulemaking for distribution transformers made it difficult to manufacture compliant transformers 

for certain kVA ranges. DOE welcomes comment on the scaling approach used and whether an 

improved scaling methodology exists. DOE also welcomes comment on the extent of the impact 

that the previous scaled standard levels have had on the low kVA units for MVDT or for any 

other market segments.

ES.3.12 Design Option Combinations

 DOE seeks comment on the design option combinations selected for analyzing each 

design line. DOE would like comments on any additional design option combinations that yield 
ES-23

efficiency ratings greater than the domain refined steels used in DOE’s analysis. DOE 

considered ZDMH for liquid-immersed designs and H-0 DR for dry-type designs.

ES.3.13 Materials Prices

 During its previous rulemaking on distribution transformers, DOE collected five years of 

historical materials prices and used five-year average prices in its analysis. During preliminary 

interviews, manufacturers indicated that current (2010) materials prices would better predict the 

future price of materials than a five-year average price. As such, DOE used 2010 materials 

prices for its analysis, and conducted high-price and low-price sensitivities using 2008 and 2006 

materials prices, respectively. DOE requests comment on its tentative decision to consider the 

current (2010) materials prices as the reference case materials price rather than a five-year 

average price.

ES.3.14 Factory Overhead Markup for Designs Using a Prefabricated Amorphous Core 

DOE welcomes comment on its tentative decision to use the same factory overhead 

markup for designs using a prefabricated amorphous core as for designs for which the 

manufacturer produces the core. DOE used a factory overhead markup of 12.5 percent on all 

direct material production costs for all designs. 

ES.3.15 Shipping Costs

DOE welcomes comment on its tentative decision to include shipping costs in the 

engineering analysis as a component of the manufacturer’s selling price. Specifically, DOE 

seeks comment on whether profit markups are applied to the shipping cost, and if shipping costs 

are typically four to eight percent of total revenue for the sale of all sizes and types of 

distribution transformers. 

ES.3.16 Additional Costs for Amorphous Designs in Large, Dry-Type Design Lines 

 DOE accounted for additional labor and hardware costs in its amorphous designs used in 

dry-type design lines of 1500 kVA or greater. The additional labor costs account for the extra 

handling necessary for working with large, amorphous cores. The additional hardware costs 

account for bracing necessary in such large designs to contain the coil and prevent short circuit 

problems that may arise. DOE seeks comment on the additional costs DOE considered for 

amorphous designs in design lines 10, 12, and 13. Additionally, DOE seeks comment on 
ES-24

whether these additional costs should be considered for liquid-immersed design lines that are 

1500 kVA or greater, or whether the costs are specific to dry-type designs.

ES.3.17 Trial Standard Levels

 For the NOPR, DOE will develop trial standard levels (TSLs) based on the selected CSLs

for distribution transformers. DOE is considering several criteria in developing the TSLs, 

including, but not limited to, minimum LCC, maximum NPV, and maximum technologicallyfeasible efficiency. These TSLs may include combinations of CSLs and the interaction between 

proposed equipment classes. From the list of TSLs developed, DOE will select one as its 

proposed standard for the NOPR. DOE invites comment on the criteria it should use as the basis 

for selection of TSLs. 

ES.3.18 Impact on Manufacturers

 DOE requests comment on its identification of key issues and requests data and 

information from interested parties that can assist in evaluating the potential impact of amended 

standards on manufacturers. 

ES.3.19 Supply of Core Steels

 DOE welcomes comment on the supply of core steels used in its designs. In particular, 

DOE seeks comment on the global supply of grain-oriented silicon steel, such as M3 and M2, 

and amorphous core steels compared to the projected consumption based on CSLs. 

ES.3.20 Valuing Air-Borne Emission Reductions

 DOE will conduct an environmental assessment as part of the next phase of the standards 

rulemaking, the NOPR. The primary environmental effects of energy conservation standards for 

ballasts are the reduction of power plant emissions resulting from reduced consumption of 

electricity. DOE will assess these environmental effects by using the National Energy Modeling 

System-Building Technologies (NEMS-BT) to provide key inputs to its analysis. The portion of 

the environmental assessment that will be produced by NEMS-BT considers carbon dioxide 

(CO2), sulfur dioxide (SO2), nitrogen oxides (NOX), and mercury (Hg). DOE also plans on 

monetizing the emission reductions due to amended standards consistent with methods used in 

recent DOE standards rulemakings pertaining to commercial clothes washers and other consumer 

products and commercial equipment. For example, in the case of CO2, the most recent 

interagency estimates of the potential global benefits resulting from reduced CO2 emissions in 
ES-25

2010 were $4.7, $21.4, $35.1, and $64.9 per metric ton in 2007 dollars. DOE invites comments 

on the proposed approaches for monetizing the emission savings realized as a result of amended

energy conservation standards. 

ES.3.21 Hourly Load Data 

 DOE seeks comment on any additional sources of distribution transformer load data that 

could be used to validate the energy use and end-use load characterization analysis.

ES.3.22 Installation Practices

 DOE does not currently have any quantitative information on how the number of 

transformers installed in a building scales with either the building floor space or the building 

annual peak load. Thus, to account for the effect of multiple transformers on a single building, 

DOE has used a simple approach, in which the building sample weight is multiplied by the 

number of floors in the building. DOE seeks comment on whether this approach can be 

improved. 

ES.3.23 Distributer Markups

DOE estimated the distributer markups factors for liquid-immersed and dry-type 

transformers at 1.07 and 1.15, respectively. These factors are based on stakeholder comment 

from the previous distribution transformers final rule. DOE welcomes comments on these 

markup factors. 

ES.3.24 Evaluation of Energy Efficiency in the Basecase

DOE welcomes comment on the base-case evaluation rates it has tentatively selected. 

Specifically, for LVDT transformers, DOE assumed 10 percent evaluators. For MVDT

transformers, DOE assumed 50 percent evaluators for small-capacity transformers—design line 

(DL) 9 and DL 11—and 80 percent for large-capacity transformers—DLs 10, 12, and 13. DOE 

would particularly like comments on the most appropriate base-case evaluation rate for MVDT

transformers.

ES.3.25 Replacement and Maintenance Practices

 DOE seeks comment on recent changes in utility distribution transformer replacement 

and maintenance practices. In particular, DOE would like comments on any additional sources of 
ES-26

utility replacement rates or maintenance and repair costs that should be considered in the 

analysis.

ES.3.26 Sizing Practices

 DOE seeks comment on recent changes in distribution transformer sizing practices. In 

particular, DOE would like comments on any additional sources of data regarding trends in 

market share across equipment classes for either liquid-immersed or dry-type transformers that 

should be considered in the analysis. 

ES.3.27 Efficiency Trends

 The Department seeks further comment on its decision to use frozen efficiencies for the 

analysis period. Specifically, DOE would like comments on additional sources of data on trends 

in efficiency improvement.