The attached document, issued on May 29, 2012, provides a supplemental analysis to be 

addressed during the public meeting concerning the DOE’s notice of proposed rulemaking: 

Energy Conservation Standards for Distribution Transformers, a rulemaking action issued by the 

DOE. Though it is not intended or expected, should any discrepancy occur between the Notice of 

Public Meeting and Supplemental Analysis and the document herein, the Federal Register 

publication controls, including any documents or analysis to which it refers. This document is 

being made available solely as a means to facilitate the public's access to this document. 
1-A-i

APPENDIX 1-A. SUMMARY OF SUPPLEMENTAL POST-NOTICE OF PROPOSED 

RULEMAKING ANALYSES FOR DISTRIBUTION TRANSFORMERS

TABLE OF CONTENTS

1-A.1 INTRODUCTION ................................................................................................. 1-A-1

1-A.2 BACKGROUND ................................................................................................... 1-A-2

1-A.3 REVISED EQUIPMENT CLASSES .................................................................... 1-A-3

1-A.3.1 Summary of Design Line Coverage ....................................................................... 1-A-5

1-A.3.2 Proposed Equipment Class 1A and 2A for Pad-mounted Distribution 

Transformers .......................................................................................................... 1-A-6

1-A.3.3 Proposed Equipment Class 1B and 2B for Pole-mounted Distribution 

Transformers .......................................................................................................... 1-A-7

1-A.3.4 Potential Equipment Class 2C for Network/Vault Distribution Transformers ...... 1-A-8

1-A.3.5 Potential Equipment Class 2D for Distribution Transformers with ≥ 200 kV 

BIL ......................................................................................................................... 1-A-9

1-A.4 REVISED TRIAL STANDARD LEVELS ........................................................... 1-A-9

1-A.5 ADDITIONAL LIFE-CYCLE COST AND PAYBACK PERIOD RESULTS .. 1-A-10

1-A.5.6 Design Line 1 Life-Cycle Cost and Payback Period Results ............................... 1-A-11

1-A.5.7 Design Line 2 Life-Cycle Cost and Payback Period Results ............................... 1-A-12

1-A.5.8 Design Line 3 Life-Cycle Cost and Payback Period Results ............................... 1-A-13

1-A.5.9 Design Line 4 Life-Cycle Cost and Payback Period Results ............................... 1-A-14

1-A.5.10 Design Line 5 Life-Cycle Cost and Payback Period Results ............................... 1-A-15

1-A.6 ADDITIONAL NATIONAL IMPACTS ANALYSIS RESULTS...................... 1-A-16

1-A.6.11 Summary National Impact Analysis Results ....................................................... 1-A-17

1-A.6.12 Summary National Impact Analysis Results for Single-phase Liquidimmersed Distribution Transformers ................................................................... 1-A-17

1-A.6.13 Summary National Impact Analysis Results for Three-phase Liquid-immersed 

Distribution Transformers .................................................................................... 1-A-19

1-A.7 REQUEST FOR COMMENT ............................................................................. 1-A-20

LIST OF TABLES

Table 1-A.3.1 Equipment Classes for Liquid-immersed Distribution Transformers 

Presented in the Notice of Proposed Rulemaking ...................................... 1-A-5

Table 1-A.5.1 Potential Equipment Class 1A and 2A for Pad-mounted Distribution 

Transformers .............................................................................................. 1-A-6

Table 1-A.6.1 Potential Equipment Class 1B for single-phase pole mounted 

distribution transformers ............................................................................ 1-A-7

Table 1-A.6.2 Summary of Weight for Pole-mounted Design Lines by Efficiency 

Level (lbs) .................................................................................................. 1-A-8

Table 1-A.6.3 Summary of Relative Weight Changes from the Base Case for Polemounted Design-lines by Efficiency Level (%) ......................................... 1-A-8
1-A-ii

Table 1-A.9.1 Notice of Proposed Rulemaking Trial Standard Levels for LiquidImmersed Distribution Transformers ....................................................... 1-A-10

Table 1-A.9.2 Notice of Public Meeting Trial Standard Level for Liquid-immersed 

Distribution Transformers ........................................................................ 1-A-10

Table 1-A.10.1 Summary Life-Cycle Cost Results for Design Line 1 Representative 

Unit .......................................................................................................... 1-A-11

Table 1-A.10.2 Summary Payback Period Results for Design Line 1 Representative 

Unit .......................................................................................................... 1-A-12

Table 1-A.10.3 Summary Life-Cycle Cost Results for Design Line 2 Representative 

Unit .......................................................................................................... 1-A-12

Table 1-A.10.4 Summary Payback Period Results for Design Line 2 Representative 

Unit .......................................................................................................... 1-A-13

Table 1-A.10.5 Summary Life-Cycle Cost Results for Design Line 3 Representative 

Unit .......................................................................................................... 1-A-13

Table 1-A.10.6 Summary Payback Period Results for Design Line 3 Representative 

Unit .......................................................................................................... 1-A-14

Table 1-A.10.7 Summary Life-Cycle Cost Results for Design Line 4 Representative 

Unit .......................................................................................................... 1-A-14

Table 1-A.10.8 Summary Payback Period Results for Design Line 4 Representative 

Unit .......................................................................................................... 1-A-15

Table 1-A.10.9 Summary Life-Cycle Cost Results for Design Line 5 Representative 

Unit .......................................................................................................... 1-A-15

Table 1-A.10.10 Summary Payback Period Results for Design Line 5 Representative 

Unit .......................................................................................................... 1-A-16

Table 1-A.12.1 National Impact Analysis Results for Liquid-immersed Transformers ... 1-A-17

Table 1-A.13.1 Results for Notice of Proposed Rulemaking Equipment Class 1 ............ 1-A-17

Table 1-A.13.2 Results for Notice of Public Meeting Equipment Class 1A – Padmounted Distribution Transformers ......................................................... 1-A-18

Table 1-A.13.3 Results for Notice of Pubic Meeting Equipment Class 1B – Polemounted Distribution Transformer .......................................................... 1-A-18

Table 1-A.14.1 Results for Notice of Proposed Rulemaking Equipment Class 2 ............ 1-A-19

Table 1-A.14.2 Results for Notice of Public Meeting Equipment Class 2B – Padmounted Transformers ............................................................................. 1-A-19

Table 1-A.14.3 Results for Notice of Public Meeting Equipment Class 2B – Polemounted Distribution Transformers ......................................................... 1-A-20

Table 1-A.15.1 Estimated Shipments of Liquid-Immersed, Medium-Voltage 

Transformers, 2009 .................................................................................. 1-A-20

LIST OF FIGURES

Figure 1-A.4.1 Liquid-Immersed Design Lines and Representative Units ........................ 1-A-6
1-A-1

APPENDIX 1-A. SUMMARY OF SUPPLEMENTAL POST-NOTICE OF PROPOSED 

RULEMAKING ANALYSES FOR DISTRIBUTION TRANSFORMERS

1-A.1 INTRODUCTION

Section 6295(o)(2)(A) of 42 United States Code (U.S.C.) requires the U.S. Department of 

Energy (DOE) to set forth energy conservation standards that are technologically feasible and 

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

chapter provides a description of the analysis performed following DOE’s Notice of Proposed 

Rulemaking (NOPR) of February10, 2011.a

http://www1.eere.energy.gov/buildings/appliance_standards/commercial/distribution_transforme

rs.html

 This supplementary analysis builds upon of DOE’s 

NOPR analysis, available on the Distribution Transformers rulemaking webpage: 

. DOE announced the availability of this analysis in its notice of public meeting issued 

May 29, 2012.

In the NOPR and at the public meeting of February 23, 2012, DOE asked for comment on 

whether certain types of liquid-immersed distribution transformers that are currently part of the 

same equipment classes warranted separation into distinct equipment classes. For example, poleand pad-mounted transformers are in the same equipment class and DOE asked for comment on 

whether they would be more appropriately evaluated as separate equipment classes.

A number of interested parties submitted written comments supporting an approach that 

separated pole- and pad-mounted liquid-immersed distribution transformers into separate 

equipment classes. Furthermore, many interested parties also urged DOE to consider separate 

equipment classes for network and vault distribution transformers, as well as those with basic 

impulse level (BIL) ratings above 200 kV.

 In light of these comments, DOE decided to supplement its NOPR analysis to include 

several new trial standard levels (TSLs), which consider additional standards scenarios that 

represent the separate equipment classes that were supported by comments from several 

interested parties. The new TSLs, lettered “A” through “C,” contain separate standards for poleand pad-mounted distribution transformers, and also incorporate the separation of network- and 

vault-based distribution transformers and distribution transformers with BIL ratings 200 kV and 

above into separate equipment classes. The new TSLs relate only to liquid-immersed distribution 

transformers. No modifications have been made to the dry-type distribution transformers analysis 

for the purposes of this notice and the public meeting of June 20, 2012.

 Furthermore, DOE used these TSLs to supplement certain NOPR analyses, including the 

life-cycle cost and payback period analysis and provide interested parties with a perspective on 

 

a 77 FR 7282.
1-A-2

how separate equipment classes may alter the analytical results presented with the NOPR. This 

information, as well as the analytical tools from the NOPR, is available on DOE’s distribution 

transformer rulemaking website, located at: 

http://www1.eere.energy.gov/buildings/appliance_standards/commercial/distribution_transforme

rs.html.

1-A.2 BACKGROUND

Since 1997, when DOE initiated the rulemaking process for distribution transformers, 

DOE has conducted numerous, rigorous analyses, while maintaining a robust public involvement 

process. For example, as outlined in the February 10, 2011, NOPR, beyond utilizing notice and 

comment rulemaking, DOE has held many public meeting and webinars. DOE has extensively 

documented these efforts on its website at:

http://www1.eere.energy.gov/buildings/appliance_standards/commercial/distribution_tra

nsformers.html.

In addition, DOE engaged a broad array of interested parties in negotiations of its 

proposed standards for the energy efficiency of distribution transformers through establishment 

of a subcommittee under the Energy Efficiency and Renewable Energy Advisory Committee 

(ERAC), in accordance with the Federal Advisory Committee Act and the Negotiated 

Rulemaking Act. 77 FR 7792-7793. The subcommittee negotiated about three types of 

distribution transformers: low-voltage dry-type; medium-voltage dry-type; and medium-voltage 

liquid-immersed. While there was a consensus on medium-voltage dry-type distribution 

transformers, for the other two types, there was no consensus, though considerable data was 

generated during these discussions for use in the current supplemental analyses. Of these three, 

however, this TSD focuses upon and medium-voltage liquid-immersed distribution transformers, 

as further detailed below.b

Based on the negotiation process and additional public comment, DOE issued its NOPR. 

In the NOPR DOE presented analysis based on a certain equipment class structure, in which 

liquid-immersed distribution transformers were distinguished only by their phase count and kVA 

rating. The new equipment class structure further distinguishes these transformers by tank type, 

with separate consideration for liquid-immersed distribution transformers with tanks designed for 

network use or mounting on pads, poles, or in vaults. 

 DOE received numerous comments regarding the NOPR. Of importance to the current 

supplemental analysis was DOE’s question number 12 regarding whether “separate equipment 

classes (EC) are warranted for pole-mounted, pad-mounted or other types of liquid-immersed 

 

b Transcripts of the subcommittee meetings, the names of the participants, and all data and materials presented at the 

subcommittee meetings are available at the DOE website at: 

http://www.eere.energy.gov/buildings/appliance_standards/commercial/

distribution_transformers.html. 
1-A-3

transformers.” 77 FR at 7378. A coalition of interested parties (Advocates)c in their NOPR 

comments of 4/10/12, implied that DOE should consider: (1) separate ECs for pad- and polemounted equipment at EL 1.5 (pads) and EL 0.5 (poles) (Id. at p. 13); and (2) urged DOE to 

examine a new trial standard level (TSL) 3.5, which would “correspond to efficiency level (EL) 

1.5” for all medium-voltage liquid-immersed (MVLI) transformer classes (Id. at p. 9). 

Furthermore, Advocates joined these issues by stating “if DOE were to set a standard at the 

levels we suggest (modified TSL 4)” (e.g., a new TSL 3.5) “then we would be open to 

establishing a separate class product class for pole-mounted transformers” (Id. at p. 13). Other 

interested parties, including the Edison Electric Institute and National Electrical Manufacturers 

Association, support the concept of creating new ECs for polls and pads, but do not want 

resolution of this issue to delay issuance of the final rule beyond the 10/01/12 deadline. In 

addition their support is contingent on their ability to “evaluate” the proposal.d

 

Following publication of the NOPR, DOE began analyzing the comments, including 

those raised by the Advocates and others. In light of these comments taken as a whole, DOE 

presents a supplemental analysis and is providing additional time for notice and comment on the 

issues discussed in this TSD.

1-A.3 REVISED EQUIPMENT CLASSES

 DOE divides covered equipment into classes by: (a) the type of energy used; (b) the 

capacity; or (c) any performance-related features that affect consumer utility or efficiency. (42 

U.S.C. 6295(q)) Different energy efficiency standards may apply to different equipment classes. 

In this document DOE presents an expansion of the 10 equipment classes in the NOPR analysis

to 14 equipment classes and increase in the TSLs considered in the NOPR from 7 to 10, as 

explained in detail in section 1-A.4 below. First, this supplemental analysis expands the 

equipment classes by dividing the population of distribution transformers according to: 

a) Type of transformer insulation - liquid-immersed or dry-type, 

b) Number of phases - single or three, 

c) Voltage class - low or medium (for dry-type units only), 

d) Basic impulse insulation (BIL) level (for medium-voltage, dry-type and liquid-immersed 

and units only) and

e) Tank type: pad, pole, network/vault (for liquid-immersed units only). 

 DOE understands that distribution transformers may be manufactured with a wide variety 

of tank types, depending on the specific requirements of their purchasers. The tanks provide 

different utility to the consumer in the form of protection and containment, and also affect the 

 

c The individual members of this coalition include American Council for an Energy-Efficient Economy (ACEEE), 

Appliance Standards Awareness Project (ASAP), National Resources Defense Council (NRDC) and Northwest 

Power Conservation Council (NPCC). Docket comment No 186

d EEI sought to review such ELs for technical and economic feasibility and questioned whether this could be better 

accomplished in a new rulemaking. NEMA said that if DOE decides to raise the levels higher, the notion of separate 

classes “will need to be studied and evaluated.”
1-A-4

ability of a distribution transformer to be made more efficient. For these reasons, DOE is 

considering establishing equipment classes by tank type. 

“Pole-mounted” transformerse

 are designed for mounting on vertical poles and out of 

easy reach. Relative to other distribution transformer types, pole-mounted transformers are 

required to be compact and lightweight to be safely mounted by their poles. They most often 

have round tanks. Furthermore, three-phase pole mounted units are ordinarily constructed by 

triplexing three, single-phase cores. For this reason, DOE believes it is appropriate for a threephase pole-mounted transformer to receive the same standard as that of a single-phase polemounted transformer of one third of its kVA rating.

“Pad-mounted” transformersf are designed for mounting on (e.g.) concrete pads. Though 

they may have added levels of protection to prevent tampering or electrical shock, pad-mounted 

transformers have fewer of the size and weight concerns that pole-mounted transformers 

experience and, therefore, see lower incremental costs for added efficiency.

“Networkg” and “Vault” transformers are designed for use in vaults and for occasional 

submerged operation which requires that they be built to a much higher level of ruggedness and 

durability. Furthermore, compactness is of utmost importance because the vaults themselves are 

frequently in dense urban environments where expanding a vault to accommodate a larger, moreefficient unit could be done only at great cost that would far outweigh any savings in operating 

cost.

 Equipment classes are discussed in greater detail in chapter 3, section 3.4 of the NOPR 

TSD.

 Second, regarding TSLs, the newly presented TSLs provide for different stringency 

levels for above-mentioned tank types, so that a standard may pursue maximum energy savings 

where it is economically justified to do so without risk of harming the utility of certain 

equipment types. 

 DOE presented analysis for liquid-immersed distribution transformer equipment classes 

for the NOPR and NOPR public meeting, these equipment classes separated the liquid-immersed 

design-space by transformer service type, either single or three-phase (Table 1-A.3.1). DOE 

requested and received comment on further refinements of the liquid-immersed design space. 

Based on these comment DOE proposes to modify the existing liquid-immersed equipment 

classes to separate pole and pad mounted distribution transformers and to include additional 

equipment classes for network/vault, and distribution transformers with greater than 200 kV 

BIL.h

 

e Perhaps as specified in IEEE standard C57.12.20 f Perhaps as specified in IEEE standards C57.12.38 and C57.12.34

g Perhaps as specified in IEEE standard C57.12.40

Perhaps as specified in IEEE standards C57.12.23 or C57.12.24

h Basic Impulse Level
1-A-5

Table 1-A.3.1 Equipment Classes for Liquid-immersed Distribution Transformers 

Presented in the Notice of Proposed Rulemaking

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, 95kV BIL 

2 

Liquid-immersed, 

single-phase, round 

tank

10–167 

25 kVA, 65°C, single-phase, 60Hz, 14400V 

primary, 120/240V secondary, round tank, 

125 kV BIL

3 Liquid-immersed, 

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

primary, 277V secondary, 150kV BIL

2 

4 Liquid-immersed, 

three-phase 15–500

150 kVA, 65°C, three-phase, 60Hz, 

12470Y/7200V primary, 208Y/120V 

secondary, 95kV BIL

5 Liquid-immersed, 

three-phase 750–2500

1500 kVA, 65°C, three-phase, 60Hz, 

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

secondary, 125 kV BIL

1-A.3.1 Summary of Design Line Coverage 

 The following two figures summarize the coverage of each of the liquid-immersed design 

lines in relation to the various equipment classes and kVA ratings. Note that these figures are 

similar to those presented in the NOPR, but reflect new possibilities with respect to structuring 

equipment classes. The abbreviation DL stands for design line, and the row in the table where the 

phrase “Rep Unit” appears indicates the kVA rating of the representative unit from that design 

line. The representative unit is the kVA rating that DOE analyzed in the engineering and LCC 

analyses. For example, DL1 stands for design line 1, spanning from 10 to 833 kVA liquid-type, 

single-phase. The label “Rep Unit” appears in row 50 kVA, indicating that the 50 kVA is the 

representative unit for DL1. Similarly, the representative unit for DL2 is the 25 kVA unit. 

There are five liquid-immersed transformer design lines, three single-phase and two 

three-phase, as shown in Figure 1-A.4.1. To capture any design differences between a singlephase pole and a pad-mounted transformer, DOE analyzed units in both DL1, and DL2 and DL3, 

spanning the same kVA ratings (10 kVA to 833 kVA).
1-A-6

Figure 1-A.3.2 Liquid-Immersed Design Lines and Representative 

Units

1-A.3.2 Proposed Equipment Class 1A and 2A for Pad-mounted Distribution 

Transformers

 Classes 1A and 2A respectively correspond to single- and three-phase pad-mounted 

liquid-immersed distribution transformers. Representative units remain unchanged from the 

NOPR, with a 50 kVA single-phase unit and both 150 and 1500 kVA three-phase units in design 

lines 1, 4, and 5. 

Table 1-A.3.2 Potential Equipment Class 1A and 2A for Pad-mounted Distribution 

Transformers

EC DL Type of Distribution 

Transformer

kVA 

Range

Representative Unit for this Engineering 

Design Line

1A 1 

Liquid-immersed, 

single-phase, pad mount, 

rectangular tank

10–833 

50 kVA, 65°C, single-phase, 60Hz, 14400V 

primary, 240/120V secondary, rectangular 

tank, 95kV BIL

2A 

4 Liquid-immersed, threephase, pad-mount 15–500

150 kVA, 65°C, three-phase, 60Hz, 

12470Y/7200V primary, 208Y/120V 

secondary, 95kV BIL 

5 Liquid-immersed, threephase, pad-mount 750–2500

1500 kVA, 65°C, three-phase, 60Hz, 

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

secondary, 125 kV BIL

Equipment Class 

1A

Equipment Class 

1B

kVA Pad Mount Pole Mount

10

15

25

37.5

50

75

100

167

250

333

500

667

833

Liquid-immersed, Single-phase DL 1

DL 2 DL 3

Rep Unit

Rep Unit

Rep Unit

Equipment Class 

2A Equipment Class 2B

kVA Pad Mount Pole Mount

15

20

45

75

112.5

150

225

300

500

750

1000

1500

2000

2500

Liquid-immersed, Three-phase DL 4 DL 5

Scaled from DL2

Scaled 

from DL3

Rep Unit

Rep Unit

Rep Unit Rep Unit
1-A-7

Pad-mounted transformers represent a significant portion of liquid-immersed transformer 

shipments. DOE estimates that approximately 30 percent of single phase, and 95 percent of three 

phase shipments by capacity as pad-mounted transformers.

DOE analyzed EC 1A and 2A at a new EL of 1.5. 

1-A.3.3 Proposed Equipment Class 1B and 2B for Pole-mounted Distribution 

Transformers

 Classes 1B and 2B correspond to single- and three-phase pole-mounted liquid-immersed 

distribution transformers. Representative units remain unchanged from the NOPR, with 25 and 

500 kVA single-phase units in design lines 2 and 3. Although no representative unit exists for 

three-phase pole-mounted transformers, DOE understands that three-phase pole-mounted units 

are typically built by triplexing three single-phase units and, therefore, plans to set a standard for 

these units equal to that of the single-phase unit of one third the capacity. 

Table 1-A.3.3 Potential Equipment Class 1B for single-phase pole mounted distribution 

transformers

EC DL Type of Distribution 

Transformer

kVA 

Range

Representative Unit for this Engineering 

Design Line

1B 

2 

Liquid-immersed, 

single-phase, pole 

mount, round tank 

10–167 

25 kVA, 65°C, single-phase, 60Hz, 14400V 

primary, 120/240V secondary, round tank, 

125 kV BIL

3 

Liquid-immersed, 

single-phase, pole 

mount, round tank

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

primary, 277V secondary, 150kV BIL

 Pole-mounted transformers represent a significant portion of liquid-immersed transformer 

shipments. DOE estimates that approximately 70 percent of single phase, and 5 percent of three 

phase shipments by capacity as pole-mounted transformers. 

DOE recognizes that for utilities, as the primary purchaser of pole-mounted transformers, 

there is concern about increases in transformer size and weight and. Utility stakeholders have 

maintained during the negotiations, and in written comment that increases to weight and volume 

disproportionately increase the installation cost for pole-mounted transformers and in extreme 

cases necessitating that a utility replace existing poles with a new stronger pole to support the 

weight of the new heavier transformer. To address these concerns DOE has estimated additional 

installation costs associated with pole replacement, this methodology is described in chapter 6, 

section 6.3.1of the NOPR TSD. This methodology has been maintained for design line 3, with 

adjustment for the larger and heavier design line 3 described in section 2.2 of this document. 

Table 1-A.6.2 shows the average weight increase for single-phase pole-mounted 

distribution transformers. 
1-A-8

Table 1-A.3.4 Summary of Weight for Pole-mounted Design Lines by Efficiency Level 

(lbs)

Efficiency Level

Base 0.5 1 2 3 4 5 6 7

DL 2

min 463 467 480 540 558 601 692 799 663

avg 473 487 522 544 561 602 697 799 664

max 545 535 625 582 586 606 748 799 699

DL 3

min 2653 2802 2343 2802 2937 2985 3149 3773 4832

avg 2812 2984 2932 2905 2979 3020 3177 3827 4864

max 3218 3370 3285 3192 3144 3212 3269 3985 4950

Table 1-A.3.5 Summary of Relative Weight Changes from the Base Case for Polemounted Design-lines by Efficiency Level (%)

Efficiency Level

Base 0.5 1 2 3 4 5 6 7

DL 2

min 0.0 0.9 3.8 16.5 20.5 29.7 49.4 72.6 43.2 

avg 0.0 2.9 10.2 14.9 18.5 27.1 47.2 68.9 40.3

max 0.0 -1.9 14.7 6.8 7.6 11.2 37.3 46.7 28.4 

DL 3

min 0.0 5.6 -11.7 5.6 10.7 12.5 18.7 42.2 82.1

avg 0.0 6.1 4.2 3.3 5.9 7.4 13.0 36.1 73.0

max 0.0 4.7 2.1 -0.8 -2.3 -0.2 1.6 23.8 53.8

DOE analyzed EC 1A and 2A at a new EL of 0.5. 

1-A.3.4 Potential Equipment Class 2C for Network/Vault Distribution Transformers

DOE received many comments indicating stakeholders’ support of the work done by the 

negotiating committee on this topic. This work includes both the definition of the new equipment 

class and recommends that due to potential size increases with increased efficiency, the standard

for this new equipment class remain at level of the 2007 Final Rule. DOE estimates network and 

vault transformers to make up roughly 5 percent of sales by capacity of distribution transformers. 

The definition outlined in the NOPR: 
1-A-9

i. A “network transformer” is one– 

(i) designed for use in a vault, 

(ii) designed for occasional submerged operation in water, 

(iii) designed to feed a system of variable capacity system of interconnected 

secondaries, and

(iv) built per the requirements of IEEE C57.12.40. 

ii. A “vault-type” transformer is one– 

(i) designed for use in a vault, 

(ii) designed for occasional submerged operation in water, and 

(iii) built per the requirements of IEEE C57.12.23 or IEEE C57.12.24, 

respectively.

1-A.3.5 Potential Equipment Class 2D for Distribution Transformers with ≥ 200 kV BIL 

In the 2007 final rule, DOE established equipment classes for medium-voltage, dry-type 

(MVDT) transformers using basic impulse insulation level (BIL) rating, a measure of resistance 

to very high voltages resulting from (e.g.) lightning strikes. Although certain consumers derive 

utility from transformers of greater BIL rating, it is costlier (and in some cases impossible) to 

build transformers of greater BIL rating to given efficiency levels. Because liquid-immersed 

transformers are less affected performance-wise by BIL rating than are MVDT transformers, 

DOE did not previously separate them by BIL rating. However, as higher standards are 

considered, BIL may start to become a more important consideration for even liquid-immersed 

units. 

Several interested parties commented that in many cases, units built to the highest BIL 

rating ordinarily used in DOE’s scope of coverage (200 kV) are difficult to construct even to 

current standard levels. Further increases could cause these units to become expensive to a 

degree that far outweighs any potential savings from reduced losses.

 For this reason, DOE is considering establishing a separate equipment class for liquidimmersed transformers of BIL rating 200 kV and above.

1-A.4 REVISED TRIAL STANDARD LEVELS 

 DOE presented analysis for liquid-immersed distribution transformers for a series of trial 

standard levels (TSLs) in the NOPR and at the NOPR public meeting. The current TSL 

composition for liquid-immersed transformers is shown below in Table 1-A.9.1. These TSL are 

described in detail in the chapter 10 of the NOPR TSD.
1-A-10

Table 1-A.4.1 Notice of Proposed Rulemaking Trial Standard Levels for LiquidImmersed Distribution Transformers

EC DL Trial Standard Levels by Efficiency Level

TSL 1 TSL 2 TSL 3 TSL 4 TSL 5 TSL 6 TSL 7

1 1 EL 1 EL 1 EL 1 EL 2 EL 3 EL 4 EL 6 

1 2 Base EL 1 EL 1 EL 2 EL 3 EL 4 EL 6

1 3 EL 1 EL 1 EL 2 EL 4 EL 3 EL 5 EL 7

2 4 EL 1 EL 1 EL 1 EL 2 EL 3 EL 4 EL 7

2 5 EL 1 EL 1 EL 2 EL 4 EL 3 EL 5 EL 6 

 DOE received comment in the NOPR from the Advocates requesting that their final 

negotiating position from the negotiation committee be analyzed. Their final position was stated 

as efficiency level (EL) 2 [Advocates 186 pg 9] for all liquid-immersed equipment classes. DOE 

analyzed EL 3 as their final position in the NOPR, this is represented by TSL C In addition, DOE 

is presenting two TSLs to examine potential energy savings below EL 2. 

Table 1-A.4.2 Notice of Public Meeting Trial Standard Level for Liquid-immersed 

Distribution Transformers

EC DL Phases Type 

Trial Standard Levels by Efficiency 

Level

A B C

1A 1 1 pad EL 1 EL 1.5 EL 2 

1B 2 1 pole EL 0.5 EL 0.5 EL 2

1B 3 1 pole EL 1 EL 1 EL 2

2A 4 3 pad EL 1 EL 1.5 EL 2

2A 5 3 pad EL 1 EL 1.5 EL 2

2B - 3 pole scaled scaled scaled

2C - 3 network/vault EL 0 EL 0 EL 0

2D - 3 ≥ 200 kV BIL EL 0 EL 0 EL 0

1-A.5 ADDITIONAL LIFE-CYCLE COST AND PAYBACK PERIOD RESULTS

The analytical results presented here are based on the NOPR LCC spreadsheet tools 

available from the DOE website.i

These spreadsheets were prepared with a “custom” efficiency 

input that was added so end-users could examine the impacts of efficiencies other than those 

presented by DOE. For this analysis DOE used this feature to examine the impacts of the new 

efficiency levels.

 

i

http://www.eere.energy.gov/buildings/appliance_standards/commercial/distribution_transformers.html
1-A-11

 To address the pole replacement costs for DL3 DOE used the same methodology that was 

used for DL2. For DL 3 the following inputs were changed to better approximate the costs 

associated with installing a larger capacity, 500 kVA transformers. For DL3 DOE used RSMeans 

2011 to estimate the range of installation costs to include the use of a heavier crane, and 

additional crew. The estimated range of installation costs associated with pole replacement for a 

500 kVA transformer is between $5877 and $7935. DOE also adjusted the weight change-out 

threshold by scaling the 150 pounds use for DL2 with the 0.75 scaling rule to 1418 pounds for 

DL3. The changes to the design line 3 spreadsheet tool have been made available from the DOE 

websitej

. 

1-A.5.6 Design Line 1 Life-Cycle Cost and Payback Period Results 

Table 1-A.5.1 Summary Life-Cycle Cost Results for Design Line 1 Representative Unit

Efficiency Level

1 1.5 2 3 4 5 6 

Efficiency (%) 99.16 99.19 99.22 99.25 99.31 99.42 99.50

Transformers with Net 

Increase in LCC (%) 57.94 36.30 4.77 4.77 8.00 13.63 55.36 

Transformers with No 

Impact on LCC (%) 0.23 0.10 0.23 0.23 0.00 0.00 0.00

Transformers with Net LCC 

Savings (%) 41.83 63.60 95.00 95.00 92.00 86.37 44.64 

Mean LCC Savings ($) 36 305 641 641 532 629 50

Median LCC Savings ($) -64 44 650 650 540 563 -104

 

j

http://www.eere.energy.gov/buildings/appliance_standards/commercial/distribution_transformers.html
1-A-12

Table 1-A.5.2 Summary Payback Period Results for Design Line 1 Representative Unit

Efficiency Level

1 1.5 2 3 4 5 6

Mean Payback (Years) 32.2 21.1 8.2 8.2 10.4 12.0 19.9 

Median Payback (Years) 20.2 17.9 7.9 7.9 10.0 11.5 19.2 

Transformers having Well 

Defined Payback (%) 85.02 89.40 99.77 99.77 99.89 99.99 99.95 

Transformers having Undefined 

Payback (%) 14.98 10.60 0.23 0.23 0.11 0.01 0.05

Mean Retail Cost ($) 2,244 2,240 2,446 2,446 2,549 2,802 3,333 

Mean Installation Costs ($) 2,230 2,229 2,271 2,271 2,344 2,415 2,606

Mean Operating Costs ($) 209 218 156 156 153 132 126 

Mean Incremental First Cost ($) 327 327 569 569 746 1,070 1,792

Mean Operating Cost Savings 

($) 18 21 71 71 74 95 100

Payback of Average 

Transformer 18.2 15.8 8.0 8.0 10.1 11.2 17.8 

 

1-A.5.7 Design Line 2 Life-Cycle Cost and Payback Period Results 

Table 1-A.5.3 Summary Life-Cycle Cost Results for Design Line 2 Representative Unit

Efficiency Level

0.5 1 2 3 4 5 6 7 

Efficiency (%) 98.95 99.00 99.07 99.11 99.18 99.31 99.41 99.46 

Transformers with Net LCC 

Cost (%) 42.80 14.23 9.82 11.20 15.75 58.18 80.16 86.51 

Transformers with No 

Change in LCC (%) 3.70 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Transformers with Net LCC 

Benefit (%) 53.50 85.77 90.18 88.80 84.25 41.82 19.84 13.49 

Mean LCC Savings ($) 54 309 338 300 250 -445 -736 -599 

Median LCC Savings ($) -558 322 341 308 262 -91 -390 -535
1-A-13

Table 1-A.5.4 Summary Payback Period Results for Design Line 2 Representative Unit

 

Efficiency Level

0.5 1 2 3 4 5 6 7

Mean Payback (Years) 18.3 10.0 9.7 11.3 13.4 27.9 32.7 30.3

Median Payback (Years) 6.47 6.9 8.0 9.5 11.5 18.7 24.3 26.3 

Transformers having Well 

Defined Payback (%) 72.00 98.55 99.93 99.71 99.83 99.75 99.77 99.90

Transformers having 

Undefined Payback (%) 28.00 1.45 0.07 0.29 0.17 0.25 0.23 0.10

Mean Retail Cost ($) 1,281 1,437 1,480 1,530 1,598 1,846 2,052 2,577 

Mean Installation Costs ($) 1635 1722 1761 1790 1859 2500 2678 2093

Mean Operating Costs ($) 146 101 95 93 89 79 75 71 

Mean Incremental First Cost 

($) 140 235 317 396 533 1,422 1,807 1,746 

Mean Operating Cost 

Savings ($) 66 34 40 41 46 55 60 64 

Payback of Average 

Transformer 2.1 7.0 8.0 9.6 11.7 25.8 30.2 27.4 

1-A.5.8 Design Line 3 Life-Cycle Cost and Payback Period Results 

Table 1-A.5.5 Summary Life-Cycle Cost Results for Design Line 3 Representative Unit

Efficiency Level

0.5 1 2 3 4 5 6 7 

Efficiency (%) 99.50 99.48 99.51 99.54 99.57 99.61 99.69 99.73

Transformers with Net 

Increase in LCC (%) 13.44 16.07 11.86 5.35 3.87 3.65 7.37 24.82

Transformers with No 

Impact on LCC (%) 0.35 0.35 0.30 0.00 0.00 0.00 0.00 0.00

Transformers with Net LCC 

Savings (%) 86.21 83.58 87.84 94.65 96.13 96.35 92.63 75.18

Mean LCC Savings ($) 2777 2370 3809 5218 5586 6576 6924 4294

Median LCC Savings ($) 3421 1751 3652 5269 5607 6631 6587 3421
1-A-14

Table 1-A.5.6 Summary Payback Period Results for Design Line 3 Representative Unit

 

Efficiency Level

0.5 1 2 3 4 5 6 7

Mean Payback (Years) 8.2 9.2 6.7 5.6 5.4 6.0 9.4 15.2 

Median Payback (Years) 6.4 6.1 4.0 4.6 4.7 5.2 8.1 13.3

Transformers having Well 

Defined Payback () 97.14 95.56 97.38 99.89 99.98 100.00 99.94 99.74

Transformers having 

Undefined Payback () 2.86 4.44 2.62 0.11 0.02 0.00 0.06 0.26

Mean Retail Cost ($) 7,698 8,546 8,944 9,534 9,679 10,280 12,500 15,917 

Mean Installation Costs ($) 4,234 4,334 4,311 4,370 4,402 4,523 4,996 5,732

Mean Operating Costs ($) 1,422 1,222 1,104 984 957 872 724 656

Mean Incremental First Cost 

($) 1,184 948 1,323 1,972 2,149 2,871 5,564 9,717

Mean Operating Cost 

Savings ($) 1,161 200 318 438 465 550 698 766 

Payback of Average 

Transformer 1.0 4.7 4.2 4.5 4.6 5.2 8.0 12.7

1-A.5.9 Design Line 4 Life-Cycle Cost and Payback Period Results 

Table 1-A.5.7 Summary Life-Cycle Cost Results for Design Line 4 Representative Unit

Efficiency Level

1 1.5 2 3 4 5 6 7 

Efficiency (%) 99.16 99.19 99.22 99.25 99.31 99.42 99.50 99.60

Transformers with Net LCC 

Cost (%) 5.95 12.62 1.91 1.91 1.86 1.82 4.87 31.10

Transformers with No 

Change in LCC (%) 0.58 0.62 0.58 0.58 0.58 0.17 0.00 0.00

Transformers with Net LCC 

Benefit (%) 93.47 86.76 97.51 97.51 97.56 98.01 95.13 63.87 

Mean LCC Savings ($) 862 857 3356.0 3356.0 3362.3 3437.2 3193 1274 

Median LCC Savings ($) 670 577 3418.7 3418.7 3423.6 3489.8 3054 956
1-A-15

Table 1-A.5.8 Summary Payback Period Results for Design Line 4 Representative Unit

 

Efficiency Level

1 1.5 2 3 4 5 6 7

Mean Payback (Years) 6.6 9.4 4.4 4.4 4.4 4.6 8.2 15.1 

Median Payback (Years) 5.0 7.2 4.1 4.1 4.1 4.3 7.9 14.6

Transformers having Well 

Defined Payback (%) 99.37 99.38% 99.27 99.27 99.33 99.81 99.94 94.96

Transformers having 

Undefined Payback (%) 0.63 0.62% 0.73 0.73 0.67 0.19 0.06 0.01

Mean Retail Cost ($) 5,894 5,892 6,443 6,443 6,451 6,536 7,615 10,601

Mean Installation Costs ($) 4,090 4,095 4,184 4,184 4,183 4,223 4,584 4,709

Mean Operating Costs ($) 668 420 483 483 482 471 400 334

Mean Incremental First Cost 

($) 438 440 1,081 1,081 1,088 1,214 2,653 5,763

Mean Operating Cost 

Savings ($) 76 74 261 261 262 274 344 414 

Payback of Average 

Transformer 5.7 6.0 4.1 4.1 4.1 4.4 7.7 13.9

1-A.5.10 Design Line 5 Life-Cycle Cost and Payback Period Results 

Table 1-A.5.9 Summary Life-Cycle Cost Results for Design Line 5 Representative Unit

Efficiency Level

1 1.5 2 3 4 5 6

Efficiency (%) 99.48 99.50 99.51 99.54 99.57 99.61 99.69 

Transformers with Net Increase 

in LCC (%) 19.05 16.99 13.15 10.41 7.77 7.88 39.92 

Transformers with No Impact on 

LCC (%) 0.39 0.28 0.09 0.01 0.00 0.00 0.00

Transformers with Net LCC 

Savings (%) 80.56 82.73 86.76 89.58 92.23 92.12 60.08

Mean LCC Savings ($) 7787 9010 10288 11395 12513 12746 3626 

Median LCC Savings ($) 8300 9649 10741 11658 12666 12838 3083
1-A-16

Table 1-A.5.10 Summary Payback Period Results for Design Line 5 Representative Unit

 

Efficiency Level

1 1.5 2 3 4 5 6

Mean Payback (Years) 7.0 7.3 6.5 7.8 7.8 9.7 18.7 

Median Payback (Years) 4.0 4.1 4.2 5.7 6.3 8.3 16.9 

Transformers having Well 

Defined Payback (%) 91.63 89.93 96.04 98.89 99.82 99.97 100.00

Transformers having Undefined 

Payback (%) 8.37 10.07 3.96 1.11 0.18 0.03 0.00

Mean Retail Cost ($) 28,574 25,391 29,040 30,872 31,980 35,448 56,798 

Mean Installation Costs ($) 8,551 8,438 8,631 8,875 9,030 9,498 9,834 

Mean Operating Costs ($) 3,407 4,414 3,259 3,105 2,994 2,802 2,185 

Mean Incremental First Cost ($) 3,296 3,721 3,842 5,918 7,181 11,116 32,803

Mean Operating Cost Savings 

($) 718 3,434 866 1,020 1,131 1,323 1,940

Payback of Average 

Transformer 4.6 1.1 4.4 5.8 6.3 8.4 16.9 

1-A.6 ADDITIONAL NATIONAL IMPACTS ANALYSIS RESULTS

The national impacts analysis results present here we estimated using the NOPR 

spreadsheet tool available from the DOE website.k

 

k

To disaggregate the impacts for pad- and 

pole-mounted transformers from the equipment classes presented in the NOPR DOE associated 

the fraction of savings with the volume of capacity shipment for each of the new proposed 

equipment classes.

http://www.eere.energy.gov/buildings/appliance_standards/commercial/distribution_transformers.html
1-A-17

1-A.6.11 Summary National Impact Analysis Results 

Table 1-A.6.1 National Impact Analysis Results for Liquid-immersed Transformers

 

NOPR Trial Standard Level NOPM Trial 

Standard Level

Base 1 2 3 4 5 6 7 A B C 

Transformer Shipments 

2015-2044 (Billion KVA) 1.95 1.95 1.95 1.95 1.94 1.94 1.94 1.91 1.95 1.95 1.95

Equipment Cost ($Billions) 32.28 -1.26 -2.51 -2.61 -4.26 -4.48 -6.32 -19.88 -1.57 -2.00 -3.72

Operating Cost (Savings in 

TSLs) ($Billions) 23.26 2.01 4.03 4.33 7.22 7.13 8.08 11.64 2.50 3.21 6.71

Cumulative Source Savings 

2044 (Quads) 0.36 0.74 0.82 1.44 1.42 1.70 2.70 0.45 0.60 1.30

Net Present Value at 3% 

Discount Rate ($Billions) 3.66 7.39 8.24 14.21 13.48 13.17 -1.11 4.66 6.04 13.51

Net Present Value at 7% 

Discount Rate ($Billions) 0.75 1.51 1.73 2.96 2.65 1.76 -8.25 0.93 1.21 2.99

1-A.6.12 Summary National Impact Analysis Results for Single-phase Liquid-immersed 

Distribution Transformers

Table 1-A.6.2 Results for Notice of Proposed Rulemaking Equipment Class 1

 

NOPR Trial Standard Level

NOPM Trial 

Standard Level

Base 1 2 3 4 5 6 7 A B C 

Transformer Shipments 

2015-2044 (Billion 

KVA)

0.80 0.80 0.80 0.80 0.80 0.80 0.80 0.79 0.80 0.80 0.80

Equipment Cost 

($Billions) 22.36 -0.52 -1.78 -1.79 -2.61 -3.03 -4.05 -12.11 -0.84 -1.13 -2.60

Operating Cost 

(Savings in TSLs) 

($Billions)

11.37 0.34 2.36 2.38 3.76 3.89 4.23 5.84 0.78 1.23 3.69

Cumulative Source 

Savings 2044 (Quads) 0.09 0.47 0.47 0.75 0.80 0.90 1.37 0.18 0.27 0.75

Net Present Value at 

3% Discount Rate 

($Billions) 

0.13 3.87 3.93 6.64 6.28 5.51 -4.64 0.94 1.78 6.44

Net Present Value at 

7% Discount Rate 

($Billions) 

-0.19 0.58 0.60 1.15 0.85 0.19 -6.27 -0.06 0.10 1.09
1-A-18

Table 1-A.6.3 Results for Notice of Public Meeting Equipment Class 1A – Pad-mounted 

Distribution Transformers

Trial Standard Level NOPM Trial 

Standard Level

Base 1 2 3 4 5 6 7 A B C 

Transformer Shipments 

2015-2044 (Billion KVA) 0.24 0.24 0.24 0.24 0.24 0.24 0.24 0.24 0.24 0.24 0.24

Equipment Cost 

($Billions) 6.71 -0.16 -0.53 -0.54 -0.78 -0.91 -1.21 -3.63 -0.25 -0.34 -0.78

Operating Cost (Savings 

in TSLs) ($Billions) 3.41 0.10 0.71 0.72 1.13 1.17 1.27 1.75 0.23 0.37 1.11 

Cumulative Source 

Savings 2044 (Quads) 0.03 0.14 0.14 0.23 0.24 0.27 0.41 0.05 0.08 0.22

Net Present Value at 3% 

Discount Rate ($Billions) 0.04 1.16 1.18 1.99 1.88 1.65 -1.39 0.28 0.53 1.93 

Net Present Value at 7% 

Discount Rate ($Billions) -0.06 0.17 0.18 0.34 0.26 0.06 -1.88 -0.02 0.03 0.33

Table 1-A.6.4 Results for Notice of Pubic Meeting Equipment Class 1B – Pole-mounted 

Distribution Transformer

Trial Standard Level NOPM Trial 

Standard Level

Base 1 2 3 4 5 6 7 A B C 

Transformer Shipments 

2015-2044 (Billion KVA) 0.56 0.56 0.56 0.56 0.56 0.56 0.56 0.55 0.56 0.56 0.56

Equipment Cost 

($Billions) 15.65 -0.37 -1.25 -1.25 -1.83 -2.12 -2.83 -8.48 -0.59 -0.79 -1.82 

Operating Cost (Savings 

in TSLs) ($Billions) 7.96 0.24 1.65 1.67 2.63 2.72 2.96 4.09 0.55 0.86 2.58 

Cumulative Source 

Savings 2044 (Quads) 0.07 0.33 0.33 0.53 0.56 0.63 0.96 0.13 0.19 0.52

Net Present Value at 3% 

Discount Rate ($Billions) 0.09 2.71 2.75 4.65 4.40 3.85 -3.25 0.66 1.24 4.51 

Net Present Value at 7% 

Discount Rate ($Billions) -0.13 0.41 0.42 0.80 0.60 0.13 -4.39 -0.04 0.07 0.77
1-A-19

1-A.6.13 Summary National Impact Analysis Results for Three-phase Liquid-immersed 

Distribution Transformers

Table 1-A.6.5 Results for Notice of Proposed Rulemaking Equipment Class 2

NOPR Trial Standard Level NOPM Trial 

Standard Level

Base 1 2 3 4 5 6 7 A B C 

Transformer Shipments 

2015-2044 (Billion KVA) 1.15 1.15 1.15 1.15 1.15 1.15 1.14 1.13 1.15 1.15 1.15 

Equipment Cost 

($Billions) 9.92 -0.73 -0.73 -0.82 -1.65 -1.45 -2.27 -7.78 -0.73 -0.87 -1.12 

Operating Cost (Savings 

in TSLs) ($Billions) 11.88 1.67 1.67 1.95 3.46 3.25 3.84 5.80 1.72 1.98 3.01

Cumulative Source 

Savings 2044 (Quads) 0.27 0.27 0.35 0.69 0.63 0.80 1.33 0.27 0.33 0.55

Net Present Value at 3% 

Discount Rate ($Billions) 3.53 3.53 4.31 7.57 7.21 7.66 3.53 3.71 4.26 7.07

Net Present Value at 7% 

Discount Rate ($Billions) 0.94 0.94 1.13 1.82 1.80 1.57 -1.98 0.99 1.11 1.90

Table 1-A.6.6 Results for Notice of Public Meeting Equipment Class 2B – Pad-mounted 

Transformers

 

Trial Standard Level NOPM Trial 

Standard Level

Base 1 2 3 4 5 6 7 A B C 

Transformer Shipments 

2015-2044 (Billion KVA) 1.10 1.09 1.09 1.09 1.09 1.09 1.09 1.07 1.09 1.09 1.09

Equipment Cost 

($Billions) 9.42 -0.70 -0.70 -0.78 -1.57 -1.38 -2.16 -7.39 -0.70 -0.83 -1.06

Operating Cost (Savings 

in TSLs) ($Billions) 11.29 1.58 1.58 1.85 3.29 3.08 3.65 5.51 1.64 1.88 2.86 

Cumulative Source 

Savings 2044 (Quads) 0.26 0.26 0.33 0.65 0.60 0.76 1.26 0.26 0.31 0.53

Net Present Value at 3% 

Discount Rate ($Billions) 3.35 3.35 4.10 7.19 6.85 7.28 3.35 3.53 4.05 6.72 

Net Present Value at 7% 

Discount Rate ($Billions) 0.89 0.89 1.07 1.72 1.71 1.49 -1.88 0.94 1.05 1.80
1-A-20

Table 1-A.6.7 Results for Notice of Public Meeting Equipment Class 2B – Polemounted Distribution Transformers

Trial Standard Level NOPM Trial 

Standard Level

Base 1 2 3 4 5 6 7 A B C 

Transformer Shipments 

2015-2044 (Billion KVA) 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06

Equipment Cost 

($Billions) 0.50 -0.04 -0.04 -0.04 -0.08 -0.07 -0.11 -0.39 -0.04 -0.04 -0.06

Operating Cost (Savings 

in TSLs) ($Billions) 0.59 0.08 0.08 0.10 0.17 0.16 0.19 0.29 0.09 0.10 0.15

Cumulative Source 

Savings 2044 (Quads) 0.01 0.01 0.02 0.03 0.03 0.04 0.07 0.01 0.02 0.03

Net Present Value at 3% 

Discount Rate ($Billions) 0.18 0.18 0.22 0.38 0.36 0.38 0.18 0.19 0.21 0.35

Net Present Value at 7% 

Discount Rate ($Billions) 0.05 0.05 0.06 0.09 0.09 0.08 -0.10 0.05 0.06 0.09

1-A.7 REQUEST FOR COMMENT

1. DOE requests comment on the new equipment class definitions. 

2. DOE requests data on distribution transformer shipments for each of the presented

equipment classes by kVA rating. similar to the data presented in Table 9.3.2 of the 

NOPR TSD, presented here for reference.

Table 1-A.7.1 Estimated Shipments of Liquid-Immersed, Medium-Voltage 

Transformers, 2009 

Single-Phase Three-Phase

Capacity kVA Units Shipped Capacity kVA Units Shipped

10 58,090 15 –

15 169,083 30 –

25 243,583 45 1,438

37.5 41,755 75 3,753

50 119,455 112.5 790

75 26,338 150 7,426

100 18,679 225 1,969

167 4,357 300 7,340

250 1,905 500 6,650

333 238 750 3,502

500 238 1,000 3,171

667 5 1,500 2,941

833 – 2,000 2,497

– 2,500 2,260
1-A-21

3. DOE requests comment on the appropriate efficiency levels for network/vault and ≥200 

kV BIL equipment classes. 

4. DOE request from utilities pole replacement costs by transformer capacity.