i TO: Distribution Transformers Negotiation Committee

FROM: The Department of Energy

DATE: Tuesday, 20 September 2011

RE: Updates to the Analytical Methodology since the Preliminary Analysis

As requested by the Negotiation Committee, Lawrence Berkeley National Laboratory and Navigant have prepared a summary of changes made to the preliminary analysis since its publication in March of 2011. The details, by chapter, are listed below.ii **TABLE OF CONTENTS**

1. Chapter 3

– Market and Technology Assessment

................................ ................................ ................ 1

1.1. (no changes)

................................ ................................ ................................ ................................ .. 1

2. Chapter 4

– S creening Analysis

................................ ................................ ................................ ............. 1

2.1. (no changes)

................................ ................................ ................................ ................................ .. 1

3. Chapter 5

– Engineering Analysis

................................ ................................ ................................ .......... 1

3.1. Additional Design Line

................................ ................................ ................................ .................. 1
3.2. Additional Design Option Combinations (DOCs)

................................ ................................ ........... 2
3.3. Conductor Pricing

................................ ................................ ................................ .......................... 2
3.4. Terminology

................................ ................................ ................................ ................................ .. 2
3.5. Small Adjustments to Tank Dimensions and Oil Quantities

................................ ......................... 3
3.6. Large Amorphous Labor Hours

................................ ................................ ................................ ..... 3
3.7. Shipping

................................ ................................ ................................ ................................ ......... 3
3.8. Material Prices

................................ ................................ ................................ .............................. 3
3.9. Impedance

................................ ................................ ................................ ................................ .... 4

4. Chapter 6

– Markups Analysis

................................ ................................ ................................ ............... 5

5. Chapter 7

– Energy Use and End

- Use Loan Characterization

................................ ............................... 7
6. Chapter 8

– Life

- Cycle Cost and Payback Period Analysis

................................ ................................ ..... 7

7. Chapter 9

– Shipments Analysis

................................ ................................ ................................ ............ 9
8. Chapter 10

– National Impacts Analysis

................................ ................................ ............................. 10

8.1. Mapping of Draft Efficiency Levels to Draft Trial Standard Levels

................................ .............. 11

8.1.1. Mapping of dELs to dTSL for Liquid

- Immers ed Transformers

................................ ............ 12
8.1.2. Mapping of dELs to dTSL for Low

- Voltage Dry

- Type Transformers

................................ .... 12
8.1.3. Mapping of dELs to dTSL for Medium Voltage Dry

- Type Transformers

............................. 12

8.2. Scaling of Draft Trial Standard Levels across Equipment Classes

................................ ............... 13

8.2.1. Proposed Scal ing of Efficiencies for Liquid

- Immersed Transformers

................................ . 14
8.2.2. Proposed Scaling of Efficiencies for Low

- Voltage Dry

- Type Transformers

......................... 16
8.2.1. Proposed Scaling of Efficiencies for Medium

- Voltage Dry

- Type Transformers

.................. 18

9. Chapter 11

– Life

- Cycle Cost Subgroups Analysis

................................ ................................ ............... 24

9.1. Rural Cooperatives and Municipal Utilities

................................ ................................ ................. 24
9.2. Vault Installed Transformers

................................ ................................ ................................ ....... 25iii **LIST OF TABLES**

Table 3.1 Design Option Combinations from Design Line 1 (Preliminary Analysis)

................................ 2
Table 3.2 Design Option Combinations from Design Line 1 (NOPR)

................................ ....................... 2
Table 3.3 Normal Impedance Ranges for Liquid

- Immersed Transformers

................................ ............. 4
Table 3.4 Normal Impedance Ranges for Dry

- Type Transformers

................................ .......................... 5
Table 4.1 Summary of Changes and Key Issues to the Markups Analysis

................................ ............... 5
Table 5.1 Summary of Changes and Key Issues to the Energy Use Analysis

................................ ........... 7
Table 6.1 Summary of Changes and Key Issues to the Life

- Cycle Cost and Payback Period Analysis

..... 7
Table 7.1 Summary of Changes and Key Issues to the Shipments Analysis

................................ ............ 9
Table 8.1 Summary of Changes and Key Issues to the National Impact Analysis

................................ . 10
Table 8.2 Mapping of Draft Efficiency Levels to Draft Trial Standard Levels for Liquid

- Immersed
Transformers

................................ ................................ ................................ ......................... 12
Table 8.3 Proposed Efficiencies for Draft Trial Standard Levels for Liquid

- Immersed Transformers

... 12
Table 8.4 Mapping of D raft Efficiency Levels to Draft Trial Standard Levels for Low

- Voltage Dry

- Type
Transformers

................................ ................................ ................................ ......................... 12
Table 8.5 Proposed Efficiencies for Draft Trial Standard Levels for Low

- Voltage Dry

- Type
Transformers

................................ ................................ ................................ ......................... 12
Table 8.6 Mapping of Draft Efficiency Levels to Draft Trial Standard Levels for Medium

- Voltage Dry

Type Transformers

................................ ................................ ................................ ................. 13
Table 8.7 Proposed Draft Trial Standard Levels for Medium

- Voltage Dry

- Ty pe Transformers

............ 13
Table 8.8 Scaled Efficiencies for Single Phase Liquid

- Immersed Transformers

................................ .... 14
Table 8.9 Scaled Efficiencies for Three Phase Liquid

- Immersed Transformers

................................ .... 15
Table 8.10 Scaled Efficiencies for Single Phase Low

- Voltage Dry

- Type Transformers

............................ 16
Table 8.11 Scaled Efficiencies for Three Phase Low

- Voltage Dry

- Type Transformers

............................ 17
Table 8.12 Single Phase Scaled Efficiencies for Medium

- Voltage Dry

- Type Transformers 20

- 45BIL

...... 18
Table 8.13 Three Phase Scaled Efficiencies for Medium

- Voltage Dry

- Type Transformers 20

- 45BIL

...... 19
Table 8.14 Single Phase Scaled Efficiencies for Medium

- Voltage Dry

- Type Transformers 46

- 95BIL

...... 20
Table 8.15 Three Phase Scaled Efficiencies for Mediu m

- Voltage Dry

- Type Transformers 46

- 95BIL

...... 21
Table 8.16 Single Phase Scaled Efficiencies for Medium

- Voltage Dry

- Type Transformers 96

- 150BIL

.... 22
Table 8.17 Three Phase Scaled Efficiencies for Medium

- Voltage Dry

- Type Transformers 96

- 150BIL

.... 23

**LIST OF FIGURES** Figure 1 An example of the changes from the preliminary analysis CSLs to the NOPR dELs is shown
below for design line 9.

................................ ................................ ................................ ............. 3 Figure 2 Scaled Efficiency Curve for Single Phase Liquid

- Immersed Transformers

.............................. 15 Figure 3 Scaled Efficiency Curve for Single Phase Liquid

- Immersed Transformers

.............................. 16 Figure 4 Scaled Efficiency Curve for Single Phase Low

- Voltage Dry

- Type Transformers

...................... 17 Figure 5 Scaled Efficiency Curves for Three Phase Low

- Voltage Dry

- Type Transformers

.................... 18iv Figure 6 Scaled Efficiency Curves for Single Phase Medium

- Voltage Dry

- Type Transformers

20

- 45BIL

................................ ................................ ................................ ................................ ... 19 Figure 7 Scaled Effici ency Curves for Three Phase Medium

- Voltage Dry

- Type Transformers

20

- 45BIL

................................ ................................ ................................ ................................ ... 20 Figure 8 Scaled Efficiency Curves Single Phase Medium

- Voltage Dry

- Type Transformers 46

- 95BIL

.... 21 Figure 9 Scaled Efficiency Curves Three Phase Medium

- Voltage Dry

- Type Transformers 46

- 95BIL

.... 22 Figure 10 Scaled Efficiency Curves Single Phase Medium

- Voltage Dry

- Type Transformers 96

- 150BIL

.. 23 Figure 11 Scaled Efficiency Curves Three Phase Medium

- Voltage Dry

- Type Transformers 96

- 150BIL

.. 241 

## Updates to the Analytical Methodology since the Preliminary Analysis

**1. Chapter 3** 

**– Market and Technology Assessment** 

**1.1. (no changes)** 

**2. Chapter 4** 

**– Screening Analysis** 

**2.1. (no changes)** 

**3. Chapter 5** 

**– Engineering Analysis** 

**3.1. Additional Design Line**  In the preliminary analysis, DOE modeled the medium

- voltage, dry

- type transformer market using five design lines over three BIL ranges. Although the lower two BIL ranges (20

- 45 kV and 46

- 95 kV) each had high (1500) and low (300) kVA representative units, the highest BIL level ( ≥96 kV) was covered by a single, high (2000) kVA representative unit. DOE received comment s that it should analyze high BIL, low kVA units directly and opted to add a representative unit at 125 kV ( ≥96 kV class) and 300 kVA. The chart below illustrates relative placement of the representative units as they currently stand.

EC 6 EC 8 EC 10
20-45kV 46-95kV >96kV
15

- 30

- 45

- 75

- 112.5

- 150

- 225
300
500
750
1000
1500
2000
2500 Dry-Type, Medium Voltage, Three-PhaseDL 9DL 11DL 13 (A & B)DL 10DL 12 Rep Unit

Rep Unit Rep Unit

Rep Unit Rep Unit Rep Unit2 **3.2. Additional Design Option Combinations (DOCs)**  Within a design line, DOE models several combinations of steel, conductor, transformer geometry (e.g. core, or shell) and core conductor (e.g. full miter, distributed gap) to represent what is commonly found in the market. It adjusts those DOCs continually to reflect market trends, such as including more designs with partially or wholly aluminum windings and fewer with wholly copper windings. Chapter 5 of the technical support document (TSD) contains the details of the changes

– below is an example of how o ne design line changed following the preliminary analysis.

**Table 3** 

**. 1**  **Design Option Combinations from Design Line 1 (Preliminary Analysis)**

Core Material High

- Voltage Conductor Low

- Voltage Conductor Core Design Type

M5 Cu

– wire Al

– strip Shell

– DG* Wound Core
M3 Al

– wire Al

– strip Shell

– DG Wound Core
M3 Cu

– wire Al

– strip Shell

– DG Wound Core
M2 Cu

– wire Al

– strip Shell

– DG Wound Core
ZDMH Cu

– wire Cu

– strip Shell

– DG Wound Core
SA1 (Amorphous) Cu

– wire Cu

– strip Shell

– DG Wound Core

**Table 3** 

**. 2**  **Design Option Combinations from Design Line 1 (NOPR)**

Core Material High

- Voltage Conductor Low

- Voltage Conductor Core Design Type

M5 Cu

– wire Al

– strip Shell

– DG* Wound Core
M3 Al

– wire Al

– strip Shell

– DG Wound Core
M3 Cu

– wire Al

– strip Shell

– DG Wound Core
M2 Al

– wire Al

– strip Shell

– DG Wound Core
M2 Cu

– wire Al

– strip Shell

– DG Wound Core
ZDMH Al

– wire Al

– strip Shell

– DG Wound Core
ZDMH Cu

– wire Cu

– strip Shell

– DG Wound Core SA1 (Amorphous) Al

– wire Al

– strip Shell

– DG Wound Core SA1 (Amorphous) Cu

– wire Cu

– strip Shell

– DG Wound Core

**3.3. Conductor**  **Pricing** Ordinarily, DOE develops materials prices by surveying manufacturers who regularly purchase those materials. Following the preliminary analysis, several parties suggested that copper and aluminum commodity volatility led to quickly changing prices for all sizes of conductor. Subsequently, DOE moved to a pricing model that applies a fixed processing cost to an index

- derived commodity price for raw copper or aluminum. It believes this pricing methodology will both produce more current prices and permit DOE to update prices without burdening manufacturers with frequent data requests.

**3.4. Terminology**  In the preliminary analysis, DOE used the term “candidate standard level” (CSL) to refer to the progressively higher efficiency benchmarks within a design line. In the NOPR, DOE begins referring to those same things as “efficiency levels” (ELs). For the purposes of the negotiation proceedings,3 DOE has labeled the engineering plots with “draft efficiency levels,” or dELs. It is combinations of these dELs or ELs that are p ackaged together into “trial standard levels”, or TSLs.

**Figure 1**  **An example of the changes from the preliminary analysis CSLs to the NOPR dELs is shown below for design line 9.** 

**3.5. Small Adjustments**  **to Tank Dimensions and Oil Quantities**
DOE solicits feedback on engineering data during interviews with manufacturers and often makes small adjustments to des ign parameters where warranted. Following the preliminary analysis, DOE made minor adjustments to tank dimensions and oil quantities for certain designs.

**3.6. Large Amorphous Labor Hours**  DOE received feedback that large medium

- voltage, dry

- type units (Design Lines 10, 12, and 13B) may require additional labor when constructed with amorphous cores, and adjus ted labor hours accordingly.

**3.7. Shipping**  To reflect current rates, DOE raised its calculated shipping cost from 22 to 28 cents per pound.

**3.8. Material Prices**  DOE populates each respective design line’s cost

- efficiency space with a large number of designs of varyi ng specifications. As time passes and the prices of the constituent materials fluctuate, DOE4 has two options for updating the cost

- efficiency cloud of points. The first method is to apply more recent material prices to existing designs . This can work well with a large number of designs, because those that were “suboptimal” with at previous material price levels can become “optimal” at the new ones. If conductor prices rise relative to core steel, for example, the designs that contain relatively less conduct or at a given efficiency will be found to be more cost effective.

Even further accuracy can be gained by reoptiziming, or creating entirely new designs with the new material prices as inputs. DOE had reoptimized many, but not all, design option combinations for the preliminary analysis. Presently, all design lines have been optimized with respect to 2010 materials prices.

**3.9. Impedance**  DOE revised its respective design line impedance ranges to align with those published under 10

CFR 431.192 (see tab les 1 and 2 below) . This change affects a very small number of designs and does not substantively change the covered cost

- efficiency space for any design lines.

**Table 3** 

**. 3**  **Normal Impedance Ranges for Liquid**

**- Im**  **mersed Transformers**
Single

- phase transformers Three

- phase transformers

kVA Impedance (%) kVA Impedance (%)

10 1.0

– 4.5 15 1.0

– 4.5

15 1.0

– 4.5 30 1.0

– 4.5

25 1.0

– 4.5 45 1.0

– 4.5

37.5 1.0

– 4.5 75 1.0

– 5.0

50 1.5

– 4.5 112.5 1.2

– 6.0

75 1.5

– 4.5 150 1.2

– 6.0

100 1.5

– 4.5 225 1.2

– 6.0

167 1.5

– 4.5 300 1.2

– 6.0

250 1.5

– 6.0 500 1.5

– 7.0

333 1.5

– 6.0 750 5.0

– 7.5

500 1.5

– 7.0 1000 5.0

– 7.5

667 5.0

– 7.5 1500 5.0

– 7.5

833 5.0

– 7.5 2000 5.0

– 7.5

2500 5.0

– 7.55 **Table 3** 

**. 4**  **Normal Impedance Ranges for Dry** 

**- Type Transformers** 
Single

- phase transformers Three

- phase transformers

kVA Impedance (%) kVA Impedance (%)

15 1.5

– 6.0 15 1.5

– 6.0

25 1.5

– 6.0 30 1.5

– 6.0

37.5 1.5

– 6.0 45 1.5

– 6.0

50 1.5

– 6.0 75 1.5

– 6.0

75 2.0

– 7.0 112.5 1.5

– 6.0

100 2.0

– 7.0 150 1.5

– 6.0

167 2.5

– 8.0 225 3.0

– 7.0

250 3.5

– 8.0 300 3.0

– 7.0

333 3.5

– 8.0 500 4.5

– 8.0

500 3.5

– 8.0 750 5.0

– 8.0

667 5.0

– 8.0 1000 5.0

– 8.0

833 5.0

– 8.0 1500 5.0

– 8.0

2000 5.0

– 8.0

2500 5.0

– 8.0

**4. Chapter 6** 

**– Markups Analysis**  The markups analysis (chapter 6) develops appropriate markups in the distribution chain to convert the estimates of manufacturer selling price derived in the engineering analysis to customer prices. In the preliminary analysis, DOE determined the distribut ion channels for distribution transformers, their shares of the market, and the markups associated with the main parties in the distribution chain, distributors, contractors and electric utilities. The following table lists the changes to the preliminary a nalysis.

**Table 4** 

**. 1**  **Summary of Changes and Key Issues to the Markups Analysis** Topic Preliminary Analysis Description Changes for Proposed Rule Sales Tax T he factor that accounts for sales tax, estimated to be 1.069 No change

Distributor Markup

Described in TSD Chapter 6 Section
6.2 The manufacturer selling price for l iquid

type distribution transformers have a 7% markup, accounting for distributor markup. While t he manufacturer selling prices for dry

- type transformers include two price mark ups: a distributor markup The department eliminated the 7% distributor mar kup liquid

- immersed for a fraction of cases to account for transformer sales that are from manufacturers directly to utilities. The fraction of cases is determined by the6 of 15% and a contracto r materials markup of 10% . DOE based these markups (expressed as average multipliers) on RS Means Electrical Cost
Data 2010 amount of electricity reportedly sold by
IOUs in EIA’s Form 861, is 82%.

No change f or dry

- type transformers.

Labor and Equipment

Described in TSD Chapter 6 Section
6.3 The l abor cost required for installation, including unloading, uncrating, hauling within 200 feet of the loading dock, setting in place, connecting to the distribution network, and testing ; estimated from RS Means 2010 at 1.43 Updated using RS Means 2011 to 1.47

Impact of Transformer Weight on Installation Costs

Described in TSD Chapter 6 Section
6.3.2 None DOE derived the weight

- versus

- capacity relationship for typic al transformers from the design data produced by the engineering analysis. It used the weight

versus

- capacity relationship to estimate the transformer weight corresponding to the transformer costs reported in RS
Means . DOE estimated a scaling relationship between transformer weight and direct installation labor and equipment costs by fitting the correlation between weight and installation costs to a power

- law equation. Pole Replacement

Described in TSD Chapter 6 Section
6.3.1 DOE included a pole

- replac ement cost function as a part of the installation cost equation for DL2, which covers pole

mounted transformers. Because not all transformer installations require a change

- out of existing equipment even in the most extreme case, DOE assumed

a maximum chang e - out fraction . DOE selected 25 percent as the maximum change

- out fraction estimate based on stakeholder input from the 2007 final rule . This analysis assumed that a pole change

- out cost of $2,000 occurs for up to 25 percent of pole

- mounted transformers w hen the weight of the transformer exceeds 1,000 pounds. DOE also included a transformer pole support cost of $0.12/lb to account for the cost of a sturdier pole. The highest transformer weight at CSL 7 from the LCC results is just over 700 lbs. Therefor e, DOE believes that pole replacement would not be a factor for the representative capacity for design line 2. DOE acknowledges that there may be situations where pole change

outs may be necessary when transformers are replaced with the same size unit, but DOE has no information to estimate the fraction of installations that may be impacted

No change7 **5. Chapter 7** 

**– Energy Use and End** 

**- Use Loa**  **d Characterization**  The energy use and end

- use load characterization analysis (chapter 7 ) produced energy use estimates and end

- use load shapes for distribution transformers. The energy use estimates enabled evaluation of energy savings from the operation of distribution transformer equipment at various efficiency levels, while the end

- use load characterization al lowed evaluation of the impact on monthly and peak demand for electricity from the operation of transformers. The following table lists the changes to the preliminary analysis.

**Table 5** 

**. 1**  **Summary of Changes an d Key Issues to the Energy Use Analysis**  Topic Preliminary Analysis Description Changes for Proposed Rule Joint Distribution
Function

Described in TSD Chapter 7 Section
7.2 .1 & Appendix
7A Section 7A.2.2 L oad on an individual transformer correlates somewhat with system load, there is some correlation between transformer load losses and the price of electricity. To capture those correlations, DOE developed a statistical model based on hourly electric system load data, marginal hourly electric system p roduction prices : a joint probability distribution (JPDF) between transformer and system load levels. Separate JPDFs were constructed for residential, and commercial and industrial customers. For liquid

- immersed transformers to capture the differences in l oad profiles of commercial, and industrial customers. The JPDF for commercial and industrial customers has been separated into two distinct entities with one JPDF for commercial customers and one JPDF for industrial customers.

No change for dry

- type trans formers

**6. Chapter 8** 

**– Life** 

**- Cycle Cost and Payback Period Analysis** 

DOE conducts LCC and PBP analyses (chapter 8) to evaluate the economic impacts on individual customers of potential energy conservation standards for distribution transformers. The LCC is the total customer expense over the life of a product, consisting of purchase and installation costs plus operating costs (expenses for energy use, maintenance and repair). To compute the operating costs, DOE discounts future operating costs to the time of purchase and sums them over the lifetime of the product. The PBP is the estimated amount of time (in years) it takes customers to recover the increased purchase cost (including installation) of a more efficient product through lower operating costs. DOE

c alculates the PBP by dividing the change in purchase cost (normally higher) due to a more stringent standard by the change in average annual operating cost (normally lower) that results from the standard. The following table lists the changes to the preliminary analysis.

**Table 6** 

**. 1**  **Summary of Changes and Key Issues to the Life** 

**- Cycle Cost and Payback Period**  **Analysis** Topic Preliminary Analysis Description Changes for Proposed Rule Affecting Installed Costs8 Equipment price Derived by multiplying manufacturer selling price (from the engineering analysis) by distributor markup and contractor markup plus sales tax for dry

type transformers

. For liquid

- immersed transformers, DOE used manufacturer selling price plus small distributor markup plus sales tax

. Additional weigh related costs were included for both types of transformers. See Markups Analysis

Baseline and standard design selection

Descr ibed in TSD Chapter 8 Section
8.3.1 The selection of baseline and standard

compliant transformers depended on customer behavior

. For liquid

- immersed transformers, the fraction of purchases evaluated was 75%, while for dry

- type transformers, the fraction of evaluated purchases was 50% for small capacity medium voltage and 80% for large

capacity medium voltage Based on stakeholder feedback and research DOE a djusted the percent of evaluators to: 50% for liquid

- immersed transformers, 2% for low

- voltage dry

type transformers, and 10 and 20% for low and high capacity medium voltage dry

- type transformers respectively

.

Affecting Operating Costs Transformer loading Loading depended on customer and transformer characteristics

. No change

Load growth 1 % per year for liquid

- immersed and 0% per year for dry

- type transformers. No change

Power factor Assumed to be unity. No change.

Annual energy use and demand Derived from a statistical hourly load simulation for liquid

- immersed transformers, and estimated from the 1992 and 1995 Commercial Building Energy Consumption Survey See Energy Use Analysis data for dry

- type transformers using factors derived from hourly load data

. Load losses v aried as the square of the load and were equal to rated load losses at 100% loading.

Electricity costs Derived from tariff

- based and hourly based electricity prices

. Capacity costs provided extra value for reducing losses at peak

. No change

Electricity price trend Obtained from Annual Energy Outlook 2010 (AEO2010). Updated to Annual Energy Outlook 201 1 (AEO201 1 ).

Maintenance cost Annual maintenance cost did not vary as a function of efficiency. No change.

Compliance date Assumed to be 2016. No change.9 Discount rates

Described in TSD Chapter 8 Section
8.3.8 Mean real discount rates ranged from
4.0 % for owners of pole

- mounted, liquid

immersed transformers to 5.1 % for dry

type transformer owners. The mean real discount rates were adjusted to 3.7% for owners of liquid

immersed transformers and 4.6% for dry

type transformers.

Lifetime Distribution of lifetimes, with mean lifetime for both liquid and dry

- type transformers assumed to be 32 years. * No change.

* Source: ORNL

- 6847, Determination Analysis of Energy Conservation Standards for Distribution Transformers, 1996

**7. Chapter 9** 

**– Shipments Analysis**  DOE developed a shipments model to predict shipments of distribution transformers (chapter 8) . The shipments model provides an estimate of the rate at which an in

- service stock of existing transformers may be replaced by new, more efficient transformers after the enactment of an energy conservation standard. The core of the shipments analysis is an acc ounting model that DOE developed to simulate how existing and future purchases are incorporated into an in

- service stock of aging transformers that are gradually replaced. In estimating the effects of potential new standard levels on product shipments, th e model accounts for the combined effects on the purchase decision of increases in purchase price, decreases in annual operating costs, and consumer income. The following table lists the changes to the preliminary analysis. The following table lists the ch anges to the preliminary analysis.

**Table 7** 

**. 1**  **Summary of Changes and Key Issues to the Shipments Analysis**

Topic Preliminary Analysis Description Changes for Proposed Rule Shipments data Third

- party expert (HVOLT) for
2009. No change.

Shipments forecast 2016

- 2044: Based on AEO 2010 Updated to

. Dry

- type/liquid

immersed market shares AEO 2011 Based on EIA’s electricity sales data and AEO2010 Updated to

.

Regular replacement market AEO 2011

Based on a survival function constructed from a Weibull distribution function normalized to produce a 32

- year mean lifetime

. Source: ORNL 6804/R1, The Feasibility of Replacing or Upgrading Utility Distribution Transformers During Routine
Maintenance No ch ange.

, page D

- 1.10 Elasticities, liquid

immersed For liquid

- immersed transformers:

**•** Low: 0.00

**•** Medium:

- 0.04

**•** High:

- 0.20 For dry

- type transformers:

**•** Low: 0.00

**•** Medium:

- 0.02

**•** High:

- 0.20 No change.

**8. Chapter 10** 

**– National Impacts Analysis** 
DOE’s NIA assessed the national energy savings (NES) and the national NPV of total customer costs and savings that would be expected to result from amended standards at specific efficiency levels (chapter 10)

. The following table lists the changes to the preliminary analysis.

**Table 8** 

**. 1**  **Summary of Changes and Key Issues to the National Impact Analysis** Topic Preliminary Analysis Description Changes for Proposed Rule Shipments Annual shipments from shipments model. No change.

Compliance date of standard 2016. No change.

Base case efficiencies Constant efficiency through 2044

. Equal to weighted

- average efficiency in 2016. No change.

Standards case efficiencies Constant efficiency at the specified standard level from 2016 to 2044. No change.

Annual energy consumption per unit Average rated transformer losses are obtained from the LCC analysis, and are then scaled for different size categories, weighted by size market share, and adjusted for transformer loading (also obtained from the LCC analysis). No change.

Total installed cost per unit Weighted

- average values as a function of efficiency level (from LCC analysis). No change.

Electricity expense per unit Energy and capacity savings for the two types of transformer losses are each multip lied by the corresponding average marginal costs for capacity and energy, respectively, for the two types of losses (marginal costs are from the LCC analysis). No change.11 Escalation of electricity prices AEO 2010 Updated the escalation of electricity prices forecast using forecasts (to 2035) and extrapolation for 2044 and beyond. Electricity site

- to

source conversion AEO 2011

Described in TSD Chapter 10 Section
10.2.2.8 A time series conversion factor; includes electric generation, transmission, and distribution losses

. Conversion varies yearly and is generated by DOE/EIA’s National Energy Modeling System (NEMS)

program. Updated conversion factors from
NEMS.

Discount rates 3% and 7% real discount rates mandated by OMB. No change

Equipment Price Trend

Described in TSD Chapter 8 Section 8.2.1.1 & Chapter 10
Section 10.3.2.8 None DOE observed changes in the inflation

- adjusted index of the PPI for electric power and specialty transformer manufacturing over
1967

- 2010. These data show a long

term dec line from 1975 to 2003, and then a steep increase since then. DOE believes that there is considerable uncertainty as to whether the recent trend has peaked, and would be followed by a return to the previous long

- term declining trend, or whether the

recent trend represents the beginning of a long

- term rising trend due to global demand for distribution transformers and rising commodity costs for key transformer components. Given the uncertainty, DOE has chosen to use constant prices (2010 levels) for both its LCC and PBP analysis and the NIA. For the NIA, DOE also analyzed the sensitivity of results to alternative transformer price forecasts. DOE developed one forecast in which prices decline after 2010, and one in which prices rise

. Present year Equipment a nd operating costs are discounted to the year of equipment price data, 2010. No change

**8.1. Mapping of Draft Efficiency Levels to Draft Trial Standard Levels**  The mapping of dEL to dTSL is expand in greater detail in chapter 10 section 10.2.2.2 and 10.2.2.3. The result of this mapping is presented in the tables below.12 **8.1.1. Mapping of dELs to dTSL for Liquid** 

**- Immersed Transformers** 

**Table 8** 

**. 2**  **Mapping of Draft Efficiency Levels to Draft Trial Standard Levels for L iquid** 

**** **Immersed Transformers** Design Line dTSL1 dTSL2 dTSL3 dTSL4 dTSL5

1 Liquid

- Immersed, 50kVA, single

- phase dEL1 dEL2 dEL3 dEL4 dEL7

2 Liquid

- Immersed, 25kVA, single

- phase dEL1 dEL2 dEL3 dEL4 dEL7

3 Liquid

- Immersed, 500kVA, single

- phase dEL2 dEL3 dEL4 dEL5 dEL7

4 Liquid

- Immersed, 150kVA, three

- phase dEL1 dEL2 dEL3 dEL4 dEL7

5 Liquid

- Immersed, 1500kVA, three

- phase dEL2 dEL3 dEL4 dEL5 dEL7

**Table 8** 

**. 3**  **Proposed Efficiencies for**  **Draft Trial Standard Levels for Liquid** 

**- Immersed**  **Transformers** Design

Line Base d TSL

1 2 3 4 5

1 99.08 99.16 99.22 99.25 99.31 99.50

2 98.91 99.00 99.07 99.11 99.18 99.46
3 99.42 99.51 99.54 99.57 99.61 99.73

4 99.08 99.16 99.22 99.25 99.31 99.60

5 99.42 99.51 99.54 99.57 99.61 99.69

**8.1.2. Mapping of dELs to dTSL for Low** 

**- Voltage Dry** 

**- Type Transformers** 

**Table 8** 

**. 4**  **Mapping of Draft Efficiency Levels to Draft Trial Standard Levels for Low**

  ** Voltage Dry**

**- Type**  **Transformers** Design Line dTSL1 dTSL2* dTSL3 dTSL4 dTSL5 dTSL6

6 LVDT, 25kVA, single

- phase dEL2 dEL3* dEL3 dEL4 dEL5 dEL7

7 LVDT, 75kVA, three

- phase dEL2 dEL3* dEL3 dEL4 dEL5 dEL7

8 LVDT, 300kVA, three

- phase dEL3 dEL2* dEL4 dEL5 dEL6 dEL7
*NEMA Premium

**Table 8** 

**. 5**  **Proposed Efficiencies for**  **Draft Trial Standard Levels for Low** 

**- Voltage Dry** 

**- Type**  **Transformers** Design

Line Base TSL

1 2 3 4 5 6

6 98.00 98.47 98.60 98.80 98.93 99.44 98.00

7 98.00 98.47 98.60 98.80 98.93 99.44 98.00

8 98.60 99.14 99.25 99.32 99.44 99.58 98.60

**8.1.3. Mapping of dELs to dTSL for Medium Voltage Dry** 

**- Type Transformers** 13 **Table 8** 

**. 6**  **Mapping of Draft Efficiency Levels to Draft Trial Standard Levels for Medium** 

**** **Voltage Dry**

**- Type Transformers**  Design Line dTSL1 dTSL2 dTSL3 dTSL4 dTSL5

9 MVDT, 300kVA, three

- phase, 45kV BIL dEL1 dEL2 dEL3 dEL4 dEL7

10 MVDT, 1500kVA, three

- phase, 45kV BIL dEL2 dEL3 dEL4 dEL5 dEL7

11 MVDT, 300kVA, three

- phase, 95kV BIL dEL1 dEL2 dEL3 dEL4 dEL7

12 MVDT, 1500kVA, three

- phase, 95kV BIL dEL2 dEL3 dEL4 dEL5 dEL7

13A MVDT, 300kVA, three

- phase, 125kV BIL dEL1 dEL2 dEL3 dEL4 dEL7

13B MVDT, 2000kVA, three

- phase, 125kV BIL dEL2 dEL3 dEL4 dEL5 dEL7

**Table 8** 

**. 7**  **Proposed Draft Trial Standard Levels for Medium** 

**- Voltage Dry** 

**- Type**  **Transformers** Design

Line Base TSL

1 2 3 4 5

9 98.82 98.99 99.12 99.28 99.38 99.59
10 99.22 99.40 99.50 99.53 99.60 99.67

11 98.67 98.81 98.94 99.06 99.13 99.50

12 99.12 99.30 99.39 99.46 99.53 99.65
13A 98.63 98.76 98.85 98.92 99.10 99.48
13B 99.15 99.31 99.38 99.43 99.49 99.58

**8.2. Scaling of Draft Trial Standard Levels across Equipment Classes**  Transformers are produced over a broad range of capacities, only a few of which are modeled explicitly in this analysis. The modeled designs are referred to as representative units. Any given equipment type includes 2

- 4 representative units at different ca pacity, or kVA values. DOE used a scaling relationship, or equation, to project the economic results from a given transformer design line to similar transformers of different sizes. This relationship is a key element in adjusting losses and costs from a

re presentative transformer in the LCC to the distribution of transformer sizes incorporated in the calculation of NES and subject to potential standards. The Department uses the 0.75 scaling rule to scale the cost and efficiency results for the modeled kVA values to the full capacity range for each type, the 0.75 scaling rule is discussed in greater detail in chapter 5. This rule assumes that both the physical and cost characteristics are determined by the quantity of material required to build the transform er, and is approximately true. In practice, if the kVA

- range over which cost and efficiency data are to be scaled is large, the 0.75 rule is less accurate. This manifests as kinks or angles in the curve of efficiency as a function of capacity for a given e quipment type.

The Department has implemented a correction to the 0.75 scaling rule to produce smoother curves of efficiency vs. capacity. This correction adjusts the value of the exponent (the 0.75 of the scaling rule) so that the curve extrapolates cor rectly between any two representative units

.14 The method use to calculate these efficiencies is described in detail in chapter 10 section

10.2.2.1.

**8.2.1. Proposed Scaling of Efficiencies for Liquid** 

**- Immersed Transformers** 

**Table 8** 

**. 8**  **Scaled Efficiencies for Single Phase Liquid** 

**- Immersed Transformers** 

TSL

kVA Base 1 2 3 4 5

10 98.62 98.74 98.83 98.88 98.97 99.25

15 98.76 98.86 98.95 98.99 99.07 99.32

DL2 25 98.91 99.00 99.07 99.11 99.18 99.46

37.5 99.01 99.10 99.16 99.19 99.26 99.48

DL1 50 99.08 99.16 99.22 99.25 99.31 99.50

75 99.17 99.24 99.29 99.32 99.38 99.55

100 99.23 99.29 99.33 99.37 99.42 99.58

167 99.25 99.37 99.41 99.44 99.49 99.64

250 99.32 99.42 99.46 99.49 99.54 99.67

333 99.36 99.46 99.49 99.53 99.57 99.70

DL3 500 99.42 99.51 99.54 99.57 99.61 99.73

667 99.46 99.54 99.57 99.60 99.64 99.75

833 99.49 99.57 99.60 99.62 99.66 99.7615 **Figure 2**  **Scaled Efficiency Curve for Single Phase Liquid** 

**- Immersed**  **Transformers**

**Table 8** 

**. 9**  **Scaled Efficiencies for Three Phase Liquid** 

**- Immersed Transformers** 

TSL

kVA kVA/Phase Base 1 2 3 4 5

15 5 98.36 98.51 98.61 98.67 98.77 99.29

30 10 98.62 98.74 98.83 98.88 98.97 99.40

45 15 98.76 98.86 98.95 98.99 99.07 99.46

75 25 98.91 99.00 99.07 99.11 99.18 99.52

112.5 38 99.01 99.10 99.16 99.19 99.26 99.57

DL4 150 50 99.08 99.16 99.22 99.25 99.31 99.60

225 75 99.17 99.24 99.29 99.32 99.38 99.62

300 100 99.23 99.29 99.33 99.37 99.42 99.63

500 167 99.25 99.37 99.41 99.44 99.49 99.65

750 250 99.32 99.42 99.46 99.49 99.54 99.67

1000 333 99.36 99.46 99.50 99.53 99.57 99.68

DL5 1500 500 99.42 99.51 99.54 99.57 99.61 99.69

2000 667 99.46 99.54 99.57 99.60 99.64 99.71

2500 833 99.49 99.57 99.60 99.62 99.66 99.73 Rep Unit Rep Unit Rep Unit

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

98.50 98.70 98.90 99.10 99.30 99.50 99.70 99.90

10 100 1000Efficiency (%)

kVA 

# Liquid

- Immersed, 1

- Phase

Base

1

2

3

4

516 **Figure 3**  **Scaled Efficiency Curve for Single Phase Liquid** 

**- Immersed Transformers** 

**8.2.2. Proposed Scaling of Efficiencies for**  **Low**

**- Voltage Dry** 

**- Type Transformers** 

**Table 8** 

**. 10**  **Scaled Efficiencies for Single Phase Low** 

**- Voltage Dry** 

**- Type Transformers** 

TSL

kVA Base 1 2 (NEMA Premium) 3 4 5 6

15 97.70 98.26 98.39 98.39 98.64 98.78 99.36

DL6 25 98.00 98.47 98.60 98.60 98.80 98.93 99.44

37.5 98.20 98.71 98.74 98.83 98.99 99.12 99.49

50 98.30 98.85 98.81 98.97 99.10 99.23 99.52

75 98.50 99.03 98.95 99.15 99.23 99.36 99.55

100 98.60 99.14 99.02 99.25 99.32 99.44 99.58

167 98.70 99.24 99.09 99.34 99.40 99.51 99.63

250 98.80 99.32 99.16 99.40 99.46 99.55 99.67

333 98.90 99.36 99.23 99.44 99.50 99.59 99.69 Rep Unit Rep Unit

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

98.30 98.50 98.70 98.90 99.10 99.30 99.50 99.70 99.90 100.10

10 100 1000Efficiency (%)

kVA 

# Liquid

- Immersed, 3

- Phase

Base

1

2

3

4

517 **Figure 4**  **Scaled Efficiency Curve for Single Phase Low** 

**- Voltage Dry** 

**- Type Transformers** 

**Table 8** 

**. 11**  **Scaled Efficiencies for Three Phase Low** 

**- Voltage Dry** 

**- Type Transformers** 

TSL

kVA Base 1 2 (NEMA Premium) 3 4 5 6

15 97.00 97.71 97.90 97.90 98.21 98.40 99.16

30 97.50 98.08 98.25 98.25 98.49 98.65 99.30

45 97.70 98.26 98.39 98.39 98.64 98.78 99.36

DL7 75 98.00 98.47 98.60 98.60 98.80 98.93 99.44

112.5 98.20 98.71 98.74 98.83 98.98 99.11 99.49

150 98.30 98.85 98.81 98.97 99.10 99.23 99.52

225 98.50 99.03 98.95 99.15 99.23 99.36 99.55

DL8 300 98.60 99.14 99.02 99.25 99.32 99.44 99.58

500 98.70 99.24 99.09 99.34 99.40 99.51 99.63

750 98.80 99.32 99.16 99.40 99.46 99.55 99.67

1000 98.90 99.36 99.23 99.44 99.50 99.59 99.69 Rep Unit

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

97.50 98.00 98.50 99.00 99.50 100.00

10 100Efficiency (%)

kVA 

# Low

- Voltage Dry

- Type, 1

- Phase

Base

1
2 (NEMA Premium)

3

4

5

618 **Figure 5**  **Scaled Efficiency Curves for Three Phase Low** 

**- Voltage Dry** 

**- Type Transformers** 

**8.2.1. Proposed Scaling of Efficiencies for Medium** 

**- Voltage Dry** 

**- Type Transformers** 

The efficiencies for single phase Medium

- Voltage Dry

- Type Transformers are scaled from the corresponding single phase design line. See the chapter 5. Engineering Analysis section X. X.X

**Table 8** 

**. 12**  **Single Phase Scaled Efficiencies for Medium** 

**- Voltage Dry** 

**- Type Transformers**  **20**

**- 45BIL** 

TSL

kVA Base 1 2 3 4 5

15 98.10 98.38 98.59 98.84 99.00 99.34

25 98.33 98.57 98.76 98.98 99.12 99.42

37.5 98.49 98.71 98.88 99.08 99.21 99.48

50 98.60 98.80 98.95 99.14 99.26 99.51

75 98.73 98.91 99.05 99.23 99.33 99.56

100 98.82 98.99 99.12 99.28 99.38 99.59

167 98.96 99.14 99.26 99.37 99.46 99.62

250 99.07 99.25 99.36 99.44 99.52 99.64

333 99.14 99.32 99.42 99.48 99.55 99.65

500 99.22 99.40 99.50 99.53 99.60 99.67

667 99.27 99.44 99.53 99.56 99.63 99.69

833 99.31 99.47 99.56 99.59 99.65 99.71 Rep Unit Rep Unit

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

96.50 97.00 97.50 98.00 98.50 99.00 99.50 100.00

10 100 1000Efficiency (%)

kVA 

# Low

- Voltage Dry

- Type, 3

- Phase

Base

1
2 (NEMA Premium)

3

4

5

619 **Table 8** 

**. 13**  **Three Phase Scaled Efficiencies for Medium** 

**- Voltage Dry** 

**- Type Transformers**  **20**

**- 45BIL** 

TSL

kVA Base 1 2 3 4 5

15 97.50 97.86 98.14 98.48 98.69 99.13

30 97.90 98.20 98.44 98.72 98.90 99.27

45 98.10 98.38 98.59 98.84 99.00 99.34

75 98.33 98.57 98.76 98.98 99.12 99.42

112.5 98.49 98.71 98.88 99.08 99.21 99.48

150 98.60 98.80 98.95 99.14 99.26 99.51

225 98.73 98.91 99.05 99.23 99.33 99.56

DL9 300 98.82 98.99 99.12 99.28 99.38 99.59

500 98.96 99.14 99.26 99.37 99.46 99.62

750 99.07 99.25 99.36 99.44 99.52 99.64

1000 99.14 99.32 99.42 99.48 99.55 99.65

DL10 1500 99.22 99.40 99.50 99.53 99.60 99.67

2000 99.27 99.44 99.53 99.56 99.63 99.69

2500 99.31 99.47 99.56 99.59 99.65 99.71

**Figure 6**  **Scaled Efficiency Curves for Single Phase Medium** 

**- Voltage**  **Dry**

**- Type**  **Transformers 20** 

**- 45BIL** 

0 0.2 0.4 0.6 0.8 1 1.2

97.50 98.00 98.50 99.00 99.50 100.00

10 100 1000Efficiency (%)

kVA 

# Medium

- Voltage Dry

- Type, 20

- 45 kV BIL,
1

- Phase

Base

1

2

3

4

520 **Figure 7**  **Scaled Efficiency Curves for Three Phase Medium** 

**- Voltage Dry** 

**- Type**  **Transformers 20** 

**- 45BIL** 

**Table 8** 

**. 14**  **Single Phase Scaled Efficiencies for Medium** 

**- Voltage Dry** 

**- Type Transformers**  **46**

**- 95BIL** 

TSL

kVA Base 1 2 3 4 5

15 97.86 98.09 98.30 98.49 98.60 99.20

25 98.12 98.32 98.50 98.67 98.77 99.29

37.5 98.30 98.48 98.65 98.80 98.89 99.36

50 98.42 98.58 98.74 98.88 98.97 99.41

75 98.57 98.72 98.86 98.99 99.07 99.46

100 98.67 98.81 98.94 99.06 99.13 99.50

167 98.83 98.99 99.11 99.21 99.28 99.55

250 98.95 99.12 99.23 99.31 99.39 99.59

333 99.03 99.20 99.30 99.38 99.45 99.62

500 99.12 99.30 99.39 99.46 99.53 99.65

667 99.18 99.35 99.43 99.50 99.56 99.67

833 99.23 99.38 99.46 99.52 99.59 99.69 Rep Unit Rep Unit

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

97.40 97.90 98.40 98.90 99.40 99.90

10 100 1000Efficiency (%)

kVA 

# Medium

- Voltage Dry

- Type, 20

- 45 kV BIL,
3

- Phase

Base

1

2

3

4

521 **Table 8** 

**. 15**  **Three Phase Scaled Efficiencies for Medium** 

**- Voltage Dry** 

**- Type Transformers**  **46**

**- 95BIL** 

TSL

kVA Base 1 2 3 4 5

15 97.19 97.48 97.76 98.01 98.16 98.94

30 97.63 97.88 98.12 98.33 98.45 99.11

45 97.86 98.09 98.30 98.49 98.60 99.20

75 98.12 98.32 98.50 98.67 98.77 99.29

112.5 98.30 98.48 98.65 98.80 98.89 99.36

150 98.42 98.58 98.74 98.88 98.97 99.41

225 98.57 98.72 98.86 98.99 99.07 99.46

DL11 300 98.67 98.81 98.94 99.06 99.13 99.50

500 98.83 98.99 99.11 99.21 99.28 99.55

750 98.95 99.12 99.23 99.31 99.39 99.59

1000 99.03 99.20 99.30 99.38 99.45 99.62

DL12 1500 99.12 99.30 99.39 99.46 99.53 99.65

2000 99.18 99.35 99.43 99.50 99.56 99.67

2500 99.23 99.38 99.46 99.52 99.59 99.69

**Figure 8**  **Scaled Efficiency Curves Single Phase Medium** 

**- Voltage Dry** 

**- Type Transformers**  **46**

**- 95BIL** 

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

97.70 98.20 98.70 99.20 99.70

10 100 1000Efficiency (%)

kVA 

# Medium

- Voltage Dry

- Type, 46

- 95 kV BIL, 1

- Phase

Base

1

2

3

4

522 **Figure 9**  **Scaled Efficiency Curves Three Phase Medium** 

**- Voltage Dry** 

**- Type Transformers**  **46**

**- 95BIL** 

**Table 8** 

**. 16**  **Single Phase Scaled Efficiencies for Medium** 

**- Voltage Dry** 

**- Type Transformers**  **96**

**- 150BIL** 

TSL

kVA Base 1 2 3 4 5

15 97.80 98.01 98.15 98.26 98.55 99.16

25 98.06 98.25 98.37 98.47 98.73 99.26

37.5 98.25 98.42 98.53 98.62 98.85 99.34

50 98.37 98.53 98.63 98.72 98.93 99.38

75 98.53 98.67 98.76 98.84 99.03 99.44

100 98.63 98.76 98.85 98.92 99.10 99.48

167 98.80 98.94 99.03 99.09 99.23 99.51

250 98.91 99.07 99.15 99.21 99.32 99.53

333 98.99 99.14 99.22 99.28 99.37 99.55

500 99.09 99.25 99.32 99.37 99.44 99.57

667 99.15 99.31 99.38 99.43 99.49 99.58

833 99.20 99.35 99.41 99.46 99.52 99.60 Rep Unit Rep Unit

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

97.00 97.50 98.00 98.50 99.00 99.50 100.00

10 100 1000Efficiency (%)

kVA 

# Medium

- Voltage Dry

- Type, 46

- 95 kV BIL, 3

- Phase

Base

1

2

3

4

523 **Table 8** 

**. 17**  **Three Phase Scaled Efficiencies for Medium** 

**- Voltage Dry** 

**- Type Transformers**  **96**

**- 150BIL** 

TSL

kVA Base 1 2 3 4 5

15 97.10 97.38 97.57 97.72 98.10 98.90

30 97.56 97.79 97.95 98.08 98.40 99.08

45 97.80 98.01 98.15 98.26 98.55 99.16

75 98.06 98.25 98.37 98.47 98.73 99.26

112.5 98.25 98.42 98.53 98.62 98.85 99.34

150 98.37 98.53 98.63 98.72 98.93 99.38

225 98.53 98.67 98.76 98.84 99.03 99.44

DL13A 300 98.63 98.76 98.85 98.92 99.10 99.48

500 98.80 98.94 99.03 99.09 99.23 99.51

750 98.91 99.07 99.15 99.21 99.32 99.53

1000 98.99 99.14 99.22 99.28 99.37 99.55

1500 99.09 99.25 99.32 99.37 99.44 99.57

DL13B 2000 99.15 99.31 99.38 99.43 99.49 99.58

2500 99.20 99.35 99.41 99.46 99.52 99.60

**Figure 10**  **Scaled Efficiency Curves Single Phase Medium** 

**- Voltage Dry** 

**- Type Transformers**  **96**

**- 150BIL** 

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

97.70 98.20 98.70 99.20 99.70

10 100 1000Efficiency (%)

kVA 

# Medium

- Voltage Dry

- Type, 96

- 150 kV BIL, 1

- Phase

Base

1

2

3

4

524 **Figure 11**  **Scaled Efficiency Curves Three Phase Medium** 

**- Voltage Dry** 

**- Type Transformers**  **96**

**- 150BIL** 

**9. Chapter 11** 

**– Life** 

**- Cycle Cost Subgroups Analys**  **is** In analyzing the potential impacts of new or amended standards, DOE evaluates impacts on identifiable groups (i.e., subgroups) of customers that may be disproportionately affected by a national standard (see chapter 11). For this rulemaking, DOE identi fied rural electric cooperatives, municipal utilities and purchasers of vault

- installed transformers (mainly utilities concentrated in urban areas) as subgroups that could be disproportionately affected, and examined the impact of proposed standards on the se groups using the methodology of the LCC and PBP analysis.

**9.1. Rural Cooperatives and Municipal Utilities** 

The Department selected two key data inputs that it adjusted for the consumer subgroup analysis:

Table 8

— Consumer Subgroup Economic Adjustment Facto rs Subgroup Transformer Loading A and B Factors National sample 1.00 1.00 Rural cooperatives 0.75 0. 75 Municipal utilities 1.20 1.00 Rep Unit Rep Unit

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

97.00 97.50 98.00 98.50 99.00 99.50 100.00

10 100 1000Efficiency (%)

kVA 

# Medium

- Voltage Dry

- Type, 96

- 150 kV BIL, 3

- Phase

Base

1

2

3

4

525 For transformer loading estimates, the data available to the Department consisted of rough loading
estimates mentioned in stakeholder comments. The Department’s estimate of average root mean square (RMS) loading for a 50 kVA pad

- mounted transformer for the national sample is 35 percent. Stakeholders commented that rural cooperative transformers tend to be loaded less be cause of oversizing for voltage flicker and lack of load diversity, while municipal utility transformers tend to have more diversity and subsequently higher loading. The typical rural cooperative transformer will serve a single customer while the typical urban transformer will serve multiple customers. Thus the Department estimated an adjustment factor of 0.75 for rural cooperatives, and 1.20 for municipal utilities, which results in average RMS loading estimates of 26 percent and 42 percent for 50 kVA

tr ansformers for rural cooperatives and municipal utilities, respectively.

In the 2007 final rule T he Department found the evaluation parameters for rural cooperatives to be lower than the national sample average and the parameters for municipal utilities t o be slightly higher as the national sample average for the available data. Thus, DOE estimated and adjusted evaluation rate of 38 perc ent for rural cooperatives and 60 percent for municipal utilities.

**9.2. Vault Installed Transformers** 

DOE calculated the volum es of those transformers selected by the LCC spreadsheets, as a function of CSL, for the two design lines (DLs) identified in the 2007 Final Rule for which transformer vault constraints are most likely to be an issue: DL4 and DL5. DOE examined the impacts of increasing transformer volume with regard to costs for vault enlargement. DOE assumed that if the volume of a transformer in a standard case is larger than the volume of the unit in the base case, a vault
modification would be warranted. DOE also consi dered the instances where it would not be practical to modify the existing vault to overcome the space

- constrained issues through vault modification and that a selected transformer must be of equal or lower volume then the initial baseline unit.

To estimate the cost of vault modification, DOE compared the difference in volume between the unit selected in the base case against the unit selected in the standard case, and applied fixed and variable costs. In the 2007 notice of data availability, DOE estimated the fixed cost as $1,740 per transformer and the variable cost as $26 per transformer cubic foot, these costs were adjusted to 2010$ using the chained price index for non

- residential construction for power and communications to $1854 per transfo rmer and $28 per transformer cubic foot. DOE considered instances where it may be extremely difficult to modify existing vaults by adding a Very High Vault Replacement Cost option to the LCC spreadsheet. Under this option, the fixed cost is $30,000 and the variable cost is $733 per
transformer cubic foot.