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combinations of materials can be found by their exhaustive search computer programs 

that are designed to consider all combinations of materials and flux and current densities. 

Therefore, it has been their contention that there must be a problem in the DOE analytic 

tools that produced the DOE efficiency levels. The manufacturers, both NEMA and NonNEMA have asked me to get involved to try to understand where the problems were 

rooted. 

In 2010, I was retained by Navigant Consulting with to assist their activities with Market 

Analysis and Design verification. This gave me a good opportunity to examine some of 

the design data that had been collected by their consultant, Optimized Program Services. 

The OPS design data base is immense and has been collected over an extended period 

of years. It is not possible to determine accuracy of the OPS data by looking at the 

computed selling prices versus efficiencies since there a large quantity of variables that 

are involved in the computations. The only practical way to examine the data is to take 

selected ratings and produce new designs by sufficient numbers of manufacturers, both 

small and large, who are in the industry and to compare the results of their computations 

with those of OPS. 

In comparing designs, I have developed a comprehensive spreadsheet that displays 

more than 30 parameters including DOE efficiencies, Selling prices, material types, 

weights, costs, sizes and performance information in sufficient detail to be credible. 

Individual manufacturer inputs are not displayed but the averages of their designs are 

placed side by side with the OPS derived data. This data comparison has allowed a 

determination of likely errors in OPS but more importantly has allowed the determination 

of incremental costs to the end user of higher proposed efficiencies as well as the watts 

saved at the RMS equivalent lad of 50% of nameplate. This should be an accurate 

depiction of the incremental dollars/per watt for each incremental efficiency level under 

consideration and lead to a quick determination of potential energy savings for the 

respective efficiency increments under consideration. 

My close working relationship with the Navigant team, members of OPS, the core steel 

manufacturers, makers of conductors, various user groups and the many manufacturers 

both NEMA and Non-NEMA have allowed this report to take on accuracy and 

significance for the stakeholders who will be trying to select future energy efficiency 

levels based on reality and economic justification. 

I am not a stakeholder but will gladly participate where needed to be sure that the 

findings in this report are understood by those who will be selecting the next round of 

energy efficiencies for Medium Voltage Distribution Transformers. Regardless of the 

efficiency levels that are selected and of any predisposed positions of any of the 

stakeholders, this attempt to display factual information should prove useful to the team. 

B. Objectives: 

1. Determine Cost-Based Selling Prices for select Design Lines by the transformer 

manufacturers versus DOE efficiencies when constrained to use M3 Core Steel, 

Aluminum Primary Conductors and Aluminum Secondary Conductors. These 

materials were selected to be sure that buildable designs with the most abundant low 

cost materials would be a part of the analysis. 

2. Compare the manufacturers’ costs and selling prices versus the OPS Generated 

Designs. 

3. Determine causes of cost differences of the manufacturers versus OPS 

4. Determine the present worth of a watt saved. 

5. Provide Guidance and recommendations to the DOE Energy Efficiency Stakeholders. 
3

 

C. Scope 

1. Single Phase Pad mounted Transformers in Design Line 1 represented by the 50 

kVA rating at 14,400 volts primary and 240/120 Volt Secondary

2. Single Phase Pole Type Transformers in Design Line 2 represented by the 25 kVA 

rating at 14,400 volts primary and 120/240 Volt Secondary

3. Small (0-500 kVA) Three Phase Pad mounted Transformers in Design Line 4 

represented by the 150 kVA rating with a 14,400 volt primary and a 208 Y/120 volt 

secondary.

4. Large Three Phase Pads from 750 kVA -2,500 kVA, in Design Line 5 represented 

by the 1500 kVA rating with a 24,940 GrY /14,400 volt Primary and a 480 Y/277 Volt 

Secondary.

5. Medium Voltage Dry Type Transformers from 750 kVA to 2,500 kVA from Design 

Line 12 represented by the 1,500 kVA rating with a 12,470 GrY /7,200 Volt Primary 

and a 480 Y/277 Volt Secondary.

D. Assumptions 

1. Manufacturers participating in the summary of designs were selected to be 

sure that small as well as large manufacturers were included, both NEMA 

and Non-NEMA members, representative of the industry. 

2. Material prices in the manufacturer-produced designs are at 2011 values. 

3. Baseline manufacturer material costs and selling prices were developed 

starting with relationships for designs close to 2010 minimum efficiencies. 

4. Selling prices for higher efficiencies were derived from the relationship of a 

constant Selling price to material basis. 

5. Selling prices were developed to reflect the selling price to the end user of 

each type of transformer. 

6. M3 core material and aluminum conductor were generally used to determine 

the upper limits of efficiency that a manufacturer could be requested to 

achieve. This constraint does not prevent a manufacturer from choosing a 

better core material or from using copper conductor bur rather assures that 

the maximum flexibility in design options are available to the industry. 

7. The average selling prices of the participating manufacturers were used as 

the basis for determining the incremental impact on selling price that the end 

user would see for each proposed increase in efficiency. 

8. An assumed economic life of 30 years was applied to determine the present 

worth value of a watt saved. 

9. Present worth values for watts saved are determined assuming 3% rate of 

inflation, 7% cost of funds, virtually no load growth, and a 30 year economic 

life. 

10. Incremental Transformer Selling Prices / Incremental watts saved are the 

incremental costs of such incremental change in efficiency. 

11. Any incremental increases in selling prices for any of the proposed new 

efficiencies that are less than the present worth value of a watt saved are 

worthy of consideration. 

12. Any incremental increases in selling prices for any of the proposed new 

efficiencies that are more costly than the value of a watt saved are not 

economically justifiable and do not pass the economics test. 

. 
4

E. Present Worth Value of a watt saved in an inflationary economy: 

One watt for all 8760 hours per calendar years will consume 8.76 kwh. The cost of 

operating that watt of loss is quite different depending on the nature of the user. The 

Energy Information Administration (EIA) has suggested that the average cost of energy at 

retail in the United States is about $0.12/kWH in 2009. They also show wholesale cost at 

between $0.04 to $0.05andkWH and Industrial power cost averaging $0.067/kWH for 

contracts as recently as September of 2011. Clearly the cost of power varies 

considerably across the country but the residential average of $0.12/kWH is reasonable 

and is the average rate that each household pays to their electric company. The cost to 

the types of users of interest in this report are as follows: 

1. Electric Utilities costs for generation, transmission and distribution down to the 

distribution transformer are assumed to be equal to the wholesale price of power 

and are valued at $0.045/kWH. Hence, on a yearly basis, one watt of power for 

all 8,760 hours per year will cost the utility $0.045/kWH *8.76 kHrs/yr = 

$0.394/watt. (1) 

2. Industrial and large Commercial users costs for power are identified as 

$0.067/kwh. Here the annual cost of a watt = $0.067/kWH *8.76 

=$0.587/watt. (2) 

. Another interesting consideration is the relationship between three groups of power 

users; the electric utilities themselves, commercial and industrial users and residential 

Users. Electric Utilities with their own generating plants have the lowest delivered cost 

of energy and may average out at $0.08/kWH. Commercial and Industrial users with 

their own transformers may average out at $0.10/kWH after demand and usage charges 

are added in. Now we must address the type of user of the transformer. A few years 

back, it could be said that 35% of the electric power was consumed by residential 

consumers and 65% by commercial or industrial users. However, the most important first 

consideration is for who owns the transformers and pays the bills. The following is my 

best estimate of ownership: 

1. Single Phase Pad mounted Transformers, signified by Design Line 1 are almost 

100% owned by Electric Utilities. 

2. Single Phase Poles, signified by Design Line 2 are almost 100% Electric Utilities 

3. Small Three Phase Pads, signified by Design Line 4 (150 kVA representing 0-500 

kVA) are about 75% owned by Electric Utilities and the remaining 25% by 

Commercial or Industrial Users. 

4. Large Three Phase transformers signified by Design Line 5 (1500 kVA representing 

750 kVA-2500 kVA) are 50% owned by Commercial and Industrial users. 

5. Medium Voltage Dry Type Transformers are nearly 100% owned by Commercial or 

Industrial Users. 

For both types of transformers the desire is that they be amortized over a 30 year period. There 

is considerable uncertainty about economics between now and 30 years out but reasonable 

assumptions would be the following: 

1. The rate of annual inflation will average 3%/year. 

2. The cost of borrowed money will average out at 7%/year. 

3. Load growth is low and perhaps at 0% 

In order to determine the present worth value of a watt saved over a 30 year period, we must use 

the present worth of an inflation series as: 
5

USPWF = (((1+i)^n-(1+r)^n*(1+g)^2n)/(1+i)^n) *( 1/((1+i)-(1+r)*(1+g)^2) (3) 

Here: 

 USPWF = the Uniform Series Present Worth Factor (4) 

 I = the interest rate in per unit = 0.07 ` (5) 

 a = the inflation rate in per unit =0.03 (6) 

 g = the per unit load growth rate per year = 0 (7) 

 n = the number of years = 30 (8) 

From these relationships, USPWF =17.0284 (9) 

Now with the annual cost of energy and the Uniform Series Present Worth Factor, we can 

compute the present worth value of a watt saved for either type of user as: 

1. For Utility transformers =$0.394/watt year * 17.03 year value = $6.71/watt. (10) 

2. For Commercial/Industrial =$0.587/watt * 17.0284 year value =$9.91/watt (11) 

These relationships define the present worth of one watt of energy saved in the as-purchased 

transformer when measured at the RMS equivalent load that will be applied to the transformer. 

Since the RMS equivalent load is defined as 50% of nameplate load then the total watts 

consumed by the transformer are approximately 100% of the core loss and 25% of the full load 

loss. Other factors may be added to change the calculations and in fact the variables of inflation, 

cost of money, and years of economic life can easily be adjusted if more appropriate relationships 

are found by the team. 

The purchase relationship in such transformers where A is the value of core loss and B is the 

value of load loss will be as follows: 

1. For Utility owned transformers: 

a. A = value of Core Loss = $6.71/watt. (12) 

b. B = value of Load Loss = $6.71/4 = $1.68/watt (13) 

2. For Commercial or Industrial transformers 

a. A = value of Core Loss = $9.91/watt (14) 

b. B = value of Load Loss = $9.91/4 = $2.48/watt (15) 

Discussion of this derivation. 

This is a reasonable starting point for consideration of design options. However other values of 

losses may also have relevance attributed to the following: 

1. Geographical differences in the country will have a large bearing on the cost of electricity, 

with some being significantly lower than the assumption and some higher. 

2. Inflation rates. High inflation will result in a higher value of a watt saved while low 

inflation will reduce the value. 
6

3. Load growth rate. No appreciable load growth was assumed since that has been the 

trend for the last decade. However, if plug-in electric vehicles or other high energy use 

devices are planned then the expression in equation (5) may need to be revisited. We 

assume that a transformer has 50% RMS equivalent load on it as a start. A 1% load 

growth would add 35% more load and bring the RMS equivalent up from 50% of 

nameplate to nearly 70% of nameplate over its expected 30 year life. 

4. Economic life of 30 years. This is longer than the IEEE insulation life presumption of 20.5 

years but is consistent with the US Electric Utility ownership experience. Longer time 

considerations than 30 years will generally increase the value of a watt saved while 

shorter economic life will bring it down. 

5. An overall value of watt saved sensitivity analysis may be worthy of exploration by the 

stakeholders and should be mathematically possible using equation (5). 

F. Summary Of Results 
7

Design Line 1 Single Phase Pads The figure below shows the results of the cost study for 

Design Line 1 Single Phase Pads: 

Figure 1a shows the summary of Selling Prices versus Efficiency for Design Line 1 

Design Line Design Line 1 Single Phase Padmounted Transformer

kVA 50 kVA

Selling Prices, Costs, and Efficiencies as seen by the Manufacturers in 2011 with M3, Al, Al

DOE Efficiency Level DEL 0 DEL 1 DEL 2 DEL 3 DEL 4 DEL 5

% Efficiency at 50% Load 99.08 99.16 99.22 99.25 99.31 99.5

Incremental Efficiency 0.08 0.06 0.03 0.06 0.19

Watts saved 20 15 7.5 15 47.5

Selling Price $      1,800.00 $       2,200.00 $      2,650.00 $      3,050.00

Incremental Selling Price $          400.00 $          450.00 $          400.00

Incremental $/Watt Cost to End User $             20.00 $            30.00 $            53.33

Selling Prices, Costs, and Efficiencies by the DOE (OPS 1) in Preliminary Analysis with M3, Al, Al

DOE Efficiency Level DEL 0 DEL 1 DEL 2 DEL 3 DEL 4 DEL 5

% Efficiency at 50% Load 99.08 99.16 99.22 99.25 99.31 99.5

Incremental Efficiency 0.08 0.06 0.03 0.06 0.19

Watts saved 20 15 7.5 15 47.5

Selling Price $      1,817.00 $       2,036.00 $      2,400.00 $      2,650.00

Incremental Selling Price $          219.00 $          364.00 $          250.00

Incremental $/Watt Cost to End User $             10.95 $            24.27 $            33.33

Selling Prices, Costs, and Efficiencies as seen by OPS 2 (DOE September) M3 Steel, Al, Al

DOE Efficiency Level DEL 0 DEL 1 DEL 2 DEL 3 DEL 4 DEL 5

% Efficiency at 50% Load 99.08 99.16 99.22 99.25 99.31 99.5

Incremental Efficiency 0.08 0.06 0.03 0.06 0.19

Watts saved 20 15 7.5 15 47.5

Selling Price $      1,971.00 $       2,178.00 $      2,714.00

Incremental Selling Price $          207.00 $          536.00

Incremental $/Watt Cost to End User $             10.35 $            35.73

OPS2 Data with ZDMH Materials

DOE Efficiency Level DEL 0 DEL 1 DEL 2 DEL 3 DEL 4 DEL 5

% Efficiency at 50% Load 99.08 99.15 99.22 99.25 99.31 99.5

Incremental Efficiency 0.07 0.07 0.03 0.06 0.19

Watts saved 17.5 17.5 7.5 15 47.5

Selling Price $      1,997.00 $       2,192.00 $      2,485.00 $      2,836.00

Incremental Selling Price $          195.00 $          293.00 $          351.00

Incremental $/Watt Cost to End User $             11.14 $            16.74 $            46.80

Present Worth of Wattsaved $6.71 $6.71 $6.71 $6.71 $6.71

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Figure 1c shows Design Line 1 Comparisons between Manufacturers and OPS 1. 

Conclusions for Design Line 1, represented by 50 kVA Single Phase Pad with primary Coil 

Voltage 14,400 (2 bushing) and low voltage 240 / 120 Volts: 

i. Manufacturers had higher material costs than OPS1. 

ii. Oil Gallons in OPS1 were in error and under-calculated. 

iii. Total Weights of transformers in OPS 1 were under-calculated and 

in error. 

iv. Tank cost in OPS1 was under-calculated. 

v. All other material in OPS 1 was under-calculated. 

vi. Manufacturers’ selling prices for base case were at market levels. 

vii. Manufacturers’ selling prices to material cost were kept constant at 

base case ratios. 

viii. OPS2 is OPS1 revised. However revisions are not explained. 

ix. OPS2 data is extracted from the engineering analysis from August 

31 with M3, Al, Al the base case. 

x. A ZDMH alternative by OPS2 is shown that shows the calculated 

data by OPS (August 31) for a ZDMH alternative. 

xi. Cost/watt saved Design Efficiency levels lower than the present 

worth values/watt are worthy of consideration as they return 

investment in less than 30 years. 

xii. Cost/watt saved Design Efficiency levels greater than the present 

worth values/watt are not economical unless there are other 

considerations. 

Design Line 1:  50 kVA Single Phase Pad

Parameter OPS MFG AVG Parameter OPS MFG AVG Parameter OPS MFG AVG

Efficiency at 50% load @55C 99.08 99.10 Efficiency at 50% load @55C 99.16 99.17 Efficiency at 50% load @55C 99.26 99.26

Selling Price $             1,817.05 $              1,884.34 Selling Price $           2,036.37 $          2,298.05 Selling Price $            2,709.32 $               3,311.51

Core Loss @20 C 97.9 92.8 Core Loss 109.5 92.0 Core Loss 108.8 91.7

Load Loss at full load @ 85C 584.2 586.7 Load Loss at full load 445.8 512.1 Load Loss at full load 306.8 414.7

Total Weight, lbs. 684.0 900.3 Total Weight, lbs. 626.0 1004.7 Total Weight, lbs. 883.0 1116.2

Core Material M3 M3 Core Material ZDMH M3 Core Material M3 M3

Core Weight, Lbs 258.5 243.5 Core Weight, Lbs. 232.3 264.4 Core Weight, Lbs. 333.0 282.9

Low Voltage Material Al AL Low Voltage Material CU AL Low Voltage Material AL CU

High Voltage Material Al AL High Voltage Material CU AL High Voltage Material CU CU

LV Weight, Lbs. 37.6 41.1 LV Weight, Lbs. 48.98 58.658 LV Weight, Lbs. 58 95.7

HV Weight, Lbs. 40 38.9 HV Weight, Lbs. 52.64 49.240 HV Weight, Lbs. 124 85.4

Gallons of oil 21.9 41.3 Gallons of oil 15.79 46.285 Gallons of oil 24.65 48.0

Primary Insulation, Lbs. 4.28 7.7 Primary Insulation, Lbs. 2.55 7.593 Primary Insulation, Lbs. 4.31 8.7

Secondary insulation, Lbs. 1.52 2.0 Secondary insulation, Lbs. 1.06 1.990 Secondary insulation, Lbs. 1.94 2.2

Core Material Cost, $ $                 484.63 $                  473.12 Core Material Cost, $ $               476.22 $              536.53 Core Material Cost, $ $                624.38 $                   550.46

LV Material Cost, $ $                   58.88 $                    71.60 LV Material Cost, $ $               208.32 $              191.62 LV Material Cost, $ $                  90.36 $                   420.53

HV Material Cost, $ $                 145.98 $                  124.48 HV Material Cost, $ $               207.58 $              208.03 HV Material Cost, $ $                539.05 $                   541.84

Primary Insulation Cost, $ $                     6.49 $                    16.00 Primary Insulation Cost, $ $                   3.86 $                15.44 Primary Insulation Cost, $ $                     6.54 $                     17.08

Secondary Insulation Cost, $ $                     2.75 $                      4.29 Secondary Insulation Cost, $ $                   1.60 $                  3.39 Secondary Insulation Cost, $ $                     2.94 $                       3.12

Oil Cost, $ $                   73.21 $                  138.68 Oil Cost, $ $                 52.92 $              154.04 Oil Cost, $ $                  82.60 $                   147.24

Tank Cost, $ $                 142.74 $                  235.91 Tank Cost, $ $               139.13 $              266.76 Tank Cost, $ $                142.74 $                   264.25

All Other Material $                   67.11 $                  104.12 All Other Material $                 69.00 $              104.02 All Other Material $                  72.85 $                   104.12

Core and Coil Cost, $ $                 698.73 $                  689.49 Core and Coil Cost, $ $               897.58 $              956.01 Core and Coil Cost, $ $            1,263.27 $               1,585.62

Tank , Oil,  & Other Cost, $ $                 283.06 $                  423.01 Tank , Oil,  & Other Cost, $ $               261.05 $              469.61 Tank , Oil,  & Other Cost, $ $                298.19 $                   460.69

Total Material Cost $                 981.79 $              1,133.10 Total Material Cost $           1,158.63 $          1,430.07 Total Material Cost $            1,561.46 $               1,951.41

Tank Width 35.0 34.3 Tank Width 35.0 35.1 Tank Width 35.0 34.3

Tank Depth 35.0 35.3 Tank Depth 32.0 36.5 Tank Depth 35.0 36.9

Tank Height 24.0 25.8 Tank Height 24.0 26.3 Tank Height 24.0 26.3

A factor $                     6.50 $                      6.50 A factor $                   9.00 $                  9.00 A factor $                  15.00 $                     15.00

B factor $                     1.20 $                      1.20 B factor $                   2.72 $                  2.72 B factor $                     5.50 $                       5.50

Total Owning Cost $             3,154.46 $              3,191.65 $           4,234.34 $          4,518.60 $            6,028.72 $               6,967.13

Note:  All other material includes core clamp, bushings, decals, leads, pallets, shipping materials, scrap, unapplied matrerials and standard accessories

Core Watts/lB 0.379 0.381 Core Watts/lB 0.471 0.348 Core Watts/lB 0.327 0.324

50 kVA Design Line 1, design option ID1: 14.4 kV: 240/120 V 50 kVA Design Line 1, design option ID3; 14.4 kV: 240/120 V 50 kVA Design Line 1, design option CSL2 14.4 kV:240/120 V
10

Design Line 2 Single Phase Poles 

Figure 2a shows the summary of Selling Prices versus Efficiency for Design Line 2 

Design Line Design Line 2 Single Phase Pole Mounted Transformer

kVA 25 kVA

Selling Prices, Costs, and Efficiencies as seen by the Manufacturers in 2011 with M3

DOE Efficiency Level DEL 0 DEL 1 DEL 2 DEL 3 DEL 4 DEL 5

% Efficiency at 50% Load 98.9 99.00 99.06 99.13 99.18 99.46

Incremental Efficiency 0.1 0.06 0.07 0.05 0.28

Watts saved 12.5 7.5 8.75 6.25 35

Selling Price $      1,031.00 $       1,200.00 $      1,400.00 $      1,815.00

Incremental Selling Price $          169.00 $          200.00 $          415.00

Incremental $/Watt Cost to End User $             13.52 $            26.67 $            47.43

Selling Prices, Costs, and Efficiencies as seen by the DOE (OPS 1) in Preliminary Analysis

DOE Efficiency Level DEL 0 DEL 1 DEL 2 DEL 3 DEL 4 DEL 5

% Efficiency at 50% Load 98.9 99.00 99.06 99.13 99.18 99.46

Incremental Efficiency 0.1 0.06 0.07 0.05 0.28

Watts saved 12.5 7.5 8.75 6.25 35

Selling Price $      1,213.77 $       1,566.00 $      1,650.00 $      1,706.00

Incremental Selling Price $          352.23 $            84.00 $            56.00

Incremental $/Watt Cost to End User $             28.18 $            11.20 $               6.40

Selling Prices, Costs, and Efficiencies as seen by OPS 2 in DOE September Analysis

DOE Efficiency Level DEL 0 DEL 1 DEL 2 DEL 3 DEL 4 DEL 5

% Efficiency at 50% Load 98.9 99.00 99.06 99.13 99.18 99.46

Incremental Efficiency 0.1 0.06 0.07 0.05 0.28

Watts saved 12.5 7.5 8.75 6.25 35

Selling Price $      1,334.00 $       1,582.00 $      1,759.00

Incremental Selling Price $          248.00 $          177.00

Incremental $/Watt Cost to End User $             19.84 $            23.60

OPS2 with ZDMH

DOE Efficiency Level DEL 0 DEL 1 DEL 2 DEL 3 DEL 4 DEL 5

% Efficiency at 50% Load 98.9 99.00 99.06 99.13 99.18 99.46

Incremental Efficiency 0.1 0.06 0.07 0.05 0.28

Watts saved 12.5 7.5 8.75 6.25 35

Selling Price $         997.00 $       1,100.00 $      1,200.00 $      1,400.00

Incremental Selling Price $          103.00 $          100.00 $          200.00

Incremental $/Watt Cost to End User $               8.24 $            13.33 $            22.86

Present Worth of Wattsaved $6.71 $11.93 $11.93 $11.93 $11.93

14,400 Volts:208Y/120
Figure 2b shows the summary

v. M is the

versus 

vi. 01 is th

March, 

vii. 02 is th

Analysi

viii. Z is the

Analysi

y of Selling P

e Manufactur

DOE Efficien

he OPS Gene

2011, using 

he OPS Gene

is from Augus

e OPS Genera

is from Augus

Prices versu

ers’ Average 

ncy Level, usin

erated data fro

M3, Al, Al. 

erated data fro

st 31, 2011, u

ated data from

st 31, 2011, u

us Efficiency 

Selling Price

ng M3, Al, Al.

om the DOE P

om the DOE r

using M2, Al, A

m the DOE re

using ZDMH, 

for Design L

es to the end C

. 

Preliminary A

reissued Eng

Al. 

eissued Engin

Al, Al and or 

1

Line 2 

Customer 

Analysis in 

ineering 

neering 

Copper. 

11
12

Figure 2c shows Design Line 2 Comparisons between Manufacturers and OPS 1. 

Conclusions for Design Line 2, represented by 25 kVA Single Phase Poles with primary 

Coil Voltage 14,400 (2 bushing) and low voltage 120 / 240 Volts: 

xiii. Manufacturers had higher commodity costs than OPS1 but lower 

total costs in most cases. 

xiv. Oil Gallons in OPS1 were not in error for any of the round tank 

designs. 

xv. Total Weights of transformers in OPS 1 were under-calculated and 

in error. 

xvi. Tank cost in OPS1 was generally over-calculated. 

xvii. All other material in OPS 1 was close to actual. 

xviii. Manufacturers’ selling prices for base case were at market levels. 

xix. Manufacturers’ selling prices to material cost were kept constant at 

base case ratios. 

xx. OPS2 is OPS1 revised. However revisions are not explained. 

xxi. OPS2 data is extracted from the engineering analysis from August 

31 with M3, Al, Al the base case. 

xxii. A ZDMH alternative by OPS2 is shown that shows the calculated 

data by OPS (August 31) for a ZDMH alternative. 

xxiii. Cost/watt saved Design Efficiency levels lower than the present 

worth values/watt are worthy of consideration as they return 

investment in less than 30 years. 

xxiv. Cost/watt saved Design Efficiency levels greater than the present 

worth values/watt are not economical unless there are other 

considerations. 

Design Line 2:  25 kVA Single Phase Pole

Parameter OPS MFG AVG Parameter OPS MFG AVG Parameter OPS MFG AVG

Efficiency at 50% load @55C 98.92 98.90 Efficiency at 50% load @55C 99.02 99.06 Efficiency at 50% load @55C 99.13 99.13

Selling Price $             1,213.77 $              1,031.85 Selling Price $           1,566.93 $       1,291.94 Selling Price $            1,706.06 $               1,815.26

Core Loss @20 C 74.2 64.9 Core Loss 78.9 59.4 Core Loss 60.9 61.2

Load Loss at full load @ 85C 249.4 323.7 Load Loss at full load 175.7 255.3 Load Loss at full load 190.3 205.9

Total Weight, lbs. 437.0 424.6 Total Weight, lbs. 625.2 495.6 Total Weight, lbs. 512.2 638.0

Core Material ZDMH M3 Core Material M3 M3 Core Material ZDMH M3

Core Weight, Lbs 190.6 167.9 Core Weight, Lbs. 278.9 192.8 Core Weight, Lbs. 205.8 216.0

Low Voltage Material Al AL Low Voltage Material AL AL Low Voltage Material CU AL

High Voltage Material Al AL High Voltage Material AL AL High Voltage Material CU CU

LV Weight, Lbs. 19.0 26.0 LV Weight, Lbs. 29.5 31.5 LV Weight, Lbs. 49.4 69.6

HV Weight, Lbs. 20.2 25.5 HV Weight, Lbs. 30.4 47.1 HV Weight, Lbs. 53.4 62.8

Gallons of oil 18.0 13.7 Gallons of oil 24.2 16.0 Gallons of oil 16.9 21.8

Primary Insulation, Lbs. 3.8 6.0 Primary Insulation, Lbs. 4.5 6.3 Primary Insulation, Lbs. 3.4 6.2

Secondary insulation, Lbs. 1.5 1.8 Secondary insulation, Lbs. 1.8 2.0 Secondary insulation, Lbs. 1.33 2.7

Core Material Cost, $ 3 $                  90.69 $                  199.43 Core Material Cost, $ 5 $                22.84 $           431.85 Core Material Cost, $ 4 $                 21.93 $                   439.36

LV Material Cost, $ $                   29.80 $                    31.69 LV Material Cost, $ $                 46.13 $             49.83 LV Material Cost, $ 2 $                 08.67 $                   276.39

HV Material Cost, $ $                   73.69 $                    44.45 HV Material Cost, $ 1 $                10.73 $           221.63 HV Material Cost, $ 2 $                 10.61 $                   340.22

Primary Insulation Cost, $ 5 $                      .71 $                    11.03 Primary Insulation Cost, $ 6 $                    .86 $             13.31 Primary Insulation Cost, $ 5 $                      .09 $                     13.67

Secondary Insulation Cost, $ 2 $                      .30 $                      2.67 Secondary Insulation Cost, $ 2 $                    .68 $                3.61 Secondary Insulation Cost, $ 2 $                      .01 $                       5.05

Oil Cost, $ $                   62.78 $                    43.62 Oil Cost, $ $                 91.09 $             72.98 Oil Cost, $ $                  61.76 $                     93.50

Tank Cost, $ $                   72.81 $                    68.25 Tank Cost, $ $                 72.56 $             75.25 Tank Cost, $ $                  72.56 $                     75.25

All Other Material $                   38.60 $                    50.25 All Other Material $                 40.59 $             50.25 All Other Material $                  42.00 $                     50.25

Core and Coil Cost, $ 5 $                  02.19 $                  456.68 Core and Coil Cost, $ 6 $                89.25 $           711.67 Core and Coil Cost, $ 8 $                 48.31 $               1,147.48

Tank , Oil,  & Other Cost, $ 1 $                  74.19 $                  104.05 Tank , Oil,  & Other Cost, $ 2 $                04.24 $           119.63 Tank , Oil,  & Other Cost, $ 1 $                 76.32 $                   139.51

Total Material Cost $                 676.38 $                  550.78 Total Material Cost $               893.49 $           777.29 Total Material Cost $            1,024.63 $               1,166.16

Tank Diameter, in 19 16.8 Tank Diameter, in 22 17.6 Tank Diameter, in 19.0 18.3

Tank Height 24 24.9 Tank Height 25 26.9 Tank Height 23.00 27.4

A factor $                     4.00 $                      4.00 A factor $                 13.00 $             13.00 A factor $                  15.00 15

B factor $                     2.40 $                      2.40 B factor $                   6.00 $                6.00 B factor $                     5.50 5.5

TOC $             2,109.35 $              2,068.23 TOC $           3,647.10 $       3,595.44 TOC $            3,665.78 $               3,866.08

Note:  All other material includes core clamp, bushings, decals, leads, pallets, shipping materials, scrap, unapplied matrerials and standard accessories

Core Watts/lB 0.389 0.386 Core Watts/lB 0.283 0.308 Core Watts/lB 0.296 0.283

25 kVA Design Line 2, design option ID1: 14.4 kV: 120/240 V 25 kVA Design Line 2, design option CSL1: 14.4 kV 120/240 V 25 kVA Design Line 2, design option CSL2: 14.4 kV: 120/240 V
13

Design Line 4 Small Three Phase Pads 

Figure 3a shows the summary of Selling Prices versus Efficiency for Design Line 4 

Design Line Design Line 4 Small Three Phase Padmounted Transformer

kVA 150 kVA

Selling Prices, Costs, and Efficiencies as seen by the Manufacturers in 2011 with M3

DOE Efficiency Level DEL 0 DEL 1 DEL 2 DEL 3 DEL 4 DEL 5

% Efficiency at 50% Load 99.08 99.16 99.22 99.25 99.31 99.42

Incremental Efficiency 0.08 0.06 0.03 0.06 0.11

Watts saved 60 45 22.5 45 82.5

Selling Price $      6,200.00 $       6,700.00 $       7,300.00 $         7,610.00 $      9,900.00 $     23,813.00

Incremental Selling Price $          500.00 $           600.00 $            310.00 $      2,290.00 $     13,913.00

Incremental $/Watt Cost to End User $               8.33 $             13.33 $               13.78 $            50.89 $           168.64

Selling Prices, Costs, and Efficiencies by the DOE (OPS 1) in Preliminary Analysis with M3

DOE Efficiency Level DEL 0 DEL 1 DEL 2 DEL 3 DEL 4 DEL 5

% Efficiency at 50% Load 99.08 99.16 99.22 99.25 99.31 99.42

Incremental Efficiency 0.08 0.06 0.03 0.06 0.11

Watts saved 60 45 22.5 45 82.5

Selling Price $      4,861.00 $       5,507.00 $       6,628.00 $         6,700.00 $      7,100.00 $       7,600.00

Incremental Selling Price $          646.00 $       1,121.00 $               72.00 $          400.00 $           500.00

Incremental $/Watt Cost to End User $             10.77 $             24.91 $                 3.20 $               8.89 $                6.06

Selling Prices, Costs, and Efficiencies as seen by OPS 2 (DOE September) M3 Steel

DOE Efficiency Level DEL 0 DEL 1 DEL 2 DEL 3 DEL 4 DEL 5

% Efficiency at 50% Load 99.08 99.16 99.22 99.25 99.31 99.42

Incremental Efficiency 0.08 0.06 0.03 0.06 0.11

Watts saved 60 45 22.5 45 82.5

Selling Price $      5,395.00 $       6,426.00 $       7,955.00

Incremental Selling Price $       1,031.00 $       1,529.00

Incremental $/Watt Cost to End User $             17.18 $             33.98 $                   ‐ $                 ‐ $                  ‐

OPS2 with ZDMH

DOE Efficiency Level DEL 0 DEL 1 DEL 2 DEL 3 DEL 4 DEL 5

% Efficiency at 50% Load 99.08 99.16 99.22 99.25 99.31 99.42

Incremental Efficiency 0.08 0.06 0.03 0.06 0.11

Watts saved 60 45 22.5 45 82.5

Selling Price $      5,395.00 $       5,897.00 $       6,700.00 $         7,100.00 $      8,200.00 $     23,813.00

Incremental Selling Price $          502.00 $           803.00 $            400.00 $      1,100.00 $     15,613.00

Incremental $/Watt Cost to End User $               8.37 $             17.84 $               17.78 $            24.44 $           189.25

Present Worth of Wattsaved $6.71 $6.71 $6.71 $6.71 $6.71

14,400 Volts:208Y/120
Figure 3b shows the summary

ix. M is the

versus 

x. 01 is th

March, 

xi. 02 is th

Analysi

xii. Z is the

Analysi

y of Selling P

e Manufactur

DOE Efficien

he OPS Gene

2011, using 

he OPS Gene

is from Augus

e OPS Genera

is from Augus

Prices versu

ers’ Average 

ncy Level, usin

erated data fro

M3, Al, Al. 

erated data fro

st 31, 2011, u

ated data from

st 31, 2011, u

us Efficiency 

Selling Price

ng M3, Al, Al.

om the DOE P

om the DOE r

using M2, Al, A

m the DOE re

using ZDMH, 

for Design L

es to the end C

. 

Preliminary A

reissued Eng

Al. 

eissued Engin

Al, Al and or 

1

Line 4 

Customer 

Analysis in 

ineering 

neering 

Copper. 

14
15

Figure 3c shows Design Line 4 Comparisons between Manufacturers and OPS 1. 

Conclusions for Design Line 4, represented by 150 kVA Three Phase Pad with primary 

Voltage 12,470 GrY / 7,200 and low voltage 208 Y / 120 Volts: 

xxv. Manufacturers had higher material costs than OPS1. 

xxvi. Oil Gallons in OPS1 were in error and under-calculated. 

xxvii. Total Weights of transformers in OPS 1 were under-calculated and 

in error. 

xxviii. Tank cost in OPS1 was under-calculated. 

xxix. All other material in OPS 1 was under-calculated. 

xxx. Manufacturers’ selling prices for base case were at market levels. 

xxxi. Manufacturers’ selling prices to material cost were kept constant at 

base case ratios. 

xxxii. OPS2 is OPS1 revised. However revisions are not explained. 

xxxiii. OPS2 data is extracted from the engineering analysis from August 

31 with M3, Al, Al the base case. 

xxxiv. A ZDMH alternative by OPS2 is shown that shows the calculated 

data by OPS (August 31) for a ZDMH alternative. 

xxxv. Cost/watt saved Design Efficiency levels lower than the present 

worth values/watt are worthy of consideration as they return 

investment in less than 30 years. 

xxxvi. Cost/watt saved Design Efficiency levels greater than the present 

worth values/watt are not economical unless there are other 

considerations. 

Design Line 4 Small kVA Three Phase Pads

150 kVA Design Line 4 12470Y/7200: 208Y/120 V 150 kVA Design Line 4 12470Y/7200: 208Y/120 V 150 kVA Design Line 4 12470Y/7200: 208Y/120 V 150 kVA Design Line 4 12470Y/7200: 208Y/120 V Alternate

Parameter OPS MFG AVG Parameter OPS MFG AVG Parameter OPS MFG AVG Parameter OPS MFG AVG Amorphous

Efficiency at 50% load @55C 99.08 99.10 Efficiency at 50% load @55C 99.16 99.20 Efficiency at 50% load @55C 99.21 99.25 Efficiency at 50% load @55C 99.61 99.40 99.61

Selling Price $       4,861.16 $         6,425.47 Selling Price $         5,507.48 $         7,115.30 Selling Price $        6,628.00 $        7,609.74 Selling Price $         8,643.95 $      21,622.55 $        23,813.75

Core Loss @20 C 363.33 299.8 Core Loss 337.99 271.7 Core Loss 397.06 254.7 Core Loss 155.08 240.0 114.0

Load Loss at full load @ 85C 1410.60 1597.0 Load Loss at full load 1298.42 1417.3 Load Loss at full load 877.36 1325.0 Load Loss at full load 602.94 883.7 762.0

Total Weight, lbs.                1,743 2712.7 Total Weight, lbs.                  1,934 3089.0 Total Weight, lbs.                 2,300 3178.0 Total Weight, lbs.                  2,601 4653.3 5729.0

Core Material M3 M3 Core Material M3 M3 Core Material M3 M3 Core Material SA1 M3 SA1

Core Weight, Lbs                    631 566.1 Core Weight, Lbs.                      749 729.0 Core Weight, Lbs.                     903 738.2 Core Weight, Lbs.                  1,026 1047.7 986.0

Low Voltage Material AL AL Low Voltage Material AL AL Low Voltage Material AL AL Low Voltage Material CU CU Cu

High Voltage Material CU AL High Voltage Material CU AL High Voltage Material CU AL High Voltage Material CU CU Cu

LV Weight, Lbs.                      60 104.5 LV Weight, Lbs.                        73 123.390 LV Weight, Lbs.                       90 137.5 LV Weight, Lbs.                      223 413.2 725.0

HV Weight, Lbs.                    233 120.9 HV Weight, Lbs.                      271 176.750 HV Weight, Lbs.                     359 188.4 HV Weight, Lbs.                      335 705.4 941.0

Gallons of oil 41.79 130.0 Gallons of oil 44.64 142.733 Gallons of oil 52.54 148.4 Gallons of oil 60.66 171.0 225.0

Primary Insulation, Lbs. 6.30 15.6 Primary Insulation, Lbs. 7.01 18.775 Primary Insulation, Lbs. 7.69 20.0 Primary Insulation, Lbs. 7.75 15.6 30.0

Secondary insulation, Lbs. 6.82 14.4 Secondary insulation, Lbs. 8.05 14.500 Secondary insulation, Lbs. 7.17 16.1 Secondary insulation, Lbs. 7.73 12.3 22.0

Core Material Cost, $ 1183.24 $            979.34 Core Material Cost, $ 1404.67 $         1,158.15 Core Material Cost, $ 1693.37 $        1,339.33 Core Material Cost, $ 2441.90 $        1,926.01 $          2,169.20

LV Material Cost, $ 95.23 $            185.69 LV Material Cost, $ 114.67 $             218.89 LV Material Cost, $ 142.16 $            250.07 LV Material Cost, $ 943.33 $        1,907.03 $          3,346.10

HV Material Cost, $ 920.02 $            294.30 HV Material Cost, $ 1067.53 $             422.42 HV Material Cost, $ 1413.92 $            441.26 HV Material Cost, $ 1321.14 $        4,016.17 $          5,357.47

Primary Insulation Cost, $ 9.55 $               20.71 Primary Insulation Cost, $ 10.62 $               25.28 Primary Insulation Cost, $ 11.65 $              26.57 Primary Insulation Cost, $ 11.74 $              20.49 $                50.00

Secondary Insulation Cost, $ 10.34 $               18.72 Secondary Insulation Cost, $ 12.20 $               18.77 Secondary Insulation Cost, $ 10.86 $              20.43 Secondary Insulation Cost, $ 11.72 $              15.71 $                30.00

Oil Cost, $ 140.02 $            549.19 Oil Cost, $ 149.58 $             603.49 Oil Cost, $ 176.04 $            643.16 Oil Cost, $ 203.26 $            723.95 $              952.57

Tank Cost, $ 387.37 $            629.90 Tank Cost, $ 387.37 $             646.20 Tank Cost, $ 406.27 $            654.48 Tank Cost, $ 409.43 $            753.81 $              651.00

All Other Material 144.4 $            665.70 All Other Material 148.56 $             671.12 All Other Material 155.1 $            652.20 All Other Material 193.69 $        1,183.49 $          2,754.37

Core and Coil Cost, $ $       2,218.37 $         1,485.61 Core and Coil Cost, $ $         2,609.70 $         1,828.82 Core and Coil Cost, $ $        3,271.97 $        2,061.99 Core and Coil Cost, $ $         4,729.83 $        7,885.42 $        10,952.77

Tank , Oil,  & Other Cost, $ $          671.74 $         1,844.79 Tank , Oil,  & Other Cost, $ $             685.52 $         1,920.82 Tank , Oil,  & Other Cost, $ $            737.44 $        1,949.83 Tank , Oil,  & Other Cost, $ $            806.38 $        2,661.26 $          4,357.94

Total Material Cost $       2,890.11 $         3,330.40 Total Material Cost $         3,295.22 $         3,749.64 Total Material Cost $        4,009.40 $        4,011.82 Total Material Cost $         5,536.22 $      10,546.68 $        15,310.71

Tank Width 57 45.0 Tank Width 57 45.7 Tank Width 61 46.7 Tank Width 65 51.0 54.0

Tank Depth 46 27.0 Tank Depth 46 27.3 Tank Depth 50 27.7 Tank Depth 47 30.7 24.0

Tank Height 50 44.8 Tank Height 50 46.1 Tank Height 50 46.4 Tank Height 50 46.8 48.5

A factor $4.00 $                 4.00 A factor $               13.00 $               13.00 A factor $16.00 $              16.00 A factor $15.00 $              15.00 $                15.00

B factor 2 $                 2.00 B factor $                 4.00 $                  4.00 B factor 7.5 $                 7.50 B factor 8 $                 8.00 $                   8.00

Total Owning Cost $       9,135.67 $      10,818.67 Total Owning Cost $       15,095.03 $       16,316.30 Total Owning Cost $      19,561.20 $      21,621.90 Total Owning Cost $      15,793.61 $      32,291.88 $        31,619.75

Note:  All other material includes core clamp, bushings, decals, leads, pallets, shipping materials, scrap, unapplied matrerials and standard accessories

Core Watts/lB 0.576 0.530 Core Watts/lB 0.451 0.373 Core Watts/lB 0.440 0.345 Core Watts/lB 0.151 0.229 0.116
16

Design Line 5 Large Three Phase Transformers 

Figure 4a shows the summary of Selling Prices versus Efficiency for Design Line 5 

Design Line Design Line 5 Large Three Phase Transformers

kVA 1500 kVA

Selling Prices, Costs, and Efficiencies as seen by the Manufacturers in 2011 with M3

DOE Efficiency Level DEL 0 DEL 1 DEL 2 DEL 3 DEL 4 DEL 5

% Efficiency at 50% Load 99.42 99.48 99.51 99.54 99.57 99.61

Incremental Efficiency 0.06 0.03 0.03 0.03 0.04

Watts saved 450 225 225 225 300

Selling Price $   24,000.00 $    32,000.00 $     37,000.00 $      42,300.00 $    53,000.00 $     87,863.00

Incremental Selling Price $       8,000.00 $       5,000.00 $         5,300.00 $    10,700.00 $     34,863.00

Incremental $/Watt Cost to End User $             17.78 $             22.22 $               23.56 $            47.56 $           116.21

Selling Prices, Costs, and Efficiencies as seen by the DOE (OPS 1) in Preliminary Analysis

DOE Efficiency Level DEL 0 DEL 1 DEL 2 DEL 3 DEL 4 DEL 5

% Efficiency at 50% Load 99.42 99.48 99.51 99.54 99.57 99.61

Incremental Efficiency 0.06 0.03 0.03 0.03 0.04

Watts saved 450 225 225 225 300

Selling Price $   22,947.00 $    27,500.00 $     29,500.00 $      32,000.00 $    34,000.00 $     37,000.00

Incremental Selling Price $       4,553.00 $       2,000.00 $         2,500.00 $      2,000.00 $       3,000.00

Incremental $/Watt Cost to End User $             10.12 $                8.89 $               11.11 $               8.89 $             10.00

Selling Prices, Costs, and Efficiencies as seen by OPS 2 in DOE September Analysis

DOE Efficiency Level DEL 0 DEL 1 DEL 2 DEL 3 DEL 4 DEL 5

% Efficiency at 50% Load 99.42 99.48 99.51 99.54 99.57 99.61

Incremental Efficiency 0.06 0.03 0.03 0.03 0.04

Watts saved 450 225 225 225 300

Selling Price $   24,853.00 $    31,269.00 $     33,653.00

Incremental Selling Price $       6,416.00 $       2,384.00 $                  ‐

Incremental $/Watt Cost to End User $             14.26 $             10.60 $                   ‐ $                 ‐ $                  ‐

OPS2 with ZDMH

DOE Efficiency Level DEL 0 DEL 1 DEL 2 DEL 3 DEL 4 DEL 5

% Efficiency at 50% Load 99.42 99.48 99.51 99.54 99.57 99.61

Incremental Efficiency 0.06 0.03 0.03 0.03 0.04

Watts saved 450 225 225 225 300

Selling Price $   24,926.00 $    28,354.00 $     30,684.00 $      37,915.00

Incremental Selling Price $       3,428.00 $       2,330.00 $         7,231.00 $                  ‐

Incremental $/Watt Cost to End User $               7.62 $             10.36 $               32.14 $                 ‐ $                  ‐

Present Worth of Wattsaved $8.31 $8.31 $8.31 $8.31 $8.31

24,940 GRY/14,400: 480 Y/277
Figure 4b shows the summary

xiii. M is the

versus 

xiv. 01 is th

March, 

xv. 02 is th

Analysi

xvi. Z is the

Analysi

y of Selling P

e Manufactur

DOE Efficien

he OPS Gene

2011, using 

he OPS Gene

is from Augus

e OPS Genera

is from Augus

Prices versu

ers’ Average 

ncy Level, usin

erated data fro

M3, Al, Al. 

erated data fro

st 31, 2011, u

ated data from

st 31, 2011, u

us Efficiency 

Selling Price

ng M3, Al, Al.

om the DOE P

om the DOE r

using M2, Al, A

m the DOE re

using ZDMH, 

for Design L

es to the end C

. 

Preliminary A

reissued Eng

Al. 

eissued Engin

Al, Al and or 

1

Line 5 

Customer 

Analysis in 

ineering 

neering 

Copper. 

17
18

Figure 4c shows Design Line 5 Comparisons between Manufacturers and OPS 1. 

Conclusions For Design Line 5, represented by 1500 kVA Three Phase Pad with primary 

Voltage 24,9400 GrY / 14,400 and low voltage 480 Y / 277 Volts: 

xxxvii. Manufacturers had higher material costs than OPS1. 

xxxviii. Oil Gallons in OPS1 were in error and under-calculated. 

xxxix. Total Weights of transformers in OPS 1 were under-calculated and 

in error. 

xl. Tank cost in OPS1 was under-calculated. 

xli. All other material in OPS 1 was under-calculated. 

xlii. Manufacturers’ selling prices for base case were at market levels. 

xliii. Manufacturers’ selling prices to material cost were kept constant at 

base case ratios. 

xliv. OPS2 is OPS1 revised. However revisions are not explained. 

xlv. OPS2 data is extracted from the engineering analysis from August 

31 with M3, Al, Al the base case. 

xlvi. A ZDMH alternative by OPS2 is shown that shows the calculated 

data by OPS (August 31) for a ZDMH alternative. 

xlvii. Cost/watt saved Design Efficiency levels lower than the present 

worth values/watt are worthy of consideration as they return 

investment in less than 30 years. 

xlviii. Cost/watt saved Design Efficiency levels greater than the present 

worth values/watt are not economical unless there are other 

considerations. 

Design Line 5 Large Three Phase Pads

1500 kVA Design Line 5 24940GRY/14400: 480Y/277 1500 kVA Design Line 5 24940GRY/14400: 480Y/277 1500 kVA Design Line 5 24940GRY/14400: 480Y/277 Alternate

Parameter OPS MFG AVG Parameter OPS MFG AVG Parameter OPS MFG AVG Amorphous

Efficiency at 50% load @55C 99.42 99.45 Efficiency at 50% load @55C 99.54 99.54 Efficiency at 50% load @55C 99.69 99.62 99.67

Selling Price $         22,946.76 $         26,027.79 Selling Price $          32,354.04 $             42,285.32 Selling Price $            42,045.06 $         87,862.79 $              76,479.77

Core Loss @20 C 2147.36 1868.1 Core Loss 1867.59 1494.5 Core Loss 616.18 1345.2 675.0

Load Loss at full load @ 85C 8257.03 9752.3 Load Loss at full load 5969.99 8403.0 Load Loss at full load 7189.91 6159.4 7212.0

Total Weight, lbs.                    8,583 11335.3 Total Weight, lbs.                     8,917 13301.3 Total Weight, lbs.                     10,499 20647.2 19013.0

Core Material M3 M3 Core Material ZDMH M3 Core Material SA1 M3 SA1

Core Weight, Lbs                    3,829 3532.5 Core Weight, Lbs.                     3,300 4354.9 Core Weight, Lbs.                       4,044 6167.0 6120.0

Low Voltage Material AL AL Low Voltage Material CU AL Low Voltage Material CU CU Al

High Voltage Material AL AL High Voltage Material CU AL High Voltage Material CU CU Cu

LV Weight, Lbs.                        579 421.3 LV Weight, Lbs.                     1,184 726.300 LV Weight, Lbs.                       1,383 1904.8 985.0

HV Weight, Lbs.                        894 781.5 HV Weight, Lbs.                     1,632 1207.210 HV Weight, Lbs.                       1,904 3273.7 3472.0

Gallons of oil 241.43 431.7 Gallons of oil 196.89 457.667 Gallons of oil 248.00 496.3 608.0

Primary Insulation, Lbs. 83.03 99.8 Primary Insulation, Lbs. 54.30 105.390 Primary Insulation, Lbs. 75.29 118.2 80.0

Secondary insulation, Lbs. 43.07 65.6 Secondary insulation, Lbs. 27.19 78.095 Secondary insulation, Lbs. 44.55 80.5 40.0

Core Material Cost, $ $           7,179.94 $           6,128.79 Core Material Cost, $ $            6,764.28 $               8,958.46 Core Material Cost, $ $              9,623.91 $         13,098.33 $              13,464.00

LV Material Cost, $ $               915.49 $               748.86 LV Material Cost, $ $            4,998.85 $               2,516.44 LV Material Cost, $ $              5,842.69 $         10,998.44 $                 5,687.45

HV Material Cost, $ $           3,261.51 $           1,877.55 HV Material Cost, $ $            6,433.62 $               4,480.76 HV Material Cost, $ $              7,508.95 $         18,041.28 $              19,134.21

Primary Insulation Cost, $ $               125.79 $               131.60 Primary Insulation Cost, $ $                  82.26 $                   139.08 Primary Insulation Cost, $ $                  114.07 $               225.51 $                    130.00

Secondary Insulation Cost, $ $                 65.25 $                 84.44 Secondary Insulation Cost, $ $                  41.19 $                   101.04 Secondary Insulation Cost, $ $                    67.50 $               105.08 $                       80.00

Oil Cost, $ $               857.92 $           1,827.52 Oil Cost, $ $                694.03 $               1,938.11 Oil Cost, $ $                  857.15 $           2,093.98 $                 2,565.08

Tank Cost, $ $               934.31 $           1,666.05 Tank Cost, $ $                906.02 $               1,627.52 Tank Cost, $ $              1,043.83 $           1,602.88 $                 1,357.00

All Other Material $               455.48 $           1,355.17 All Other Material $                519.10 $               1,608.19 All Other Material $                  688.84 $           2,318.75 $                 3,019.91

Core and Coil Cost, $ $         11,547.98 $           8,899.23 Core and Coil Cost, $ $          18,320.19 $             16,115.73 Core and Coil Cost, $ $            23,157.12 $         42,358.44 $              38,495.66

Tank , Oil,  & Other Cost, $ $           2,247.71 $           4,848.74 Tank , Oil,  & Other Cost, $ $            2,119.15 $               5,173.82 Tank , Oil,  & Other Cost, $ $              2,589.82 $           6,015.61 $                 6,941.99

Total Material Cost $         13,795.68 $         13,747.97 Total Material Cost $          20,439.34 $             21,289.55 Total Material Cost $            25,746.94 $         48,374.05 $              45,437.65

Tank Width 86 65.8 Tank Width 86 68.8 Tank Width 86 80.9 80.0

Tank Depth 69 40.5 Tank Depth 67 42.0 Tank Depth 67 49.6 36.0

Tank Height 70 64.1 Tank Height 70 64.1 Tank Height 70 70.5 69.5

A factor $6.50 $                    6.50 A factor $13.00 $                     13.00 A factor $15.00 $                 15.00 $                       15.00

B factor 3.6 $                    3.60 B factor 6.5 $                       6.50 B factor 5.5 $                    5.50 $                         5.50

Total Owning Cost $         66,629.89 $         73,279.05 Total Owning Cost $          95,437.63 $          116,332.88 Total Owning Cost $            90,832.26 $       141,918.15 $            126,270.77

Note:  All other material includes core clamp, bushings, decals, leads, pallets, shipping materials, scrap, unapplied matrerials and standard accessories

Core Watts/lB 0.561 0.529 Core Watts/lB 0.566 0.343 Core Watts/lB 0.152 0.218 0.110
19

Design Line 12 Medium Voltage Dry Transformers 

Figure 5a shows the summary of Selling Prices versus Efficiency for Design Line 12 

Design Line Design Line 12 Three Phase Medium Voltage Dry Type

kVA 1500 kVA 12,470: 480Y/277 Volts

Selling Prices, Costs, and Efficiencies as seen by the Manufacturers in 2011 with M3

DOE Efficiency Level DEL 0 DEL 1 DEL 2 DEL 3 DEL 4 DEL 5

% Efficiency at 50% Load 99.12 99.22 99.3 99.39

Incremental Efficiency 0.095 0.085 0.09

Watts saved 712.5 637.5 675

Selling Price $   37,000.00 $    42,000.00 $    49,000.00 $    61,229.00

Incremental Selling Price $       5,000.00 $      7,000.00 $    12,229.00

Incremental $/Watt Cost to End User $               7.02 $            10.98 $            18.12

Selling Prices, Costs, and Efficiencies as seen by the DOE (OPS 1) in Preliminary Analysis

DOE Efficiency Level DEL 0 DEL 1 DEL 2 DEL 3 DEL 4 DEL 5

% Efficiency at 50% Load 99.12 99.22 99.3 99.39

Incremental Efficiency 0.095 0.085 0.09

Watts saved 712.5 637.5 675

Selling Price $   35,242.00 $    36,500.00 $    37,486.00 $    43,373.00

Incremental Selling Price $       1,258.00 $          986.00 $      5,887.00

Incremental $/Watt Cost to End User $               1.77 $               1.55 $               8.72

Selling Prices, Costs, and Efficiencies as seen by OPS 2 in DOE September Analysis

DOE Efficiency Level DEL 0 DEL 1 DEL 2 DEL 3 DEL 4 DEL 5

% Efficiency at 50% Load 99.12 99.22 99.3 99.39 99.46

Incremental Efficiency 0.095 0.085 0.09 0.07

Watts saved 712.5 637.5 675 525

Selling Price $   36,822.00 $    39,723.00 $    39,952.00 $    46,456.00 $    50,019.00

Incremental Selling Price $       2,901.00 $          229.00 $      6,504.00 $      3,563.00

Incremental $/Watt Cost to End User $               4.07 $               0.36 $               9.64 $               6.79

OPS2 with HO Hi B

DOE Efficiency Level DEL 0 DEL 1 DEL 2 DEL 3 DEL 4 DEL 5

% Efficiency at 50% Load 99.12 99.22 99.3 99.39 99.46

Incremental Efficiency 0.095 0.085 0.09 0.07

Watts saved 712.5 637.5 675 525

Selling Price $   33,544.00 $    36,716.00 $    39,040.00 $    43,040.00 $    46,670.00

Incremental Selling Price $       3,172.00 $      2,324.00 $      4,000.00 $      3,630.00

Incremental $/Watt Cost to End User $               4.45 $               3.65 $               5.93 $               6.91

Present Worth of Wattsaved $9.91 $9.91 $9.91 $9.91 $9.91
Figure 5b shows 

x

the summary

xvii. M is the

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xviii. 01 is th

March, 

xix. 02 is th

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st 31, 2011, u

ated data from

st 31, 2011, u

us Efficiency 

Selling Price

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m the DOE re

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20
21

Figure 5c shows Design Line 12 Comparisons between Manufacturers and OPS 1. 

Conclusions for Design Line 12, represented by 1500 kVA Three Phase Medium Voltage 

Dry with primary Voltage 12,470 and low voltage 480 Y / 277 Volts: 

xlix. Manufacturers had higher material costs than OPS1. 

l. Core weight in OPS1 was in error and under-calculated. 

li. Total Weights of transformers in OPS 1 were under-calculated and 

in error. 

lii. Cabinet cost in OPS1 was over-calculated. 

liii. All other material in OPS 1 was over-calculated. 

liv. Manufacturers’ selling prices for base case were at market levels. 

lv. Manufacturers’ selling prices to material cost were kept constant at 

base case ratios. 

lvi. OPS2 is OPS1 revised. However revisions are not explained. 

lvii. OPS2 data is extracted from the engineering analysis from August 

31 with M3, Al, Al the base case. 

lviii. A Hi B (HO) alternative by OPS2 is shown that shows the 

calculated data by OPS (August 31) for a Hi B alternative. 

lix. Cost/watt saved Design Efficiency levels lower than the present 

worth values/watt are worthy of consideration as they return 

investment in less than 30 years. 

lx. Cost/watt saved Design Efficiency levels greater than the present 

worth values/watt are not economical unless there are other 

considerations. 

Design Line 12 Medium Voltage Dry

M3,  AL, AL, 12470: 480Y/277 95 kV BIL, with taps M3,  AL, AL, 12470: 480Y/277 95 kV BIL, with taps M3,  AL, AL, 12470: 480Y/277 95 kV BIL, with taps

Parameter OPS MFG AVG Parameter OPS MFG AVG Parameter OPS MFG AVG

Efficiency at 50% load @75C 99.12 99.135 Efficiency at 50% load @75C 99.3 99.3085 Efficiency at 50% load @75C 99.39 99.3975

Selling Price $           35,242.12 $            37,234.95 Selling Price $         37,486.98 $     49,644.54 Selling Price $          43,373.01 $             61,228.80

Core Loss @20 C 2616.21 3755 Core Loss 2725.35 2961 Core Loss 2935.98 2481.5

Load Loss at full load @ 85C 20002.95 12142.5 Load Loss at full load 11868.27 10449 Load Loss at full load 7370.75 9446.5

Total Weight, lbs.                      7,829 8763 Total Weight, lbs.                    8,534 10869 Total Weight, lbs.                   10,190 11711.5

Core Material M3 M4 Core Material M3 M3 Core Material M3 M3

Core Weight, Lbs                      5,720 5996 Core Weight, Lbs.                    6,002 7406.5 Core Weight, Lbs.                      6,960 7933.5

Low Voltage Material AL AL Low Voltage Material AL AL Low Voltage Material AL AL

High Voltage Material AL AL High Voltage Material AL AL High Voltage Material AL AL

LV Weight, Lbs.                          302 434 LV Weight, Lbs.                        443 578.5 LV Weight, Lbs.                         655 668.5

HV Weight, Lbs.                          508 567 HV Weight, Lbs.                        761 880.5 HV Weight, Lbs.                      1,134 973

Gallons of impregnation 31.79 25 Gallons of impregnation 33.09 25 Gallons of impregnation 39.83 25

Primary Insulation, Lbs. 0.00 135 Primary Insulation, Lbs. 0.00 192 Primary Insulation, Lbs. 0.00 192

Secondary insulation, Lbs. 132.34 127 Secondary insulation, Lbs. 132.31 225 Secondary insulation, Lbs. 142.93 225

Core Material Cost, $ $           10,724.76 $              8,080.00 Core Material Cost, $ $         11,254.65 $     11,598.00 Core Material Cost, $ $          13,050.04 $             15,068.00

LV Material Cost, $ 4 $                  73.01 $                  831.50 LV Material Cost, $ 6 $                92.71 $       1,103.50 LV Material Cost, $ 1 $             ,025.65 $               1,283.50

HV Material Cost, $ 1 $              ,110.00 $              1,608.00 HV Material Cost, $ 1 $            ,663.17 $       2,343.50 HV Material Cost, $ 2 $             ,478.08 $               2,533.50

Primary Insulation Cost, $ $                       ‐ $                  789.00 Primary Insulation Cost, $ $                     ‐ $           850.00 Primary Insulation Cost, $ $                       ‐ $                   850.00

Secondary Insulation Cost, $ 3,242.39 $              $              1,814.00 Secondary Insulation Cost, $ 3,241.60 $            $       1,973.50 Secondary Insulation Cost, $ 3,501.86 $             $               2,166.00

Cabinet Cost, $ 8 $                  10.25 $                  780.00 Cabinet Cost, $ 8 $                15.36 $           780.00 Cabinet Cost, $ 8 $                 42.20 $                   820.00

All Other Material $             4,499.67 $              1,181.00 All Other Material $           4,740.96 $       1,462.00 All Other Material $            5,466.61 $               1,496.50

Core and Coil Cost, $ $           15,550.15 $            13,122.50 Core and Coil Cost, $ $         16,852.13 $     17,868.50 Core and Coil Cost, $ $          20,055.62 $             21,901.00

Cabinet & Other Cost, $ 5 $              ,309.92 $              1,961.00 Cabinet & Other Cost, $ 5 $            ,556.32 $       2,242.00 Cabinet & Other Cost, $ 6 $             ,308.81 $               2,316.50

Total Material Cost $           20,860.07 $            15,083.50 Total Material Cost $         22,408.45 $     20,110.50 Total Material Cost $          26,364.43 $             24,217.50

Tank Width 90 99 Tank Width 89 99 Tank Width 95 107

Tank Depth 43 56 Tank Depth 45 56 Tank Depth 47 58

Tank Height 90 98 Tank Height 90 98 Tank Height 90 105

A factor $0.75 $                      0.75 A factor $                   9.00 $                9.00 A factor $                  16.00 $                     16.00

B factor 0.2 $                      0.20 B factor $                   0.56 $                0.56 B factor $                     4.00 $                       4.00

Total Owning Cost $           41,204.87 $            42,479.70 Total Owning Cost $         68,661.33 $     82,144.98 Total Owning Cost $        119,831.64 $          138,718.80

Note:  All other material includes core clamp, bushings, decals, leads, pallets, shipping materials, scrap, unapplied matrerials and standard accessories

1500 kVA 3‐phase Vented Dry Design Line 12 1500 kVA 3‐phase Vented Dry Design Line 12 1500 kVA 3‐phase Vented Dry Design Line 12
22

G. Thoughts on OPS 

1. OPS is a calculation tool which has a multiplicity of design algorithms imbedded to 

calculate performance and cost as a function of the many variables that influence the 

design. The manufacturers optimizing programs are constantly being recalibrated with 

bills of material that are compared with actual financial results such that their accuracy is 

normally quite good. I have used OPS software and can say that it is capable of correctly 

optimizing the design as long as it is properly calibrated. The calibration requires 

accurate portrayal of: 

a. Available materials, both applied and unapplied and their costs 

b. Labor content, both direct and indirect and their costs 

c. Manufacturing overhead including energy costs, supervision, scrap (natural and 

errors) and rework 

d. Inventory carrying costs 

e. Engineering 

f. Selling 

g. Advertising 

h. Administration 

i. Taxes, etc. 

2. It is difficult to accumulate a model that accurately captures all elements and the 

programmers of OPS need a lot of information that is not normally available to truly 

represent the industry. 

3. Even if the information is basically available, each product line needs to be accurately 

modeled in strict accordance to the relevant industry standards to get a complete 

embodiment of the full costs that are mandatory. 

4. The analysis that I have completed with the help of the manufacturers is based on a 

combination of 2011 standards and current 2011 costs. 

5. The OPS data has been accumulated in more than one time period. OPS1 information 

was published in the DOE Preliminary Analysis of March 2011. It was intended to reflect 

material costs at 2010 levels but there turned out to be some limitations in the accuracy 

of such costs. 

6. After manufacturing designs were compared for liquid filled transformers (Dry 

transformers came later), errors were detected and OPS 2 was created to repair the 

errors and bring material costs up to 2011 levels. 

7. No feedback was given to OPS about the Dry Type Transformer Designs and it appears 

that OPS2 and OPS1 for dry types are showing the same selling prices, suggesting few 

changes were made to the computer program. 

8. Selling prices for the base efficiency levels should truly be at market since those are the 

efficiencies in the market today. However, OPS1 appeared to be different and usually 

lower than the averages supplied to HVOLT Inc. by the manufacturers. These 

differences are attributed to the data base that was available to OPS. 
23

9. The Manufacturer data shown in the plots was accumulated with the presumption that M3 

core steel and aluminum conductors were run in order to reflect the interests of the US 

Domestic Magnetic Steel makers. 

10. OPS1 designs were selected to compare to the Manufacturers data that also contained 

M3 core steel and aluminum conductor. 

11. OPS2 designs were selected from the August 31 DOE Engineering Analysis that also 

contained M3 core steel and aluminum conductors. 

12. OPS2 with Hi B core steel (ZDMH for wound cores and HO for stacked cores) was 

compared against OPS2 with M3 to show that if the M3 constraint was not applied that 

other designs may be theoretically more economical at a given efficiency and shown on 

the plots. 

13. The manufacturers hit the brick wall where no designs could be found with conventional 

materials (M3 core steel, Copper LV and Copper HV) at 99.40% for Design Line 4 and at 

99.62% for Design Line 5 and different for the other product lines. This upper limit of 

efficiency was tested for each of the product lines. 

14. Hi BIL and Dual Voltage designs were created but not shown in this analysis that showed 

the brick wall to be much closer to the present minimum efficiency. More analysis may 

be desired in this area in the future. 

15. In both Design Lines 4 and 5, only amorphous core material would be able to move 

further than the brick wall to the highest efficiency requested for the study (99.61% for 

Design Line 4 and 99.69% for Design Line 5). However, two other considerations make 

amorphous not necessarily the best choice. If loading turns out to be greater than the 

assumed 50% RMS equivalent load then higher winding losses in the amorphous design 

would quickly eat up the benefits. Amorphous metal also has higher magnetostriction, 

audible sound, and more intense vibration than silicon iron. Many cases already are 

apparent where splinters of amorphous metal have been pumped into the windings and 

have resulted in catastrophic failures. Hence, reliability is a factor that must be assessed 

as worse than silicon. 

16. Accuracy of OPS for some of the design lines still needs to be tested. For example, each 

of the 3-phase designs submitted by the manufacturers appears to be considerably 

heavier than OPS has shown with more than 1000 pounds difference and in some cases 

up to double or 10,000 pounds. This error is extremely significant. 

17. The gallons of oil were understated by OPS for liquid filled pad mounted transformers but 

were repaired for OPS2. 

18. Dry Type designs for OPS2 do not appear to be appreciably different than OPS1. In all 

fairness, we did not have feedback for the OPS personnel on the Medium Voltage Dry 

transformers prior to our design review and they may have been unaware of any errors. 

19. One limitation of OPS that becomes increasingly apparent at high efficiencies is the lack 

of precision for core clamps, leads, busses, and stray and eddy losses. These items 

require larger cores and coils to compensate for their otherwise reduction of efficiencies 

in both liquid and dry transformers. 

The bottom line of the comparison is that OPS has projected a considerably easier job of moving 

to higher efficiencies than the manufacturers when using M3 core steel as well as real 

manufacturer-based cost data. It is also most likely that any program and design errors have 

been present in the previous rulemaking which accounts for the difficulties expressed by many 

manufacturers to find buildable designs at upper efficiencies. 

A logical question is why this steep cost curve outcome is occurring for 3-Phase Liquid Filled 

Transformers when the present standard from the 2007 NOPR and effective January 1, 2010 is 

presented as meeting <TSL3 for kVA ratings up to 500 kVA while single phase transformers in 

the lower kVA range up to 167 kVA were required to meet >TSL4. Factually, the 3-Phase 

transformers were also at the original equivalent TSL 4 as well when the 3-Phase core loss 

adjustment of 1.3 times the single phase equivalent was included to account for 3rd harmonic core 

losses in the wound cores. 
24

H. Overall Conclusions and Recommendations 

This report should provide the stakeholders with an accurate picture of manufacturer’s cost as a 

function of DOE efficiency and should be a useful tool for the negotiators to determine the 

efficiency levels that best meet the National and DOE objectives with real buildable options. 

High BIL and Dual Voltage Designs have been prepared but time constraints prevented me from 

adding them to this report. However, in both cases, they reach the limitations of core materials 

and conductors at a little over DEL1 and may want to be examined by the team in a future 

publication. 

Sincerely, 

Philip J Hopkinson 

Philip J Hopkinson, PE 

President and CEO, HVOLT Inc.