1 | Building Technologies Program eere.energy.gov

The Parker Ranch installation in Hawaii

BUILDING TECHNOLOGIES PROGRAM

Distribution Transformers

Energy Conservation Program

LBNL Staff on behalf of

U.S. Department of Energy

Energy Efficiency & Renewable Energy

November 3, 2011
2 | Building Technologies Program eere.energy.gov

Draft Life-Cycle Cost, Payback Period Sensitivity Results: High and 

Low Material Prices for Medium Voltage Liquid-Immersed 

Transformers 

Prepared for the Medium Voltage Distribution Transformers Negotiated 

Rulemaking Working Group

November 7, 2011

Contents

• Life-Cycle Cost Low Price Scenario Results for Design Lines 1 – 5

• Payback Period Low Price Scenario Results for Design Lines 1 – 5

• Life-Cycle Cost High Price Scenario Results for Design Lines 1 – 5

• Payback Period High Price Scenario Results for Design Lines 1 – 5

Contents
3 | Building Technologies Program eere.energy.gov

Design Line 1 LCC Results: 2006 – 

25% Material Prices

Efficiency Level

1 2 3 4 5 6

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

Transformers with Net Increase in LCC (%) 40.05% 0.15% 0.15% 0.70% 1.45% 16.60%

Transformers with No Impact on LCC (%) 0.15% 0.15% 0.15% 0.00% 0.00% 0.00%

Transformers with Net LCC Savings (%) 59.80% 99.70% 99.70% 99.30% 98.55% 83.40%

Mean LCC Savings ($) 227 1133 1133 1064 1375 961

Median LCC Savings ($) 92 1136 1136 1048 1282 737

-1000

-500

0 

500

1000

1500

2000

2500

3000

3500

CSL 1 CSL 2 CSL 3 CSL 4 CSL 5 CSL 6

Average LCC Savings ($)

Efficiency Level

Design Line 1 Average LCC Savings

Average; Median; Box 25%-75%; Whisker 5%-95%

median

average
4 | Building Technologies Program eere.energy.gov

Design Line 2 LCC Results : 2006 – 

25% Material Prices

Efficiency Level

1 2 3 4 5 6 7

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

Transformers with Net LCC Cost (%) 6.60% 2.25% 2.85% 21.95% 26.00% 34.65% 37.30%

Transformers with No Change in LCC (%) 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%

Transformers with Net LCC Benefit (%) 93.40% 97.75% 97.15% 78.05% 74.00% 65.35% 62.70%

Mean LCC Savings ($) 651 722 700 227 146 -58 -73

Median LCC Savings ($) 713 768 749 630 497 260 222

-3500

-3000

-2500

-2000

-1500

-1000

-500

0 

500

1000

1500

2000

CSL 1 CSL 2 CSL 3 CSL 4 CSL 5 CSL 6 CSL 7

Average LCC Savings ($)

Efficiency Level

Design Line 2 Average LCC Savings

Average; Median; Box 25%-75%; Whisker 5%-95%

median

average
5 | Building Technologies Program eere.energy.gov

Design Line 3 LCC Results : 2006 – 

25% Material Prices

Efficiency Level

1 2 3 4 5 6 7

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

Transformers with Net Increase in LCC (%) 5.10% 4.35% 0.55% 0.45% 0.75% 1.75% 6.50%

Transformers with No Impact on LCC (%) 0.55% 0.50% 0.05% 0.05% 0.00% 0.00% 0.00%

Transformers with Net LCC Savings (%) 94.35% 95.15% 99.40% 99.50% 99.25% 98.25% 93.50%

Mean LCC Savings ($) 2334 6787 8103 8690 10085 11408 9708

Median LCC Savings ($) 2123 7322 8374 8977 10243 10952 8633

-5000

0 

5000

10000

15000

20000

25000

CSL 1 CSL 2 CSL 3 CSL 4 CSL 5 CSL 6 CSL 7

Average LCC Savings ($)

Efficiency Level

Design Line 3 Average LCC Savings

Average; Median; Box 25%-75%; Whisker 5%-95%

median

average
6 | Building Technologies Program eere.energy.gov

Design Line 4 LCC Results : 2006 – 

25% Material Prices

Efficiency Level

1 2 3 4 5 6 7

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

Transformers with Net LCC Cost (%) 0.15% 0.05% 0.05% 0.05% 0.15% 0.95% 4.75%

Transformers with No Change in LCC (%) 1.00% 1.00% 1.00% 1.00% 0.35% 0.00% 0.00%

Transformers with Net LCC Benefit (%) 98.85% 98.95% 98.95% 98.95% 99.50% 99.05% 90.15%

Mean LCC Savings ($) 1422 5077.9 5077.9 5143.2 5191.1 5089 4131

Median LCC Savings ($) 1056 5148.1 5148.1 5218.9 5229.4 4949 3863

0 

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

CSL 1 CSL 2 CSL 3 CSL 4 CSL 5 CSL 6 CSL 7

Average LCC Savings ($)

Efficiency Level

Design Line 4 Average LCC Savings

Average; Median; Box 25%-75%; Whisker 5%-95%

median

average
7 | Building Technologies Program eere.energy.gov

Design Line 5 LCC Results : 2006 – 

25% Material Prices

Efficiency Level

1 2 3 4 5 6 

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

Transformers with Net Increase in LCC (%) 0.95% 2.40% 1.80% 1.95% 3.25% 8.15%

Transformers with No Impact on LCC (%) 0.40% 0.20% 0.00% 0.00% 0.00% 0.00%

Transformers with Net LCC Savings (%) 98.65% 97.40% 98.20% 98.05% 96.75% 91.85%

Mean LCC Savings ($) 7306 21443 22427 23323 23202 20292

Median LCC Savings ($) 6779 22739 23649 24399 24258 20764

-10000

0 

10000

20000

30000

40000

50000

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

Average LCC Savings ($)

Efficiency Level

Design Line 5 Average LCC Savings

Average; Median; Box 25%-75%; Whisker 5%-95%

median

average
8 | Building Technologies Program eere.energy.gov

Design Line 1 PBP Results : 2006 – 

25% Material Prices

 

Efficiency Level 

1 2 3 4 5 6 

Mean Payback (Years) 27.8 7.7 7.7 9.6 10.9 17.9

Median Payback (Years) 16.5 7.4 7.4 9.2 10.5 17.0

Transformers having Well Defined Payback (%) 85.60% 99.85% 99.85% 99.95% 100.00% 100.00%

Transformers having Undefined Payback (%) 14.40% 0.15% 0.15% 0.05% 0.00% 0.00%

Mean Retail Cost ($) 1,801 1,990 1,990 2,062 2,263 2,672

Mean Installation Costs ($) 2,226 2,263 2,263 2,336 2,411 2,604

Mean Operating Costs ($) 200 151 151 149 127 122

Mean Incremental First Cost ($) 271 497 497 642 918 1,521

Mean Operating Cost Savings ($) 18 67 67 70 91 97

Payback of Average Transformer 14.8 7.4 7.4 9.2 10.1 15.7

0 

20

40

60

80

100

120

CSL 1 CSL 2 CSL 3 CSL 4 CSL 5 CSL 6

Average Payback Period (years)

Efficiency Level

Design Line1 Average Payback Period

Average; Median; Box 25%-75%; Whisker 5%-95%

median

average
9 | Building Technologies Program eere.energy.gov

Design Line 2 PBP Results : 2006 – 

25% Material Prices

 

Efficiency Level

1 2 3 4 5 6 7 

Mean Payback (Years) 6.4 6.4 8.2 20.2 24.0 28.2 28.7

Median Payback (Years) 3.3 4.8 6.4 9.2 14.5 19.5 20.6

Transformers having Well Defined Payback (%) 98.40% 99.90% 99.75% 99.75% 99.65% 99.70% 99.80%

Transformers having Undefined Payback (%) 1.60% 0.10% 0.25% 0.25% 0.35% 0.30% 0.20%

Mean Retail Cost ($) 1,156 1,186 1,228 1,282 1,463 1,627 1,949

Mean Installation Costs ($) 1732 1775 1815 2354 2515 2675 2470

Mean Operating Costs ($) 97 92 90 86 76 72 68

Mean Incremental First Cost ($) 148 221 304 896 1,238 1,562 1,679

Mean Operating Cost Savings ($) 35 40 42 46 56 60 64

Payback of Average Transformer 4.3 5.5 7.2 19.3 22.2 26.0 26.2

0 

10

20

30

40

50

60

70

80

90

CSL 1 CSL 2 CSL 3 CSL 4 CSL 5 CSL 6 CSL 7

Average Payback Period (years)

Efficiency Level

Design Line 2 Average Payback Period

Average; Median; Box 25%-75%; Whisker 5%-95%
10 | Building Technologies Program eere.energy.gov

Design Line 3 PBP Results : 2006 – 

25% Material Prices

 

Efficiency Level

1 2 3 4 5 6 7 

Mean Payback (Years) 10.6 5.0 5.1 5.0 5.6 8.7 14.1

Median Payback (Years) 8.2 3.4 4.2 4.3 4.9 7.5 12.1

Transformers having Well Defined Payback (%) 98.50% 98.40% 99.95% 99.95% 100.00% 99.95% 99.80%

Transformers having Undefined Payback (%) 1.50% 1.60% 0.05% 0.05% 0.00% 0.05% 0.20%

Mean Retail Cost ($) 6,783 7,190 7,609 7,718 8,181 9,889 12,532

Mean Installation Costs ($) 4,407 4,247 4,368 4,390 4,515 4,985 5,677

Mean Operating Costs ($) 1,167 947 878 852 780 655 602

Mean Incremental First Cost ($) 1,024 1,270 1,811 1,942 2,530 4,708 8,043

Mean Operating Cost Savings ($) 131 351 419 446 518 642 696

Payback of Average Transformer 7.8 3.6 4.3 4.4 4.9 7.3 11.6

0 

5 

10

15

20

25

CSL 1 CSL 2 CSL 3 CSL 4 CSL 5 CSL 6 CSL 7

Average Payback Period (years)

Efficiency Level

Design Line 3 Average Payback Period

Average; Median; Box 25%-75%; Whisker 5%-95%
11 | Building Technologies Program eere.energy.gov

Design Line 4 PBP Results : 2006 – 

25% Material Prices

 

Efficiency Level

1 2 3 4 5 6 7 

Mean Payback (Years) 5.9 3.9 3.9 4.0 4.4 8.1 13.8

Median Payback (Years) 5.8 3.7 3.7 3.8 4.1 7.5 13.0

Transformers having Well Defined Payback (%) 98.85% 98.85% 98.85% 98.95% 99.65% 99.90% 94.90%

Transformers having Undefined Payback (%) 1.15% 1.15% 1.15% 1.05% 0.35% 0.10% 0.00%

Mean Retail Cost ($) 4,684 5,113 5,113 5,118 5,184 5,996 8,023

Mean Installation Costs ($) 4,036 4,152 4,152 4,178 4,225 4,580 4,707

Mean Operating Costs ($) 553 379 379 375 369 325 279

Mean Incremental First Cost ($) 375 921 921 952 1,065 2,233 4,388

Mean Operating Cost Savings ($) 74 247 247 251 258 302 350

Payback of Average Transformer 5.1 3.7 3.7 3.8 4.1 7.4 12.5

0 

2 

4 

6 

8 

10

12

14

CSL 1 CSL 2 CSL 3 CSL 4 CSL 5 CSL 6 CSL 7

Average Payback Period (years)

Efficiency Level

Design Line 4 Average Payback Period

Average; Median; Box 25%-75%; Whisker 5%-95%
12 | Building Technologies Program eere.energy.gov

Design Line 5 PBP Results : 2006 – 

25% Material Prices

 

Efficiency Level

1 2 3 4 5 6 

Mean Payback (Years) 5.1 4.8 6.4 6.8 8.8 15.6

Median Payback (Years) 4.3 3.3 4.5 5.1 7.0 13.5

Transformers having Well Defined Payback (%) 99.50% 98.65% 99.90% 99.90% 99.65% 100.00%

Transformers having Undefined Payback (%) 0.50% 1.35% 0.10% 0.10% 0.35% 0.00%

Mean Retail Cost ($) 21,665 22,828 24,292 25,165 27,829 41,967

Mean Installation Costs ($) 7,819 8,602 8,857 9,016 9,492 9,828

Mean Operating Costs ($) 3,127 2,487 2,380 2,303 2,183 1,724

Mean Incremental First Cost ($) 1,453 3,399 5,118 6,150 9,289 23,764

Mean Operating Cost Savings ($) 348 988 1,095 1,172 1,291 1,751

Payback of Average Transformer 4.2 3.4 4.7 5.2 7.2 13.6

0 

5 

10

15

20

25

30

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

Average Payback Period (years)

Efficiency Level

Design Line 5 Average Payback Period

Average; Median; Box 25%-75%; Whisker 5%-95%

median

average
13 | Building Technologies Program eere.energy.gov

Design Line 1 LCC Results: 2008 + 

25% Material Prices

Efficiency Level

1 2 3 4 5 6

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

Transformers with Net Increase in LCC (%) 56.90% 2.35% 2.35% 5.70% 11.50% 57.10%

Transformers with No Impact on LCC (%) 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%

Transformers with Net LCC Savings (%) 43.10% 97.65% 97.65% 94.30% 88.50% 42.90%

Mean LCC Savings ($) 41 872 872 716 856 56

Median LCC Savings ($) -60 877 877 701 758 -169

-2000

-1500

-1000

-500

0 

500

1000

1500

2000

2500

CSL 1 CSL 2 CSL 3 CSL 4 CSL 5 CSL 6

Average LCC Savings ($)

Efficiency Level

Design Line 1 Average LCC Savings

Average; Median; Box 25%-75%; Whisker 5%-95%

median

average
14 | Building Technologies Program eere.energy.gov

Design Line 2 LCC Results : 2008 + 

25% Material Prices

Efficiency Level

1 2 3 4 5 6 7

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

Transformers with Net LCC Cost (%) 11.35% 16.40% 26.30% 28.30% 52.50% 75.55% 85.60%

Transformers with No Change in LCC (%) 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%

Transformers with Net LCC Benefit (%) 88.65% 83.60% 73.70% 71.70% 47.50% 24.45% 14.40%

Mean LCC Savings ($) 379 163 -75 -120 -341 -667 -956

Median LCC Savings ($) 468 450 343 290 -30 -395 -710

-4000

-3500

-3000

-2500

-2000

-1500

-1000

-500

0 

500

1000

1500

CSL 1 CSL 2 CSL 3 CSL 4 CSL 5 CSL 6 CSL 7

Average LCC Savings ($)

Efficiency Level

Design Line 2 Average LCC Savings

Average; Median; Box 25%-75%; Whisker 5%-95%

median

average
15 | Building Technologies Program eere.energy.gov

Design Line 3 LCC Results : 2008 + 

25% Material Prices

Efficiency Level

1 2 3 4 5 6 7

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

Transformers with Net Increase in LCC (%) 9.90% 6.60% 2.05% 1.40% 1.70% 6.15% 30.75%

Transformers with No Impact on LCC (%) 0.05% 0.05% 0.00% 0.00% 0.00% 0.00% 0.00%

Transformers with Net LCC Savings (%) 90.05% 93.35% 97.95% 98.60% 98.30% 93.85% 69.25%

Mean LCC Savings ($) 3687 5987 6986 7499 8457 8213 4164

Median LCC Savings ($) 2959 6528 7198 7683 8584 7731 3130

-5000

0 

5000

10000

15000

20000

CSL 1 CSL 2 CSL 3 CSL 4 CSL 5 CSL 6 CSL 7

Average LCC Savings ($)

Efficiency Level

Design Line 3 Average LCC Savings

Average; Median; Box 25%-75%; Whisker 5%-95%

median

average
16 | Building Technologies Program eere.energy.gov

Design Line 4 LCC Results : 2008 + 

25% Material Prices

Efficiency Level

1 2 3 4 5 6 7

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

Transformers with Net LCC Cost (%) 2.20% 0.30% 0.30% 0.15% 0.35% 3.55% 35.20%

Transformers with No Change in LCC (%) 0.45% 0.45% 0.45% 0.45% 0.10% 0.00% 0.00%

Transformers with Net LCC Benefit (%) 97.35% 99.25% 99.25% 99.40% 99.55% 96.45% 59.70%

Mean LCC Savings ($) 1035 4543.2 4543.2 4550.4 4649.9 3843 1164

Median LCC Savings ($) 761 4603.5 4603.5 4605.8 4705.4 3695 874

0 

1000

2000

3000

4000

5000

6000

7000

8000

CSL 1 CSL 2 CSL 3 CSL 4 CSL 5 CSL 6 CSL 7

Average LCC Savings ($)

Efficiency Level

Design Line 4 Average LCC Savings

Average; Median; Box 25%-75%; Whisker 5%-95%

median

average
17 | Building Technologies Program eere.energy.gov

Design Line 5 LCC Results : 2008 + 

25% Material Prices

Efficiency Level

1 2 3 4 5 6 

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

Transformers with Net Increase in LCC (%) 41.00% 3.20% 3.60% 3.85% 7.15% 52.90%

Transformers with No Impact on LCC (%) 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%

Transformers with Net LCC Savings (%) 59.00% 96.80% 96.40% 96.15% 92.85% 47.10%

Mean LCC Savings ($) 4170 15970 15909 16150 13989 -97

Median LCC Savings ($) 1669 16494 16241 16275 14252 -895

-30000

-20000

-10000

0 

10000

20000

30000

40000

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

Average LCC Savings ($)

Efficiency Level

Design Line 5 Average LCC Savings

Average; Median; Box 25%-75%; Whisker 5%-95%

median

average
18 | Building Technologies Program eere.energy.gov

Design Line 1 PBP Results : 2008 + 

25% Material Prices

 

Efficiency Level 

1 2 3 4 5 6 

Mean Payback (Years) 40.2 11.9 11.9 14.8 17.0 28.6

Median Payback (Years) 28.2 11.4 11.4 14.3 16.4 27.3

Transformers having Well Defined Payback (%) 89.30% 100.00% 100.00% 100.00% 100.00% 100.00%

Transformers having Undefined Payback (%) 10.70% 0.00% 0.00% 0.00% 0.00% 0.00%

Mean Retail Cost ($) 2,913 3,240 3,240 3,384 3,753 4,549

Mean Installation Costs ($) 2,222 2,260 2,260 2,335 2,411 2,604

Mean Operating Costs ($) 202 151 151 149 127 122

Mean Incremental First Cost ($) 409 773 773 991 1,437 2,426

Mean Operating Cost Savings ($) 16 68 68 70 91 97

Payback of Average Transformer 25.2 11.4 11.4 14.2 15.8 25.1

0 

20

40

60

80

100

120

CSL 1 CSL 2 CSL 3 CSL 4 CSL 5 CSL 6

Average Payback Period (years)

Efficiency Level

Design Line1 Average Payback Period

Average; Median; Box 25%-75%; Whisker 5%-95%

median

average
19 | Building Technologies Program eere.energy.gov

Design Line 2 PBP Results : 2008 + 

25% Material Prices

 

Efficiency Level

1 2 3 4 5 6 7 

Mean Payback (Years) 13.8 19.8 25.9 27.5 32.9 39.0 13.8

Median Payback (Years) 9.3 11.0 14.3 16.8 24.8 32.2 9.3

Transformers having Well Defined Payback (%) 99.65% 99.95% 99.90% 99.90% 99.90% 99.90% 99.65%

Transformers having Undefined Payback (%) 0.35% 0.05% 0.10% 0.10% 0.10% 0.10% 0.35%

Mean Retail Cost ($) 1,920 1,967 2,060 2,150 2,486 2,771 1,920

Mean Installation Costs ($) 1784 2087 2292 2367 2514 2675 1784

Mean Operating Costs ($) 97 92 90 86 76 72 97

Mean Incremental First Cost ($) 379 729 1,027 1,192 1,675 2,120 379

Mean Operating Cost Savings ($) 32 38 40 44 53 58 32

Payback of Average Transformer 11.7 19.4 26.0 27.1 31.5 36.8 11.7

0 

20

40

60

80

100

120

CSL 1 CSL 2 CSL 3 CSL 4 CSL 5 CSL 6 CSL 7

Average Payback Period (years)

Efficiency Level

Design Line 2 Average Payback Period

Average; Median; Box 25%-75%; Whisker 5%-95%
20 | Building Technologies Program eere.energy.gov

Design Line 3 PBP Results : 2008 + 

25% Material Prices

 

Efficiency Level

1 2 3 4 5 6 7 

Mean Payback (Years) 9.3 7.3 7.7 7.5 8.7 14.1 23.1

Median Payback (Years) 6.8 4.9 6.3 6.4 7.6 12.3 20.4

Transformers having Well Defined Payback (%) 96.60% 98.45% 100.00% 100.00% 100.00% 99.95% 99.85%

Transformers having Undefined Payback (%) 3.40% 1.55% 0.00% 0.00% 0.00% 0.05% 0.15%

Mean Retail Cost ($) 11,858 12,109 12,865 13,054 13,977 17,237 22,210

Mean Installation Costs ($) 4,171 4,251 4,370 4,385 4,518 4,989 5,681

Mean Operating Costs ($) 1,060 948 879 853 780 656 603

Mean Incremental First Cost ($) 1,427 1,758 2,633 2,837 3,892 7,624 13,289

Mean Operating Cost Savings ($) 226 338 407 434 506 631 683

Payback of Average Transformer 6.3 5.2 6.5 6.5 7.7 12.1 19.4

0 

5 

10

15

20

25

CSL 1 CSL 2 CSL 3 CSL 4 CSL 5 CSL 6 CSL 7

Average Payback Period (years)

Efficiency Level

Design Line 3 Average Payback Period

Average; Median; Box 25%-75%; Whisker 5%-95%
21 | Building Technologies Program eere.energy.gov

Design Line 4 PBP Results : 2006 – 

25% Material Prices

 

Efficiency Level

1 2 3 4 5 6 7 

Mean Payback (Years) 11.0 6.6 6.6 6.6 7.0 12.6 22.8

Median Payback (Years) 10.8 6.2 6.2 6.2 6.5 11.9 21.8

Transformers having Well Defined Payback (%) 99.45% 99.45% 99.45% 99.50% 99.90% 99.90% 94.90%

Transformers having Undefined Payback (%) 0.55% 0.55% 0.55% 0.50% 0.10% 0.10% 0.00%

Mean Retail Cost ($) 7,854 8,620 8,620 8,629 8,755 10,203 13,911

Mean Installation Costs ($) 4,041 4,179 4,179 4,179 4,214 4,586 4,707

Mean Operating Costs ($) 558 376 376 376 365 323 279

Mean Incremental First Cost ($) 668 1,571 1,571 1,580 1,741 3,561 7,392

Mean Operating Cost Savings ($) 70 252 252 253 263 305 352

Payback of Average Transformer 9.5 6.2 6.2 6.3 6.6 11.7 21.0

0 

2 

4 

6 

8 

10

12

14

16

18

20

CSL 1 CSL 2 CSL 3 CSL 4 CSL 5 CSL 6 CSL 7

Average Payback Period (years)

Efficiency Level

Design Line 4 Average Payback Period

Average; Median; Box 25%-75%; Whisker 5%-95%
22 | Building Technologies Program eere.energy.gov

Design Line 5 PBP Results : 2008 + 

25% Material Prices

 

Efficiency Level

1 2 3 4 5 6 

Mean Payback (Years) 27.6 8.7 10.9 11.5 15.1 28.1

Median Payback (Years) 13.7 7.0 9.0 9.9 13.2 25.7

Transformers having Well Defined Payback (%) 88.65% 99.35% 99.95% 100.00% 99.80% 100.00%

Transformers having Undefined Payback (%) 11.35% 0.65% 0.05% 0.00% 0.20% 0.00%

Mean Retail Cost ($) 38,113 39,202 41,712 43,106 47,943 73,255

Mean Installation Costs ($) 7,968 8,604 8,856 9,016 9,491 9,828

Mean Operating Costs ($) 3,024 2,487 2,380 2,308 2,183 1,724

Mean Incremental First Cost ($) 4,275 5,999 8,762 10,316 15,628 41,277

Mean Operating Cost Savings ($) 336 873 981 1,052 1,177 1,636

Payback of Average Transformer 12.7 6.9 8.9 9.8 13.3 25.2

0 

20

40

60

80

100

120

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

Average Payback Period (years)

Efficiency Level

Design Line 5 Average Payback Period

Average; Median; Box 25%-75%; Whisker 5%-95%

median

average