CHAPTER 12. LIFE-CYCLE COST SUBGROUP ANALYSIS 

TABLE OF CONTENTS 

12.1 INTRODUCTION ......................................................................................................... 12-1 

12.2 SUBGROUP DEFINITIONS ........................................................................................ 12-1 

12.2.1 Senior-Only Households................................................................................................ 12-2 

12.2.2 Low-Income Households............................................................................................... 12-2

12.3 INPUTS TO THE SUBGROUP ANALYSIS FOR SENIOR-ONLY AND LOWINCOME HOUSEHOLDS ............................................................................................ 12-2 

12.4 RESULTS FOR COOKING PRODUCT SUBGROUPS.............................................. 12-5 

LIST OF TABLES 

Table 12.2.1 RECS 2001 Definitions of Low-Income Households........................................ 12-2 

Table 12.3.1 Electric and Gas Cooktops: Comparison of Input Values for All 

Households, Senior-Only Households, and Low-Income Households.............. 12-3 

Table 12.3.2 Electric and Gas Ovens: Comparison of Input Values for All Households, 

Senior-Only Households, and Low-Income Households................................... 12-4 

Table 12.3.3 Microwave Ovens: Comparison of Input Values for All Households, 

Senior-Only Households, and Low-Income Households................................... 12-5 

Table 12.4.1 Electric and Gas Cooktops: LCC and PBP Results for Low-Income

Households......................................................................................................... 12-6 

Table 12.4.2 Electric and Gas Cooktops: LCC and PBP Results for Senior-Only 

Households......................................................................................................... 12-6 

Table 12.4.3 Electric and Gas Ovens: LCC and PBP Results for Low-Income

Households......................................................................................................... 12-7 

Table 12.4.4 Electric and Gas Ovens: LCC and PBP Results for Senior-Only 

Households......................................................................................................... 12-8 

Table 12.4.5 Microwave Ovens: LCC and PBP Results for Low-Income Households ........ 12-9 

Table 12.4.6 Microwave Ovens: LCC and PBP Results for Senior-Only Households ......... 12-9 

12-i 

EERE-2006-STD-0127 COMMENT 64.2
CHAPTER 12. LIFE-CYCLE COST SUBGROUP ANALYSIS 

12.1 INTRODUCTION 

Chapter 8 describes the Life-Cycle Cost (LCC) and Payback Period (PBP) Analysis that 

examines impacts of energy efficiency standards on the U.S. population. In analyzing the 

potential impact of new or amended standards on residential and commercial consumers, DOE 

further evaluates the impact on identifiable groups of consumers (i.e., subgroups) that may be 

disproportionately affected by a national standard level. The LCC subgroup analysis evaluates 

impacts by analyzing the LCC and PBPs for subgroups of households or commercial consumers. 

For cooking products, DOE identified two consumer subgroups that warranted further study: 

households composed of people 65 years of age or older (senior-only) and households at or 

below the poverty line (low-income). 

DOE determined the impact on consumer subgroups for cooking products using the LCC 

Spreadsheet Model, which allows for the examination of particular consumer subgroups. The 

LCC analysis for the general population (described in Chapter 8) focuses on the households that 

use cooking products. DOE has the ability to use the LCC Spreadsheet Model to analyze the 

LCC for any subgroup by sampling only the data that apply to that subgroup. (Chapter 8 explains 

in detail the inputs to the model used in determining LCC and PBPs.) As described in section 

12.3, the energy use and energy price characteristics of the two subgroups (senior-only and lowincome households) are different than that for the general population. 

This chapter describes the subgroup identification in further detail and gives the results of 

the LCC and PBP analyses for cooking products. Section 12.4 details the results for the cooking 

products (cooktops, ovens, and microwave ovens). 

The technical support document (TSD) for DOE’s notice of proposed rulemaking 

(NOPR) covered conventional cooking products (i.e., cooktops and ovens), microwave oven 

energy factor (EF), microwave oven standby power consumption, and commercial clothes 

washers (CCW).1

 This chapter presents information and results pertaining solely to conventional 

cooking products and microwave oven EF. The impact of more-efficient equipment on 

microwave oven standby power and CCWs will be addressed in subsequent TSDs. 

12.2 SUBGROUP DEFINITIONS 

DOE considered two subgroups for the LCC and PBP analyses for cooking products 

(cooktops, ovens, and microwave ovens). The two subgroups comprised: (1) households with 

senior-only occupants and (2) households with incomes at or below the poverty line. This section 

describes the subgroup identification process. 

12-1 

EERE-2006-STD-0127 COMMENT 64.2
12.2.1 Senior-Only Households 

Senior-only households have occupants who are all at least 65 years of age. Based on 

DOE’s Energy Information Administration (EIA)’s Residential Energy Consumption Survey of 

2001 (RECS 2001), senior-only households comprise 18 percent of the country’s households.2 

12.2.2 Low-Income Households 

As defined in DOE’s RECS 2001,1 the “poverty line” varies with household size, head of 

household age, and family income. Table 12.2.1 summarizes the criteria given for selecting lowincome households from the RECS 2001 sample. 

Table 12.2.1 RECS 2001 Definitions of Low-Income Households 

Household Size Owner Age Family Income 

1 65 and over less than $7,525 

1 64 and under less than $8,163 

2 65 and over less than $9,491 

2 64 and under less than $10,507 

3 Any less than $12,516 

4 Any less than $16,036 

5 Any less than $18,952 

6 Any less than $21,389 

7 Any less than $24,268 

8 Any less than $27,091 

9 or more Any less than $31,971 

12.3 INPUTS TO THE SUBGROUP ANALYSIS FOR SENIOR-ONLY AND LOWINCOME HOUSEHOLDS 

DOE performed the consumer subgroup analysis by analyzing the LCC and PBP of 

senior-only or low-income households with the spreadsheet models used for the LCC and PBP 

analysis. With the exception of energy use and energy prices, DOE used the same inputs in the 

subgroup analysis as it used for the general population. Because the senior-only and low-income 

household samples are smaller than that for the general population, the energy use and energy 

price characteristics will be different. 

Table 12.3.1 summarizes the household population, weighted-average annual cooking 

energy use, and energy prices for the senior-only and low-income households analyzed in the 

consumer subgroup analysis for electric and gas cooktops. Each of the above values is compared 

to the weighted-average values for the general population. In general, the annual cooking energy 

12-2 

EERE-2006-STD-0127 COMMENT 64.2
use and energy prices for the two consumer subgroups are roughly the same as the general 

population. 

Table 12.3.1 Electric and Gas Cooktops: Comparison of Input Values for All 

Households, Senior-Only Households, and Low-Income Households 

Category All Households Senior-Only Low-Income 

Electric Cooktops 

Household Population Data 

Number of Household Records 2896 557 340 

Sum of Weights (million households) 64,345,040 12,716,529 7,773,433 

Percent of Household Population - 19.8% 12.1% 

Weighted-Average Annual Cooking Energy Use 

Electricity (kWh/year) 128.2 127.7 132.3 

Weighted-Average Energy Prices (2006$) 

Electricity Price (¢/kWh) 10.5 11.6 10.2 

Gas Cooktops 

Household Population Data 

Number of Household Records 1598 218 289 

Sum of Weights (million households) 36,557,346 5,040,286 6,261,018 

Percent of Household Population - 13.8% 17.1% 

Weighted-Average Annual Cooking Energy Use 

Natural Gas (MMBtu/year) 0.724 0.718 0.779 

Weighted-Average Energy Prices (2006$) 

Natural Gas Price ($/therm) 14.99 15.16 14.95 

Table 12.3.2 summarizes the household population, weighted-average annual cooking 

energy use, and energy prices for the senior-only and low-income households analyzed in the 

consumer subgroup analysis for electric and gas ovens. Each of the above values is compared to 

the weighted-average values for the general population. In general, the energy prices for the two 

consumer subgroups are roughly the same as the general population but there are significant 

differences in some of the annual cooking energy use values. 

12-3 

EERE-2006-STD-0127 COMMENT 64.2
Table 12.3.2 Electric and Gas Ovens: Comparison of Input Values for All 

Households, Senior-Only Households, and Low-Income Households 

Category All Households Senior-Only Low-Income 

Electric Standard Ovens 

Household Population Data 

Number of Household Records 1460 267 247 

Sum of Weights (million households) 32,392,395 5,963,913 5,533,775 

Percent of Household Population - 18.4% 17.1% 

Weighted-Average Annual Cooking Energy Use 

Electricity (kWh/year) 132.4 100.6 131.5 

Weighted-Average Energy Prices (2006$) 

Electricity Price (¢/kWh) 10.4 10.2 10.4 

Electric Self-Cleaing Ovens 

Household Population Data 

Number of Household Records 1302 254 72 

Sum of Weights (million households) 28,637,032 5,781,754 1,707,285 

Percent of Household Population - 20.2% 6.0% 

Weighted-Average Annual Cooking Energy Use 

Electricity (kWh/year) 116.6 120.8 133.9 

Weighted-Average Energy Prices (2006$) 

Electricity Price (¢/kWh) 10.7 10.1 10.9 

Gas Standard Ovens 

Household Population Data 

Number of Household Records 1082 121 233 

Sum of Weights (million households) 24,414,838 2,760,101 5,053,019 

Percent of Household Population - 11.3% 20.7% 

Weighted-Average Annual Cooking Energy Use 

Gas (MMBtu/year) 0.82 0.66 0.77 

Weighted-Average Energy Prices (2006$) 

Natural Gas Price ($/therm) 15.00 15.07 15.50 

Gas Self-Cleaning Ovens 

Household Population Data 

Number of Household Records 373 56 29 

Sum of Weights (million households) 8,709,722 1,369,743 635,749 

Percent of Household Population - 15.7% 7.3% 

Weighted-Average Annual Cooking Energy Use 

Gas (MMBtu/year) 0.68 0.50 0.54 

Weighted-Average Energy Prices (2006$) 

Natural Gas Price ($/therm) 15.03 15.00 14.97 

12-4 

EERE-2006-STD-0127 COMMENT 64.2
Table 12.3.3 summarizes the household population, weighted-average annual cooking 

energy use, and energy prices for the senior-only and low-income households analyzed in the 

consumer subgroup analysis for microwave ovens. Each of the above values is compared to the 

weighted-average values for the general population. In general, the energy prices for the two 

consumer subgroups are roughly the same as the general population. The annual cooking energy 

use for the low-income subgroup is significantly greater than the general population. 

Table 12.3.3 Microwave Ovens: Comparison of Input Values for All Households, 

Senior-Only Households, and Low-Income Households 

Category All Households Senior-Only Low-Income 

Household Population Data 

Number of Household Records 4150 689 496 

Sum of Weights (million households) 92,147,608 15,533,938 11,013,087 

Percent of Household Population - 16.9% 12.0% 

Weighted-Average Annual Cooking Energy Use 

Electricity (kWh/year) 131.0 128.5 149.2 

Weighted-Average Energy Prices (2006$) 

Electricity Price (¢/kWh) 10.8 10.5 10.8 

12.4 RESULTS FOR COOKING PRODUCT SUBGROUPS 

Tables 12.4.1 through 12.4.6 below summarize the LCC results for low-income and 

senior-only households for each of the cooking products: cooktops, ovens, and microwave ovens. 

For each product two tables are displayed and candidate standard levels (CSL) and trial standard 

levels (TSL) are listed. The LCC results provide the average or mean LCC, the relative LCC 

savings or costs, and the percentage of consumers that are burdened with net costs, realize net 

savings, or incur no impact. 

12-5 

EERE-2006-STD-0127 COMMENT 64.2
Table 12.4.1 Electric and Gas Cooktops: LCC and PBP Results for Low-Income 

Households 

CSL TSL 

Life-Cycle Cost Life-Cycle Cost Savings 

Payback Period 

(Years)** 

Average 

Installed 

Price 

Average 

Operating 

Cost 

Average 

LCC 

Average 

Savings 

Households with 

Median Average 

Net 

Cost 

No 

Impact* 

Net 

Benefit 

Electric – Open Coil Elements 

Baseline 1 $272 $180 $452 - - - - - -

1 2, 3, 4 $276 $172 $448 $4.2 31.9% 0.0% 68.1% 7.2 23.2 

Electric – Smooth Elements 

Baseline 1, 2, 3 $309 $180 $489 - - - - - -

1 4 $550 $177 $727 -$238.2 100.0% 0.0% 0.0% 1,490.9 4,807.7 

Gas Cooktops 

Baseline - $310 $561 $871 - - - - - -

1 1, 2, 3 $335 $245 $580 $21.5 0.2% 90.2% 9.6% 4.5 3.6 

2 4 $364 $239 $603 -$1.1 90.5% 0.0% 9.5% 64.2 153.5 

* “No impact” means that the base case forecast cooktop assigned to the household has greater efficiency than the level 

indicated, so the household is not affected. 

** Based on the payback calculation, a very small change in operating cost can result in a few extremely large paybacks, 

which will skew the average payback. In these cases, median is probably a better indicator. 

Table 12.4.2 Electric and Gas Cooktops: LCC and PBP Results for Senior-Only 

Households 

CSL TSL 

Life-Cycle Cost Life-Cycle Cost Savings 

Payback Period 

(Years)** 

Average 

Installed 

Price 

Average 

Operating 

Cost 

Average 

LCC 

Average 

Savings 

Households with 

Median Average 

Net 

Cost 

No 

Impact* 

Net 

Benefit 

Electric – Open Coil Elements 

Baseline 1 $273 $150 $422 - - - - - -

1 2, 3, 4 $276 $144 $419 $2.9 42.0% 0.0% 58.0% 8.9 20.7 

Electric – Smooth Elements 

Baseline 1, 2, 3 $309 $150 $459 - - - - - -

1 4 $551 $148 $698 -$239.1 100.0% 0.0% 0.0% 1,835.3 4,284.4 

Gas Cooktops 

Baseline - $310 $558 $868 - - - - - -

1 1, 2, 3 $332 $237 $569 $15.8 0.0% 93.6% 6.4% 4.0 3.0 

2 4 $361 $231 $592 -$7.2 93.6% 0.0% 6.4% 69.8 146.7 

* “No impact” means that the base case forecast cooktop assigned to the household has greater efficiency than the level 

indicated, so the household is not affected. 

** Based on the payback calculation, a very small change in operating cost can result in a few extremely large paybacks, 

which will skew the average payback. In these cases, median is probably a better indicator. 

12-6 

EERE-2006-STD-0127 COMMENT 64.2
Table 12.4.3 Electric and Gas Ovens: LCC and PBP Results for Low-Income 

Households 

CSL TSL 

Life-Cycle Cost Life-Cycle Cost Savings 

Payback Period 

(Years)** 

Average 

Installed 

Price 

Average 

Operating 

Cost 

Average 

LCC 

Average 

Savings 

Households with 

Median Average 

Net 

Cost 

No 

Impact* 

Net 

Benefit 

Electric – Standard Oven 

Baseline 1 $414 $225 $639 - - - - - -

1 - $416 $216 $632 $6.3 39.1% 0.0% 60.9% 7.7 46.7 

2 2, 3 $421 $208 $629 $10.0 48.3% 0.0% 51.7% 11.6 70.4 

3 - $426 $205 $631 $7.5 54.5% 0.0% 45.5% 17.6 106.4 

4 - $484 $201 $685 -$46.3 92.6% 0.0% 7.4% 83.4 505.5 

5 4 $489 $201 $689 -$50.9 93.4% 0.0% 6.6% 87.5 530.4 

Electric – Self-cleaning Oven 

Baseline 1, 2, 3 $484 $250 $734 - - - - - -

1 - $490 $249 $740 -$101.3 73.8% 0.0% 26.2% 152.4 997.2 

2 4 $548 $245 $793 -$154.5 79.1% 0.0% 20.9% 206.6 1,352.1 

Gas Standard Oven 

Baseline - $430 $400 $831 - - - - - -

1a 1, 2, 3 $465 $258 $723 $8.7 5.7% 82.3% 12.0% 9.4 7.3 

1 - $461 $494 $955 -$32.6 17.7% 82.3% 0.0% 11.4 8.8 

2 - $466 $486 $952 -$48.7 69.8% 0.0% 30.2% 14.0 74.5 

3 - $468 $484 $952 -$48.9 71.0% 0.0% 29.0% 14.2 83.1 

4 - $500 $481 $981 -$77.8 92.1% 0.0% 7.9% 23.9 522.8 

5 - $502 $480 $983 -$79.5 92.3% 0.0% 7.7% 24.5 1,390.8 

6 4 $508 $479 $987 -$83.9 93.4% 0.0% 6.6% 26.9 747.4 

Gas Self-Cleaning Oven 

Baseline 1, 2 $551 $583 $1,135 - - - - - -

1 3 $567 $570 $1,137 -$2.5 66.9% 0.0% 33.1% 16.7 180.2 

2 - $574 $569 $1,143 -$8.5 72.8% 0.0% 27.2% 23.9 290.8 

3 4 $575 $569 $1,144 -$9.6 73.5% 0.0% 26.5% 26.5 923.8 

* “No impact” means that the base case forecast cooktop assigned to the household has greater efficiency than the level 

indicated, so the household is not affected. 

** Based on the payback calculation, a very small change in operating cost can result in a few extremely large paybacks, 

which will skew the average payback. In these cases, median is probably a better indicator. 

12-7 

EERE-2006-STD-0127 COMMENT 64.2
Table 12.4.4 Electric and Gas Ovens: LCC and PBP Results for Senior-Only 

Households 

CSL TSL 

Life-Cycle Cost Life-Cycle Cost Savings 

Payback Period 

(Years)** 

Average 

Installed 

Price 

Average 

Operating 

Cost 

Average 

LCC 

Average 

Savings 

Households with 

Median Average 

Net 

Cost 

No 

Impact* 

Net 

Benefit 

Electric – Standard Oven 

Baseline 1 $413 $192 $605 - - - - - -

1 - $416 $185 $600 $4.6 42.8% 0.0% 57.2% 10.6 46.9 

2 2, 3 $420 $178 $598 $6.7 53.6% 0.0% 46.4% 16.0 70.8 

3 - $426 $176 $601 $3.6 61.3% 0.0% 38.7% 24.2 107.0 

4 - $483 $173 $656 -$50.8 95.8% 0.0% 4.2% 114.9 508.4 

5 4 $488 $172 $661 -$55.5 96.5% 0.0% 3.5% 120.6 533.5 

Electric – Self-cleaning Oven 

Baseline 1, 2, 3 $484 $267 $751 - - - - - -

1 - $491 $266 $757 -$151.9 80.6% 0.0% 19.4% 152.0 1,134.3 

2 4 $548 $262 $810 -$204.9 85.6% 0.0% 14.5% 206.1 1,537.9 

Gas Standard Oven 

Baseline - $431 $398 $829 - - - - - -

1a 1, 2, 3 $464 $250 $714 $8.8 4.7% 84.2% 11.2% 9.5 6.9 

1 - $459 $479 $938 -$26.8 15.8% 84.2% 0.0% 10.9 7.8 

2 - $464 $471 $935 -$43.0 70.6% 0.0% 29.4% 15.0 88.7 

3 - $466 $470 $936 -$43.3 71.8% 0.0% 28.2% 16.4 99.0 

4 - $498 $466 $964 -$71.8 92.4% 0.0% 7.7% 29.8 938.7 

5 - $501 $465 $966 -$73.6 92.6% 0.0% 7.4% 30.9 319.5 

6 4 $506 $464 $970 -$78.0 93.5% 0.0% 6.5% 33.2 518.0 

Gas Self-Cleaning Oven 

Baseline 1, 2 $551 $578 $1,129 - - - - - -

1 3 $567 $565 $1,132 -$2.5 71.8% 0.0% 28.2% 34.6 512.2 

2 - $573 $564 $1,138 -$8.5 76.9% 0.0% 23.1% 47.6 400.8 

3 4 $575 $564 $1,139 -$9.6 77.5% 0.0% 22.5% 49.8 325.2 

* 

** 

“No impact” means that the base case forecast cooktop assigned to the household has greater efficiency than the level 

indicated, so the household is not affected. 

Based on the payback calculation, a very small change in operating cost can result in a few extremely large paybacks, 

which will skew the average payback. In these cases, median is probably a better indicator. 

12-8 

EERE-2006-STD-0127 COMMENT 64.2
Table 12.4.5 Microwave Ovens: LCC and PBP Results for Low-Income Households 

CSL / 

TSL 

Life-Cycle Cost Life-Cycle Cost Savings 

Payback Period 

(Years)** 

Average 

Installed 

Price 

Average 

Operating 

Cost 

Average 

LCC 

Average 

Savings 

Households with 

Median Average 

Net 

Cost 

No 

Impact* 

Net 

Benefit 

Baseline $220 $140 $360 - - - - - -

1 $233 $135 $367 -$7.0 88.3% 0.0% 11.7% 29.9 115.4 

2 $246 $134 $381 -$20.1 96.1% 0.0% 4.0% 58.1 224.0 

3 $267 $133 $400 -$39.7 98.5% 0.0% 1.5% 82.8 319.5 

4 $294 $132 $426 -$65.8 99.8% 0.0% 0.2% 116.6 449.9 

* “No impact” means that the base case forecast cooktop assigned to the household has greater efficiency than the level 

indicated, so the household is not affected. 

** Based on the payback calculation, a very small change in operating cost can result in a few extremely large paybacks, 

which will skew the average payback. In these cases, median is probably a better indicator. 

Table 12.4.6 Microwave Ovens: LCC and PBP Results for Senior-Only Households 

CSL / 

TSL 

Life-Cycle Cost Life-Cycle Cost Savings 

Payback Period 

(Years)** 

Average 

Installed 

Price 

Average 

Operating 

Cost 

Average 

LCC 

Average 

Savings 

Households with 

Median Average 

Net 

Cost 

No 

Impact* 

Net 

Benefit 

Baseline $220 $130 $350 - - - - - -

1 $232 $125 $357 -$7.5 91.5% 0.0% 8.5% 28.9 76.3 

2 $246 $125 $370 -$20.7 97.9% 0.0% 2.1% 56.1 148.0 

3 $267 $123 $390 -$40.4 99.1% 0.0% 0.9% 80.0 211.1 

4 $294 $122 $416 -$66.6 99.7% 0.0% 0.3% 112.7 297.3 

* “No impact” means that the base case forecast cooktop assigned to the household has greater efficiency than the level 

indicated, so the household is not affected. 

** Based on the payback calculation, a very small change in operating cost can result in a few extremely large paybacks, 

which will skew the average payback. In these cases, median is probably a better indicator. 

The low-income and senior-only consumer subgroups show the same trend in average 

LCC differences and consumer impacts (i.e., percentage of consumers significantly or 

insignificantly impacted) as the overall sample. For all three cooking products, the average LCC 

costs, savings and payback periods for low-income and senior-only households mirror the 

savings for the general population. 

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EERE-2006-STD-0127 COMMENT 64.2
REFERENCES 

1 U.S. Department of Energy-Office of Energy Efficiency and Renewable Energy. Technical 

Support Document: Energy Efficiency Program for Consumer Products and Commercial and 

Industrial Equipment: Residential Dishwashers, Dehumidifiers, Cooking Products, and 

Commercial Clothes Washers, September, 2008. Washington, DC. 

<http://www1.eere.energy.gov/buildings/appliance_standards/residential/home_appl_tsd.html> 

2 U.S. Department of Energy-Energy Information Administration. Residential Energy 

Consumption Survey, 2001 Public Use Data Files, 2001. Washington, DC. 

<http://www.eia.doe.gov/emeu/recs/recs2001/publicuse2001.html> 

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EERE-2006-STD-0127 COMMENT 64.2