11-i

CHAPTER 11. CONSUMER SUBGROUP ANALYSIS

TABLE OF CONTENTS

11.1 INTRODUCTION ......................................................................................................... 11-1

11.2 SUBGROUPS DEFINITION ........................................................................................ 11-1

11.2.1 Senior-Only Households................................................................................................ 11-1

11.2.2 Low-Income Households............................................................................................... 11-1

11.3 INPUTS TO THE LIFE-CYCLE COST AND PAYBACK PERIOD SUBGROUP 

ANALYSIS.................................................................................................................... 11-2

11.4 RESULTS ...................................................................................................................... 11-3

11.4.1 Senior-Only.................................................................................................................... 11-3

11.4.2 Low-Income................................................................................................................... 11-4

LIST OF TABLES

Table 11.2.1 RECS 2005 Definitions of Low-Income Households by Yearly Income.......... 11-2

Table 11.3.1 Household Population........................................................................................ 11-2

Table 11.3.2 Weighted-Average Annual Energy Use for Microwaves and Countertop 

Combination Ovens ........................................................................................... 11-3

Table 11.3.3 Weighted-Average Annual Energy Use for Over the Range Combination 

Ovens ................................................................................................................. 11-3

Table 11.4.1 Microwave and Countertop Combination Ovens: LCC and PBP Results 

for Senior-Only Households.............................................................................. 11-3

Table 11.4.2 Over the Range Combination Ovens: LCC and PBP Results for SeniorOnly Households................................................................................................ 11-4

Table 11.4.3 Microwave and Countertop Combination Ovens:: LCC and PBP Results 

for Low-Income Households............................................................................. 11-4

Table 11.4.4 Over the Range Combination Ovens: LCC and PBP Results for LowIncome Households............................................................................................ 11-4
11-1

CHAPTER 11. CONSUMER SUBGROUP ANALYSIS

11.1 INTRODUCTION

Chapter 8 describes the life-cycle cost (LCC) and payback period (PBP) analyses that 

examine impacts of energy conservation standards on the U.S. population. In analyzing the potential 

impact of new or amended standards on residential 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 consumer subgroup analysis evaluates impacts by analyzing the LCC 

and PBPs for subgroups of residential consumers. 

For microwave oven standby mode and off mode, DOE identified two consumer subgroups 

that warranted further study: (a) households composed of people 65 years of age or older (senioronly); and (b) households at or below the poverty line (low-income). 

DOE determined the impact on consumer subgroups for microwave and combination 

ovens using the LCC Spreadsheet Model, which allows for the examination of particular 

consumer subgroups. Chapter 8 explains in detail the inputs to the model used in determining 

LCC and PBPs.

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

LCC and PBP analyses for the considered subgroups.

11.2 SUBGROUPS DEFINITION

11.2.1 Senior-Only Households

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

DOE Energy Information Administration (EIA)’s Residential Energy Consumption Survey of 2005

(RECS), senior-only households comprise 17 percent of the country’s households.

1

11.2.2 Low-Income Households

As defined in the RECS survey, low-income households are considered to be those at or 

below the “poverty line.” The “poverty line” varies with household size, head of household age, 

and family income. Table 11.2.1 summarizes the income level baselines for selecting lowincome households from the RECS sample. The RECS survey classifies 15 percent of the 

country’s households as low-income.
11-2

Table 11.2.1 RECS 2005 Definitions of Low-Income Households by Yearly Income

Average Income in $

Household Size 48 Contiguous States 

and D.C.

Alaska Hawaii

1 9,570 11,950 11,010

2 12,830 16,030 14,760

3 16,090 20,100 18,510

4 19,350 24,190 22,260

5 22,610 28,270 26,010

6 25,870 32,350 29,760

7 29,130 36,430 33,510

8 32,390 40,510 37,260

9 35,650 44,590 41,010

10 38,910 48,670 44,760

11 42,170 52,750 48,510

12 45,430 56,830 52,260

13 48,690 60,910 56,010

14 51,950 64,990 59,760

15 55,210 69,070 63,510

11.3 INPUTS TO THE LIFE-CYCLE COST AND PAYBACK PERIOD 

SUBGROUP ANALYSIS

Table 11.3.1 summarizes the household population for microwave and combination ovens, 

while Tables 11.3.2 and 11.3.3 summarize the weighted-average annual energy use for the 

households analyzed in the consumer subgroup analyses. These values are compared against the 

weighted-average values for the national sample.

Table 11.3.1 Household Population 

All Models

Count Weight

National 3835 97,672,832

Senior-Only 596 16,420,843

Senior-Only % 15.5% 16.8%

Low-Income 633 13,556,627

Low-Income % 16.5% 13.9
11-3

Table 11.3.2 Weighted-Average Annual Energy Use for Microwaves and Countertop 

Combination Ovens (kWh)

All

Households

Senior

-Only

LowIncome

Baseline 34.75 34.69 34.74 

CSL 1 17.38 17.35 17.37 

CSL 2 13.03 13.01 13.03 

CSL 3 8.69 8.67 8.68 

CSL 4 0.17 0.17 0.17 

Table 11.3.3 Weighted-Average Annual Energy Use for Over the Range Combination 

Ovens (kWh)

All

Households

Senior

-Only

LowIncome

Baseline 39.10 39.03 39.08

CSL 1 32.15 32.09 32.13

CSL 2 23.46 23.42 23.45

CSL 3 19.11 19.08 19.11

CSL 4 0.35 0.35 0.35

11.4 RESULTS

Tables 11.4.1 through 11.4.4 below summarize the LCC results for microwave and 

combination ovens. The LCC results provide the average installed price; average lifetime operating 

cost (discounted); average life-cycle cost; average life-cycle cost savings; the percentage of 

consumers that are burdened with net costs, realize net savings, or are not impacted; and the median 

payback period.

11.4.1 Senior-Only

Table 11.4.1 Microwave and Countertop Combination Ovens: LCC and PBP Results 

for Senior-Only Households

Standby

(W)

Life-Cycle Cost (2010$) Life-Cycle Cost Savings Payback 

Period

Average 

Installed 

Price

Average 

Operating 

Cost

Average 

LCC

Average 

Savings 

(2010$)

Households with

Median 

(years) Net

Cost

No 

Impact*

Net 

Benefit

4.00 $223 $31 $254 NA 0% 100% 0% NA

2.00 $224 $15 $239 $7 0% 54% 46% 0.2

1.50 $224 $12 $236 $10 0% 19% 81% 0.4

1.00 $225 $8 $233 $12 0% 0% 100% 1.0

0.02 $230 $0 $230 $15 0% 0% 100% 2.4

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

indicated, so the household is not affected.
11-4

Table 11.4.2 Over the Range Combination Ovens: LCC and PBP Results for SeniorOnly Households

Standby

(W)

Life-Cycle Cost (2010$) Life-Cycle Cost Savings Payback 

Period

Average 

Installed 

Price

Average 

Operating 

Cost

Average 

LCC

Average 

Savings 

(2010$)

Households with

Median 

(years) Net

Cost

No 

Impact*

Net 

Benefit

4.50 $482 $35 $517 NA 0% 100% 0% NA

3.70 $482 $28 $511 $6 0% 0% 100% 0.0

2.70 $486 $21 $506 $10 0% 0% 100% 2.0

2.20 $496 $17 $513 $4 25% 0% 75% 6.4

0.04 $490 $0 $490 $27 0% 0% 100% 1.8

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

indicated, so the household is not affected.

11.4.2 Low-Income

Table 11.4.3 Microwave and Countertop Combination Ovens:: LCC and PBP Results 

for Low-Income Households

Standby

(W)

Life-Cycle Cost (2010$) Life-Cycle Cost Savings Payback 

Period

Average 

Installed 

Price

Average 

Operating 

Cost

Average 

LCC

Average 

Savings 

(2010$)

Households with

Median 

(years) Net

Cost

No 

Impact*

Net 

Benefit

4.00 $223 $31 $254 NA 0% 100% 0% NA

2.00 $223 $15 $239 $7 0% 54% 46% 0.2

1.50 $224 $12 $236 $10 0% 19% 81% 0.4

1.00 $225 $8 $233 $12 0% 0% 100% 1.0

0.02 $230 $0 $230 $15 0% 0% 100% 2.4

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

indicated, so the household is not affected.

Table 11.4.4 Over the Range Combination Ovens: LCC and PBP Results for LowIncome Households

Standby

(W)

Life-Cycle Cost (2010$) Life-Cycle Cost Savings Payback 

Period

Average 

Installed 

Price

Average 

Operating 

Cost

Average 

LCC

Average 

Savings 

(2010$)

Households with

Median 

(years) Net

Cost

No 

Impact*

Net 

Benefit

4.50 $482 $35 $516 NA 0% 100% 0% NA

3.70 $482 $28 $510 $6 0% 0% 100% 0.0

2.70 $485 $21 $506 $10 0% 0% 100% 2.0

2.20 $496 $17 $513 $4 25% 0% 75% 6.4

0.04 $489 $0 $490 $27 0% 0% 100% 1.8

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

indicated, so the household is not affected.
11-5

REFERENCES

1. U.S. Department of Energy - Energy Information Administration, Residential Energy 

Consumption Survey: 2005 Public Use Data Files, 2005.

<http://www.eia.doe.gov/emeu/recs/recspubuse05/pubuse05.html>