8-i

CHAPTER 8. LIFE-CYCLE COST AND PAYBACK PERIOD ANALYSIS

TABLE OF CONTENTS

8.1 INTRODUCTION....................................................................................................... 8-1

8.1.1 General Approach for Life-Cycle Cost and Payback Period Analysis........................... 8-1

8.1.2 Overview of Life-Cycle Cost and Payback Period Inputs............................................. 8-2

8.2 INPUTS TO LIFE-CYCLE COST ANALYSIS........................................................... 8-6

8.2.1 Total Installed Cost Inputs........................................................................................... 8-7

8.2.1.1 Forecasting Future Product Prices .............................................................. 8-8

8.2.1.2 Baseline Manufacturer Selling Price........................................................... 8-9

8.2.1.3 Increases in Manufacturer Costs................................................................. 8-9

8.2.1.4 Overall Markup........................................................................................ 8-10

8.2.1.5 Installation Cost ....................................................................................... 8-10

8.2.1.6 Total Installed Cost .................................................................................. 8-11

8.2.2 Operating Cost Inputs.................................................................................................8-12

8.2.2.1 Annual Energy and Water Consumption................................................... 8-13

8.2.2.2 Energy and Water Prices .......................................................................... 8-15

8.2.2.3 Energy and Water Price Trends................................................................ 8-19

8.2.2.4 Repair and Maintenance Costs.................................................................. 8-21

8.2.3 Product Lifetimes.......................................................................................................8-21

8.2.4 Discount Rates............................................................................................................8-23

8.2.4.1 Residential Discount Rates for Products Purchased in Existing 

Households .............................................................................................. 8-23

8.2.4.2 Residential Discount Rates for Products Installed in New Housing........... 8-27

8.2.5 Compliance Date ........................................................................................................8-28

8.2.6 Product Assignment for the Base Case........................................................................8-29

8.3 INPUTS TO PAYBACK PERIOD ANALYSIS .........................................................8-31

8.4 RESULTS OF LIFE-CYCLE COST AND PAYBACK PERIOD ANALYSES ..........8-32

8.4.1 Distributions of Life-Cycle Cost for Baseline Units....................................................8-33

8.4.2 Distributions of Life-Cycle Cost Under New Standard Levels ....................................8-34

8.4.3 Distribution of Payback Period Under New Standard Level........................................8-36

8.4.4 Life-Cycle Cost and Payback Period Summary Results...............................................8-37

8.5 REBUTTABLE PAYBACK PERIOD........................................................................8-40

8.5.1 Inputs.........................................................................................................................8-41

8.5.2 Results........................................................................................................................8-41

LIST OF TABLES

Table 8.1.1 Dishwashers: Summary of LCC and PBP Inputs.............................................. 8-5

Table 8.2.1 Dishwashers: Baseline Manufacturer Selling Price........................................... 8-9

Table 8.2.2 Standard-Sized Dishwashers: Standard-Level Manufacturer Cost Increases ....8-10
8-ii

Table 8.2.3 Compact Dishwashers: Standard-Level Manufacturer Cost Increases..............8-10

Table 8.2.4 Dishwashers: Overall Markups.......................................................................8-10

Table 8.2.5 Dishwashers: Baseline Installation Costs.........................................................8-11

Table 8.2.6 Standard-Sized Dishwashers: Consumer Product Prices, Installation Costs, 

and Total Installed Costs.................................................................................8-11

Table 8.2.7 Compact Dishwashers: Consumer Product Prices, Installation Costs, and 

Total Installed Costs........................................................................................8-11

Table 8.2.8 Standard Dishwashers: Annual Energy and Water Use by Efficiency Level ....8-14

Table 8.2.9 Compact Dishwashers: Annual Energy and Water Use by Efficiency Level ....8-15

Table 8.2.10 Average Residential Electricity Prices.............................................................8-16

Table 8.2.11 Average Residential Natural Gas Prices ..........................................................8-17

Table 8.2.12 Average Monthly Residential Oil Prices in 2009 .............................................8-18

Table 8.2.13 Average Water and Wastewater Prices per Unit Volume .................................8-19

Table 8.2.14 Average Shares of Considered Household Debt and Equity Types: % .............8-24

Table 8.2.15 Average Nominal Interest Rates for Household Debt ......................................8-25

Table 8.2.16 Average Real Effective Interest Rates for Household Debt..............................8-25

Table 8.2.17 Average Nominal and Real Interest Rates for Household Equity .....................8-26

Table 8.2.18 Shares and Interest or Return Rates Used for Household Debt and Equity.......8-27

Table 8.2.19 Data Used to Calculate Real Effective Mortgage Rates...................................8-28

Table 8.2.20 Standard Dishwashers: Efficiency Market Share Data and Base-Case 

Forecast: % .....................................................................................................8-30

Table 8.2.21 Standard-Sized Dishwashers: Base-Case Efficiency Market Shares for 

2018................................................................................................................8-31

Table 8.2.22 Compact Dishwashers: Base Case Efficiency Market Shares for 2018.............8-31

Table 8.4.1 Standard-Sized Dishwashers: Life-Cycle Cost and Payback Period Results.....8-37

Table 8.4.2 Compact Dishwashers: Life-Cycle Cost and Payback Period Results ..............8-37

Table 8.5.1 Standard-Sized Dishwashers: Rebuttable Payback Periods..............................8-41

Table 8.5.2 Compact Dishwashers: Rebuttable Payback Periods........................................8-42

LIST OF FIGURES

Figure 8.1.1 Flow Diagram for the Determination of LCC and PBP..................................... 8-4

Figure 8.2.1 Electricity Price Trends...................................................................................8-20

Figure 8.2.2 Inflation-Adjusted Water Price Trend..............................................................8-21

Figure 8.2.3 Weibull Retirement Function for Dishwashers................................................8-22

Figure 8.2.4 Historic and Projected Base Case Trend in Dishwasher Average Energy 

Use .................................................................................................................8-30

Figure 8.4.1 Standard-Sized Dishwashers: Base-Case LCC Distribution .............................8-33

Figure 8.4.2 Compact Dishwashers: Base-Case LCC Distribution.......................................8-34

Figure 8.4.3 Standard-Sized Dishwashers: Distribution of LCC Impacts for Efficiency 

Level 2............................................................................................................8-35

Figure 8.4.4 Compact Dishwashers: Distribution of LCC Impacts for Efficiency Level 

1 .....................................................................................................................8-35
8-iii

Figure 8.4.5 Standard-Sized Dishwashers: Distribution of PBPs for Efficiency Level 2 ......8-36

Figure 8.4.6 Compact Dishwashers: Distribution of PBPs for Efficiency Level 1................8-37

Figure 8.4.7 Range of LCC Savings for Standard-Sized Dishwashers .................................8-38

Figure 8.4.8 Range of LCC Savings for Compact Dishwashers...........................................8-39

Figure 8.4.9 Range of Payback Periods for Standard-Sized Dishwashers ............................8-39

Figure 8.4.10 Range of Payback Periods for Compact Dishwashers......................................8-40
8-1

CHAPTER 8. LIFE-CYCLE COST AND PAYBACK PERIOD ANALYSIS

8.1 INTRODUCTION

This chapter describes the Department of Energy (DOE)’s methodology for analyzing the 

economic impacts of possible energy efficiency standards on individual consumers. Impacts

include a change in operating expense (usually decreased) and a change in purchase price 

(usually increased). This chapter describes three metrics DOE used in the consumer analysis to 

determine the effect of standards on individual consumers:

• Life-cycle cost (LCC) is the total consumer expense over the life of an appliance, 

including purchase expense and operating costs (including energy expenditures). DOE 

discounts future operating costs to the time of purchase and sums them over the lifetime 

of the product.

• Payback period (PBP) measures the amount of time it takes customers to recover the 

assumed higher purchase price of more energy-efficient products through lower operating 

costs.

• Rebuttable payback period is a special case of the PBP. Where LCC and PBP are 

estimated over a range of inputs that reflect real-world conditions, rebuttable payback 

period is based on laboratory conditions, specifically those representative of the DOE test 

procedure.

Inputs to the LCC and PBP are discussed in sections 8.2 and 8.3, respectively, of this 

chapter. Results of the LCC and PBP are presented in section 8.4. The rebuttable PBP is 

discussed in section 8.5. Key variables and calculations are presented for each metric. DOE 

performed the calculations discussed here using a series of Microsoft Excel spreadsheets, which 

are accessible on the Internet (http://www.eere.energy.gov/buildings/appliance_standards/). 

Details and instructions for using the spreadsheets are discussed in appendix 8A. 

8.1.1 General Approach for Life-Cycle Cost and Payback Period Analysis

Recognizing that several inputs to the analysis of consumer LCC and PBP are either 

variable or uncertain, DOE used Monte Carlo simulation and probability distributions to define 

inputs when appropriate. Appendix 8B provides a detailed explanation of Monte Carlo 

simulation and the use of probability distributions. DOE developed LCC and PBP spreadsheet 

models that incorporate both Monte Carlo simulation and probability distributions by using 

Microsoft Excel spreadsheets combined with Crystal Ball (a commercially available add-in 

program). 
8-2

In addition to using probability distributions to characterize several of the inputs to the 

analysis, DOE developed a sample of individual households that use dishwashers, which 

includes 2,480 household records. By developing household samples, DOE was able to perform 

the LCC and PBP calculations for each household to account for the variability in energy and 

water consumption and/or energy price associated with each household. As described in chapter 

7, DOE used the DOE Energy Information Administration (EIA)’s 2005 Residential Energy 

Consumption Survey (RECS) to develop household samples for standard and compact 

dishwashers.

1 The 2005 RECS is a national sample survey of housing units that collects 

statistical information on the consumption of and expenditures for energy in housing units along 

with data on energy-related characteristics of the housing units and occupants. The 2005 RECS, 

which represents 4,382 housing units, was constructed by EIA to be a national representation of 

the household population in the U.S. Although the standard error of the sub-samples is three 

times the size of the entire 2005 RECS, it is still less than five percent. DOE believes a standard 

error of less than five percent is still small enough to yield meaningful results. Therefore, DOE 

believes the results generated from the household samples for dishwashers are representative of 

U.S. households using these appliances.

DOE used RECS to establish the variability in annual energy use, energy pricing, annual 

water use, and water pricing. By using RECS, DOE was able to assign a unique annual energy 

use and/or energy price to each household in the sample. The large number of households 

considered in the LCC and PBP analysis resulted in a large range of annual energy and water use 

and/or prices (the actual ranges of energy consumption were presented and discussed in chapter 

7). The variability in annual energy and water use and pricing across all households contributes 

to the range of LCCs and PBPs calculated for each standard level. As described later in this 

chapter, DOE characterized the variability and uncertainty in energy and water prices through 

regional differences. 

DOE displays the LCC and PBP results as distributions of impacts compared to the base

case. Results are presented at the end of this chapter and are based on 10,000 samples per Monte 

Carlo simulation run. To illustrate the implications of the analysis, DOE generated a frequency 

chart depicting the variation in LCC and PBP for each standard level considered.

8.1.2 Overview of Life-Cycle Cost and Payback Period Inputs

The LCC is the total consumer expense over the life of the product, including purchase 

expense and operating expense (including energy and water expenditures). DOE discounts future 

operating expenses to the time of purchase and sums them over the lifetime of the product. The 

PBP is the change in purchase expense due to an increased efficiency standard divided by the 

change in annual operating cost that results from the standard. It represents the number of years 

it will take the customer to recover the increased purchase expense through decreased operating 

expenses. 

DOE categorizes inputs to the LCC and PBP analysis as follows: (1) inputs for 

establishing the total installed cost, including the purchase price, and (2) inputs for calculating 

the operating cost. 
8-3

The primary inputs for establishing the total installed cost are:

• Baseline manufacturer cost is the cost incurred by the manufacturer to produce products

meeting existing minimum efficiency standards, or the baseline product. 

• Standard-level manufacturer cost increases represent the change in manufacturer cost 

associated with producing products to meet a particular standard level.

• Markups and sales tax are costs associated with converting the manufacturer cost to a 

consumer product price. The markups and sale tax are described in detail in Chapter 6, 

Markups for Equipment Price Determination. 

• Installation cost is the cost to the consumer of installing the product after purchase, 

including costs for labor, overhead, and any miscellaneous materials and parts. Thus, the 

total installed cost equals the consumer product price plus the installation cost. 

The primary inputs for calculating the operating cost are:

• Product energy and water consumption quantify the energy and water use associated with 

operating the product. Chapter 7, Energy and Water Use Analysis, details how DOE used 

various data sources to determine the product energy and water consumption of standard 

and compact dishwashers.

• Product efficiency dictates the energy and water consumption associated with a standardlevel product (i.e., a product having an efficiency greater than a baseline product). 

Chapter 7 details how energy and water consumption change with increasing product

efficiency.

• Energy and water prices are the prices consumers pay for energy (i.e., electricity, gas, or 

oil) and water. DOE determined current energy prices based on data from the DOE- EIA

and Natural Gas Monthly (see section 8.2.2.2). DOE determined water prices based on 

data from the American Water Works Association (AWWA) and the Raftelis Financial 

Consultants (see section 8.2.2.2).

2

• Energy and water price trends: DOE used the reference case in EIA’s Annual Energy 

Outlook 2011 (AEO2011) to forecast future energy prices for the results presented in this 

chapter. DOE used the Bureau of Labor Statistics’ consumer price index (CPI) data 

specific to water and sewage services to forecast future water prices. 

• Repair and maintenance costs: Repair costs are associated with repairing or replacing 

components that have failed. Maintenance costs are associated with maintaining the 

operation of the product. Section 8.2.2.4 details DOE’s method for estimating repair and 

maintenance costs. 
8-4

• Lifetime is the age at which the product is retired from service. Section 8.2.3 describes the 

distribution DOE developed for product lifetimes. 

• Discount rate is the rate at which DOE discounted future expenditures to establish their 

present value. 

Figure 8.1.1 graphically depicts the relationships between the installed cost and operating 

cost inputs used to calculate the LCC and PBP. In the figure, the yellow boxes indicate the 

inputs, the green boxes indicate intermediate outputs, and the blue boxes indicate the final 

outputs (the LCC and PBP).

Figure 8.1.1 Flow Diagram for the Determination of LCC and PBP

Table 8.1.1 summarizes the input values that DOE used to calculate the LCC and PBP for 

standard and compact dishwashers. Inputs to calculate the total installed cost and operating cost 

include the lifetime, discount rate, and energy and water price trends. DOE characterized all of 

the total cost inputs with single-point values, but characterized several of the operating cost 

inputs with probability distributions that capture the input’s uncertainty and/or variability. For 

those inputs characterized with probability distributions, the values provided in the following 

Baseline

Manufacturer

Cost

Std-Level

Manufacturer

Cost

Manufacturer

Markup

Retailer or

Distributor

Markup

Sales Tax

Installation

Cost

Total Installed

Cost

Water Prices

Energy and

Water

Consumption

Equipment

Price

Lifetime

Operating

Expense

Annual Energy

and Water

Expense

Lifetime Repair and

Maintenance

Cost

Discount Rate

Energy and

Water Price

Trends

Annual

Operating

Expense

Payback

Period

Life-Cycle

Cost

Energy Prices
8-5

tables are the average or typical values. Table 8.1.1 also includes the section of this technical 

support document (TSD) that contains more detailed information on the inputs.

Table 8.1.1 Dishwashers: Summary of LCC and PBP Inputs

Input Product 

Class Average or Typical Value Characterization TSD Section Reference

Total Installed Cost Inputs

Baseline 

Manufacturer 

Cost

Standard 355 AEU = $190.98

Compact Single-Point Value 8.2.1.1 260 AEU = $185.72

Standard-Level 

Manufacturer 

Cost Increase

Standard

324 AEU = $18.27

307 AEU = $31.82

295 AEU = $69.23

234 AEU = $75.18

180 AEU = $82.95

Single-Point Value 5.5.1

Compact 222 AEU = $1.00

154 AEU = $12.11

Manufacturer 

Markup Both 1.24 Single-Point Value 6.2

Retailer Markup Both Baseline = 1.45

Incremental = 1.17 Single-Point Value 6.3

Sales Tax Both 7.17% (average) Variable based on 

location 6.4

Installation Cost Both $303.00 Single-Point Value 8.2.1.5

Operating Cost Inputs

Usage Both 215 cycles/year

Variability determined 

from household 

sample. Usage ranges 

from 4 to 612

cycles/year

7.4

Annual Energy 

Use*

Standard Baseline use** = 211 kWh Variability based on 

usage

7.3 Compact Baseline use** = 160 kWh

Annual Water 

Use

Standard Baseline use** = 1.40 103

gallon Variability based on 

usage

7.3 Compact Baseline use** = 0.97 103

gallon

Energy Prices Both

Electricity = 0.12 ¢/kWh

Gas = 14.35 $/MMBtu

Oil = 17.09 $/MMBtu

Variable based on 

location 8.2.2.2

Water and 

Wastewater Both Water = 3.30 $/103 gallonWastewater = 3.87 $/103

Variable based on 

location 8.2.2.2
8-6

Input Product 

Class Average or Typical Value Characterization TSD Section Reference

Prices gallon

Repair and 

Maintenance 

Costs

Both Not included

No appreciable 

difference between 

baseline and efficiency 

level repair costs

8.2.2.4

Lifetime Both 15.4 years Weibull distribution 8.2.3

Discount Rate Both 4.91% Custom distribution 8.2.4

Energy Price 

Trend Both AEO 2011 AEO reference case 8.2.2.3

Water and 

Wastewater 

Price Trend

Both

Extrapolated based on growth 

in 1970–2009 for CPI for 

water and sewerage.

Single forecast 8.2.2.3

* Annual use based on electric water heating.

** Annual use provided for baseline product only. Annual use decreases with increased product efficiency.

8.2 INPUTS TO LIFE-CYCLE COST ANALYSIS

Life-cycle cost is the total customer expense over the life of an appliance, including 

purchase price and operating costs (including energy and water costs). DOE discounts future 

operating costs to the time of purchase and sums them over the lifetime of the product. DOE 

defines LCC by the following equation:

( ) ∑= + = +

N

t

t

t

r

OC LCC IC

1 1

Where:

LCC = life-cycle cost in dollars,

IC = total installed cost in dollars,

∑ = sum over the lifetime, from year 1 to year N,

N = lifetime of appliance in years,

OC = operating cost in dollars,

r = discount rate, and

t = year for which operating cost is being determined.

Because DOE gathered most of its data for the LCC and PBP analysis in 2010, DOE 

expresses dollar values in 2010$. The following sections discuss total installed cost, operating 

cost, lifetime, and discount rate.
8-7

8.2.1 Total Installed Cost Inputs

DOE defines the total installed cost using the following equation:

IC = EQP + INST

Where:

EQP = Product price (i.e., price the consumer pays for the product, including taxes), 

expressed in dollars, and 

INST = Installation cost (i.e., the cost to the consumer to install the product, including 

labor and materials), also in dollars.

The product price is based on how the consumer purchases the product. As discussed in 

chapter 6, DOE defined markups and sales taxes for converting manufacturing costs into 

consumer product prices. The inputs for the total installed cost are:

• Baseline manufacturer cost is the cost incurred by the manufacturer to produce a product

meeting existing minimum efficiency standards. 

• Standard-level manufacturer cost increases are the change in manufacturer cost 

associated with producing a product at a standard level. 

• Manufacturer and retailer markups and sales tax convert the manufacturer cost to a 

consumer product price. 

• Installation cost is the cost to the consumer of installing the product and represents all 

costs required to install the product other than the marked-up consumer product price. 

The installation cost includes labor, overhead, and any miscellaneous materials and parts. 

Thus, the total installed cost equals the consumer product price plus the installation cost. 

DOE calculated the total installed cost for baseline products based on the following equation:

MFG OVERALL BASE BASE

BASE BASE BASE

COST MU INST

IC EQP INST

= × +

= +

_

Where:

ICBASE = total installed cost for baseline product,

EQPBASE = consumer product price for baseline product, 

INSTBASE = installation cost for baseline product,

COSTMFG = manufacturer cost for baseline product, and

MUOVERALL_BASE = overall baseline markup (product of manufacturer markup, baseline 

retailer markup, and sales tax).

DOE calculated the total installed cost for standard-level products based on the following

equation:
8-8

( ) ( )

( ) ( )

( ) BASE MFG OVERALL INCR STD

BASE BASE STD STD

BASE STD BASE STD

STD STD STD

IC COST MU INST

EQP INST EQP INST

EQP EQP INST INST

IC EQP INST

= + ∆ × + ∆

= + + ∆ + ∆

= + ∆ + + ∆

= +

_

Where:

ICSTD = standard-level total installed cost,

EQPSTD = consumer product price for standard-level models, 

INSTSTD = standard-level installation cost,

EQPBASE = consumer product price for baseline models, 

ΔEQPSTD = change in product price for standard-level models,

INSTBASE = baseline installation cost,

ΔINSTSTD = change in installation cost for standard-level models,

ICBASE = baseline total installed cost,

ΔCOSTMFG = change in manufacturer cost for standard-level models, and

MUOVERALL_INCR = incremental overall markup (product of manufacturer markup, 

incremental retailer or distributor markup, and sales tax).

The remainder of this section provides information about each of the above input 

variables that DOE used to calculate the total installed cost for standard and compact residential 

dishwashers. 

8.2.1.1 Forecasting Future Product Prices

Examination of historical price data for certain appliances and products that have been 

subject to energy conservation standards indicates that the assumption of constant real prices and 

costs may, in many cases, overestimate long-term trends in appliance and product prices. 

Economic literature and historical data suggest that the real costs of these products may in fact 

trend downward over time according to “learning” or “experience” curves. On February 22, 

2011, DOE published a notice of data availability (NODA, 76 FR 9696) stating that DOE may 

consider improving regulatory analysis by addressing product price trends. In the NODA, DOE 

proposed that when sufficiently long-term data are available on the cost or price trends for a 

given product, it would analyze the available data to forecast future trends.

For the default price trend for this final rule, DOE estimated an experience rate for

residential dishwashers based on an analysis of long-term historical data. DOE derived a 

dishwasher price index from 1988 to 2010 using Producer Price Index (PPI) data for 

miscellaneous household appliances from the Bureau of Labor Statistics’ (BLS). (PPI data 

specific to residential dishwashers were not available.) An inflation-adjusted price index was 

calculated using the GDP price deflator for the same years. This proxy for historic price data was 

then regressed on the quantity of dishwashers produced, based on a corresponding series for total 

shipments of dishwashers.
8-9

To calculate an experience rate, a least-squares power-law fit was performed on the 

dishwasher price index versus cumulative shipments. DOE then derived a price factor index,

with the price in 2010 equal to 1, to forecast prices in the year of compliance for amended energy 

conservation standards in the LCC and PBP analysis, and for the NIA, for each subsequent year 

through 2047. The index value in each year is a function of the experience rate and the 

cumulative production through that year. To derive the latter, DOE used projected shipments 

from the base-case projections made for the NIA (see section IV.G.1 of this notice). The average 

annual rate of price decline in the default case is 1.27 percent. DOE’s forecast of product prices 

for dishwashers in the LCC and PBP analysis is described further in appendix 8C.

8.2.1.2 Baseline Manufacturer Selling Price

DOE used data from AHAM to develop the baseline manufacturer selling prices for 

standard-sized and compact dishwashers.3

Table 

8.2.1

Based on a manufacturer markup of 1.24 for all 

dishwashers (see section 6.2 of chapter 6), DOE arrived at a baseline manufacturer selling price 

(MSP) of $190.98 for standard-size dishwashers and $185.72 for compact dishwashers. 

presents the baseline manufacturer costs along with the associated baseline annual energy 

use for the product classes of residential dishwashers.

Table 8.2.1 Dishwashers: Baseline Manufacturer Selling Price

Product 

Class

Baseline Annual 

Energy Use 

Baseline Water 

Use

kWh/year

Baseline 

Manufacturer Cost

gallons/cycle

Standard

2010$

355 6.50 190.98 

Compact 260 4.50 185.72 

8.2.1.3 Increases in Manufacturer Costs

DOE used cost data submitted by AHAM, along with a reverse engineering analysis, to 

develop manufacturer cost increases associated with increases in standard levels for residential 

dishwashers. Refer to Chapter 5, Engineering Analysis, for details. Table 8.2.2 and Table 8.2.3

present the standard-level manufacturer cost increases and associated annual energy use for the 

product classes.
8-10

Table 8.2.2 Standard-Sized Dishwashers: Standard-Level Manufacturer Cost Increases

Efficiency 

Level

Annual Energy 

Use Water Use

kWh/year

Standard-Level 

Manufacturer Cost Increases gallons/cycle

Baseline

2010$

355 6.50 --

1 324 5.80 18.27

2 307 5.00 31.82

3 295 4.25 69.23

4 234 3.80 75.18

5 180 1.60 82.95

Table 8.2.3 Compact Dishwashers: Standard-Level Manufacturer Cost Increases

Efficiency 

Level

Annual Energy 

Use Water Use Standard-Level Manufacturer Cost Increases

kWh/year gallons/cycle

Baseline

2010$

260 4.50 --

1 222 3.50 1.00

2 154 2.10 12.11

8.2.1.4 Overall Markup

The overall markup is the value determined by multiplying the manufacturer and retailer 

markups and the sales tax together to arrive at a single markup value. Table 8.2.4shows the 

overall baseline and incremental markups for dishwashers. Refer to Chapter 6, Markups for 

Equipment Price Determination, for details. 

Table 8.2.4 Dishwashers: Overall Markups

Markup Baseline Incremental

Manufacturer 1.24

Retailer 1.45 1.17

Sales Tax 1.0717

Overall 1.93 1.55

8.2.1.5 Installation Cost

DOE derived baseline installation costs for dishwashers from data in the RS Means 

Plumbing Cost Data, 2010,

4

Table 8.2.5

which provides estimates on the labor required to install residential 

dishwashers. summarizes the nationally representative average bare costs and 

installation costs of a four-or-more-cycle dishwasher. DOE determined that installation costs 

would not be impacted with increased standard levels.
8-11

Table 8.2.5 Dishwashers: Baseline Installation Costs 

Bare Costs 2010$ Including Overhead & Profit 2010$

Installation Type Material Labor Total Total Material* Labor**

Average 370 202 572 710 407 303

Average 2010$ 303

* Material costs including O&P equal bare costs plus 10% profit.

** DOE derived labor costs including O&P by subtracting material with O&P from total with O&P.

Source: RS Means, Plumbing Cost Data, 2010.

8.2.1.6 Total Installed Cost

The total installed cost is the sum of the consumer product price and the installation cost. 

Recall section 8.2.1 for the equations DOE used to calculate the total installed cost for baseline 

and standard-level products.

Table 8.2.6 and Table 8.2.7 present the consumer product price, installation cost, and 

total installed cost for standard-sized and compact dishwashers, respectively, at the baseline level 

and each standard level. 

Table 8.2.6 Standard-Sized Dishwashers: Consumer Product Prices, Installation Costs, 

and Total Installed Costs

Efficiency 

Level

Annual 

Energy Use Water Use

kWh/year

Product

Price gallons/cycle

Installation 

Cost

2010$

Total Installed 

Cost

2010$

Baseline

2010$

355 6.50 327.45 303.00 630.45

1 324 5.80 352.73 303.00 655.73

2 307 5.00 371.47 303.00 674.47

3 295 4.25 423.23 303.00 726.23

4 234 3.80 431.47 303.00 734.47

5 180 1.60 442.22 303.00 745.22

Table 8.2.7 Compact Dishwashers: Consumer Product Prices, Installation Costs, and 

Total Installed Costs

Efficiency 

Level

Annual 

Energy Use Water Use

kWh/year

Product

Price gallons/cycle

Installation 

Cost

2010$

Total Installed 

Cost

2010$

Baseline

2010$

260 4.50 318.43 303.00 621.43

1 222 3.50 319.82 303.00 622.82

2 154 2.10 335.19 303.00 638.19
8-12

8.2.2 Operating Cost Inputs

DOE uses the following equation to define the operating cost of an appliance:

OC = EC +WC + RC + MC

Where:

OC = operating cost,

EC = energy cost associated with operating the product, 

WC = water cost associated with operating the product,

RC = repair costs associated with component failure, and 

MC = service costs for maintaining product operation.

The inputs for calculating operating costs are also necessary to determine lifetime 

operating costs, which include the energy and water price trends, product lifetime, discount rate, 

and effective date of the standard.

• Annual energy consumption is the site energy use associated with operating the product. 

• Annual water consumption is the site water use associated with operating the product. 

Both the annual energy and water consumption vary with the product efficiency. That is, 

the energy and water consumption associated with standard-level products (i.e., products 

having efficiencies greater than baseline product) are less than the consumptions 

associated with baseline products. 

• Energy and water prices are the prices paid by consumers for energy (i.e., electricity, gas, 

or oil) and water. Multiplying the annual energy and water consumption by the energy 

and water prices yields the annual energy cost and water cost, respectively. 

• Repair costs are associated with repairing or replacing components that have failed. 

• Maintenance costs are associated with maintaining the operation of the product. 

• DOE used energy and water price trends to forecast energy and water prices into the 

future and, along with the product lifetime and discount rate, to establish the lifetime 

energy and water costs. 

• Product lifetime is the age at which the product is retired from service. 

• The discount rate is the rate at which DOE discounted future expenditures to establish 

their present value. 

DOE calculated the operating cost for baseline products based on the following equation:

BASE ENERGY BASE WATER BASE BASE

BASE BASE BASE BASE BASE

AEC PRICE AWC PRICE RC MC

OC EC WC RC MC

= × + × + +

= + + +

Where:

OCBASE = operating cost for the baseline product,

ECBASE = energy cost associated with operating the baseline product, 
8-13

WCBASE = water cost associated with operating the baseline product,

RCBASE = repair cost associated with component failure for the baseline product,

MCBASE = service cost for maintaining baseline product operation,

AECBASE = annual energy consumption for baseline product, 

PRICEENERGY = energy price,

AWCBASE = annual water consumption for baseline product, and

PRICEWATER = water price.

DOE calculated the operating cost for standard-level products based on the following 

equation:

( ) ( )

( ) ( ) BASE STD BASE STD

BASE STD ENERGY BASE STD WATER

STD ENERGY STD WATER STD STD

STD STD STD STD STD

RC RC MC MC

AEC AEC PRICE AWC AWC PRICE

AEC PRICE AWC PRICE RC MC

OC EC WC RC MC

+ + ∆ + + ∆

= ∆ × + ∆ ×

= × + × + +

= + + +

__ __

Where:

OCSTD = operating cost for standard-level product,

ECSTD = energy cost associated with operating standard-level product, 

WCSTD = water cost associated with operating standard-level product,

RCSTD = repair cost associated with component failure for standard-level product,

MCSTD = service cost for maintaining standard-level product operation,

AECSTD = annual energy consumption for standard-level product, 

PRICEENERGY = energy price,

AWCSTD = annual water consumption for standard-level product,

PRICEWATER = water price,

ΔAECSTD = change in annual energy consumption caused by standard-level product, 

ΔAWCSTD = change in annual water consumption caused by standard-level product,

ΔRCSTD = change in repair cost caused by standard-level product, and

ΔMCSTD = change in maintenance cost caused by standard-level product.

The remainder of this section provides information about each of the above input 

variables that DOE used to calculate the operating costs for dishwashers. 

8.2.2.1 Annual Energy and Water Consumption

Chapter 7, Energy and Water Use Analysis, details how DOE determined the annual 

energy and water consumption for baseline and standard-level products. 

As described in section 7.4 of chapter 7 and section 8.1.1, DOE developed a sample of 

individual households that use one of the product classes of dishwashers. By developing 

household samples, DOE was able to perform the LCC and PBP calculations for each household 

to account for the variability in the usage and price of both energy and water associated with 
8-14

each household. DOE used EIA’s 2005 RECS to develop the household samples and, in turn, to 

establish the variability in both annual energy and water consumption and energy and water

pricing. Refer to chapter 6 to review the variability of annual energy consumption for 

dishwashers. 

The tables presented below are based on the energy and water use analysis described in 

chapter 7. Keep in mind that the annual energy and water consumption values in the tables below 

are averages. DOE captured the variability in energy and water consumption in the LCC and 

PBP analysis.

Table 8.2.8 and Table 8.2.9 provide the average annual energy and water consumption by 

efficiency level for standard-sized and compact dishwashers, respectively. These tables are

similar to those in section 7.3 of chapter 7 with the exception that, in Table 8.2.8 and Table 8.2.9, 

the electric, gas, and oil water-heating consumption takes into account the percentage of 

households in the United States that use electric, gas, and oil water heaters, respectively. In 

others words, the electric, gas, and oil water heating consumption is weighted by the share of 

households that use electric, gas, and oil water heaters. Based on data from the RECS, 37.2 

percent of households use electric water heaters, 58.9 percent use gas, and 3.9 percent use oil. 

Table 8.2.8 Standard Dishwashers: Annual Energy and Water Use by Efficiency Level

Efficiency 

Level

Annual 

Energy Use

Annual Energy Use Annual

Water

Use

Water Heating*

1,000 gal/year

Electric Gas

kWh/year

Oil

MMBtu/year

Baseline

MMBtu/year

355 211 0.62 0.04 1.40

1 324 195 0.55 0.04 1.25

2 307 196 0.47 0.03 1.08

3 295 201 0.40 0.03 0.92

4 234 150 0.36 0.02 0.82

5 180 145 0.15 0.01 0.35

* Electric, gas, and oil water heating based on water heater efficiencies of 100% for electric, 

75% for gas, 75% for oil. 
8-15

Table 8.2.9 Compact Dishwashers: Annual Energy and Water Use by Efficiency Level

Efficiency

Level

Annual 

Energy Use

Annual Energy Use Annual

Water

Use

Water Heating*

1,000 gal/year

Electric Gas

kWh/year

Oil

MMBtu/year

Baseline

MMBtu/year

260 160 0.43 0.03 0.97

1 222 144 0.33 0.02 0.75

2 154 107 0.20 0.01 0.45

* Electric, gas, and oil water heating based on water heater efficiencies of 100% for electric, 

75% for gas, 75% for oil. 

8.2.2.2 Energy and Water Prices

DOE used probability distributions to characterize the regional variability in energy and 

water prices. DOE developed the probability associated with each regional energy and water 

price based on the population weight of each region. DOE’s method for deriving energy and 

water prices is described below. 

Electricity Prices

DOE derived average energy prices from data that are published annually based on EIA 

Form 861. Those data include, for every utility that serves final consumers, annual electricity 

sales in kilowatt-hours; revenues from electricity sales; and number of customers in the 

residential, commercial, and industrial sectors. DOE calculated prices for each of 13 geographic 

areas: the nine U.S. Census divisions plus four large states (New York, Florida, Texas, and 

California). For Census divisions that contain one of the large states, DOE removed the data for 

that state from the calculation of the regional average. The Pacific region average does not 

include California, for example, and the West South Central does not include Texas. 

The calculation of average residential electricity price proceeded in two steps.

1. For each utility, DOE estimated an average residential price by dividing residential 

revenues by residential sales.

2. DOE calculated a regional average price, weighting each utility that serves residences in 

a region by the number of residential customers served in that region.

Table 8.2.10 shows results for the 13 geographic regions.
8-16

Table 8.2.10 Average Residential Electricity Prices 

Geographic Area

Average Price 

New England

2010$/kWh

0.178

Middle Atlantic (excluding New York) 0.139

East North Central 0.113

West North Central 0.094

South Atlantic (excluding Florida) 0.111

East South Central 0.098

West South Central (excluding Texas) 0.087

Mountain 0.104

Pacific (excluding California) 0.102

New York 0.188

Florida 0.151

Texas 0.126

California 0.126

Source: EIA Form 861 for 2009.

Natural Gas Prices

DOE obtained data for calculating regional prices of natural gas from the EIA 

publication, Natural Gas Navigator.

5 This publication presents monthly volumes of natural gas 

deliveries and average prices by state for residential, commercial, and industrial customers. The 

Department used the complete annual data for 2010 to calculate an average annual price for each 

geographic area. The calculation of average prices proceeded in two steps.

1. For each state, DOE calculated the annual residential price of natural gas using a simple 

average of data.

2. DOE then calculated a regional price, weighting each state in a region by its population.

The method used to calculate natural gas prices differs from that used to calculate 

electricity prices, because the EIA does not provide consumer- or utility-level data on gas 

consumption and prices. The prices in Table 8.2.11 are in dollars per million BTU ($/MMBtu).
8-17

Table 8.2.11 Average Residential Natural Gas Prices

Geographic Area

Average Price 

New England

2010$/MMBtu

15.68

Middle Atlantic (excluding New York) 14.26

East North Central 12.47

West North Central 12.07

South Atlantic (excluding Florida) 17.14

East South Central 14.00

West South Central (excluding Texas) 13.89

Mountain 11.41

Pacific (excluding California) 13.14

New York 15.69

Florida 10.00

Texas 12.86

California 19.93

Source: EIA Natural Gas Monthly, 2010

Because DOE conducted the LCC and PBP analysis in 2010, all natural gas prices are in 

2010$.

Residential Oil Prices

DOE collected 2009 oil prices from EIA’s Petroleum Navigator,6

Table 8.2.12

which includes 

monthly oil prices for residential, commercial, industrial, and transportation consumers by 

Petroleum Administration for Defense Districts (PADD). The first four PADD follow the U.S. 

Census divisions. However, Arizona is not included in the PADD for the Pacific Region and 

New Mexico is excluded altogether. In addition, data was not provided for the East South 

Central region, West South Central region, Florida, Texas, and California, so national averages 

were used for these regions. DOE weighted the average residential oil prices for each PADD by 

the amount of oil consumed in each PADD. DOE then transformed the data in units of 

cents/gallon to $/MMBtu. Finally, the prices were aggregated and averaged by nine geographic 

areas ( ). The EIA oil price data do not include taxes, so DOE determined the average 

tax rate for the four Census regions (Northeast, South, Midwest, and West)7 and applied it to the 

annual average data.
8-18

Table 8.2.12 Average Monthly Residential Oil Prices in 2009

Geographic Area

Average Price 

New England

2010$/MMBtu

18.64

Middle Atlantic (excluding New York) 18.35

East North Central 16.41

West North Central 16.46

South Atlantic (excluding Florida) 17.95

East South Central 16.09

West South Central (excluding Texas) 14.54

Mountain 16.14

Pacific (excluding California) 18.21

New York 19.08

Florida 18.43

Texas 14.65

California 17.51

*National average

**Pacific Division average

***South Atlantic Division average

Water Prices

DOE obtained data on water prices for 2010 from the Water and Wastewater Rate Survey

conducted by Raftelis Financial Consultants and the American Water Works Association.2 The 

survey covers approximately 308 water utilities and 228 wastewater utilities, analyzing each 

industry (water and wastewater) separately. The water survey includes, for each utility, the cost 

to consumers of a given volume of water. The total consumer cost is divided into fixed and 

volumetric charges. DOE’s calculation of water prices uses only volumetric charges, because 

only those charges would be affected by a change in water consumption. Including the fixed 

charge in the average would lead to a slightly higher water price. 

For wastewater utilities, the data format is similar, except that the price represents the 

cost to treat a given volume of wastewater. A sample of 308 or 228 utilities is too small to 

calculate regional prices for all U.S. Census divisions and large states (for comparison, data from 

EIA Form 861 cover more than 3,000 utilities). Therefore, DOE calculated regional costs for 

wastewater service at the level of Census regions only (Northeast, South, Midwest, and West). 

The calculation of average prices per unit volume proceeds in three steps.

1. For each water or wastewater utility, DOE calculated the price per unit volume by 

dividing the total volumetric cost by the volume delivered.

2. DOE calculated a state-level average price by weighting each utility in a given state by 

the number of residential customers it serves.
8-19

3. DOE calculated a regional average by combining the state-level averages, weighting each 

by the state’s population. This third step helps reduce any bias in the sample that may 

result from the relative under-sampling of large states.

Table 8.2.13 presents the results of the calculation of costs for water and wastewater 

service. The price units in the table are 2010 dollars per thousand gallons (/tg).

Table 8.2.13 Average Water and Wastewater Prices per Unit Volume 

Census Region

Water Wastewater 

2010$/tg 2010$/tg

Northeast 4.07 3.53

Midwest 2.21 2.77

South 3.01 4.68

West 4.06 3.96

National Average 3.30 3.87

8.2.2.3 Energy and Water Price Trends

DOE used EIA price forecasts to estimate the trends in natural gas, oil, and electricity 

prices. To arrive at prices in future years, it multiplied the average prices described in the 

preceding section by the forecast of annual average price changes in EIA’s AEO 2011.

8 To 

estimate the trend after 2030, DOE followed past guidelines provided to the Federal Energy 

Management Program (FEMP) by EIA and used the average rate of change during 2020–2035.

The Department calculated LCC and PBP using three separate projections from AEO

2011: Reference, Low Economic Growth, and High Economic Growth. These three cases reflect 

the uncertainty of economic growth in the forecast period. The high and low growth cases show 

the projected effects of alternative growth assumptions on energy markets. Figure 8.2.1 shows

the residential electricity price trend based on the three AEO 2011 projections. For the LCC 

results presented in section 8.4, DOE used only the energy price forecasts from the AEO 

Reference case.
8-20

Figure 8.2.1 Electricity Price Trends

To estimate the future trend for water and wastewater prices, DOE used data on the 

historic trend in the national water price index (U.S. city average) from 1970 through 2005,

9

Figure 8.2.2

combined with the all-products CPI for this same period. It extrapolated a future trend based on 

the linear inflation-adjusted growth during the 1970–2005 period. shows the

projected inflation-adjusted water price trend. DOE used this fit to forecast water and wastewater 

prices for residential dishwashers.

0.84

0.86

0.88

0.9

0.92

0.94

0.96

0.98

1

1.02

1.04

1.06

2008 2013 2018 2023 2028 2033 2038 2043

AEO 2011 Electricity Forecasts

Reference

High

Low
8-21

Figure 8.2.2 Inflation-Adjusted Water Price Trend

8.2.2.4 Repair and Maintenance Costs

Typically, small incremental changes in product efficiency produce no, or only slight, 

changes in repair and maintenance costs over baseline products. However, products having

significantly higher efficiencies, compared to baseline products, are more likely to incur higher 

repair and maintenance costs because their increased complexity and higher part count typically 

increases the cumulative probability of failure. DOE requested that manufacturers and other 

stakeholders assist in developing appropriate repair and maintenance, but it did not receive any 

input. Thus DOE did not include any changes in repair and maintenance costs for products more 

efficient than baseline products.

8.2.3 Product Lifetimes

RECS records the presence of various appliances in each household and places the age of 

each appliance into bins comprising several years. Data from the U.S. Census’s American 

Housing Survey (AHS),10 which surveys all housing including vacant and second homes, enabled 

DOE to adjust the RECS data to reflect some appliance use outside of primary residences. By 

combining the results of both surveys with the known history of appliance shipments (collected 

from Appliance magazine or directly from manufacturer trade associations), DOE estimated the 

percentage of appliances of a given age still in operation. This survival function, which DOE 

assumed has the form of a cumulative Weibull distribution, provides an average and a median 

appliance lifetime. DOE calculated the average lifetime for both product classes at 15.4 years.

y = 2.06x - 3,990.11

R2 = 0.95

0

20

40

60

80

100

120

140

160

180

1980 1985 1990 1995 2000 2005 2010

Inflation-Adjusted Water CPI

Inflation-Adjusted CPI

Linear (Inflation-Adjusted CPI)
8-22

The Weibull distribution is a probability distribution commonly used to measure failure 

rates.a Its form is similar to an exponential distribution, which models a fixed failure rate, except 

that a Weibull distribution allows for a failure rate that changes over time in a particular fashion. 

The cumulative Weibull distribution takes the form:

e x

P x

β

α

θ 



 



 − −

( ) = for x > θ and

P(x) = 1 for x ≤ θ

Where:

P(x) = probability that the appliance is still in use at age x,

x = appliance age,

α = scale parameter, which would be the decay length in an exponential distribution,

β = shape parameter, which determines the way in which the failure rate changes 

through time, and

θ = delay parameter, which allows for a delay before any failures occur.

When β = 1, the failure rate is constant over time, giving the distribution the form of a 

cumulative exponential distribution. In the case of appliances, β commonly is greater than 1, 

reflecting an increasing failure rate as appliances age. Figure 8.2.3 shows the Weibull retirement 

function for dishwashers.

Figure 8.2.3Weibull Retirement Function for Dishwashers

 

a For reference on the Weibull distribution, see sections 1.3.6.6.8 and 8.4.1.3 of the NIST/SEMATECH e-Handbook 

of Statistical Methods, <www.itl.nist.gov/div898/handbook/>.

0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

7.0%

8.0%

0 5 10 15 20 25 30 35 40 45 50

Weibull Retirement Function for Dishwashers 

(mean = 15.43 years)
8-23

Appendix 8D presents the Weibull distributions that DOE used in the LCC and PBP 

analysis.

8.2.4 Discount Rates

The discount rate is the rate at which DOE discounted future consumer expenditures to 

establish their present value. DOE derived the discount rates for the LCC and PBP analyses from 

estimates of the finance cost of purchasing the considered products. Following financial theory, 

the finance cost of raising funds to purchase appliances can be interpreted as: (1) the financial 

cost of any debt incurred to purchase products, or (2) the opportunity cost of any equity used to 

purchase products. DOE considers both of these interpretations.

In the case of individual households, the financing of purchasing products installed in 

new homes is different from the financing of appliances bought directly by consumers (i.e., as a 

replacement for a failed unit or as a new purchase for an existing household that does not already 

own the appliance). Thus, DOE used different discount rates for these residential purchases. 

8.2.4.1 Residential Discount Rates for Products Purchased in Existing Households

Households use a variety of methods to finance the purchase of major appliances. In 

principle, one could estimate the interest rates on the actual financing methods used to purchase 

appliances. However, the shares of different financing methods in total appliance purchases are 

unknown. 

DOE’s approach involves identifying all possible debt or asset classes that might be used 

to purchase the considered appliances, including household assets that might be affected

indirectly.

b DOE excluded debt from primary mortgages or assets considered non-liquid (such as 

retirement accounts), because those financing methods are unlikely to be used by households in 

existing housing to purchase appliances. DOE estimated the average percentage shares of the

various debt and equity classes in the average U.S. household equity and debt portfolios using 

data from the Federal Reserve Board’s Survey of Consumer Finances (SCF) for 1989, 1992, 

1995, 1998, 2001, 2004, and 2007.11 Table 8.2.14 shows the average percentages of each 

considered type of debt or equity. DOE derived the mean percentage shares of each source of 

financing for each of the seven surveys as a basis for estimating the weight of the classes in the 

direct or indirect financing of the considered appliances.

 b An indirect effect would arise if a household sold some assets in order to pay off a loan or credit card debt that 

might have been used to finance the appliance purchase. 
8-24

Table 8.2.14 Average Shares of Considered Household Debt and Equity Types: %

Type

1989 

SCF

1992 

SCF

1995 

SCF

1998 

SCF

2001 

SCF

2004 

SCF

2007 

SCF Mean 

Home equity loans 4.3 4.5 2.7 2.8 2.8 4.4 4.6 3.7

Credit cards 1.6 2.1 2.6 2.2 1.7 2.0 2.4 2.1

Other installment loans 2.8 1.7 1.4 1.7 1.1 1.3 1.1 1.6

Other residential loans 4.4 6.9 5.2 4.3 3.1 5.8 7.1 5.3

Other lines of credit 1.1 0.6 0.4 0.2 0.3 0.5 0.3 0.5

Checking accounts 5.8 4.7 4.9 3.9 3.6 4.2 3.4 4.4

Savings & money market 19.2 18.8 14.0 12.8 14.2 15.1 13.0 15.3

Certificates of deposit 14.5 11.7 9.4 7.0 5.4 5.9 6.5 8.6

Savings bonds 2.2 1.7 2.2 1.1 1.2 0.9 0.7 1.4

Bonds 13.8 12.3 10.5 7.0 7.9 8.4 6.7 9.5

Stocks 22.4 24.0 25.9 36.9 37.5 28.0 28.6 29.0

Mutual funds 8.0 11.1 20.9 20.1 21.3 23.4 25.5 18.6

Total 100 100 100 100 100 100 100 100

DOE estimated interest or return rates associated with each type of equity and debt. The 

source for the interest rates for loans, credit cards, and lines of credit was the Federal Reserve 

Board’s SCF in 1989, 1992, 1995, 1998, 2001, 2004, and 2007. Table 8.2.15 shows the average 

nominal rates in each year, and the inflation rates used to calculate real rates. DOE calculated 

effective interest rates for home equity loans in a similar manner as for mortgage rates, because 

interest on both such loans is tax deductible. Table 8.2.16 shows the average effective real rates 

in each year and the mean rate across the years. Because the interest rates for each type of 

household debt reflect economic conditions throughout numerous years, they are expected to be 

representative of rates in the year in which amended standards would take effect. 
8-25

Table 8.2.15 Average Nominal Interest Rates for Household Debt

Type of Debt

Average Nominal Interest Rate 

1989

% 

1992 1995 1998 2001 2004 2007 Mean

Home equity loans 11.5 9.6 9.6 9.8 8.7 5.7 7.9 9.0

Credit cards* - - 14.2 14.5 14.2 11.7 12.6 13.4

Other installment 

loans 9.0 7.8 9.3 7.8 8.7 7.4 10.4 8.6

Other residential 

loans 8.8 7.6 7.7 7.7 7.5 6.0 6.3 7.4

Other line of credit 14.8 12.7 12.4 11.9 14.9 8.8 12.7 12.6

Inflation rate 4.82 3.01 2.83 1.56 2.85 2.66 2.85

Sources: Federal Reserve Board. Survey of Consumer Finances (SCF) for 1989, 1992, 1995, 1998, 2001, 2004, and 2007.

* No interest rate data available for credit cards in 1989 or 1992.

Table 8.2.16 Average Real Effective Interest Rates for Household Debt

Type of Debt

Average Real Interest Rate %

1989 1992 1995 1998 2001 2004 2007 Mean

Home equity loans 3.8 4.3 4.4 5.8 3.8 1.9 3.3 3.9

Credit cards* - - 11.0 12.7 11.1 9.1 9.7 10.7

Other installment 

loans 4.9 5.8 7.0 6.6 6.1 5.4 5.8 6.0

Other residential 

loans 4.0 4.7 4.8 6.0 4.6 3.3 3.4 4.4

Other lines of credit 9.6 9.4 9.3 10.2 7.3 6.0 9.7 8.8

Sources: Federal Reserve Board. Survey of Consumer Finances (SCF) for 1989, 1992, 1995, 1998, 2001, 2004, and 2007.

* No interest rate data available for credit cards in 1989 or 1992.

DOE developed a probability distribution of interest rates for each debt class based on the 

SCF data. To account for variation among households, DOE sampled a rate for each household 

from the distributions for the appropriate debt class. Appendix 8E presents the probability

distribution of interest rates for each debt class that DOE used in the LCC and PBP analyses. 

No similar rate data are available from the SCF for the asset classes, so the Department 

derived data for these classes from national historical data. The interest rates associated with 

certificates of deposit (CDs),12 savings bonds,13 and bonds (AAA corporate bonds)14 are from 

Federal Reserve Board time-series data covering 1977–2010. DOE assumed rates on checking 

accounts to be zero. Rates on savings and money market accounts are from Cost of Savings 

Index data covering 1984–2010.15 The rates for stocks are the annual returns on the Standard and 

Poor’s (S&P) 500 in 1977–2010.16 Rates for mutual fund are a weighted average of the stock 
8-26

rates (two-thirds weight) and the bond rates (one-third weight) in each year from 1977–2010. 

DOE adjusted the nominal rates to real rates using the annual inflation rate for each year. 

Average nominal and real interest rates for the classes of assets are listed in Table 8.2.17. 

Because the interest and return rates for each type of asset reflect economic conditions 

throughout numerous years, they are expected to be representative of rates in the year in which 

amended standards would take effect. 

Table 8.2.17 Average Nominal and Real Interest Rates for Household Equity

Type of Equity

Average Nominal 

Rate %

Average Real 

Rate %

Checking accounts - 0.0

Savings and money market 5.2 2.2 

CDs 6.3 2.1 

Savings bonds 7.5 3.3 

Bonds 8.3 4.1

Stocks 12.1 7.8 

Mutual funds 10.6 6.3 

Table 8.2.18 summarizes the mean real effective rates of each type of equity or debt as 

well as the average percentage of the debt and asset for all U.S. households over the 7 years of 

survey data. DOE determined the average percentage of each type of debt and asset using SCF 

data for 1989, 1992, 1995, 1998, 2001, 2004, and 2007. Each year of SCF data provides the 

amount of debts and assets held by each U.S. household. DOE averaged the percentages for the 7 

years of survey data to arrive at the percentages shown in Table 8.2.18. The average rate across 

all types of household debt and equity, weighted by the shares of each class, is 5.1 percent.
8-27

Table 8.2.18 Shares and Interest or Return Rates Used for Household Debt and Equity

Average Share of 

Household Debt plus 

Equity %*

Mean Effective 

Real Rate %**

Home equity loans 3.7 3.9 

Credit cards 2.1 10.7 

Other installment loans 1.6 6.0 

Other residential loans 5.3 4.4 

Other line of credit 0.5 8.8 

Checking accounts 4.4 0.0 

Savings and money market accounts 15.3 2.2 

Certificates of deposits 8.6 2.1

Savings bonds 1.4 3.3 

Bonds 9.5 4.1 

Stocks 29.0 7.8 

Mutual funds 18.6 6.3 

Total/weighted-average discount rate 100 5.1

* Not including primary mortgage or retirement accounts.

** Adjusted for inflation and, for home equity loans, loan interest tax deduction.

DOE developed a normal probability distribution of interest rates for each asset type by 

using the mean value and standard deviation from the distribution. To account for variation 

among households, DOE sampled a rate for each household from the distributions for the 

appropriate asset class. Appendix 8E presents the probability distribution of interest rates for

each asset type that DOE used in the LCC and PBP analyses.

8.2.4.2 Residential Discount Rates for Products Installed in New Housing 

Appliances installed in new homes (“new-housing appliances”) are purchased as part of 

the home, which is almost always financed with a mortgage loan. DOE estimated discount rates 

for new-housing appliances using the effective real (after-inflation) mortgage rate for 

homebuyers. This rate corresponds to the interest rate after deduction of mortgage interest for 

income tax purposes and after adjusting for inflation (using the Fisher formula).c For example, a 

6-percent nominal mortgage rate has an effective nominal rate of 4.5 percent for a household at 

the 25-percent marginal tax rate. When adjusted for an inflation rate of 2 percent, the effective 

real rate becomes 2.45 percent.

The data sources DOE used for mortgage interest rates were the SCF in 1989, 1992, 

1995, 1998, 2001, 2004, and 2007. Using the appropriate SCF data for each year, DOE adjusted 

 

c Fisher formula is given by: Real Interest Rate = [(1 + Nominal Interest Rate) / (1 + Inflation Rate)] – 1.
8-28

the mortgage interest rate for each relevant household in the SCF for mortgage tax deduction and 

inflation (see Table 8.2.19). In cases where the effective interest rate is equal to or below the 

inflation rate (resulting in a negative real interest rate), DOE set the real effective interest rate to 

zero.

The average nominal mortgage rate carried by homeowners in these 6 years was 7.9

percent. Since the mortgage rates carried by households in these years were established over a 

range of time, DOE believes they are representative of rates that may apply when amended

standards take effect. After adjusting for inflation and interest tax deduction, effective real 

interest rates on mortgages across the six surveys averaged 3.0 percent.

Table 8.2.19 Data Used to Calculate Real Effective Mortgage Rates

Year Mortgage Interest Rates in Selected Years %

Average 

Nominal 

Interest Rate

Inflation Rate17

Marginal Tax Rate 

Applicable to 

Mortgage Interest18

Average Real 

Effective Interest 

Rate

1989 9.7 4.82 24.3 2.4

1992 9.1 3.01 23.4 3.8

1995 8.2 2.83 24.1 3.3

1998 7.9 1.56 23.9 4.4

2001 7.6 2.85 22.9 2.9

2004 6.2 2.66 20.6 2.2

2007 6.3 2.85 21.6 2.1

Average 7.9 3.0

To account for variation among households, DOE sampled a rate for each household in 

the RECS samples from a distribution of mortgage rates. DOE developed the distribution based 

on the SCF data. Appendix 8E presents the probability distribution that DOE used in the LCC

and PBP analyses.

8.2.5 Compliance Date 

In the context of EPCA, the compliance date is the future date when parties subject to the 

requirements of a new or amended standard must comply. EPCA requires DOE, no later than 

January 1, 2015, to determine whether amended standards for dishwashers are warranted. The 

compliance date for any amended standards would be January 1, 2018. (42 U.S.C. 

6295(g)(10)(B)) Where appropriate, DOE calculated the LCC and PBP for dishwashers as if 

consumers would purchase new products in 2018. Trial Standard Level (TSL) 2, which 

corresponds to the Consensus Agreement level for standard dishwashers, has a compliance date 

of Jan. 1, 2013. Thus, for TSL 2, DOE used 2013 as the compliance year. Further discussion of 

the TSLs is provided in chapter 10, section 10.1.1.
8-29

DOE calculated the LCC for all consumers as if they each would purchase a new product 

in the year of compliance with an amended standard takes effect. 

8.2.6 Product Assignment for the Base Case

To accurately estimate the percentage of consumers that would be affected by a particular 

standard level, DOE took into account the distribution of product efficiencies expected for the 

compliance year. In other words, rather than analyzing the impacts of a particular standard level 

assuming that all consumers are currently purchasing products at the baseline level, DOE 

conducted the analysis by taking into account the full breadth of product efficiencies that 

consumers purchase under the base case (i.e., the case without new energy efficiency standards).

As noted in section 8.1.1, DOE’s approach for conducting the LCC analysis for 

residential dishwashers relied on developing samples of households that use each product class. 

DOE used a Monte Carlo simulation technique to perform the LCC calculations for the 

households in the sample. Using the base-case distribution of product efficiencies, DOE assigned 

each household in the sample a unique product efficiency. Because it performed the LCC 

calculations on a household-by-household basis, DOE based the LCC for a particular candidate 

standard level (CSL) on the efficiency of the product assigned to each given household. For 

example, if a household was assigned a product efficiency that is greater than or equal to the 

efficiency of the CSL under consideration, the LCC calculation would reveal that this household 

is not impacted by an increase in product efficiency that is equal to the standard level. The 

distributions of product efficiencies that DOE used for the LCC analysis for dishwashers are 

discussed below.

AHAM provided the distribution of standard-sized and compact dishwashers efficiencies 

sold in 2010.19

Figure 8.4.2

Based on these shipment-weighted efficiency data, the base-case distributions for 

standard-sized and compact dishwashers were calculated. DOE used an exponential function, 

displayed in , to model the historical decline in shipment-weighted annual average 

energy use shown in the AHAM data and forecast that decline into the future. 
8-30

Figure 8.2.4 Historic and Projected Base Case Trend in 

Dishwasher Average Energy Use

DOE then combined this predicted trend with the market share trends for various 

efficiency levels to predict the market shares for each efficiency level in 2013 and 2018. To 

predict the market shares by efficiency level in 2013 and 2018, DOE observed the market trends 

present in the AHAM data and assumed those trends would continue in a manner consistent with 

the decline in total average energy use shown above. The historical and forecast market shares 

are shown in Table 8.2.20 and Table 8.2.21, along with shipment-weighted annual energy use 

(SWAEU).

Table 8.2.20 Standard Dishwashers: Efficiency Market Share Data and Base-Case 

Forecast: %

Efficiency Level 2008 2009 2010 2013 2018

Baseline 56.4 38.7 3.8 3.8 3.8

1 30.0 41.1 51.8 32.3 25.2

2 7.8 8.9 21.5 28.0 32.7

3 5.8 5.2 15.3 16.4 18.5

4 0.0 4.0 5.0 13.8 10.8

5 0.0 2.0 2.5 5.6 9.0

SWAEU 338.4 326.5 309.0 295.1 291.6

275

285

295

305

315

325

335

345

355

365

375

2002200320042005200620072008200920102011201220132014201520162017201820192020

Shipment-Weight AEU (kWh/yr)

Forecast

AHAM Data
8-31

Table 8.2.21 Standard-Sized Dishwashers: Base-Case Efficiency Market Shares for 2018

Efficiency 

Level

Annual Energy 

Use kWh/year

Water Use Market Share

gal/cycle %

Baseline 355 6.50 3.8

1 324 5.80 25.2

2 307 5.00 32.7

3 295 4.25 18.5

4 234 3.80 10.8

5 180 1.60 9.0

For compact dishwashers, AHAM data for efficiency distributions were not available. 

Thus, DOE first considered 2010 market data from the NPD Group, Inc. Those data show that 

nearly all shipments for both standard and compact dishwashers are at the baseline efficiency 

level. For the compact class base-case distribution, however, there were only two types of 

compact dishwashers in the NPD data set: “countertop” and “portable.” DOE is not aware of any 

portable dishwashers currently on the market in the United States that would be classified as 

compact size based on the number of place settings. Further, there are no compact dishdrawer 

platforms included in the NPD dataset, which DOE believes represent a sizeable fraction of 

compact dishwasher shipments. As a result, DOE estimated compact base-case efficiencies from 

its research on the number of models available at each efficiency level. Of the eight compact 

dishwashers listed in the FTC database for manufacturer certifications in 2010, four are 

dishdrawer models with similar performance. Therefore, DOE allocated half of shipments to the 

dishdrawer platform that meets CSL 2. DOE further estimated, based on the number of 

countertop models and underlying platforms contained within the CEC and FTC databases, that 

half of remaining shipments (25 percent of total compact dishwasher shipments) would meet 

CSL 1, while the remaining 25 percent of compact shipments are at the baseline. Table 8.2.22

presents the market shares of the efficiency levels in the base case in 2018 for compact 

dishwashers.

Table 8.2.22 Compact Dishwashers: Base Case Efficiency Market Shares for 2018

Efficiency 

Level

Annual Energy Use Water Use 

kWh/year

Market Share

gal/cycle %

Baseline 260 4.50 25.0

1 222 3.50 25.0

2 154 2.10 50.0

8.3 INPUTS TO PAYBACK PERIOD ANALYSIS

The payback period (PBP) is the amount of time it takes the consumer to recover, through 

lower operating costs, the assumed higher purchase price of a more energy efficient product.

Numerically, the PBP is the ratio of the increase in purchase price (i.e., from a less efficient 

design) to the decrease in annual operating costs. This type of calculation is known as a “simple” 
8-32

payback period because it ignores changes in operating expense over time or the time value of 

money. That is, the calculation is done at an effective discount rate of zero percent. 

The equation for PBP is:

OC

IC PBP

∆

∆ =

Where:

ΔIC = difference in the total installed cost between the standard level unit and the 

baseline unit, and 

ΔOC = difference in annual operating expenses. 

Payback periods are expressed in years. A payback period greater than the life of the

product means that the increased total installed cost is not recovered in reduced operating costs.

The data inputs to PBP are the total installed cost of the product to the consumer for each 

efficiency level and the annual (first year) operating expenditures for each standard level. The 

inputs to the total installed cost are the product price and the installation cost. The inputs to the 

operating costs are the annual costs of energy and water, repair, and maintenance. The PBP uses 

the same inputs as the LCC analysis, as described in section 8.2, except that PBP does not 

require energy and water price trends or discount rates. Considering the PBP is a “simple” 

payback, the required energy and water prices are only for the year in which a new standard will

take effect—in this case, 2018 (2013 for TSL 2). The energy and water prices DOE used in the 

PBP calculation was the price projected for that year. 

8.4 RESULTS OF LIFE-CYCLE COST AND PAYBACK PERIOD ANALYSES

This section presents the LCC and PBP results for residential dishwashers. As discussed 

in section 8.1.1, DOE’s approach to conducting the LCC analysis relied on developing samples 

of households that use each product class. DOE also used probability distributions to characterize

the uncertainty of many of the inputs. DOE applied a Monte Carlo simulation to calculate the 

LCC for the households in the sample. For each set of sample households using each product 

class, DOE calculated the average LCC and LCC savings and the median and average PBP for 

each of the standard levels. 

DOE calculated LCC savings and PBPs relative to the base-case product it assigned to 

the households. As discussed in section 8.2.6, DOE assigned some households a base-case 

product that is more efficient than some of the standard levels. For that reason, the average LCC 

impacts are not equal to the difference between the LCC of a specific standard level and the LCC 

of the baseline product. 
8-33

LCC and PBP calculations were performed 10,000 times on the sample of households 

established for each product class. Each LCC and PBP calculation was performed on a single 

household, which was selected from the sample based on its weight (i.e., how representative a 

particular household is of other households in the distribution). Each LCC and PBP calculation 

also sampled from the probability distributions that DOE developed to characterize many of the 

inputs to the analysis. 

The results from the Monte Carlo simulations on 10,000 samples provided the basis for 

DOE to calculate the share of households with a net LCC benefit, with a net LCC cost, and with 

no impact for the base case and each successive efficiency level. DOE considered a household to 

receive no impact at a given efficiency level if DOE assigned it a base-case product having an 

efficiency equal to or greater than the efficiency level in question. The following sections

illustrate the distributions of LCC impacts and PBPs for each product class at base-case

efficiency and each efficiency level analyzed.

8.4.1 Distributions of Life-Cycle Cost for Baseline Units

The figures below are presented as frequency charts that show the distribution of LCCs, 

LCC impacts, and PBPs with their corresponding probability of occurrence. DOE generated the 

figures for the distributions from a Monte Carlo simulation run based on 10,000 samples.

Figure 8.4.1 and Figure 8.4.2 show the frequency charts for the baseline LCC for 

standard-sized and compact dishwashers, respectively. 

Figure 8.4.1 Standard-Sized Dishwashers: Base-Case LCC Distribution 
8-34

Figure 8.4.2 Compact Dishwashers: Base-Case LCC Distribution 

8.4.2 Distributions of Life-Cycle Cost Under New Standard Levels

Figure 8.4.3 and Figure 8.4.4 are examples of frequency charts showing the distribution 

of LCC differences for standard-sized and compact dishwashers at the efficiency levels 

corresponding to TSL2. Refer back to section 8.2.6 on the distribution of product efficiencies 

under the base case. DOE can generate a frequency chart like the one shown in Figure 8.4.3 for 

every standard level.
8-35

Figure 8.4.3 Standard-Sized Dishwashers: Distribution of LCC Impacts for 

Efficiency Level 2 

Figure 8.4.4 Compact Dishwashers: Distribution of LCC Impacts for Efficiency 

Level 1
8-36

8.4.3 Distribution of Payback Period Under New Standard Level

Figure 8.4.5 and Figure 8.4.6 are examples of frequency charts showing the distribution 

of payback periods for dishwashers at the efficiency levels corresponding to standard level 2.

DOE can generate a frequency chart like the one shown in Figure 8.4.5 for every standard level.

Figure 8.4.5 Standard-Sized Dishwashers: Distribution of PBPs for Efficiency Level 2
8-37

Figure 8.4.6 Compact Dishwashers: Distribution of PBPs for Efficiency Level 1

8.4.4 Life-Cycle Cost and Payback Period Summary Results

Table 8.4.1 and Table 8.4.2 show the LCC and PBP results for standard-sized 

dishwashers and compact dishwashers, respectively. The average operating cost is the discounted 

sum.

Table 8.4.1 Standard-Sized Dishwashers: Life-Cycle Cost and Payback Period

Results

Level

Annual 

Energy 

Use 

Life-Cycle Cost

kWh

Life-Cycle Cost Savings Payback 

Period 

Median

years

Average 

Installed 

Price $

Average 

Operating 

Cost $

Average 

LCC $

Average 

Savings

% 

Net

Cost

Households with

No 

Impact

Net 

Benefit

Baseline 355 630 489 1,120 NA 0 100 0 NA

1 324 656 445 1,101 $1 2 96 2 5.9

2 307 674 417 1,092 $4 14 71 15 10.9

3 295 726 396 1,122 -$15 51 38 10 33.7

4 234 734 318 1,052 $41 30 20 50 6.6

5 180 745 232 977 $108 23 9 68 4.5

Table 8.4.2 Compact Dishwashers: Life-Cycle Cost and Payback Period Results

Level Annual Life-Cycle Cost Life-Cycle Cost Savings Payback 
8-38

Energy 

Use Average 

Installed 

Price $ kWh

Average 

Operating 

Cost $

Average 

LCC $

Average 

Savings

% Households with Period 

Median

Net years

Cost

No 

Impact

Net 

Benefit

Baseline 260 621 356 977 NA 0 100 0 NA

1 222 623 301 923 $13 6 76 18 0.3

2 154 638 206 844 $52 5 50 44 2.1

Figure 8.4.7 and Figure 8.4.8 show the range of LCC savings for all efficiency levels 

considered for standard-sized and compact dishwashers, respectively. For each efficiency level, 

the top and the bottom of the box indicate the 75th and 25th percentiles, respectively. The bar in

the middle of the box indicates the median, which means that with that efficiency level, 50 

percent of the households have LCC savings above this value. The ‘whiskers’ at the bottom and 

the top of the box indicate the 5th and 95th percentiles, respectively. The small box shows the 

average LCC savings for each efficiency level. 

Figure 8.4.7 Range of LCC Savings for Standard-Sized Dishwashers

-100

0

100

200

300

400

500

600

Level 1 Level 2 Level 3 Level 4 Level 5

Average LCC Savings ($)

Efficiency Level

Standard Dishwashers: Average LCC Savings

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

median

average
8-39

Figure 8.4.8 Range of LCC Savings for Compact Dishwashers

Figure 8.4.9 and Figure 8.4.10 show the range of PBPs for all efficiency levels for 

standard-sized and compact-sized dishwashers, respectively. Households that are not affected by 

the new standard are not included in the figures. 

Figure 8.4.9 Range of Payback Periods for Standard-Sized Dishwashers

-50

0

50

100

150

200

250

300

Level 1 Level 2

Average LCC Savings ($)

Efficiency Level

Compact Dishwashers: Average LCC Savings

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

median

average

0

50

100

150

200

250

300

350

400

450

500

Level 1 Level 2 Level 3 Level 4 Level 5

Average Payback Period (years)

Efficiency Level

Standard Dishwashers: Average Payback Period

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

median

average
8-40

Figure 8.4.10 Range of Payback Periods for Compact Dishwashers

8.5 REBUTTABLE PAYBACK PERIOD

DOE develops rebuttable PBPs to support the legally established rebuttable presumption 

that an energy efficiency standard is economically justified if the additional product costs 

attributed to the standard are less than three times the value of the first-year energy and water

cost savings. (42 U.S.C. §6295 (o)(2)(B)(iii))

The basic equation for rebuttable PBP is the same as that shown in section 8.3 on inputs 

to the payback period analysis. Unlike the analyses described in sections 8.2 and 8.3, however, 

the rebuttable PBP is not based on the use of household samples and probability distributions. 

Rather, the rebuttable PBP is based on discrete, single-point values. For example, DOE uses a 

probability distribution of regional energy prices in the distributional payback period analysis, 

but it uses only the national average energy and water prices from the probability distribution to 

determine the rebuttable PBP.

Other than the use of single-point values, the most notable difference between the 

distribution PBP and the rebuttable PBP is the latter’s reliance on the DOE test procedure to 

determine a product’s annual energy and water consumption. To determine the rebuttable PBP 

for dishwashers, DOE based the annual energy and water consumption values on the number of 

cycles per year specified in the DOE test procedure.20

0

2

4

6

8

10

12

14

Level 1 Level 2

Average Payback Period (years)

Efficiency Level

Compact Dishwashers: Average Payback Period

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

median

average

The number of cycles from the DOE test 

procedure, 215 cycles per year, is equal to the average number of cycles that DOE used in its 

determination of distribution PBPs. 
8-41

8.5.1 Inputs

As noted in section 8.5.1, the calculation for the rebuttable PBP differs from that of the 

general PBP in that the inputs are discrete values rather than distributions. For the general PBP, 

inputs for determining total installed cost were based on single-point values. However, the 

variability and/or uncertainty in the inputs for determining operating costs required using 

distributions to calculate the general PBP. DOE used the following single-point values in 

determining the rebuttable PBP. 

• Manufacturing costs, markups, sales taxes, and installation costs were the same as the 

single-point values used in the general LCC and PBP analyses.

• As described in section 8.5.1, annual energy and water consumption were based on the 

usage in the DOE test procedure.

• Energy and water prices were based on national average values for the year that new 

standards are assumed to take effect (2013 for the consensus agreement levels; 2015 for 

all other efficiency levels).

• Neither an average discount rate nor a lifetime is required in the rebuttable PBP 

calculation.

8.5.2 Results

DOE calculated rebuttable PBPs for each efficiency level relative to the distribution of 

product efficiencies assumed for the base case (refer back to section 8.2.6 for more details on the 

base-case efficiency distributions for each product). In other words, DOE did not determine the 

rebuttable PBP relative to the baseline efficiency level, but relative to the current distribution of 

product efficiencies DOE determined for the base case (i.e., the case without new standards). 

Table 8.5.1 and Table 8.5.2 present the rebuttable PBPs for standard-sized and compact 

dishwashers, respectively.

Table 8.5.1 Standard-Sized Dishwashers: Rebuttable Payback Periods

Efficiency 

Level

AEU Water Use 

kWh/year

Rebuttable PBP

gal/cycle

Baseline

years

355 6.50 -

1 324 5.80 5.26

2 307 5.00 5.40

3 295 4.25 8.85

4 234 3.80 5.57
8-42

5 180 1.60 4.00

Table 8.5.2 Compact Dishwashers: Rebuttable Payback Periods

Efficiency 

Level

AEU Water Use 

kWh/year

Rebuttable PBP

gal/cycle

Baseline

years

260 4.50 -

1 222 3.50 0.23

2 154 2.10 1.02
8-43

REFERENCES

 

1 U.S. Department of Energy–Energy Information Administration. Residential Energy 

Consumption Survey, 2005 Public Use Data Files. 2009. Washington, D.C. (Last accessed 

July 11, 2012.) <http://www.eia.gov/emeu/recs/recspubuse05/pubuse05.html> 

2 Raftelis Financial Consulting, 2010 RFC/AWWA Water and Wastewater Rate Survey. 2011. 

Charlotte, NC.

3 Association of Home Appliance Manufacturers (AHAM). AHAM 2010. Washington, D.C.

4 RS Means. Plumbing Cost Data, 33rd Annual Edition. 2010. Kingston, MA. p.70. 

5 U.S. Department of Energy–Energy Information Administration. Natural Gas Navigator. 

2010. (Last accessed July 11, 2012, although data are newly released for 2012.) 

<http://tonto.eia.doe.gov/dnav/ng/ng_pri_sum_dcu_nus_m.htm> 

6 Energy Information Administration. Petroleum Navigator: No. 2 Distillate Prices by Sales 

Type. August, 2008. Washington, DC. (last accessed July 11, 2012, although data has been 

updated to 2012.) <http://www.eia.gov/dnav/pet/pet_pri_dist_dcu_nus_m.htm> 

7 Sales Tax Clearinghouse, Inc. State sales tax rates along with combined average city and 

county rates. (Last accessed July 10, 2012.) <http://thestc.com/STrates.stm>.

8 Energy Information Administration, Annual Energy Outlook 2011 with Projections to 2035,

2011. Washington, DC. Report Number: DOE/EIA-0383(2011). (Last accessed July 11, 

2012.) <http://www.eia.gov/oiaf/aeo/aeoref_tab.html>

9 U.S. Department of Labor-Bureau of Labor Statistics. Consumer Price Indexes, Item: Water 

and sewerage maintenance, Series Id: CUUR0000SEHG01, U.S. city average (not seasonally 

adjusted). 2006. Washington, DC. (Last accessed July 11, 2012.) 

<http://www.bls.gov/cpi/cpid06av.pdf>

10 U.S. Census Bureau–Housing and Household Economic Statistics Division. American 

Housing Survey. Washington, DC. (Last accessed July 11, 2012; data has been updated to 

2011.) <http://www.census.gov/hhes/www/housing/ahs/ahs.html> 

11 The Federal Reserve Board, Survey of Consumer Finances 1989, 1992, 1995, 1998, 2001, 

2004, 2007. (Last accessed July 11, 2012.) 

<http://www.federalreserve.gov/econresdata/scf/scfindex.htm>

12 The Federal Reserve Board, Federal Reserve Statistical Release, Selected Interest Rates, 

Historical Data, Instrument: CDs (secondary market), Maturity: 6-month, Frequency: 

Annual, Description: Average rate on 6-month negotiable certificates of deposit (secondary 
8-44

 

market), quoted on an investment basis, 2011. (Last accessed July 11, 2012.) 

<http://www.federalreserve.gov/releases/H15/data.htm>

13 The Federal Reserve Board, Federal Reserve Statistical Release, Selected Interest Rates, 

Historical Data, Instrument: State and local bonds, Maturity: 20-year, Frequency: Monthly, 

Description: Bond buyer go 20-bond municipal bond index, 2011. (Last accessed July 11, 

2012.) <http://www.federalreserve.gov/releases/H15/data.htm>

14 The Federal Reserve Board, Federal Reserve Statistical Release, Selected Interest Rates, 

Historical Data, Instrument: Corporate bonds/Moody's Seasoned AAA, Frequency: Annual, 

Description: Moody's yield on seasoned corporate bonds - all industries, AAA, 2011. (Last 

accessed July 11, 2012.) <http://www.federalreserve.gov/releases/H15/data.htm>

15 Mortgage-X - Mortgage Information Service, Cost of Savings Index (COSI) Index History, 

2011. (Last accessed July 11, 2012.) <http://mortgage-x.com/general/indexes/default.asp>

16 Damodaran Online Data Page, Historical Returns on Stocks, Bonds and Bills-United States, 

2011. Damodaran. (Last accessed July 11, 2012.) <http://pages.stern.nyu.edu/~adamodar/>

17 U.S. Department of Labor–Bureau of Labor Statistics, Bureau of Labor Statistics Data, 

Prices & Living Conditions, 2011. (Last accessed July 11, 2012.) 

<http://www.bls.gov/data/archived.htm >

18 National Bureau of Economic Research. U.S. Federal and State Average Marginal Income 

Tax Rates, 2010. (Last accessed July 11, 2011.) <http://users.nber.org/~taxsim/marginal-taxrates/at.html>

19 Association of Home Appliance Manufacturers. AHAM Data on Dishwashers for Efficiency 

Standards Rulemaking, September 7, 2006. Letter to Building Technologies Program, U.S. 

Department of Energy.

20 U.S. Office of the Federal Register. Code of Federal Regulations, Title 10, Part 430–Energy 

Conservation Program for Consumer Products, Subpart B, Appendix C: Uniform Test 

Method for Measuring the Energy Consumption of Dishwasher, January 1, 2007. 

Washington, DC.