15-i 

CHAPTER 15. ENVIRONMENTAL IMPACTS ANALYSIS

TABLE OF CONTENTS

15.1 INTRODUCTION ......................................................................................................... 15-1

15.2 AIR EMISSIONS ANALYSIS ...................................................................................... 15-1

15.2.1 Air Emissions Descriptions.......................................................................... 15-1

15.2.2 Global Climate Change ................................................................................ 15-5

15.2.3 Analytical Methods for Air Emissions ........................................................ 15-9

15.2.4 Effects on Power Plant Emissions ............................................................... 15-9

15.2.5 Effects on Upstream Fuel-Cycle Emissions .............................................. 15-14

15.3 WETLAND, ENDANGERED AND THREATENED SPECIES, AND 

CULTURAL RESOURCES ........................................................................................ 15-15

15.4 SOCIOECONOMIC IMPACTS .................................................................................. 15-15

15.5 ENVIRONMENTAL JUSTICE IMPACTS ................................................................ 15-15

15.6 NOISE AND AESTHETICS ....................................................................................... 15-15

15.7 SUMMARY OF ENVIRONMENTAL IMPACTS ..................................................... 15-16

LIST OF TABLES

Table 15.2.1 Reduction in Cumulative Energy-Related Emissions of CO2 from 2014 

through 2043 from Residential Clothes Dryer and Room Air Conditioner 

Energy Conservation Standards ......................................................................... 15-8

Table 15.2.2 Power Sector Emissions Forecast from AEO2010 Reference Case................. 15-10

Table 15.2.3 Power Sector Emissions Impacts Forecasts for Clothes Dryer TSLs .............. 15-11

Table 15.2.4 Power Sector Emissions Impact Forecasts for Room Air Conditioner TSLs .. 15-12

Table 15.2.5 Household Emissions Impact Forecasts for Clothes Dryer TSLs .................... 15-13

Table 15.2.6 Estimated Upstream Emissions of Air Pollutants as a Percentage of Direct 

Power Plant Combustion Emissions ................................................................ 15-14

Table 15.7.1 Cumulative Emissions Reductions Under Clothes Dryer and Room Air 

Conditioner TSLs* ........................................................................................... 15-16
15-1 

CHAPTER 15. ENVIRONMENTAL IMPACTS ANALYSIS 

15.1 INTRODUCTION

This chapter describes potential environmental effects that may result from amended 

energy conservation standards for residential clothes dryers and room air conditioners. The U.S. 

Department of Energy (DOE)’s energy conservation standards are not site-specific, and would 

apply to all 50 States and U.S. territories. Therefore, none of the standards would impact land 

uses, cause any direct disturbance to the land, or directly affect biological resources in any one 

area. 

All of the trial standard levels (TSLs) are expected to reduce energy consumption in 

comparison to the base case. These changes in energy consumption are the primary drivers in 

analyzing environmental effects. The estimates of energy savings that serve as inputs to the 

environmental impacts analysis can be found in the utility impact analysis in chapter 14 of this 

technical support document (TSD). 

The primary impact of the TSLs is on air emissions resulting from power plant 

operations. Therefore, much of this chapter describes the air emissions analysis, and the latter 

part of the chapter describes potential impacts to other environmental resources. For clothes 

dryers there are some household emissions resulting from natural gas usage. 

15.2 AIR EMISSIONS ANALYSIS

 A primary focus of the environmental analysis is the impact on air emissions of amended 

energy conservation standards for residential clothes dryers and room air conditioner products. 

The outcomes of the environmental analysis are largely driven by changes in power plant types 

and quantities of electricity generated under each of the alternatives. Changes in electricity 

generation are described in the utility impact analysis in chapter 14. 

15.2.1 Air Emissions Descriptions

For each of the TSLs, DOE calculated total power-sector emissions based on output from 

the NEMS-BT model (see chapter 14 for description of the model). This analysis considers three 

pollutants: sulfur dioxide (SO2), nitrogen oxides (NOX), and mercury (Hg). An air pollutant is 

any substance in the air that can cause harm to humans or the environment. Pollutants may be 

natural or man-made (i.e., anthropogenic) and may take the form of solid particles (i.e., 

particulates or particulate matter), liquid droplets, or gases.a This analysis also considers carbon 

dioxide (CO2). 

 

a More information on air pollution characteristics and regulations is available on the U.S. Environment Protection 

Agent (EPA)’s website at www.epa.gov.
15-2 

 Sulfur Dioxide. Sulfur dioxide, or SO2, belongs to the family of sulfur oxide gases 

(SOx). These gases dissolve easily in water. Sulfur is prevalent in all raw materials, including 

crude oil, coal, and ore that contains common metals like aluminum, copper, zinc, lead, and iron. 

SOx gases are formed when fuel containing sulfur, such as coal and oil, is burned, and when 

gasoline is extracted from oil, or metals are extracted from ore. SO2 dissolves in water vapor to 

form acid, and interacts with other gases and particles in the air to form sulfates and other 

products that can be harmful to people and their environment.1

SO2 emissions from affected Electric Generating Units (EGUs) are subject to nationwide 

and regional emissions cap and trading programs, and DOE has determined that these programs 

create uncertainty about the standards’ impact on SO2 emissions. The attainment of emissions 

caps is typically flexible among EGUs and is enforced through the use of emissions allowances 

and tradable permits. Under existing EPA regulations, any excess SO2 emissions allowances 

resulting from the lower electricity demand caused by the imposition of an efficiency standard 

could be used to permit offsetting increases in SO2 emissions by any regulated EGU. However, if 

the standard resulted in a permanent increase in the quantity of unused emissions allowances, 

there would be an overall reduction in SO2 emissions from the standards. While there remains 

some uncertainty about the ultimate effects of efficiency standards on SO2 emissions covered by 

the existing cap and trade system, the NEMS-BT modeling system that DOE uses to forecast 

emissions reductions currently indicates that no physical reductions in power sector emissions 

would occur for SO2. 

 Nitrogen Oxides. Nitrogen oxides, or NOX, is the generic term for a group of highly 

reactive gases, all of which contain nitrogen and oxygen in varying amounts. Many of the 

nitrogen oxides are colorless and odorless. However, one common pollutant, nitrogen dioxide 

(NO2), along with particles in the air can often be seen as a reddish-brown layer over many urban 

areas. NO2 is the specific form of NOX reported in this document. NOX is one of the main 

ingredients involved in the formation of ground-level ozone, which can trigger serious 

respiratory problems. It can contribute to the formation of acid rain, and can impair visibility in 

areas such as national parks. NOX also contributes to the formation of fine particles that can 

impair human health.1

 Nitrogen oxides form when fossil fuel is burned at high temperatures, as in a combustion 

process. The primary manmade sources of NOX are motor vehicles, electric utilities, and other 

industrial, commercial, and residential sources that burn fossil fuels. NOX can also be formed 

naturally. Electric utilities account for about 22 percent of NOX emissions in the United States.2

There is a cap on NOx emissions in 28 eastern states and the District of Columbia. All 

these States and D.C. have elected to reduce their NOx emissions by participating in cap-andtrade programs for EGUs. Therefore, energy conservation standards for clothes dryers and room 

air conditioners may have little or no physical effect on these emissions in the 28 eastern states 

and the D.C. for the same reasons that they may have little or no physical effect on NOX

emissions. 
15-3 

DOE is using the NEMS-BT to estimate NOx emissions reductions from possible 

standards in the states where emissions are not capped.

Mercury. Coal-fired power plants emit mercury (Hg) found in coal during the burning 

process. While coal-fired power plants are the largest remaining source of human-generated Hg 

emissions in the United States, they contribute very little to the global Hg pool or to 

contamination of U.S. waters.1 U.S. coal-fired power plants emit Hg in three different forms: 

oxidized Hg (likely to deposit within the United States); elemental Hg, which can travel 

thousands of miles before depositing to land and water; and Hg that is in particulate form. 

Atmospheric Hg is then deposited on land, lakes, rivers, and estuaries through rain, snow, and 

dry deposition. Once there, it can transform into methylmercury and accumulate in fish tissue 

through bioaccumulation. 

 

Americans are exposed to methylmercury primarily by eating contaminated fish. Because 

the developing fetus is the most sensitive to the toxic effects of methylmercury, women of 

childbearing age are regarded as the population of greatest concern. Children exposed to 

methylmercury before birth may be at increased risk of poor performance on neurobehavioral 

tasks, such as those measuring attention, fine motor function, language skills, visual-spatial 

abilities, and verbal memory.3 

 Carbon Dioxide. Carbon dioxide (CO2) is not a criteria pollutant (see below), but it is of 

interest because of its classification as a greenhouse gas (GHG). GHGs trap the sun’s radiation 

inside the Earth’s atmosphere and either occur naturally in the atmosphere or result from human 

activities. Naturally occurring GHGs include water vapor, CO2, methane (CH4), nitrous oxide 

(N2O), and ozone (O3). Human activities, however, add to the levels of most of these naturally 

occurring gases. For example, CO2 is emitted to the atmosphere when solid waste, fossil fuels 

(oil, natural gas, and coal), wood, and wood products are burned. In 2007, over 90 percent of 

anthropogenic (i.e., human-made) CO2 emissions resulted from burning fossil fuels.4

 Concentrations of CO2 in the atmosphere are naturally regulated by numerous processes, 

collectively known as the “carbon cycle.” The movement of carbon between the atmosphere and 

the land and oceans is dominated by natural processes, such as plant photosynthesis. While these 

natural processes can absorb some of the anthropogenic CO2 emissions produced each year, 

billions of metric tons are added to the atmosphere annually. In the United States, in 2007, CO2

emissions from electricity generation accounted for 39 percent of total U.S. GHG emissions.4

Particulate Matter. Particulate matter (PM) also known as particle pollution, is a 

complex mixture of extremely small particles and liquid droplets. Particle pollution is made up 

of a number of components, including acids (such as nitrates and sulfates), organic chemicals, 

metals, and soil or dust particles.

 PM impacts are of concern due to human exposures that can impact health. Particle 

pollution - especially fine particles - contains microscopic solids or liquid droplets that are so 

small that they can get deep into the lungs and cause serious health problems. Numerous 

scientific studies have linked particle pollution exposure to a variety of problems, including: 
15-4 

increased respiratory symptoms, such as irritation of the airways, coughing, or difficulty 

breathing, for example; decreased lung function; aggravated asthma; development of chronic 

bronchitis; irregular heartbeat; nonfatal heart attacks; and premature death in people with heart or 

lung disease.

DOE acknowledges that particulate matter (PM) exposure can impact human health. 

Power plant emissions can have either direct or indirect impacts on PM. A portion of the 

pollutants emitted by a power plant are in the form of particulates as they leave the smoke stack. 

These are direct, or primary, PM emissions. However, the great majority of PM emissions 

associated with power plants are in the form of secondary sulfates, which are produced at a 

significant distance from power plants by complex atmospheric chemical reactions that often 

involve the gaseous (non-particulate) emissions of power plants, mainly SO2 and NOx. The 

quantity of the secondary sulfates produced is determined by a very complex set of factors 

including the atmospheric quantities of SO2 and NOx, and other atmospheric constituents and 

conditions. Because these highly complex chemical reactions produce PM comprised of different 

constituents from different sources, EPA does not distinguish direct PM emissions from power 

plants from the secondary sulfate particulates in its ambient air quality requirements, PM 

monitoring of ambient air quality, or PM emissions inventories. For these reasons, it is not 

currently possible to determine how the amended standard impacts either direct or indirect PM 

emissions. Therefore, DOE is not planning to assess the impact of these standards on PM 

emissions. Further, as described previously, it is uncertain whether efficiency standards will 

result in a net decrease in power plant emissions of SO2 and NOx, since those pollutants are now 

largely regulated by cap and trade systems. 

Air Quality Regulation. The Clean Air Act Amendments of 1990 list 188 toxic air 

pollutants that EPA is required to control.6 EPA has set national air quality standards for six 

common pollutants (also referred to as “criteria” pollutants), two of which are SO2 and NOX. 

Also, the Clean Air Act Amendments of 1990 gave EPA the authority to control acidification 

and to require operators of electric power plants to reduce emissions of SO2 and NOX. Title IV of 

the 1990 amendments established a cap-and-trade program for SO2, in all 50 states and the 

District of Columbia (D.C.), intended to help control acid rain. 6 This cap-and-trade program 

serves as a model for more recent programs with similar features.

 In 2005, EPA issued the Clean Air Interstate Rule (CAIR) under sections 110 and 111 of 

the Clean Air Act (40 CFR Parts 51, 96, and 97).7 b

 

b See http://www.epa.gov/cleanairinterstaterule/.

CAIR will permanently cap emissions of 

SO2 and NOX in eastern States of the United States. CAIR achieves large reductions of SO2

and/or NOX emissions across 28 eastern States and the District of Columbia. CAIR will 

gradually replace the Title IV program in the 28 states and D.C. States must achieve the required 

emission reductions using one of two compliance options: 1) meet an emission budget for each 

regulated state by requiring power plants to participate in an EPA-administered interstate capand-trade system that caps emissions in two stages, or 2) meet an individual state emissions 

budget through measures of the state’s choosing. Phase 1 caps for NOX have been in place since
15-5 

2009. Phase 1 caps for SO2 are to be in place beginning in 2010. The Phase 2 caps for both NOX

and SO2 are due in 2015. 

On July 11, 2008, the U.S. Court of Appeals for the District of Columbia Circuit (D.C. 

Circuit) issued its decision in North Carolina v. Environmental Protection Agency, which 

vacated the CAIR issued by the U.S. Environmental Protection Agency on March 10, 2005.c

CAIR was the vehicle for capping NOX emissions.

d

 On December 23, 2008, the D.C. Circuit 

decided to allow CAIR to remain in effect until it is replaced by a rule consistent with the court’s 

earlier opinion. North Carolina v. EPA, 550 F.3d 1176 (D.C. Cir. 2008) (remand of vacatur).e

Thus, CAIR is currently in force. However, on July 6, 2010, EPA proposed the Transport Rule, 

a replacement for CAIR, which would limit emissions from EGUs in 32 states, potentially 

through the interstate trading of allowances, among other options. 75 FR 45210 (Aug. 2, 2010). 

 

With respect to Hg emissions, in 2005, EPA issued the final rule entitled “Standards of 

Performance for New and Existing Stationary Sources: Electric Steam Generating Units,” under 

sections 110 and 111 of the Clean Air Act (40 CFR Parts 60, 63, 72, and 75)8

. This rule, called 

the Clean Air Mercury Rule (CAMR), was closely related to the CAIR and established standards 

of performance for Hg emissions from new and existing coal-fired electric utility steam 

generating units. The CAMR regulated Hg emissions from coal-fired power plants. 

 

 On February 8, 2008, the U.S. Court of Appeals for the District of Columbia Circuit 

(D.C. Circuit) issued its decision in State of New Jersey, et al. v. Environmental Protection 

Agency,

f

15.2.2 Global Climate Change 

 in which the Court, among other actions, vacated the CAMR referenced above. 

Climate change has evolved into a matter of global concern because it is expected to have 

widespread, adverse effects on natural resources and systems. A growing body of evidence 

points to anthropogenic sources of greenhouse gases, such as carbon dioxide (CO2), as major 

contributors to climate change. Because this Rule, if finalized, will likely decrease CO2 emission 

rates from the fossil fuel sector in the United States, the Department here examines the impacts 

and causes of climate change and then the potential impact of the Rule on CO2 emissions and 

global warming. 

 Impacts of Climate Change on the Environment. Climate is usually defined as the 

average weather, over a period ranging from months to many years. Climate change refers to a 

change in the state of the climate, which is identifiable through changes in the mean and/or the 

variability of its properties (e.g., temperature or precipitation) over an extended period, typically 

decades or longer.9

 

 

c See http://www.epa.gov/cleanairinterstaterule/.

d See id. at 903. 

e State of North Carolina, et al. v. Environmental Protection Agency, 550 F.3d 1176 (D.C. Cir. 2008). 

f 517 F.3d 574, 583 (D.C. Cir. 2008).
15-6 

 The World Meteorological Organization and United Nations Environment Programme 

(UNEP) established the Intergovernmental Panel on Climate Change (IPCC) to provide an 

objective source of information about climate change. According to the IPCC Fourth Assessment 

Report (IPCC Report), published in 2007, climate change is consistent with observed changes to 

the world’s natural systems; the IPCC expects these changes to continue.9

 Changes that are consistent with warming include warming of the world’s oceans to a 

depth of 3000 meters; global average sea level rise at an average rate of 1.8 mm per year from 

1961 to 2003; loss of annual average Arctic sea ice at a rate of 2.7 percent per decade, changes in 

wind patterns that affect extra-tropical storm tracks and temperature patterns, increases in intense 

precipitation in some parts of the world, as well as increased drought and more frequent heat 

waves in many locations worldwide, and numerous ecological changes.9

 Looking forward, the IPCC describes continued global warming of about 0.2 °C per 

decade for the next two decades under a wide range of emission scenarios for carbon dioxide 

(CO2), other greenhouse gases (GHGs), and aerosols. After that period, the rate of increase is 

less certain. The IPCC Report describes increases in average global temperatures of about 1.1 °C 

to 6.4 °C at the end of the century relative to today. These increases vary depending on the model 

and emissions scenarios.9

The IPCC Report describes incremental impacts associated with the rise in temperature. 

At ranges of incremental increases to the global average temperature, IPCC reports, with either 

high or very high confidence, that there is likely to be an increasing degree of impacts such as 

coral reef bleaching, loss of wildlife habitat, loss to specific ecosystems, and negative yield 

impacts for major cereal crops in the tropics, but also projects that there likely will be some 

beneficial impacts on crop yields in temperate regions. 

 Causes of Climate Change. The IPCC Report states that the world has warmed by about 

0.74 °C in the last 100 years. The IPCC Report finds that most of the temperature increase since 

the mid-20th century is very likely due to the increase in anthropogenic concentrations of CO2

and other long-lived greenhouse gases such as methane and nitrous oxide in the atmosphere, 

rather than from natural causes. 

Increasing the CO2 concentration partially blocks the earth’s re-radiation of captured 

solar energy in the infrared band, inhibits the radiant cooling of the earth, and thereby alters the 

energy balance of the planet, which gradually increases its average temperature. The IPCC 

Report estimates that currently, CO2 makes up about 77 percent of the total CO2-equivalentg

 

g GHGs differ in their warming influence (radiative forcing) on a global climate system due to their different 

radiative properties and lifetimes in the atmosphere. These warming influences may be expressed through a common 

metric based on the radiative forcing of CO2, i.e., CO2-equivalent. CO2 equivalent emission is the amount of CO2

emission that would cause the same- time integrated radiative forcing, over a given time horizon, as an emitted 

amount of other long- lived GHG or mixture of GHGs.

global warming potential in GHGs emitted from human activities, with the vast majority (74 

percent) of the CO2 attributable to fossil fuel use.10 For the future, the IPCC Report describes a 
15-7 

wide range of GHG emissions scenarios, but under each scenario CO2 would continue to 

comprise above 70 percent of the total global warming potential.10

Stabilization of CO2 Concentrations. Unlike many traditional air pollutants, CO2 mixes 

thoroughly in the entire atmosphere and is long-lived. The residence time of CO2 in the 

atmosphere is long compared to the emission processes. Therefore, the global cumulative 

emissions of CO2 over long periods determine CO2 concentrations because it takes hundreds of 

years for natural processes to remove the CO2. Globally, 49 billion metric tons of CO2 –

equivalent of anthropogenic (man-made) greenhouse gases are emitted every year. Of this annual 

total, fossil fuels contribute about 29 billion metric tons of CO2.

11 h

 

 

Researchers have focused on considering atmospheric CO2 concentrations that likely will 

result in some level of global climate stabilization, and the emission rates associated with 

achieving the “stabilizing” concentrations by particular dates. They associate these stabilized 

CO2 concentrations with temperature increases that plateau in a defined range. For example, at 

the low end, the IPCC Report scenarios target CO2 stabilized concentrations range between 350 

ppm and 400 ppm (essentially today’s value)—because of climate inertia, concentrations in this 

low-end range would still result in temperatures projected to increase 2.0 °C to 2.4 °C above preindustrial levelsi

 (about 1.3 °C to 1.7 °C above today’s levels). To achieve concentrations 

between 350 ppm to 400 ppm, the IPCC scenarios present that there would have to be a rapid 

downward trend in total annual global emissions of greenhouse gases to levels that are 50 to 85 

percent below today’s annual emission rates by no later than 2050. Since it is assumed that there 

would continue to be growth in global population and substantial increases in economic 

production, the scenarios identify required reductions in greenhouse gas emissions intensity 

(emissions per unit of output) of more than 90 percent. However, even at these rates, the 

scenarios describe some warming and some climate change is projected due to already 

accumulated CO2 and GHGs in the atmosphere.12

The Beneficial Impact of the Rule on CO2 Emissions. It is anticipated that the Rule will 

reduce energy-related CO2 emissions, particularly those associated with energy consumption in 

buildings. The U.S. Energy Information Administration (EIA) reports in its 2010 Annual Energy 

Outlook (AEO2010)

13 that U.S. annual energy-related emissions of CO2 in 2007 were about 6.0 

billion metric tons, of which 1.2 billion tons were attributed to the residential buildings sector 

(including related energy–using products such as clothes dryer and room air conditioner 

products). Most of the greenhouse gas emissions attributed to residential buildings are emitted 

from fossil fuel-fired power plants that generate electricity used in this sector. In the AEO2010 

Reference Case, EIA projected that annual energy-related CO2 emissions would grow from 5.7 

billion metric tons in 2015 to 6.3 billion metric tons in 2035, an increase of 10 percent (see 

AEO2010), while residential emissions would grow to from 1.2 billion metric tons to 1.3 billion

metric tons, an increase of 12 percent. 

 

h Other non-fossil fuel contributors include CO2 emissions from deforestation and decay from agriculture biomass; 

agricultural and industrial emissions of methane; and emissions of nitrous oxide and fluorocarbons.

i

IPCC Working Group 3 Table TS 2
15-8 

 The estimated cumulative CO2 emission reductions from residential clothes dryers and 

room air conditioner efficiency standards (shown as a range of alternative TSLs) during the 30-

year analysis period are indicated in Table 15.2.1. Estimated CO2 emission reductions in Table 

15.2.1 come from electricity generation (i.e., power plants) and household emissions. The 

estimated CO2 emission reductions from electricity generation are calculated using the NEMSBT model. 

Table 15.2.1 Reduction in Cumulative Energy-Related Emissions of CO2 from 2014 

through 2043 from Residential Clothes Dryer and Room Air Conditioner

Energy Conservation Standards 

Trial Standard Levels

TSL 1 TSL 2 TSL 3 TSL 4 TSL 5 TSL 6

Million Metric Tons 

Clothes Dryers 0.119 2.99 17.7 18.7 70.5 187 

Room Air Conditioners 9.83 11.9 12.5 17.4 26.9 37.7

Total 9.95 14.9 30.2 36.1 97.4 224

Percent of Total Cumulative 

Emissions Reduction compared 

with the AEO2010 Reference 

Case in 2014-2043 

0.013 0.020 0.041 0.048 0.131 0.301 

The Incremental Impact of the Rule on Climate Change. It is difficult to correlate 

specific emission rates with atmospheric concentrations of CO2 and specific atmospheric 

concentrations with future temperatures because the IPCC Report describes a clear lag in the 

climate system between any given concentration of CO2 (even if maintained for long periods) 

and the subsequent average worldwide and regional temperature, precipitation, and extreme 

weather regimes. For example, a major determinant of climate response is “equilibrium climate 

sensitivity”, a measure of the climate system response to sustained radiative forcing. It is defined 

as the global average surface warming following a doubling of carbon dioxide concentrations. 

The IPCC Report describes its estimated, numeric value as about 3 °C, but the likely range of 

that value is 2 °C to 4.5 °C, with cloud feedbacks the largest source of uncertainty. Further, as 

illustrated above, the IPCC Report scenarios for stabilization rates are presented in terms of a 

range of concentrations, which then correlates to a range of temperature changes. Thus, climate 

sensitivity is a key uncertainty for CO2 mitigation scenarios that aim to meet specific temperature 

levels. 

 

Because of how complex global climate systems are, it is difficult to know to what extent 

and when particular CO2 emissions reductions will impact global warming. However, as Table 

15.2.1 indicates, the rule is expected to reduce CO2 emissions associated with energy 

consumption in buildings. 
15-9 

15.2.3 Analytical Methods for Air Emissions 

Coal-fired electric generation is the single largest source of electricity in the United 

States. Because the mix of coals used significantly affects the emissions produced, the model 

includes a detailed representation of coal supply. The model considers the rank of the coal as 

well as the sulfur contents of the fuel used when determining optimal dispatch.14

Within the NEMS-BT model, planning options for achieving emissions restrictions in the 

Clean Air Act Amendments include installing pollution control equipment on existing power 

plants and building new power plants with low emission rates. These methods for reducing 

emission are compared to dispatching options such as fuel switching and allowance trading. 

Environmental regulations also affect capacity expansion decisions. For instance, new plants are 

not allocated SO2 emissions allowances according to the Clean Air Act Amendments. 

Consequently, the decision to build a particular capacity type must consider the cost (if any) of 

obtaining sufficient allowances. This could involve purchasing allowances or over complying at 

an existing unit.

DOE’s analysis assumes the presence of nationwide emission caps on SO2 and caps on 

NOX emissions in the 28 States covered by the CAIR. The NEMS-BT modeling system that 

DOE plans to use to forecast emissions reductions currently indicates that no physical reductions 

in power sector emissions would occur for SO2. However, in contrast to the modeling forecasts 

of NEMS-BT that SO2 emissions reductions will remain at the cap, during the years 2007 and 

2008, SO2 emissions have been below the trading cap. The difference between the emissions 

levels that NEMS-BT forecasts and those that EPA forecasts is an indicator of the uncertainties 

associated with long-range energy sector forecasts. Because of such uncertainties, DOE is unable 

to estimate the economic and physical benefit from SO2 emissions reductions at this time.

With respect to Hg, in the absence of CAMR or other trading program, a DOE standard 

would likely reduce Hg emissions and DOE uses NEMS-BT to estimate these emission 

reductions. However, DOE continues to review the impact of rules that reduce energy 

consumption on Hg emissions, and may revise its assessment of Hg emission reductions in future 

rulemakings. 

 As noted in chapter 14, NEMS-BT model forecasts end in year 2035. Emissions impacts 

beyond 2035 are assumed to be equal to the impacts in 2035. 

15.2.4 Effects on Power Plant Emissions

Table 15.2.2 shows AEO2010 reference case power plant emissions in selected years. 

The Reference Case emissions are the emissions shown by the NEMS-BT model to result if none 

of the TSLs are promulgated (the base case). 
15-10

Table 15.2.2 Power Sector Emissions Forecast from AEO2010 Reference Case

NEMS-BT Results 2010 2015 2020 2025 2030 2035

CO2 (million metric tons) 2,218 2,278 2,341 2,421 2,534 2,636

NOX (million tons) 2.24 2.06 2.02 2.03 2.06 2.07

Hg (tons) 40.6 30.6 30.1 30.0 30.2 30.3

 Tables 15.2.3 and 15.2.4 show the estimated changes in power plant emissions by TSL 

for residential clothes dryers and room air conditioners. The tables display changes in CO2, NOx, 

and Hg emissions in selected years for each of the TSLs. “Mt” refers to “million metric tons.” 

Similarly Table 15.2.5 shows household emissions impacts for residential clothes dryers 

by TSL in selected years. This table displays changes in CO2, NOX, and SO2 emissions. There 

are no household emissions impacts for room air conditioners. 
15-11

Table 15.2.3 Power Sector Emissions Impacts Forecasts for Clothes Dryer TSLs

NEMS-BT Results* Difference from AEO2010 Reference Case

Total

2010 2015 2020 2025 2030 2035 2040 2043 2014-2043

Standard Level 1

CO2 (Mt/yr) 0.000 0.001 -0.002 -0.004 -0.005 -0.005 -0.005 -0.005 -0.104

NOx (1,000 tons/yr) 0.000 0.001 -0.002 -0.003 -0.004 -0.004 -0.004 -0.004 -0.084

Hg (ton/yr) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Standard Level 2

CO2 (Mt/yr) 0.008 0.039 -0.058 -0.105 -0.147 -0.136 -0.136 -0.136 -2.97

NOx (1,000 tons/yr) 0.008 0.035 -0.050 -0.088 -0.119 -0.106 -0.106 -0.106 -2.39

Hg (ton/yr) 0.000 0.000 -0.001 0.000 0.000 0.000 0.000 0.000 -0.009

Standard Level 3

CO2 (Mt/yr) 0.048 0.235 -0.345 -0.625 -0.877 -0.808 -0.808 -0.808 -17.7

NOx (1,000 tons/yr) 0.049 0.212 -0.298 -0.525 -0.712 -0.633 -0.633 -0.633 -14.2

Hg (ton/yr) 0.000 0.000 -0.003 -0.001 -0.003 -0.002 -0.002 -0.002 -0.053

Standard Level 4

CO2 (Mt/yr) 0.047 0.227 -0.333 -0.603 -0.846 -0.779 -0.779 -0.779 -17.1

NOx (1,000 tons/yr) 0.047 0.205 -0.287 -0.507 -0.687 -0.611 -0.611 -0.611 -13.7

Hg (ton/yr) 0.000 0.000 -0.003 -0.001 -0.003 -0.002 -0.002 -0.002 -0.051

Standard Level 5

CO2 (Mt/yr) 0.173 0.837 -1.231 -2.227 -3.125 -2.878 -2.878 -2.878 -63.2

NOx (1,000 tons/yr) 0.174 0.757 -1.061 -1.871 -2.537 -2.256 -2.256 -2.256 -50.8

Hg (ton/yr) 0.001 -0.001 -0.012 -0.005 -0.009 -0.007 -0.007 -0.007 -0.188

Standard Level 6

CO2 (Mt/yr) 0.421 0.826 -3.279 -6.880 -8.205 -7.971 -7.971 -7.971 -179

NOx (1,000 tons/yr) 0.425 0.747 -2.825 -5.781 -6.662 -6.248 -6.248 -6.248 -145

Hg (ton/yr) 0.006 -0.009 -0.018 -0.015 -0.012 -0.022 -0.022 -0.022 -0.569

*CO2 results are in metric tons, NOX and Hg results are in short tons.

Extrapolation
15-12

Table 15.2.4 Power Sector Emissions Impact Forecasts for Room Air Conditioner 

TSLs

NEMS-BT Results* Difference from AEO2010 Reference Case

Total

2010 2015 2020 2025 2030 2035 2040 2043 2014-2043

Standard Level 1

CO2 (Mt/yr) 0.050 0.030 -0.338 -0.480 -0.408 -0.333 -0.333 -0.333 -9.83

NOx (1,000 tons/yr) 0.051 0.027 -0.291 -0.403 -0.331 -0.261 -0.261 -0.261 -8.02

Hg (ton/yr) 0.000 0.001 -0.001 -0.001 0.000 0.000 0.000 0.000 -0.012

Standard Level 2

CO2 (Mt/yr) 0.060 0.036 -0.403 -0.573 -0.491 -0.410 -0.410 -0.410 -11.9

NOx (1,000 tons/yr) 0.061 0.033 -0.347 -0.482 -0.398 -0.321 -0.321 -0.321 -9.69

Hg (ton/yr) 0.000 0.001 -0.001 -0.001 0.000 0.000 0.000 0.000 -0.015

Sandard Level 3

CO2 (Mt/yr) 0.073 0.042 -0.455 -0.613 -0.506 -0.418 -0.418 -0.418 -12.5

NOx (1,000 tons/yr) 0.074 0.038 -0.392 -0.515 -0.410 -0.327 -0.327 -0.327 -10.2

Hg (ton/yr) 0.000 0.001 -0.002 -0.001 0.000 0.000 0.000 0.000 -0.017

Standard Level 4

CO2 (Mt/yr) 0.097 0.056 -0.607 -0.833 -0.705 -0.604 -0.604 -0.604 -17.4

NOx (1,000 tons/yr) 0.097 0.051 -0.523 -0.700 -0.572 -0.474 -0.474 -0.474 -14.2

Hg (ton/yr) 0.001 0.001 -0.002 -0.002 -0.001 0.000 0.000 0.000 -0.022

Standard Level 5

CO2 (Mt/yr) 0.139 0.081 -0.892 -1.255 -1.091 -0.970 -0.970 -0.970 -26.9

NOx (1,000 tons/yr) 0.141 0.073 -0.769 -1.054 -0.885 -0.760 -0.760 -0.760 -21.9

Hg (ton/yr) 0.001 0.002 -0.003 -0.002 -0.001 0.000 0.000 0.000 -0.032

Standard Level 6

CO2 (Mt/yr) 0.186 0.108 -1.208 -1.726 -1.528 -1.396 -1.396 -1.396 -37.7

NOx (1,000 tons/yr) 0.187 0.098 -1.041 -1.450 -1.241 -1.094 -1.094 -1.094 -30.7

Hg (ton/yr) 0.001 0.002 -0.004 -0.003 -0.001 0.000 0.000 0.000 -0.044

*CO2 results are in metric tons, NOX and Hg results are in short tons.

Extrapolation
15-13

Table 15.2.5 Household Emissions Impact Forecasts for Clothes Dryer TSLs

NEMS-BT Results* Difference from AEO2010 Reference Case

Total

2010 2015 2020 2025 2030 2035 2040 2043 2014-2043

Standard Level 1

CO2 (Mt/yr) 0.000 0.000 0.000 0.000 -0.001 -0.001 -0.001 -0.001 -0.015

NOx (1,000 tons/yr) 0.000 0.000 0.000 0.000 0.000 -0.001 -0.001 -0.001 -0.012

SO2 (1,000 tons/yr) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Standard Level 2

CO2 (Mt/yr) 0.000 0.000 0.000 -0.001 -0.001 -0.001 -0.001 -0.001 -0.021

NOx (1,000 tons/yr) 0.000 0.000 0.000 -0.001 -0.001 -0.001 -0.001 -0.001 -0.017

SO2 (1,000 tons/yr) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Standard Level 3

CO2 (Mt/yr) 0.000 0.000 0.000 -0.001 -0.001 -0.001 -0.001 -0.001 -0.021

NOx (1,000 tons/yr) 0.000 0.000 0.000 -0.001 -0.001 -0.001 -0.001 -0.001 -0.017

SO2 (1,000 tons/yr) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Standard Level 4

CO2 (Mt/yr) 0.000 -0.008 -0.031 -0.050 -0.064 -0.074 -0.074 -0.074 -1.57

NOx (1,000 tons/yr) 0.000 -0.007 -0.025 -0.040 -0.052 -0.060 -0.060 -0.060 -1.27

SO2 (1,000 tons/yr) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 -0.010

Standard Level 5

CO2 (Mt/yr) 0.000 -0.039 -0.143 -0.232 -0.298 -0.344 -0.344 -0.344 -7.31

NOx (1,000 tons/yr) 0.000 -0.032 -0.115 -0.188 -0.241 -0.278 -0.278 -0.278 -5.90

SO2 (1,000 tons/yr) 0.000 0.000 -0.001 -0.001 -0.002 -0.002 -0.002 -0.002 -0.046

Standard Level 6

CO2 (Mt/yr) 0.000 -0.039 -0.143 -0.232 -0.298 -0.344 -0.344 -0.344 -7.31

NOx (1,000 tons/yr) 0.000 -0.032 -0.115 -0.188 -0.241 -0.278 -0.278 -0.278 -5.90

SO2 (1,000 tons/yr) 0.000 0.000 -0.001 -0.001 -0.002 -0.002 -0.002 -0.002 -0.046

*All results in metric tons (t), equivalent to 1.1 short tons

Extrapolation
15-14

15.2.5 Effects on Upstream Fuel-Cycle Emissions

Upstream fuel-cycle emissions refer to the emissions associated with the amount of 

energy used in the upstream production and downstream consumption of electricity, including 

energy used at the power plant.17 Upstream processes include the mining of coal or extraction of 

natural gas, physical preparatory and cleaning processes, and transportation to the power plant. 

The NEMS-BT does a thorough accounting of emissions at the power plant due to downstream 

energy consumption, but does not account for upstream emissions (i.e., emissions from energy 

losses during coal and natural gas production). Thus, this analysis reports only power plant 

emissions.

 However, previous DOE environmental assessment documents have developed 

approximate estimates of effects on upstream fuel-cycle emissions. These emissions factors 

provide the reader with a sense of the possible magnitude of upstream effects. These upstream 

emissions would be in addition to emissions from direct combustion. 

 Relative to the entire fuel cycle, estimates based on the work of Dr. Mark DeLuchi, and 

reported in earlier DOE environmental assessment documents, find that an amount 

approximately equal to eight percent, by mass, of emissions (including SO2) from coal 

production are due to mining, preparation that includes cleaning the coal, and transportation from 

the mine to the power plant.18 Transportation emissions include emissions from the fuel used by 

the mode of transportation that moves the coal from the mine to the power plant. In addition, 

based on Dr. DeLuchi’s work, DOE estimated that an amount equal to approximately 14 percent 

of emissions from natural gas production result from upstream processes. 

 Emission factor estimates and corresponding percentages of contributions of upstream 

emissions from coal and natural gas production, relative to power plant emissions, are shown in 

Table 15.2.6 for CO2 and NOX. The percentages provide a means to estimate upstream emission 

savings based on changes in emissions from power plants. This approach does not address Hg 

emissions.

Table 15.2.6 Estimated Upstream Emissions of Air Pollutants as a Percentage of 

Direct Power Plant Combustion Emissions

Pollutant

Percent of Coal

Combustion Emissions

Percent of Natural Gas

Combustion Emissions

CO2 2.7 11.9

NOX 5.8 40
15-15

15.3 WETLAND, ENDANGERED AND THREATENED SPECIES, AND 

CULTURAL RESOURCES

Because residential clothes dryers and room air conditioners are not water-consuming 

products, more energy efficient operation would not reduce the amount of water discharged into 

the waste stream. As a result, the energy conservation standards do not have the effect of 

improving the quality of wetlands, nor threatened or endangered species that reside in these 

wetlands. This action is also not expected to impact cultural resources such as historical or 

archaeological sites.

15.4 SOCIOECONOMIC IMPACTS 

DOE's analysis has shown that the increase in the first cost of purchasing more efficient 

clothes dryers and room air conditioners at the proposed standard levels is, in most cases, 

completely offset by a reduction in the life-cycle cost (LCC) of owning a more efficient product 

for the average consumer. In other words, the consumer will pay less operating costs over the life 

of the product even through the first cost increases. The complete LCC analysis and its 

conclusions are presented in chapter 8 of the TSD. 

 For subgroups of low-income and senior consumers that purchase clothes dryer and room 

air conditioner products, DOE determined that the average LCC impact of the standards is 

similar to that for the full sample of consumers. Therefore, DOE concludes that the proposed 

standards would have no significant adverse socioeconomic impact. For a complete discussion 

on the LCC impacts on consumer subgroups, see chapter 11 of the TSD. 

15.5 ENVIRONMENTAL JUSTICE IMPACTS

 In view of Executive Order 12898 of February 11, 1994, “Federal Actions to Address 

Environmental Justice in Minority Populations and Low-Income Populations,” DOE examined 

the effect of the energy conservation standards on low-income households. As described in the 

LCC subgroup analysis in chapter 11 of the TSD, DOE found that there were no 

disproportionately high and adverse human health or environmental effects on low-income 

populations that would result from the proposed energy conservation standards. 

15.6 NOISE AND AESTHETICS

Improvements in efficiency of residential clothes dryers and room air conditioners are 

expected to result from changes in the choice of components and other design features. These 

changes are described in chapter 5 of this TSD. These design changes are not expected to change 

noise levels in comparison to products in today’s market. Products that are currently 

manufactured in the existing market that would meet the standards are no louder than less 
15-16

efficient products. Changes to the design to improve the efficiency levels are not anticipated to 

affect the product aesthetics.

15.7 SUMMARY OF ENVIRONMENTAL IMPACTS

Table 15.7.1 summarizes the estimated emissions impacts for each of the TSLs for 

clothes dryers and room air conditioners. It shows cumulative changes in emissions for CO2, 

NOX, and Hg for 2014 through 2043 for each of the TSLs. Cumulative CO2, NOX, and Hg 

emissions are reduced compared to the Reference case for all TSLs. For comparison, the 

cumulative power sector emissions in the AEO2010 Reference case, over the period 2014 

through 2043, are 74,571 Mt for CO2, 61,625 kt for NOx, and 917 tons for Hg. 

Upstream fuel cycle emission of CO2 and NOX are described but not quantified in section 

15.2.6. The text describes potential reductions in fuel cycle emissions as percentage of decreases 

in power plant emissions. This approach suggests that upstream fuel cycle emissions would 

decrease and provides a sense for the magnitude of effects; however DOE does not report actual 

estimates of the effects. 

 For subgroups of low-income and senior consumers that purchase room air conditioning 

and clothes dryer products, DOE determined that the average LCC impact of the standards is 

similar to that for the full sample of consumers. Therefore, DOE concludes that the proposed 

standards would have no significant adverse socioeconomic impact. 

No impacts are anticipated in the areas of environmental justice, wetlands, endangered 

and threatened species, and cultural resources; or noise and aesthetics.

Table 15.7.1 Cumulative Emissions Reductions Under Clothes Dryer and Room Air 

Conditioner TSLs* 

TSL 1 TSL 2 TSL 3 TSL 4 TSL 5 TSL 6

Clothes Dryers

 CO2 (Mt)

 NOX (1,000 tons) 

 Hg (ton) 

0.119 

0.097 

0.000 

2.99 

2.41 

0.009 

17.7 

14.3 

0.053 

18.7 

15.1 

0.051 

70.5 

57.3 

0.188 

187 

151 

0.569 

Room Air Conditioners

 CO2 (Mt)

 NOX (1,000 tons) 

 Hg (ton)

9.83 

8.02 

0.012

11.9 

9.69 

0.015

12.5 

10.2 

0.017

17.4 

14.2 

0.022

26.9 

21.9 

0.032

37.7 

30.7 

0.044

*CO2 results are in metric tons; NOX and Hg results are in short tons. 
15-17

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