CHAPTER 16. ENVIRONMENTAL IMPACT ANALYSIS

TABLE OF CONTENTS

16.1 INTRODUCTION

................................................................................................ 16­1

16.2 AIR EMISSIONS ANALYSIS............................................................................. 16­1

16.2.1 Air Emissions Descriptions.................................................................... 16­1

16.2.2 Air Quality Regulation........................................................................... 16­3

16.2.3 Global Climate Change.......................................................................... 16­4

16.2.4 Analytical Methods for Air Emissions

.................................................. 16­8

16.2.5 Effects on Power Plant Emissions

......................................................... 16­9

16.2.6 Effects on Upstream Fuel­Cycle Emissions

........................................ 16­14

16.3 WETLAND, ENDANGERED AND THREATENED SPECIES, AND CULTURAL

RESOURCES

..................................................................................................... 16­15

16.4 SOCIOECONOMIC IMPACTS......................................................................... 16­15

16.5 ENVIRONMENTAL JUSTICE IMPACTS....................................................... 16­16

16.6 NOISE AND AESTHETICS

.............................................................................. 16­16

16.7 SUMMARY OF ENVIRONMENTAL IMPACTS............................................ 16­16

LIST OF TABLES

Table 16.2.1 Impact of the PTAC and PTHP Efficiency Standard on Cumulative EnergyRelated Emissions of CO 2 Between 2012 and 2042 by Trial Standard Level

(Millions of Metric Tons CO 2 )

.............................................................. 16­7

Table 16.2.2 Power Sector Emissions Impacts Forecast for AEO2007 Reference Case16­10

Table 16.2.3 Power Sector Emissions Impact Forecasts for Standard Size PTACs. 16­11

Table 16.2.4 Power Sector Emissions Impact Forecasts for Non­Standard Size PTACs16­

12

Table 16.2.5 Power Sector Emissions Impact Forecasts for Standard Size PTHPs

. 16­13

Table 16.2.6 Power Sector Emissions Impact Forecasts for Non­Standard Size PTHPs16­14

Table 16.2.7 Estimated Upstream Emissions of Air Pollutants as a Percentage of Direct

Power Plant Combustion Emissions

.................................................... 16­15

Table 16.4.1 Mean Life­Cycle Cost Savings for All Customers and Sub­Group, Standard

Size PTHP, 9,000 Btu/h Cooling Capacity.......................................... 16­16

Table 16.7.1 Environmental Impact Analysis Results Summary

............................. 16­17

16­iCHAPTER 16. ENVIRONMENTAL IMPACT ANALYSIS

16.1 INTRODUCTION

This chapter describes potential environmental effects that may result from

amended energy conservation standards for packaged terminal air conditioners (PTACs)

and packaged terminal heat pumps (PTHPs). The U.S. Department of Energy (DOE)’s

proposed energy conservation standards are not site­specific, and would apply to all 50

States and U.S. territories. Therefore, none of the proposed standards would impact land

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

any one area.

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

consumption in comparison to a baseline efficiency level. These changes in the demand

for electricity and the costs of achieving these savings are the primary drivers in

analyzing environmental effects. Estimates of source energy savings can be found in the

utility impact analysis in Chapter 14 of this technical support document (TSD). Detailed

discussion on TSLs can be found in Chapter 9 of this TSD.

The primary impact of the TSLs is in air quality resulting from changes in power

plant operations and capacity additions. Therefore, much of this chapter describes the air

quality analysis. The latter part of the chapter describes potential impacts to other

environmental resources.

16.2 AIR EMISSIONS ANALYSIS

The primary focus of the environmental analysis is the impact on air quality of

amended energy conservation standards for PTAC and PTHP equipment. The outcomes

of the environmental analysis are driven by changes in power plant types and quantities

of electricity generated under each of the alternatives. Changes in generation are

described in the utility impact analysis in Chapter 14.

16.2.1 Air Emissions Descriptions

For each of the TSLs, DOE calculated total power­sector emissions based on

output from NEMS­BT model (see Chapter 14). This analysis considers three pollutants:

nitrogen oxides (NOx), mercury (Hg), sulfur dioxide (SO 2 ). An air pollutant is any

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

be natural or man­made (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 (CO 2 ).

Sulfur Dioxide (SO 2 )

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.

16­1In addressing SO 2 emissions, the Clean Air Act Amendments of 1990 set an SO 2

emissions cap on all power generation, but permitted flexibility among generators

through the use of emissions allowances and tradable permits. This SO 2 trading process

(sometimes called “cap and trade”) implies that the standard will have no affect on total

physical emissions because emissions will always be at, or near, the allowed emissions

ceiling. Consequently, there is no direct SO 2 environmental benefit from a reduction in

electricity use due to the proposed energy conservation standards, as long as there is

enforcement of the emissions ceiling. But to the extent reduced power generation

demand decreases the demand for and price of emissions allowance permits, there is an

environmentally related economic benefit from the proposed energy conservation

standards reducing SO 2 emissions allowance demand. Furthermore, over time, if

emissions decline, there is greater flexibility in reducing the ceiling amount. However,

since DOE does not anticipate a change in SO 2 emissions, SO 2 emission results are not

reported in this Chapter.

Nitrogen Oxides (NO

x )

Nitrogen oxides

, or NO

x , are 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

(NO 2 ), along with particles in the air can often be seen as a reddish­brown layer over

many urban areas. NO 2 is the specific form of NOx reported in this document. NO

x is

one of the main ingredients involved in the formation of ground­level 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. NO

x also contributes to the

formation of fine particles that can impair human health.

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

combustion process. The primary manmade sources of NO

x are motor vehicles, electric

utilities, and other industrial, commercial, and residential sources that burn fossil fuels.

NO

x can also be formed naturally. Electric utilities account for about 22 percent of NO

x

emissions in the United States.

Mercury

Coal­fired power plants emit mercury found in coal during the burning process.

While coal­fired power plants are the largest remaining source of human­generated

mercury emissions in the United States, they contribute very little to the global mercury

pool or to contamination of U.S. waters. U.S. coal­fired power plants emit mercury in

three different forms: oxidized mercury (likely to deposit within the United States);

elemental mercury, which can travel thousands of miles before depositing to land and

water; and mercury that is in particulate form. Atmospheric mercury is 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.

16­2Americans 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, visual­spatial abilities, and verbal memory.

Carbon Dioxide (CO 2 )

Carbon dioxide (CO 2 ) is not a regulated or 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, CO 2 , methane (CH 4 ), nitrous oxide (N 2 O), and ozone (O 3 ). Human activities, however, add to

the levels of most of these naturally occurring gases. For example, CO 2 is emitted to the

atmosphere when solid waste, fossil fuels (oil, natural gas, and coal), wood, and wood

products are burned. During the past 20 years, about three­quarters of anthropogenic

(i.e., human­made) CO 2 emissions resulted from burning fossil fuels.

Concentrations of CO 2 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 CO 2

emissions produced each year, billions of metric tons are added to the atmosphere

annually. In the U. S., CO 2 emissions from both energy generation and industrial

processes account for 84.6 percent of total U.S. GHG emissions. 7

16.2.2 Air Quality Regulation

In 1990, EPA amended Title VI section to the Clean Air Act to phase out in 2010

hydrochlorofluorocarbons (HCFC) refrigerants, which are commonly used in air

conditioning systems. The only refrigerant currently used by PTACs and PTHP

equipment is R­22, a HCFC refrigerant and therefore included in the refrigerant phaseout regulations b

. Chapter 5 of this TSD, engineering analysis, discusses an analysis to

characterize the performance and cost implications of using an alternative refrigerant

(i.e., R­410A) in PTAC and PTHP equipment. Manufacturers interviewed confirmed that

the industry is planning to switch to R­410A as a substitute refrigerant for R­22 in PTAC

and PTHP equipment. This conversion is not an impact of this rulemaking. Therefore,

the effects of this conversion are outside the scope of this environmental analysis.

The Clean Air Act Amendments of 1990 list 188 toxic air pollutants that EPA is

required to control. EPA has set national air quality standards for six common pollutants

(also referred to as “criteria” pollutants), two of which are SO 2 and NO

x . 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 SO 2 and NO

x . Title IV

b EPA’s R­22 phase­out regulations can be found at the EPA home website:

http://www.epa.gov/ozone/title6/phaseout/hcfcfaqs.html#why_epa.

16­3of the 1990 amendments established a cap­and­trade program for SO 2 intended to help

control acid rain. This cap­and­trade 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). c CAIR will permanently cap

emissions of SO 2 and NOx in eastern States of the United States. CAIR achieves large

reductions of SO 2 and/or NOx emissions across 28 eastern states and the District of

Columbia. 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 EPA­administered interstate cap­and­trade 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 NO

x are to be in place in 2009. Phase

1 caps for SO 2 are to be in place in 2010. The Phase 2 caps for both pollutants are due in

2015.

Also 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). This rule,

also called the Clean Air Mercury Rule, was closely related to the CAIR and established

standards of performance for mercury emissions from new and existing coal­fired electric

utility steam generating units. The Clean Air Mercury Rule regulated mercury emissions

from coal­fired 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

, d in which the Court, among other actions,

vacated the Clean Air Mercury Rule referenced above.

16.2.3 Global Climate Change

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

(CO 2 ), as major contributors to climate change. Because this Rule, if finalized, will

likely decrease CO 2 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 CO 2 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.

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

d No. 05­1097, 2008 WL 341338, at *1 (D.C. Cir. Feb. 8, 2008).

16­4 cThe 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.

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 % per

decade, changes in wind patterns that affect extra­tropical 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.

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 (CO 2 ), other greenhouse gases (GHG)s, 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.

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 mid20th century is very likely due to the increase in anthropogenic concentrations of CO 2

and other long­lived greenhouse gases (GHGs) such as methane and nitrous oxide in the

atmosphere, rather than from natural causes.

Increasing the CO 2 concentration partially blocks the earth’s re­radiation 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, CO 2 makes up about 77% of the

total CO 2 ­equivalent e global warming potential in GHGs emitted from human activities,

e 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 CO 2 , i.e., CO 2 ­equivalent. CO 2 equivalent

16­5with the vast majority (74%) of the CO 2 attributable to fossil fuel use. For the future, the

IPCC Report describes a wide range of GHG emissions scenarios, but under each

scenario CO 2 would continue to comprise above 70% of the total global warming

potential.

Stabilization of CO2 Concentrations

Unlike many traditional air pollutants, CO 2 mixes thoroughly in the entire

atmosphere and is long­lived. The residence time of CO 2 in the atmosphere is long

compared to the emission processes. Therefore, the global cumulative emissions of CO 2

over long periods determine CO 2 concentrations because it takes hundreds of years for

natural processes to remove the CO 2

. Globally, 49 billion metric tons of CO 2 –equivalent

of anthropogenic (man­made) greenhouse gases are emitted every year. Of this annual

total, fossil fuels contribute about 29 billion metric tons of CO 2

. f

Researchers have focused on considering atmospheric CO 2 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 CO 2 concentrations with temperature increases that plateau in a

defined range. For example, at the low end, the IPCC Report scenarios target CO 2

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 levels g (about

1.3 o C to 1.7 o 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% below

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

continue to be growth in global populations 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%. However, even at these rates,

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

already accumulated CO 2 and GHGs in the atmosphere.

The Beneficial Impact of the Rule on CO 2 Emissions

If finalized, it is anticipated that the Rule will reduce energy­related CO 2 emissions, particularly those associated with energy consumption in buildings. In the

United States, the U.S. Energy Information Administration reports in its 2007 Annual

Energy Outlook (AEO 2007) h that U.S. annual energy­related emissions of CO 2 in 2005

were about 5.9 billion metric tons (about 20% of the world energy­related CO 2 emissions

emission is the amount of CO 2 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.

f Other non­fossil fuel contributors include CO 2 emissions from deforestation and decay from agriculture

biomass; agricultural and industrial emissions of methane; and emissions of nitrous oxide and

fluorocarbons.

g IPCC Working Group 3 Table TS 2

h www.eia.doe.gov/oiaf/archive/aeo07/index.html

16­6and about 12% of total global greenhouse gas emissions), of which 2.3 billion tons were

attributed to residential and commercial buildings sector (including related energy–using

equipment such as PTACs and PTHPs). Most of the greenhouse gas emissions attributed

to residential and commercial buildings are emitted from fossil fuel­fired power plants

that generate electricity used in this sector. In the AEO2007 reference case, EIA

projected that annual energy­related CO 2 emissions would grow from 5.9 billion metric

tons in 2005 to 7.9 billion metric tons in 2030, an increase of 34% (see AEO 2007 Table

16.2.2), while emissions attributable to buildings would grow to 3.2 billion tons, an

increase of 40%.

As shown in Table 16.7.1 in the AEO 2007 reference case, the cumulative U.S.

energy­related CO 2 emissions between 2012 and 2042 are described at about 238 billion

metric tons. The estimated cumulative CO2 emission reductions from a PTAC and PTHP

Efficiency Standard (shown as a range of alternative Trial Standard Levels) during this

same 30­year period are indicated in Table 16.2.1. The estimated CO 2 emission

reductions in Table 16.2.1 are calculated using NEMS­BT model.

Table 16.2.1 Impact of the PTAC and PTHP Efficiency Standard on Cumulative

Energy­Related Emissions of CO 2 Between 2012 and 2042 by Trial

Standard Level (Millions of Metric Tons CO 2 )

TSL 1 TSL 2 TSL 3 TSL 4 TSL 5 TSL 6 TSL 7

PTACs* ­ 0.50 ­ 0.50 ­ 1.06 ­ 0.50 ­ 1.83 ­ 2.95 ­ 6.13

PTHPs* ­ 0.73 ­ 1.49 ­ 1.49 ­ 2.19 ­ 2.19 ­ 3.00 ­ 6.94

Total ­ 1.23 ­ 1.99 ­ 2.55 ­ 2.69 ­ 4.02 ­ 5.95 ­ 13.07

Percent of Total

Cumulative Emissions

Reduction from 2012 to

2042 compared with the

AEO 2007 Reference

Case 0.001 0.001 0.001 0.001 0.002 0.002 0.005

* All results in metric tons, equivalent to 1.1 short tons and negative values refer to a reduction compared with the Base Case

The estimated savings shown in Table 16.2.1, which are at most 0.005 percent of

U.S. energy­related emissions of CO 2 (TSL 7), comprise an even smaller fraction of U.S.

emissions of greenhouse gases and of world emissions of greenhouse gases. However,

the savings would likely reduce overall U.S. CO 2 emissions, as compared to U.S. CO 2

emissions absent an increase in the required efficiency of PTACs and PTHPs.

The Incremental Impact of the Rule on Climate Change

It is difficult to correlate specific emission rates with atmospheric concentrations

of CO 2 and specific atmospheric concentrations with future temperatures because the

IPCC Report describes a clear lag in the climate system between any given concentration

of CO 2 (even if maintained for long periods) and the subsequent average worldwide and

16­7regional 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 radioactive 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 CO 2 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 CO 2 emissions rates will impact global warming.

However, as Table 16.2.1 indicates, the Rule will likely reduce CO 2 emissions rates from

the fossil fuel sector.

16.2.4 Analytical Methods for Air Emissions

NEMS­BT incorporates capabilities to assess compliance with SO 2 and NO

x

restrictions specified in the Clean Air Act and its amendments. Clean air act provisions

include New Source Performance Standards, and Revised New Source Performance

Standards. NEMS­BT also includes provisions for the Clean Air Interstate Rule, which

imposes stricter restrictions on SO 2 and NO

x for some states, and the Clean Air Mercury

Rule, which imposes a national mercury constraint.

Coal­fired 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 and mercury contents of the fuel used

when determining optimal dispatch.

The CAIR and mercury rules allow for emissions banking for NO

x and mercury,

which is simulated in the NEMS­BT model. Emissions banking refers to regulated power

plant operators releasing fewer emissions than what they have allowances for in an earlier

year in order to release more emissions than permitted by their allowances in a later year.

If a power plant produces fewer emissions than they are allotted in one year, the

regulations (and the NEMS­BT model) allow the operator to over emit in a later year by

this same amount. This banking activity can mean that outer years end up with levels of

emissions that may be greater than anticipated or targeted. However, the bank tends to

encourage greater short term emissions reductions.

The value of an emission allowance within the NEMS­BT model is assumed to be

the market­clearing price, which is based on the revenue requirements for the capital and

operating expenses associated with compliance. Banking would lower the overall cost of

compliance if the discounted, present value of the compliance costs in a given year is less

16­8than the corresponding cost in a later year. Similarly, banking mercury allowances may

reduce the overall cost of complying with the mercury emissions limits specified in the

Clean Air Mercury Rule.

Within the NEMS­BT 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 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.

Modeling of SO 2 trading tends to imply that the physical emissions effects will be

zero, as long as emissions are at the allowed ceiling. Because SO 2 has been regulated

with emissions caps for more than a decade, and no emissions reductions are reported

from the NEMS­BT forecast model, DOE does not report SO 2 results here. This

assumption is consistent with previous DOE environmental assessment document. 1

As with SO 2 emissions, caps on NO

x and mercury emissions will possibly result

in no physical emissions effects resulting from equipment energy conservation standards,

but reduced power generation demand will have the benefit of generating net emissions

allowance credits relative to a base case of no energy conservation standard. Therefore,

DOE reported NO

x and mercury emissions reductions in this analysis. DOE assumed that

under emissions cap regulation, the reduction in power generation demand will result in

the creation of an equivalent amount of net emissions allowance credits.

As noted in Chapter 14, NEMS­BT model forecasts end in year 2030. Energy and

emissions impacts beyond 2030 were extrapolated for this rulemaking. The extrapolation

of emissions was handled in two ways. CO 2 extrapolations followed the approach for

energy impacts described in Chapter 14. Note that there is no CO 2 banking process. NO

x

and mercury emissions were handled differently. Absolute emissions of these pollutants

are difficult to predict in later years because of the banking processes described in the

preceding paragraphs. The affects on these emissions are small to begin with, and no

affective means of extrapolation can capture the complexities of emissions banking. In

addition, the TSL energy benefits become smaller in later years. In the far future, the

equipment entering the market replaces other equipment that meet the TSLs, rather than

replacing old equipment that does meet the TSLs. Because of these complicating factors,

the NO

x and mercury emissions reported beyond 2030 in Table 16.2.3 through Table

16.2.6 simply repeat the findings for 2030.

16.2.5 Effects on Power Plant Emissions

Table 16.2.2 shows reference power plant emissions in selected years. The

Annual Energy Outlook (AEO) 2007 Reference case emissions are the emissions shown

by the NEMS­BT model to result if none of the TSLs are promulgated. Table 16.2.3

16­9through Table 16.2.6 show estimated changes in power plant emissions in selected years

for all the PTAC and PTHP equipment under each of seven TSLs, grouping by standard

size PTACs, non­standard size PTACs, standard size PTHPs, and non­standard size

PTHPs. Changes in NO 2 and mercury emissions from power plants are shown in these

tables. Changes in CO 2 emissions from all sources are also shown in these four tables.

Table 16.2.2 Power Sector Emissions Impacts Forecast for AEO2007 Reference

Case

NEMS­BT Results*:

2005 2010 2015 2020 2025 2030

CO 2 (Million metric tons/year)** 5,945 6,216 6,594 6,950 7,433 7,953

NO X (Thousand tons/year)† 3,601 2,403 2,212 2,152 2,184 2,220

Hg (tons/year)† 51.24 37.21 25.44 19.40 17.29 15.81

* All results in metric tons, equivalent to 1.1 short tons and negative values refer to a reduction compared with the Base Case

** Comparable to Table A17 of AEO2007: Electric Generators

† Comparable to Table A8 of AEO2007: Emissions

Compared to the anticipated reference case emissions impacts forecast shown in

Table 16.2.2, changes in emission levels shown in Table 16.2.3 through Table 16.2.6 are

extremely small. In general, the NEMS­BT model results show a general trend toward

slightly reduced emission levels over time for most if not all the equipment types.

However, some years do not follow this trend

. Moreover, mercury emissions generally

show slight increases by 2030 after declining out to 2020 or 2025, depending on the TSL

and equipment type. The changes in emission levels shown in the tables are extremely

small. None of the changes come close to approaching a 1 percent change in annual

emissions, or even 1/1,000 percent of the emissions shown in the reference case.

One possible reason for this trend is emissions banking. The NEMS­BT model

assumed that power plant operators would be permitted to bank emission allowances

from years in which they release fewer emissions than the maximum permitted. Power

plant operators may then release more emissions than permitted by their allowances in a

later year. Another possible influence could be a shift from peaking type power plants to

baseload power plants. Modeling described in Chapter 14 indicates that the TSLs reduce

peak demand to the point that baseload plants are dispatched slightly more often than

would occur in the absence of the TSLs. Baseload plants tend to burn more coal, as

opposed to peaking plants that tend to use natural gas. Coal combustion produces greater

emission levels of all three pollutants. It is also possible that within the model the timing

of when power plants are replaced changes.

16­10Table 16.2.3 Power Sector Emissions Impact Forecasts for Standard Size PTACs

NEMS­BT Results*: Difference from Reference Case

Extrapolation

2015 2020 2025 2030 2035 2040 2042

TSL 1, 2, 4

CO 2 (Million metric tons/year)** ­0.002 ­0.006 ­0.011 ­0.016 ­0.019 ­0.022 ­0.024

NO X (Thousand tons/year)† ­0.002 ­0.003 ­0.002 0.000 0.000 0.000 0.000

Hg (tons/year)† 0.000 0.000 0.000 0.000 0.000 0.000 0.000

TSL 3

CO 2 (Million metric tons/year) ­0.006 ­0.014 ­0.024 ­0.037 ­0.043 ­0.050 ­0.054

NO X (Thousand tons/year) ­0.004 ­0.006 ­0.005 ­0.001 ­0.001 ­0.001 ­0.001

Hg (tons/year) 0.000 0.000 0.000 0.000 0.000 0.000 0.000

TSL 5

CO 2 (Million metric tons/year) ­0.010 ­0.024 ­0.043 ­0.065 ­0.076 ­0.089 ­0.095

NO X (Thousand tons/year) ­0.007 ­0.010 ­0.008 ­0.001 ­0.001 ­0.001 ­0.001

Hg (tons/year) 0.000 0.000 0.000 0.001 0.001 0.001 0.001

TSL 6

CO 2 (Million metric tons/year) ­0.015 ­0.037 ­0.066 ­0.100 ­0.117 ­0.138 ­0.147

NO X (Thousand tons/year) ­0.010 ­0.015 ­0.013 ­0.002 ­0.002 ­0.002 ­0.002

Hg (tons/year) 0.000 0.000 0.000 0.001 0.001 0.001 0.001

TSL 7

CO 2 (Million metric tons/year) ­0.034 ­0.084 ­0.148 ­0.225 ­0.264 ­0.310 ­0.331

NO X (Thousand tons/year) ­0.023 ­0.035 ­0.028 ­0.004 ­0.004 ­0.004 ­0.004

Hg (tons/year) ­0.001 ­0.001 0.000 0.003 0.003 0.003 0.003

* All results in metric tons, equivalent to 1.1 short tons and negative values refer to a reduction compared with the Base Case

** Comparable to Table A17 of AEO2007: Electric Generators

† Comparable to Table A8 of AEO2007: Emissions

16­11Table 16.2.4 Power Sector Emissions Impact Forecasts for Non­Standard Size

PTACs

NEMS­BT Results: Difference from Reference Case

Extrapolation

2015 2020 2025 2030 2035 2040 2042

TSL 1, 2, 4

CO 2 (Million metric tons/year) ­0.001 ­0.002 ­0.003 ­0.005 ­0.007 ­0.007 ­0.007

NO X (Thousand tons/year) ­0.001 ­0.001 ­0.001 0.000 0.000 0.000 0.000

Hg (tons/year) 0.000 0.000 0.000 0.000 0.000 0.000 0.000

TSL 3

CO 2 (Million metric tons/year) ­0.001 ­0.003 ­0.005 ­0.008 ­0.011 ­0.011 ­0.011

NO X (Thousand tons/year) ­0.001 ­0.001 ­0.001 0.000 0.000 0.000 0.000

Hg (tons/year) 0.000 0.000 0.000 0.000 0.000 0.000 0.000

TSL 5

CO 2 (Million metric tons/year) ­0.002 ­0.005 ­0.008 ­0.013 ­0.017 ­0.017 ­0.017

NO X (Thousand tons/year) ­0.001 ­0.002 ­0.002 0.000 0.000 0.000 0.000

Hg (tons/year) 0.000 0.000 0.000 0.000 0.000 0.000 0.000

TSL 6

CO 2 (Million metric tons/year) ­0.004 ­0.009 ­0.016 ­0.025 ­0.032 ­0.032 ­0.032

NO X (Thousand tons/year) ­0.003 ­0.004 ­0.003 0.000 0.000 0.000 0.000

Hg (tons/year) 0.000 0.000 0.000 0.000 0.000 0.000 0.000

TSL 7

CO 2 (Million metric tons/year) ­0.005 ­0.013 ­0.022 ­0.034 ­0.045 ­0.045 ­0.045

NO X (Thousand tons/year) ­0.003 ­0.005 ­0.004 ­0.001 ­0.001 ­0.001 ­0.001

Hg (tons/year) 0.000 0.000 0.000 0.000 0.000 0.000 0.000

16­12Table 16.2.5 Power Sector Emissions Impact Forecasts for Standard Size PTHPs

NEMS­BT Results: Difference from Reference Case

Extrapolation

2015 2020 2025 2030 2035 2040 2042

TSL 1

CO 2 (Million metric tons/year) ­0.005 ­0.011 ­0.018 ­0.025 ­0.029 ­0.034 ­0.036

NO X (Thousand tons/year) ­0.002 ­0.003 ­0.003 ­0.001 ­0.001 ­0.001 ­0.001

Hg (tons/year) 0.000 0.000 0.000 0.000 0.000 0.000 0.000

TSL 2, 3

CO 2 (Million metric tons/year) ­0.010 ­0.023 ­0.037 ­0.053 ­0.062 ­0.071 ­0.076

NO X (Thousand tons/year) ­0.004 ­0.007 ­0.006 ­0.001 ­0.001 ­0.001 ­0.001

Hg (tons/year) 0.000 0.000 0.000 0.000 0.000 0.000 0.000

TSL 4, 5

CO 2 (Million metric tons/year) ­0.015 ­0.033 ­0.055 ­0.078 ­0.090 ­0.104 ­0.111

NO X (Thousand tons/year) ­0.006 ­0.010 ­0.008 ­0.002 ­0.002 ­0.002 ­0.002

Hg (tons/year) 0.000 ­0.001 0.000 0.001 0.001 0.001 0.001

TSL 6

CO 2 (Million metric tons/year) ­0.019 ­0.042 ­0.069 ­0.099 ­0.114 ­0.132 ­0.140

NO X (Thousand tons/year) ­0.008 ­0.012 ­0.010 ­0.002 ­0.002 ­0.002 ­0.002

Hg (tons/year) ­0.001 ­0.001 0.000 0.001 0.001 0.001 0.001

TSL 7

CO 2 (Million metric tons/year) ­0.048 ­0.108 ­0.177 ­0.253 ­0.292 ­0.339 ­0.359

NO X (Thousand tons/year) ­0.020 ­0.031 ­0.027 ­0.006 ­0.006 ­0.006 ­0.006

Hg (tons/year) ­0.001 ­0.002 ­0.001 0.002 0.002 0.002 0.002

16­13Table 16.2.6 Power Sector Emissions Impact Forecasts for Non­Standard Size

PTHPs

NEMS­BT Results: Difference from Reference Case

Extrapolation

2015 2020 2025 2030 2035 2040 2042

TSL 1

CO 2 (Million metric tons/year) ­0.001 ­0.002 ­0.004 ­0.005 ­0.006 ­0.006 ­0.006

NO X (Thousand tons/year) 0.000 ­0.001 ­0.001 0.000 0.000 0.000 0.000

Hg (tons/year) 0.000 0.000 0.000 0.000 0.000 0.000 0.000

TSL 2, 3

CO 2 (Million metric tons/year) ­0.001 ­0.003 ­0.005 ­0.007 ­0.009 ­0.009 ­0.009

NO X (Thousand tons/year) ­0.001 ­0.001 ­0.001 0.000 0.000 0.000 0.000

Hg (tons/year) 0.000 0.000 0.000 0.000 0.000 0.000 0.000

TSL 4, 5

CO 2 (Million metric tons/year) ­0.002 ­0.005 ­0.008 ­0.012 ­0.015 ­0.015 ­0.015

NO X (Thousand tons/year) ­0.001 ­0.001 ­0.001 0.000 0.000 0.000 0.000

Hg (tons/year) 0.000 0.000 0.000 0.000 0.000 0.000 0.000

TSL 6

CO 2 (Million metric tons/year) ­0.004 ­0.008 ­0.014 ­0.019 ­0.025 ­0.025 ­0.025

NO X (Thousand tons/year) ­0.002 ­0.002 ­0.002 0.000 0.000 0.000 0.000

Hg (tons/year) 0.000 0.000 0.000 0.000 0.000 0.000 0.000

TSL 7

CO 2 (Million metric tons/year) ­0.005 ­0.012 ­0.019 ­0.027 ­0.035 ­0.035 ­0.035

NO X (Thousand tons/year) ­0.002 ­0.003 ­0.003 ­0.001 ­0.001 ­0.001 ­0.001

Hg (tons/year) 0.000 0.000 0.000 0.000 0.000 0.000 0.000

16.2.6 Effects on Upstream Fuel­Cycle Emissions

Fuel­cycle 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. Upstream processes include the mining of coal or

extraction of natural gas, physical preparatory and cleaning processes, and transportation

to the power plant. The NEMS­BT 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

qualitative estimates of affects on upstream fuel­cycle 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

16­14approximately equal to eight percent, by mass, of emissions (including SO 2 ) from coal

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

transportation from the mine to the power plant. 1, 2 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 approximately an

amount equal to 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 16.2.7 for CO 2 , and NOx. The percentages

are relative to power plant emissions and provide a means to estimate upstream emission

savings based on changes in emissions from power plants. The percentage effects

presented in Table 15.2.6 provide a qualitative approach to viewing effects on fuel cycle

emissions. The previous section indicates slight overall reductions in CO 2 , and NOx.

Thus, very small reductions in upstream emissions of air pollutant could be expected.

This approach does not address mercury emissions.

Table 16.2.7 Estimated Upstream Emissions of Air Pollutants as a Percentage of

Direct Power Plant Combustion Emissions

Percent of Coal Percent of Natural Gas

Combustion Emissions Combustion Emissions Pollutant

CO 2 2.7 11.9

NOx 5.8 40

16.3 WETLAND, ENDANGERED AND THREATENED SPECIES, AND

CULTURAL RESOURCES

DOE’s proposed action is not site­specific, nor would it affect land disturbance or

use due to PTACs and PTHPs being installed in commercial buildings. Therefore, none

of the proposed TSLs is expected to affect the quality of wetlands, or threatened or

endangered species. Further, this action is not expected to impact cultural resources such

as historical or archaeological sites.

16.4 SOCIOECONOMIC IMPACTS

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

efficient PTAC or PTHP at the proposed standard level is completely or nearly offset by

a reduction in the life­cycle cost (LCC) of owning a more efficient piece of equipment.

In other words, the customer will pay less operating costs over the life of the equipment

even through the first cost increases. The complete analysis and its conclusions are

presented in Chapter 8 of the TSD.

For the sub­group of customers that are independent hotels, DOE determined that

the average LCC impact is similar to that for the full sample of customers. Therefore,

16­15DOE concludes that the proposed action would have no significant socioeconomic

impact. For a complete discussion on the LCC impacts on independent hotels, see

Chapter 12 of the TSD.

Table 16.4.1 shows the mean LCC savings for both the full sample of customers

and independent hotels as the sub­group.

Table 16.4.1 Mean Life­Cycle Cost Savings for All Customers and Sub­Group,

Standard Size PTHP, 9,000 Btu/h Cooling Capacity

Trial Standard Level

TSL 1 TSL 2 TSL 3 TSL 4 TSL 5 TSL 6 TSL 7

All Customers $13 $24 $24 $32 $32 $30 $40

Independent Hotels $10 $19 $19 $26 $26 $23 $30

16.5 ENVIRONMENTAL JUSTICE IMPACTS

According to Executive Order 12898 of February 11, 1994, “Federal Actions to

Address Environmental Justice in Minority Populations and Low­Income Populations,”

DOE is required to examine the effect of more stringent energy­efficiency standards on

(1) small businesses that either manufacture or use PTAC or PTHP, (2) manufacturers of

niche products related to PTAC or PTHP, and (3) small businesses operated by

disadvantaged or minority populations.

DOE identified small businesses as a sub­group that possibly could be

disproportionately affected by PTAC and PTHP energy conservation standards. As

described in the Life­Cycle Cost Subgroup Analysis, Chapter 11 of the TSD, DOE found

that there was no disproportionately high and adverse human health or environmental

effects on small businesses that would result from the proposed energy conservation

standards. DOE believes that above conclusion also applies to minority populations.

16.6 NOISE AND AESTHETICS

Improvements in efficiency of PTAC and PTHP equipment is expected to result

from changes in the choice of components and other design features. These changes are

described in Chapter 5 of this TSD. Efficiency improvements result from improved heat

exchanger designs using increased levels of coppers, and more efficient compressors.

These design changes are not expected to change noise levels in comparison to

equipment in today’s market. Equipment that is currently manufactured in the existing

market that would meet the proposed standards is no louder than less efficient

equipment. Changes to the design to improve the efficiency levels are not anticipated to

affect the equipment’s aesthetics.

16.7 SUMMARY OF ENVIRONMENTAL IMPACTS

Table 16.7.1 summarizes anticipated environmental impacts for each of the TSLs

across all equipment types. Air quality impacts were modeled for each of the TSLs. The

summary table shows cumulative changes in emissions for CO 2 , NOx, and mercury over

16­16the period 2012 to 2042. The resulting changes in emission quantities are very small,

much less than 1 percent in comparison to the reference case. Cumulative CO 2 and NOx

emissions show a decrease compared to the reference case. Mercury emissions show a

very small increase in cumulative emissions. This increase may result from the combined

effects of emissions banking, a shift in how power plants are dispatched, or the timing

within the model of when power plants are replaced.

Upstream fuel cycle emission of CO 2 and NOx are described but not quantified in

section 16.2.6. The text describes potential reductions in fuel cycle emissions as

percentage of decreases in power plant emissions. This qualitative 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. This

approach does not address mercury emissions.

Socioeconomic impacts are presented as changes in life cycle costs. No impacts

are anticipated in the area of environmental justice; wetlands, endangered and threatened

species, and cultural resources; or noise and aesthetics.

Table 16.7.1 Environmental Impact Analysis Results Summary

Environmental Effects Reference Trial Standard Level

Case* 1 2 3 4 5 6 7

Cumulative Emission

Reductions**

CO 2 (Million metric tons) 238,439 ­1.24 ­1.99 ­2.55 ­2.69 ­4.02 ­5.95 ­13.07

NO X (Thousand tons) 69,033 ­0.08 ­0.12 ­0.17 ­0.16 ­0.28 ­0.39 ­0.93

Hg (tons) 564.2 0.00 0.01 0.02 0.01 0.02 0.04 0.07

Fuel­Cycle (Upstream)

Emissions NA *** *** *** *** *** *** ***

Wetlands, Endangered and

Threatened Species, Cultural NA None None None None None None None

Resources

Socioeconomic Impacts

­

Standard Size PTHP, 9000

Btu/h Cooling Capacity, Mean

LCC Savings†

All Customers $13 $24 $24 $32 $32 $30 $40 $13

Independent Hotels $10 $19 $19 $26 $26 $23 $30 $10

Environmental Justice NA None None None None None None None

Noise and Aesthetics NA None None None None None None None

* The reference case values reflect total cumulative emissions and life cycle cost s in the absence of an energy conservation standard.

** Cumulative total is over a time period from 2012 to 2042. Negative values refer to emission reductions.

*** DOE does not report actual estimates of the effects of standards on upstream emissions, but section 16.2.5 provides a sense for the

possible magnitude of effects.

† Values refer to life­cycle cost savings over the equipment lifetime.

16­17REFERENCES

1

. DOE. 2006. Environmental Assessment for Proposed Energy Conservation

Standards for Distribution Transformers

. DOE/EA­1565. Washington, D.C.

2. DeLuchi, M. A. Emissions of Greenhouse Gases from the Use of Transportation

Fuels and Electricity

, Volume 2: Appendixes A­S. November, 1993. Argonne

National Laboratory. Argonne, IL. Report No. ANL/ESD/TM­22­Vol.2.

16­18