9

- i CHAPTER 9

. E MISSIONS ANALYSIS

TABLE OF CONTENTS

9.1 INTRODUCTION

................................ ................................ ................................ ........... 9

- 1
9.2 AIR EMISSIONS DESCRI PTIONS AND REGULATIO N

................................ ........... 9

- 2
9.3 GLOBAL CLIMATE CHANG E

................................ ................................ ..................... 9

- 4
9.4 AN ALYTICAL METHODS FOR AIR EMISSIONS

................................ ..................... 9

- 8
9.5 EFFECTS ON POWER PLA NT EMISSIONS

................................ ............................. 9

- 10
9.6 EFFECTS ON UPSTREAM FUEL

- CYCLE EMISSIONS

................................ .......... 9

- 14
9.7 SUMMARY OF EMISSIONS IMPACTS

................................ ................................ .... 9

- 14

LIST OF TABLES

Table 9.3.1 Reduction in Cumulative Energy

- Related Emissions of CO 2 over the analysis period for ASHRAE Energy Conservation Standards*

......................... 9

- 7
Table 9.5.1 Po wer Sector Emissions Projection from AEO2011 Reference Case

................ 9

- 10
Table 9.5.2 Power Sector Emissions Impacts Forecasts for Water

- Cooled and Evaporatively

- Cooled Product Efficiency Levels

................................ ............. 9

- 11
Table 9.5.3 Power Sector Emissions Impact Forecasts for VRF Wa ter

- Source Heat Pump Efficiency Levels

................................ ................................ ..................... 9

- 12
Table 9.5.4 Power Sector Emissions Impact Forecasts for Computer Room Air
Conditioner Ef ficiency Levels

................................ ................................ ........... 9

- 13
Table 9.6.1 Estimated Upstream Emissions of Air Pollutants as a Percentage of Direct
Power Plant Combustion Emissions

................................ ................................ .. 9

- 14
Table 9.7.1 Cumulative Emissions Reductions Under ASHRAE Efficiency Levels*

......... 9

- 159

- 1 CHAPTER 9. E MISSIONS ANALYSIS

9.1 INTRODUCTION

This chapter describes potential changes to emissions of carbon dioxide (CO 2 ) and three air pollutants that may result from energy conservation standards for water

- cooled and evaporative ly

- cooled products, VRF water

- source heat pumps, and computer room air
conditioners . The impac ts on air emissions are largely driven by changes in power plant types and quantities of electricity generated under each of the considered standard levels . Changes in electricity generation are described in the utili ty impact analysis in chapter 11

.

DOE analyzed the effects of its amended standard levels on the electric utility industry using a variant of the DOE/Energy Information Administration (EIA)’s National Energy Modeling System (NEMS). a NEMS is a public domain, multi

- sectored, partial equilibrium model of the U.S. energy sector. Each year, DOE/EIA uses NEMS to produce an energy f orecast for the United States, the Annual Energy Outlook (AEO) . The AEO for 2011 (AEO2011) forecasts energy supply and demand through 2035. 1 DOE used a variant of this model, referred

to as NEMS

- BT, b

NEMS

- BT has several advantages that have led to its adoption as the forecasting tool in the analysis of energy conservation standards. NEMS

- BT uses a set of assumptions that are well
known and fairly transparent, due to the exposure and scrutiny each AEO receives. In addition, the comprehensiveness of NEMS

- BT permits the modeling of interactions among the various energy supply and demand sectors, producing a complete picture of the effects of en ergy conservation standards. Perhaps most importantly, NEMS

- BT can be used to estimate marginal effects, which yield a better estimate of the actual impact of energy conservation standards than considering only average effects. to account for the impacts of energy conservation standards for water and evaporative cooled products, VRF water sour ce heat pumps, and computer room air conditioners. DOE’s analysis consists of a comparison between model results for the AEO2011 Reference Case and for cases in which standards are in place, and applies the same basic set of assumptions
as the AEO2011 . The AEO2011 reference case corresponds to medium economic growth.

a For more information on NEMS, refer to the U.S. Department of Energy, Energy Information Administration documentation. A useful summary is National Energy Modeling System: An Overview 2003 , DOE/EIA

- 0581(2003), March, 2003.

b DOE/EIA approves use of the name NEMS to describe only an official version of the model without any modification to code or data. Because this analysis entails some minor code modifications and the model is run under various policy scenarios that are variations on DOE/EIA assumptions , DOE refers to it by the name NEMS

BT (BT is DOE’s Building Technologies Program, under whose aegis this work has been performed). NEMS

- BT was previously called NEMS

- BRS.9

- 2 9.2 AIR EMISSIONS DESCRI PTION S AND REGULATION

This analysis considers three pollutants: sulfur dioxide (SO 2 ), nitrogen oxides (NO X ), 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. c DOE’s analysis also considers carbon dioxide (CO 2 ).

Sulfur Dioxide. Sulfur dioxide, or SO 2 , 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. SO 2 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

Nitrogen Oxides. Nitrogen oxides

, or NO X , 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 an d odorless. However, one common pollutant, nitrogen dioxide (NO 2 ), along with particles in the air can often be seen as a reddish

- brown layer over many urban

areas. NO 2 is the specific form of NO X reported in this document. NO X is one of the main ingredien ts 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. NO X also contributes to the formation of fine pa rticles that can impair human health. 2

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 res idential 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. 2

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. 3 U.S. coal

- fired power plants emit Hg in thr ee 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 dev eloping fetus is the most sensitive to the toxic effects of methylmercury, women of

c More information on air pollution characteristics and regulations is available on the U.S. Environment Protection Agent (EPA)’s website at www.epa.gov.9

- 3 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 neurobeh avioral tasks, such as those measuring attention, fine motor function, language skills, visual

- spatial abilities, and verbal memory. 4

Carbon Dioxide. Carbon dioxide (CO 2 ) is not a criteria pollutant (see below), but it is of
interest because of its clas sification 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. I n 2007, over 90 percent of anthropogenic (i.e., human

- made) CO 2 emissions resulted from burning fossil fuels. 5

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

n atural 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 United States, in 2007, CO 2 emissions from electricity generation accounted for 39 percent of total U.S. GHG emissions. 5

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: increased respiratory symptoms, such as irritation of the airway s, 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 SO 2 and NO

x . The quantity of the secondary sulfates produced is determined by a very complex set of factors including the atmospheric quantities of SO 2 and NO

x , and other atmosp heric 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 power9

- 4 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, DO E is not planning to assess the impact of these standards on PM emissions. Further, as described below , it is uncertain whether efficiency standards will result in a net decrease in power plant emissions of SO 2

, and of NO

x in many States, 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 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 o f SO 2 and NO X . Title IV of the 1990 amendments established a cap

- and

- trade program for SO 2 , 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 wit h 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). d 70 FR 25162

– 25405 (May 12, 2005). CAIR
limited emissions from 28 eastern S tates and D.C. by capping emissions and creating an
allowance

- based trading program. Although, CAIR was remanded to EPA by the U.S. Court of Appeals for the District of Columbia Circuit (D.C. Circuit), (see North Carolina v. EPA , 550 F.3d 1176 (D.C. Cir. 2008),) it remained in effect temporarily, consistent with the D.C. Circuit’s earlier opinion in North Carolina v. EPA , 531 F.3d 896 (D.C. Cir. 2008).

On July 6, 2010, EPA issued the Transport Rule proposal, a replacement for CAIR

. 75 FR 45210 (Aug. 2, 2010). On July 6, 2011, EPA promulgated the final Transport Rule, entitled

“ Federal Implementation Plans: Interstate Transport of Fine Particulate Matter and Ozone and Correction of SIP Approvals,” but commonly referred to as the Cross

- State Air Pollution Rule or the Transport Rule. 76 FR 48208 (Aug. 8, 2011). On December 30, 2011, however, the D.C.
Circuit stay ed the new rules while a panel of judges reviews them, and told EPA to continue enforcing CAIR (see EME Homer City Generation v. EPA

, No. 11

- 1302, Order at *2 (D.C. Cir. Dec. 30, 2011)).

On December 21 , 2011, EPA announced national emissions standards for hazardous air pollutants (NESHAPs) for mercury and certain other pollutants emitte d from coal and oil

- fired

EGUs. 76 FR 24976

. The NESHAPs do no t include emissions caps and, as such, DOE’s energy
conservation standard s wou ld likely reduce Hg emissions.

9.3 GLOBAL CLIMATE CHANG E

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

d See http://www.epa.gov/cleanairinterstaterule/.9

- 5 points to anthropogenic sources of greenhouse gases, such as carbon dioxide (CO 2 ), as major contributors to climate change. Because this r ule, 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 r ule 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.

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 con tinue

. 7

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 wor ldwide, and numerous ecological changes

. 8

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 (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

. 8

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 like ly 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 impa cts 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 li kely due to the increase in anthropogenic concentrations of CO 2 and other long

- lived greenhouse gases such as methane and nitrous oxide in the atmosphere,
rather than from natural causes.9

- 6 Increasing the CO 2 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, CO 2 makes up about 77 percent of the total CO 2 - equivalent e global warming potential in GHGs emitted from human activities, with the vast majority (74 percent) of the CO 2 attributable to fossil fuel use. 8 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 percent of the total global warming potential. 9

Stabilization of CO 2 Concentrations. Unlike many traditional air pollutants, CO 2 mixes thoroughly in the entire atmosphe re and is long

- lived. 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 pr ocesses to remove the CO 2 . Globally, 49 billion metric tons of CO 2

– equivalent of anthropogenic (man

- made) greenhouse gases are emitted every year. f Of this annual total, fossil fuels contribute about 29 billion metric tons of CO 2

. 9

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 stabili zed

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 pre

industrial levels g (about 1.3 °C to 1.7 °C above today’s levels). To achieve concentrations between 350 ppm to 400 ppm, the IP CC 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 ra tes, the scenarios describe some warming and some climate change is projected due to already
accumulated CO 2 and GHGs in the atmosphere. 10

The Beneficial Impact of the Rule on CO 2 Emissions. It is anticipated that the Rule will reduce energy

- related CO 2 e missions, particularly those associated with energy consumption in buildings. The U.S. Energy Information Administration (EIA) reports in its 2011 Annual Energy

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 emission is the amount of CO 2 emission that would cause the same

- tim e integrated radiative forcing, over a given time horizon, as an emitted amount of other long

- lived GHG or mixture of GHGs.

f Other non

- fossil 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 29

- 7 Outlook ( AEO2011 ) 11 that U.S. annual energy

- related emissions of CO 2 in 2009 were about 5.4
bill ion metric tons, of which 1.2 billion tons were attributed to the residential buildings sector (including energy

- using products such as space cooling products). Most of the greenhouse gas emissions attributed to residential buildings are emitted from fossi l fuel

- fired power plants that generate electricity used in this sector. In the AEO2011 Reference Case, EIA projected that annual energy

- related CO 2 emissions would grow from 5.4 billion metric tons in 2009 to 6.3 billion metric tons in 2035, an increase o f 16 percent, while residential emissions would grow to from 1.17 billion metric tons to 1.23 billion metric tons, an increase of 5 percent.

The estimated cumulative CO 2 emission reductions from energy conservation standard s (shown a s a range of alternative Efficiency Level s) for water and evaporatively cooled products, VRF water source heat pumps, and computer room air conditioners, during the 30

- year analysis period are indicated in Table 9 .3 .1. Estimated CO 2 emission reductions in Table 9 .3 .1 only come
from electricity generation (i.e., power plants)

. The estimated CO 2 emission reductions from electricity generation are calc ulated using the NEMS

- BT model

.

Table 9.3.1 Reduction in Cumulative Energy

- Related Emissions of CO 2 over the analysis

per iod for ASHRAE Energy Conservation Standards * Efficiency Levels

Level 1 Level 2 Level 3 Level 4 Level 5

Million Metric Tons

Water

- cooled and Evaporative ly

- c ooled Products 0.099 0.096 0.253 0.363 0.371

VRF Water

- s ource Heat Pumps 0.000 0.054 0.823 1.96 3.58

Computer Room Air
Conditioners 0.177 2.14 8.06 18.7 31.1

Total 0.276 2.29 9.13 21.1 35.1

Percent of Total Cumulative Emissions Reduction compared
with the AEO201 1 Reference
Case in 2014

- 2043 0.00 0.00 0.01 0.03 0.05

*The analysis period for w ater

- cooled and e vaporative ly

- cooled products runs from 2013 through 2043

. The analysis period for VRF water

- source heat pumps runs from 2013 through 2042

. The analysis period Computer Room Air Conditioners runs from 2012 through 2042

.

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 regional temperature, precipitation, and extreme weather regimes. For example, a major determinant of cli mate response is “equilibrium climate sensitivity”, a measure of the climate system response to sustained radi ative forcing. It is defined as the global average surface warming following a doubling of carbon dioxide concentrations.9

- 8 The IPCC Report describe s 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 te rms 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 s ystems are, it is difficult to know to what extent and when particular CO 2 emissions reductions will impact global warming. However, as Table

16.3 .1 indicates, the rule is expected to reduce CO 2 emissions associated with energy consumption in buildings.

9.4 ANALYTICAL METHODS F OR AIR EMISSIONS

For each of the considered Efficiency Level s, DOE calculated total power

- sector emissions based on output from the NEMS

- BT model.

NEMS provides reference case load shapes for several end uses. The model uses predicted growth in demand for each end use to build up a projection of the total electric system load growth for each region, which it uses in turn to predict the necessary addi tions to capacity. DOE uses

NEMS

- BT to account for the implementation of energy conservation standards by decrementing the appropriate reference case load shape. For ASHRAE products the cooling end use load shape was
selected , and t he NEMS was decremented with commercial sector energy savings. T he energy decrements are also divided amongst the nine U.S. Census divisions based upon the share of energy end use consumption in each division, as given in NEMS.

DOE used the site energy savings developed in the na tional impact analysis (chapter 8 ) for
each Efficiency Level as input to NEMS

- BT. The magnitude of the energy decrement that would be required for NEMS

- BT to produce stable results out of the range of numerical noise is larger than the highest efficiency s tandard under consideration. Therefore, DOE estimated results corresponding to
each Efficiency Level using interpolation. DOE ran higher energy use reduction levels in NEMS

- BT, representing multipliers of each Efficiency Level , and used these outputs to li nearly interpolate the results to estimate actual changes in generation and capacity due to the standard.

Although the current time horizon of NEMS

- BT is 2035, other parts of the energy conservation standards analysis extend through the year 204 3 . It is not feasible to extend the forecast period of NEMS

- BT for the purposes of this analysis, nor does DOE/EIA have an approved method for extrapolation of many outputs beyond 2035. While it might seem reasonable to make simple linear extrapolations of results, in practice this is not advisable because outputs could be contradictory. An analysis of various trends sufficiently detailed to guarantee consistency is beyond the scope of this work, and, in any case, would involve a great deal of uncertainty. Therefore , all extrapolations beyond 2035 are simple replications of year 2035 results. To emphasize the extrapolated results wherever they appear, they are shaded in gray to distinguish them from actual

NEMS

- BT results.9

- 9 Coal

- fired electric generation is the sin gle 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.

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 build ing 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 SO 2 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 involv e purchasing allowances or over

- complying at an existing unit.

For th is analysis , DOE used the version of NEMS

- BT based on AEO 2011 , which assumes the implementation of CAIR. Thus, DOE’s analysis assume s the presence of nationwide emission caps on SO 2 and caps on NO X emissions in the 28 States covered by CAIR. DOE expects that the NEMS

- BT based on AEO 2012 will incorporate implementation of the Transport
Rule.

SO 2 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 SO 2 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 SO 2 emissions allowances resulting from the lower electricity demand caused by the imposition of an efficiency standard could be used to permit offsetting increases in SO 2 emissions by any r egulated EGU. However, if the standard resulted in a permanent increase in the quantity of unused emissions allowances,
there would be an overall reduction in SO 2 emissions from the standards. While there remains some uncertainty about the ultimate effects of efficiency standards on SO 2 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 SO 2

. h

The CAIR established a cap on NO

x 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

- and

- trade programs for EGUs. Therefore, energy conservation st andards for water and evaporatively cooled products, VRF water source heat pumps, and computer room air

h In contrast to the modeling forecasts of NEMS

- BT that SO 2 emissions will remain at the cap, during the years 2007 and 2008, SO 2 emissions were below the trading cap. This raises the possibility that standards could cause some

reduction in SO 2 emissions. However, because DOE does not have a method to predict when emissions will be below the trading cap, it continues to reply on NEMS

- BT and t hus does not estimate SO 2 emissions reductions at

this time.9

- 10 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 litt le or no physical effect on SO 2 emissions.

With respect to Hg, in the absence of emissions caps , a DOE standard would likely reduce Hg emissions and DOE uses NEMS

- BT to estimate these emission reductions.

9.5 EFFECTS ON POWER PLA NT EMISSIONS

Table 9 .5.1 shows AEO201 1 R eference C ase 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 Efficiency Level s are promulgated (the base case).

Table 9.5.1 Power Sector Emissions Projection from AEO201 1 Reference Case

NEMS

- BT Results 2010 2015 2020 2025 2030 2035

CO 2 (million metric tons) 2,303 2,138 2,225 2,360 2,444 2,526

NO X (million tons) 2.57 1.98 1.98 2.00 2.01 2.03
Hg (tons) 40.5 26.8 26.8 28.0 28.7 29.3

Table 9 .5

. 2 through Table 9 .5

. 4 show the estimated changes in power plant emissions of

CO 2 , NO X, and Hg in selected years for each of the Efficiency Level s considered in this rulemaking

. As in Table 9 .5.1 , values for CO 2 are given in metric tons , while values for NO X and Hg are given in short tons.9

- 11 Table 9.5.2 Power Sector Emissions Impact s Forecasts for Water

- C ooled and Evaporative ly

- C ooled Product Efficiency Level s

NEMS-BT Results* Difference from AEO2011 Reference Case

Total

2010 2015 2020 2025 2030 2035 2040 2042 2043 2013-2043

ASHRAE

CO 2 (Mt/yr) 0.00 0.00 0.00 -0.01 0.00 0.00 0.00 0.00 0.00 -0.099

NOx (1,000 tons/yr) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 -0.081 Hg (ton/yr) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 -0.001

13 EER (Water)/12.5 EER (Evap)

CO 2 (Mt/yr) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 -0.096
NOx (kt/yr) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 -0.079
Hg (ton/yr) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 -0.001

14 EER (13.1 Evap)

CO 2 (Mt/yr) 0.00 0.00 0.00 -0.01 -0.01 -0.01 -0.01 -0.01 -0.01 -0.253
NOx (1,000 tons/yr) 0.00 0.00 0.00 -0.01 -0.01 -0.01 -0.01 -0.01 -0.01 -0.208

Hg (ton/yr) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 -0.003

15 EER (13.1 Evap, 14.8 VL Water)

CO 2 (Mt/yr) 0.00 0.00 -0.01 -0.02 -0.02 -0.02 -0.02 -0.02 -0.02 -0.363
NOx (1,000 tons/yr) 0.00 0.00 -0.01 -0.01 -0.01 -0.01 -0.01 -0.01 -0.01 -0.298
Hg (ton/yr) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 -0.004

Max Tech

CO 2 (Mt/yr) 0.00 0.00 -0.01 -0.02 -0.02 -0.02 -0.02 -0.02 -0.02 -0.371
NOx (1,000 tons/yr) 0.00 0.00 -0.01 -0.01 -0.01 -0.01 -0.01 -0.01 -0.01 -0.305
Hg (ton/yr) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 -0.004

*CO 2 results are in metric tons, NO X and Hg results are in short tons. Extrapolation9

- 12 Table 9.5.3 Power Sector Emissions Impact Forecasts for VRF Water

- S ource Heat Pump Efficiency Level s

NEMS-BT Results* Difference from AEO2011 Reference Case

Total

2010 2015 2020 2025 2030 2035 2040 2041 2042 2013-2042

ASHRAE

CO 2 (Mt/yr) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000

NOx (1,000 tons/yr) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000 Hg (ton/yr) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Level 1

CO 2 (Mt/yr) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 -0.054
NOx (kt/yr) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 -0.044
Hg (ton/yr) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 -0.001

Level 2

CO 2 (Mt/yr) 0.00 0.01 -0.02 -0.03 -0.04 -0.04 -0.04 -0.04 -0.04 -0.823
NOx (1,000 tons/yr) 0.00 0.00 -0.01 -0.03 -0.03 -0.04 -0.04 -0.04 -0.04 -0.675

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

Level 3

CO 2 (Mt/yr) 0.00 0.01 -0.04 -0.08 -0.08 -0.10 -0.10 -0.10 -0.10 -1.96
NOx (1,000 tons/yr) 0.00 0.01 -0.03 -0.07 -0.07 -0.08 -0.08 -0.08 -0.08 -1.60
Hg (ton/yr) 0.000 0.000 0.000 -0.001 -0.001 -0.001 -0.001 -0.001 -0.001 -0.022

Max Tech

CO 2 (Mt/yr) 0.00 0.02 -0.07 -0.14 -0.15 -0.19 -0.19 -0.19 -0.19 -3.58
NOx (1,000 tons/yr) 0.00 0.02 -0.06 -0.12 -0.13 -0.15 -0.15 -0.15 -0.15 -2.93
Hg (ton/yr) 0.000 0.000 0.000 -0.001 -0.002 -0.002 -0.002 -0.002 -0.002 -0.040

*CO 2 results are in metric tons, NO X and Hg results are in short tons. Extrapolation9

- 13 Table 9.5.4 Power Sector Emissions Impact Forecasts for Computer Room Air
Conditioner Efficiency Level s

NEMS-BT Results* Difference from AEO2011 Reference Case

Total

2010 2015 2020 2025 2030 2035 2040 2041 2042 2012-2042

ASHRAE

CO 2 (Mt/yr) 0.00 0.00 -0.01 -0.01 -0.01 -0.01 -0.01 -0.01 -0.01 -0.177
NOx (kt/yr) 0.00 0.00 -0.01 -0.01 -0.01 -0.01 -0.01 -0.01 -0.01 -0.145
Hg (ton/yr) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 -0.001

Level 1

CO 2 (Mt/yr) 0.00 0.01 -0.04 -0.09 -0.10 -0.10 -0.10 -0.10 -0.10 -2.14
NOx (1,000 tons/yr) 0.00 0.01 -0.04 -0.08 -0.08 -0.08 -0.08 -0.08 -0.08 -1.76

Hg (ton/yr) 0.000 0.000 0.000 -0.001 -0.001 -0.001 -0.001 -0.001 -0.001 -0.023

Level 2

CO 2 (Mt/yr) 0.00 0.05 -0.16 -0.35 -0.38 -0.40 -0.40 -0.40 -0.40 -8.06
NOx (1,000 tons/yr) 0.00 0.05 -0.14 -0.30 -0.32 -0.32 -0.32 -0.32 -0.32 -6.62
Hg (ton/yr) 0.001 0.000 -0.001 -0.004 -0.005 -0.005 -0.005 -0.005 -0.005 -0.087

Level 3

CO 2 (Mt/yr) 0.00 0.12 -0.38 -0.81 -0.89 -0.92 -0.92 -0.92 -0.92 -18.7
NOx (1,000 tons/yr) 0.00 0.11 -0.34 -0.69 -0.73 -0.74 -0.74 -0.74 -0.74 -15.4
Hg (ton/yr) 0.002 0.001 -0.002 -0.008 -0.011 -0.012 -0.012 -0.012 -0.012 -0.203

Max Tech

CO 2 (Mt/yr) 0.00 0.20 -0.63 -1.35 -1.48 -1.53 -1.53 -1.53 -1.53 -31.1
NOx (1,000 tons/yr) 0.00 0.18 -0.56 -1.14 -1.22 -1.23 -1.23 -1.23 -1.23 -25.6
Hg (ton/yr) 0.003 0.002 -0.003 -0.014 -0.018 -0.020 -0.020 -0.020 -0.020 -0.337

*CO 2 results are in metric tons, NO X and Hg results are in short tons. Extrapolation9

- 14 9.6 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. 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 report s 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 SO 2 ) from coal production are due to mining, preparation that includes cleaning the coal, and transportation from the mine to the power plant. 12 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 9 .6.1 for CO 2 and NO X

. 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 9.6.1 Estimated Upstream Emissions of Air Pollutants as a Percentage of Direct
Power Plant Combus tion Emissions

Pollutant Percent of Coal
Combustion Emissions Percent of Natural Gas
Combustion Emissions

CO 2 2.7 11.9

NO X 5.8 40

9.7 SUMMARY OF EMISSIONS IMPACTS

Table 9 .7 .1 summarize s the estimated emissions impacts for each of the Efficiency
Level s for water and evaporatively cooled products, VRF water source heat pumps, and computer room air conditioners

. It show s cumulative changes in emissions for CO 2 , NO X , and9

- 15 Hg for 2014 through 2043 for each of the Efficiency Level s

. C umulative CO 2 , NO X , and Hg

e missions are reduced compared to the R eference case for all Efficiency Level s. For comparison,

t he cumulative power sector emissions in the AEO 201 1 R eference case, over the period 2014 through 2043

, ar e 71,472 Mt for CO 2 , 60,127 kt for NOx, and 855 ton s for H g

.

Table 9.7.1 Cumulative Emissions Reductions Under ASHRAE Efficiency Level s *

Level 1 Level 2 Level 3 Level 4 Level 5

Water

- cooled and Evaporatively

- c ooled
Products

CO 2 (Mt)

NO X (kt) Hg (t) 0.099
0.081
0.001 0.096
0.079
0.001 0.253
0.208
0.003 0.363
0.298
0.004 0.371
0.305
0.004

VRF Water

- s ource Heat Pumps
CO 2 (Mt)

NO X (kt) Hg (t) 0.000
0.000
0.000 0.054
0.044
0.001 0.823
0.675
0.009 1.96
1.60
0.022 3.58
2.93
0.040 Computer Room Air Conditioners

CO 2 (Mt)

NO X (kt) Hg (t) 0.177
0.145
0.001 2.14
1.76
0.023 8.06
6.62
0.087 18.7
15.4
0.203 31.1
25.6
0.337

* Values for CO 2 are given in metric tons, while values for NO X and Hg are given in short tons.9

- 16 REFERENCES

1

. U.S. Environmental Protection Agency, Sulfur Dioxide, 2011. http://www.epa.gov/airquality/urbanair/

2

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3

. U.S. Environmental Protection Agency, Mercury, 2011. ht tp://www.epa.gov/mercury/

4

. Trasande, L., C. Schechter, K.A. Haynes, and P.J. Landrigan,, Applying Cost Analyses to Drive Policy That Protects Children : Mercury as a Case Study. Annals of the New York Academy of Sciences, 2006. 1076

5

. U.S. Environme ntal Protection Agency, 2009 U.S. Greenhouse Gas Inventory Report,

2009. http://www.epa.gov/climatechange/emissions/usinventoryreport.html

6

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7

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wg1.ucar.edu/wg1/docs/WG1AR4_SPM_PlenaryApproved.pdf

8

. Intergovernmental Panel On Climate Change, Climate Change 2007

– Impacts, Adaptation and Vulnerability. http://www.ipcc

- wg2.gov

9

. Intergovernmental Panel On Climate Change, IPCC Special Report on Land Use, Land

Use Change And Forestry, 2000. http://www.grida.no/publications/other/ipcc_sr/?src=/Climate/ipcc/land_use/index.htm

10

. Intergovernmental Panel On Climate Change, IPCC Fourth Assessment Report Climate Change 2007: Working Group III Report "Mitigation of Climate Change", 2007. http://www.ipcc.ch/pdf/assessment

- report/ar4/wg3/ar4

- wg3

- ts.pdf

11

. Energy Information Administration, Updated Annual Energy Outlook 2011. Report No.
DOE/EIA

- 0383(2011). http://www.eia.gov/forecasts/aeo/

12

. DeLuchi, M. A., Emissions of Greenhouse Gases from the Use of Transportation Fuels and Electricity, Volume 2: Appendixes A

- S, November, 1993. Argonne National Laboratory. Argonne , IL. Report No. ANL/ESD/TM

- 22

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