EPA’s Proposed Clean Power Plan: Conversion to Mass-Based Emission Targets

Congressional research reportMar 17, 2015

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EPA’s Proposed Clean Power Plan: Conversion

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March 17, 2015

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R43942

EPA’s Proposed Clean Power Plan: Conversion to Mass-Based Emission Targets

Summary

The Environmental Protection Agency (EPA) proposed a rule in June 2014 that would require

states to address carbon dioxide (CO2) emissions from existing fossil fuel-fired electric generating

units. The proposal would create CO2 emission rate goals—measured in pounds of CO2 emissions

per megawatt-hour (MWh) of electricity generation—for each state to achieve by 2030 and an

interim goal in 2029, based on the average of a state’s emission rates between 2020 and 2029.

EPA’s proposal would allow a state to establish its emission reduction requirements by converting

the interim (2029) and final (2030) emission rate targets to mass-based targets—measured in

metric tons of CO2. A state might consider using a mass-based target for a variety of reasons,

including the opportunity to link with existing mass-based programs or to continue existing, state

emission reduction goals. In addition, this report indicates that the mass-based reduction

requirements may be less stringent in some states than the emission rate requirements.

In November 2014, EPA provided technical information to help states with this conversion

process. Converting to a mass-based target requires an estimate of electricity generation in future

years (i.e., 2020-2029). EPA’s November 2014 support document provides two possible

approaches for creating such estimates. With each approach, EPA prepared state-specific massbased targets, which, according to EPA, “could be considered equivalent to the proposed ratebased goals.”

The first approach uses (1) 2012 baseline data—emissions and electricity generation—for each

state’s fossil fuel fleet and (2) specific results from parts of the emission rate methodology to

calculate future electricity generation. The second approach is based on both historical emissions

from existing sources and projected emissions from new, fossil fuel-fired electricity generation

sources. To project emissions from new sources, EPA applied specific regional growth factors

prepared by the Energy Information Administration.

This report compares the required percentage reductions (between the 2012 baseline and 2030

targets) using the emission rate targets to the percentage reductions using the mass-based targets

(approach 1). As with the emission rate reduction requirements, the mass-based reduction targets

vary by state. For the majority of states, the percentage reductions required by the emission rates

match those required by the mass-based approach. However, the required reductions differ in

some cases.

This report examines the reasons for these differences. For example, in nine states the differences

relate to EPA’s treatment of natural gas combined cycle (NGCC) units that are under construction.

In EPA’s mass-based conversion methodology, the agency includes under-construction NGCC

units in the 2012 fossil fuel-fired generation baseline. However, in the emission rate methodology

the generation from these units is not included in the 2012 baseline. This leads to different

percentage reduction requirements. In four other states, the differences are related to EPA’s

treatment of renewable energy in its emission rate methodology.

In addition, this report compares the percentage reduction requirements resulting from massbased approaches 1 and 2. As one might expect, all of the states have lower percentage reduction

requirements in approach 2 than in approach 1, because approach 2 includes projected increases

in electricity generation. However, the range of requirements varies considerably. Several factors

may explain this outcome. For instance, the regional growth factors used to project electricity

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EPA’s Proposed Clean Power Plan: Conversion to Mass-Based Emission Targets

demand in future years vary significantly—from 0.29% in the Northeast region to 1.31% in the

Southwest region. In addition, EPA uses electricity sales data in 2012 to calculate future

electricity demand, and the sales data contain electricity generation from all sources, including

hydroelectric power. Including hydroelectric power appears to have a substantial impact in states

that use it to generate a significant percentage of their electricity.

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EPA’s Proposed Clean Power Plan: Conversion to Mass-Based Emission Targets

Contents

Introduction...................................................................................................................................... 1

Overview of EPA’s Emission Rate Methodology ............................................................................ 2

Conversion to Mass-Based Targets .................................................................................................. 3

Approach 1: Existing Sources ................................................................................................... 3

Approach 2: Existing and New Sources .................................................................................... 4

Observations About the Mass-Based Targets................................................................................... 6

Approach 1 (Existing Sources) vs. Emission Rate Targets........................................................ 7

Approach 2 (Existing and New Sources) .................................................................................. 8

Figures

Figure 1. EPA’s Assumed Growth Factors in Electricity Demand by State ..................................... 6

Tables

Table 1. EPA’s Mass-Based Targets and Emission Rate Targets Compared to 2012

Baselines ..................................................................................................................................... 10

Contacts

Author Contact Information........................................................................................................... 14

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EPA’s Proposed Clean Power Plan: Conversion to Mass-Based Emission Targets

Introduction

In June 2014, the Environmental Protection Agency (EPA) published a proposed rule that would

require states to address carbon dioxide (CO2) emissions from existing fossil fuel-fired electric

generating units.1 The proposal relies on authority asserted by EPA in Section 111(d) of the Clean

Air Act (CAA).2 However, many have questioned various aspects of EPA’s proposed rule,

including the agency’s statutory authority to issue the rule pursuant to Section 111(d).3 In

addition, the proposed rule has received considerable attention from Congress, state officials, and

a range of stakeholder groups.

The proposal creates CO2 emission rate goals—measured in pounds of CO2 emissions per

megawatt-hour (MWh) of electricity generation—for each state to achieve by 2030 and an

interim goal in 2029, based on the average of a state’s emission rates between 2020 and 2029.

EPA’s goals include potential emission reduction opportunities that are considered “outside the

fence” of fossil fuel-fired generating facilities. These include increased renewable energy

generation4 and energy efficiency improvements. Thus, the emission rate goals effectively apply

to a state’s overall electricity generation portfolio, not just the fossil fuel units. EPA estimates that

if the states achieve their individual emission rate goals, the 2030 CO2 emissions from the electric

power sector in the United States would be reduced by 30% compared to 2005 levels.

Although EPA's proposed rule measures state compliance in terms of a CO2 emissions rate, EPA

allows states considerable flexibility in terms of meeting its emissions rate goals. In particular,

EPA’s proposed rule would allow states to meet their compliance obligations by converting their

emission rate targets to mass-based targets—measured in metric tons of CO2.5 When EPA issued

its proposal, the agency published a technical support document (“Projecting EGU CO2 Emission

Performance in State Plans”) that provided one option for converting from rate-based to massbased targets. After receiving feedback from states about the conversion process, EPA provided

additional information in November 2014,6 including a new technical support document:

“Translation of the Clean Power Plan Emission Rate‐Based CO2 Goals to Mass‐Based

Equivalents.”

This report discusses EPA’s mass-based conversion methodology and the resulting state-specific

mass-based targets. The state-specific targets and percentage reduction requirements are provided

in Table 1, allowing the states to compare their compliance obligations. A state might consider

U.S. EPA, “Carbon Pollution Emission Guidelines for Existing Stationary Sources: Electric Utility Generating Units,”

Proposed Rule, 79 Federal Register 34830, June 18, 2014.

42 U.S.C. §7411(d).

For further discussion of EPA’s proposal, see CRS Report R43572, EPA’s Proposed Greenhouse Gas Regulations for

Existing Power Plants: Frequently Asked Questions, by (name redacted) et al.

EPA proposed two options for quantifying renewable energy targets. In addition, the agency is considering different

mechanisms to account for renewable energy produced in one state, but consumed in another state. See U.S. EPA,

“Carbon Pollution Emission Guidelines for Existing Stationary Sources: Electric Utility Generating Units,” Notice of

data availability, 79 Federal Register 64534, October 30, 2014.

Although EPA’s emission rates are in pounds per megawatt-hour, most national and international measures of CO2

emissions are provided in metric tons. One metric ton is approximately 2,205 pounds.

U.S. EPA, “Carbon Pollution Emission Guidelines for Existing Stationary Sources: Electric Generating Units,” Notice

of additional information, 79 Federal Register 67406, November 13, 2014.

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using a mass-based target for a variety of reasons, including the opportunity to link with existing

mass-based programs (e.g., the Regional Greenhouse Gas Initiative)7 or to continue existing, state

emission reduction goals. This report indicates that the mass-based reduction requirements may

be less stringent in some states than the emission rate requirements. Thus, some states may factor

such a comparison into their decision process.

The first section of this report provides an overview of the emission rate methodology, which

plays a role in the mass-based conversion calculations. The second section describes EPA’s massbased conversion methodologies: approach 1, which includes existing sources of electricity, and

approach 2, which includes existing and new sources of electricity. The final section provides

some observations about the results of the mass-based conversions, including a comparison of the

required percentage reductions to the percentage reductions from the emission rate formula.

This report complements two other CRS reports:

1. CRS Report R43572, EPA’s Proposed Greenhouse Gas Regulations for Existing

Power Plants: Frequently Asked Questions, by (name redacted) et al. This

report discusses a range of issues—legal, historical, and procedural—regarding

EPA’s proposed rule.

2. CRS Report R43652, State CO2 Emission Rate Goals in EPA’s Proposed Rule for

Existing Power Plants, by (name redacted). This report discusses in detail

EPA’s emission rate methodology (i.e., the “building blocks”) and the statespecific emission rates that result from EPA’s calculations.

Overview of EPA’s Emission Rate Methodology

EPA’s emission rate methodology plays a critical role in the agency’s mass-based conversion

calculations. An overview of the emission rate formula is helpful in understanding EPA’s massbased conversion calculations.

EPA determined emission rate goals by first calculating each state's 2012 emission rate baseline,

which is generally each state's portfolio of electricity generation in 2012. The resulting baselines

in each state vary considerably, reflecting, among other things, the different energy sources used

to generate electricity in each state. Next, EPA applied four “building blocks” to the state

baselines. The building blocks involve estimates of various opportunities for states to decrease

their emission rates:

•

Building block 1: Coal-fired power plant efficiency improvements, such as

operation and maintenance best practices and equipment upgrades;

•

Building block 2: Natural gas combined cycle (NGCC) displacement of more

carbon-intensive sources of electricity, particularly coal-fired generation;

•

Building block 3: Increased use of renewable energy and preservation of existing

and under-construction nuclear power; and

See CRS Report R41836, The Regional Greenhouse Gas Initiative: Lessons Learned and Issues for Policy Makers, by

(name redacted).

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EPA’s Proposed Clean Power Plan: Conversion to Mass-Based Emission Targets

•

Building block 4: Energy efficiency improvements, which result in decreased

electricity generation.

Although EPA used the building blocks to create state-specific emission rates, the agency would

not require states to precisely implement the activities EPA used in the building blocks. States

may choose to meet their emission rate goals by focusing on one or more of the building block

strategies (e.g., increase renewable energy beyond building block 3 expectations) or through

alternative methods.8 For further details about EPA’s emission rate methodology and state-specific

results, see CRS Report R43652, State CO2 Emission Rate Goals in EPA’s Proposed Rule for

Existing Power Plants, by (name redacted).

Conversion to Mass-Based Targets

EPA’s November 2014 support document describes two approaches states could use to convert

their emission rate targets to mass-based targets. EPA states that the approaches “are illustrations

of two potential options that implementing authorities may choose to adopt if they choose to use a

mass-based form of the emission rate-based goal.” With each approach, EPA prepared statespecific mass-based targets, which, according to EPA, “could be considered equivalent to the

proposed rate-based goals.”

The first approach is generally based on historical (2012) emissions from existing sources. The

second is based on historical emissions from existing sources and projected emissions from

existing and new sources.

The basic formula for converting from an emission rate to a mass-based target is the following:

CO2 mass-based target

(pounds or metric tons)

CO2 emission rate target

(pounds per MWh)

Electricity generation

(MWh)

The state-specific CO2 emission rate targets in the above formula are included in EPA’s June 2014

proposed rule. To convert a rate target to a mass-based target, a state would need an annual

estimate of its electricity generation in future years (i.e., 2020-2029). EPA’s November 2014

support document provides two methodologies that the agency used to calculate these electricity

generation estimates. These methodologies are discussed below.9

Approach 1: Existing Sources

EPA’s first mass-based conversion approach uses (1) the 2012 baseline data—emissions and

electricity generation—for each state’s fossil fuel fleet and (2) specific results from parts of the

emission rate building blocks to calculate future electricity generation. EPA’s conversion

EPA discusses several alternative options in its proposed rule. These include the construction of new NGCC units,

nuclear power generating units, or hydroelectric power plants, and employing carbon capture and storage technology at

existing fossil fuel units.

EPA’s November 2014 technical support document describes these steps in greater detail, using Ohio as an example.

See EPA, Translation of the Clean Power Plan Emission Rate‐Based CO2 Goals to Mass‐Based Equivalents, at

http://www2.epa.gov/sites/production/files/2014-11/documents/20141106tsd-rate-to-mass.pdf.

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EPA’s Proposed Clean Power Plan: Conversion to Mass-Based Emission Targets

methodology includes several steps. The example provided below demonstrates how EPA

projected the state-specific electricity generation levels for 2029.10

EPA determined the electricity generation from “affected electric generating units” in

2012; in general, an “affected EGU” is a fossil fuel-fired unit that was in operation or had

commenced construction as of January 8, 2014, has a generating capacity above a certain

threshold, and sells a certain amount of its electricity generation to the grid;11 this value

serves as the electricity generation baseline; EPA used the same data that were provided

with the emission rate methodology supporting materials;12

ii.

EPA adjusted the fossil-fuel electricity generation baseline by subtracting the estimated,

incremental generation from renewable energy in 2029 (building block 3), the underconstruction nuclear power (building block 3), and reduced generation from energy

efficiency for 2029 (building block 4);13 EPA refers to this value as the “adjusted affected

fossil fuel generation”;14

iii.

EPA combined the adjusted affected fossil fuel generation value (for 2029) with the

estimated generation from renewable energy (both existing in 2012 and incremental in

2029), at-risk and under-construction nuclear generation, and avoided generation from

energy efficiency activities (for 2029); EPA refers to this value as the “mass equivalent

generation level” for 2029.

In its supporting technical materials, EPA calculated the mass equivalent generation levels for

each year between 2020 and 2029. The agency then multiplied these electricity generation values

by the corresponding emission rate values (from the June 2014 proposed rule) to produce statespecific, mass-based, emission targets for each year. Table 1 lists each state’s 2012 CO2 emission

baseline, 2030 CO2 emission target, and the percentage reduction required to meet the 2030

target.

Approach 2: Existing and New Sources

EPA’s second mass-based conversion approach is based on both historical emissions from

existing sources (i.e., approach 1) and projected emissions from certain new, fossil fuel-fired

electricity generation sources, particularly NGCC units.15 The new units would be constructed to

Both the final emission rate targets and final mass-based targets (i.e., 2030) are the same as the 2029 targets.

For more details, see CRS Report R43652, State CO2 Emission Rate Goals in EPA’s Proposed Rule for Existing

Power Plants, by (name redacted).

This information is available in EPA’s supporting materials, at http://www2.epa.gov/carbon-pollution-standards/

clean-power-plan-proposed-rule.

This information is available in EPA’s supporting materials, at http://www2.epa.gov/carbon-pollution-standards/

clean-power-plan-proposed-rule.

EPA points out that this step was not part of the June 2014 emission rate methodology. However, in a subsequent

Federal Register notice, EPA asked for comments on approaches that would include such a step in the emission rate

calculation. See discussion in U.S. EPA, “Carbon Pollution Emission Guidelines for Existing Stationary Sources:

Electric Utility Generating Units,” Notice of data availability, 79 Federal Register 64534, October 30, 2014.

Other fossil fuel-fired units, including less efficient natural gas units, would likely not be able to meet the emission

performance standards in EPA’s proposal for new sources (U.S. EPA, “Standards of Performance for Greenhouse Gas

Emissions from New Stationary Sources: Electric Generating Units,” Proposed Rule, 79 Federal Register 1430,

January 8, 2014). However, EPA contemplated new fossil fuel-fired units that use carbon capture and storage (CCS)

(continued...)

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EPA’s Proposed Clean Power Plan: Conversion to Mass-Based Emission Targets

address the projected growth in electricity demand. In the proposed rule, and in a supplemental

notice published in November 2014, EPA specifically asked for comments on whether and how

new NGCC units could be addressed under its proposal.16 EPA offered this second mass-based

approach to account for the possibility that new units may play a role in meeting a state’s

emission rate or mass-based target.

As with the first approach, the second approach involves a series of steps to produce the

estimated electricity generation levels in future years. The following example describes how EPA

estimated the states’ 2029 electricity generation (from existing and new sources), and thus the

2030 emission targets:

EPA determined a state’s projected sales of electricity in 2029 by multiplying a

state’s 2012 electricity retail sales (i.e., in-state) by a specific growth factor; EPA

used growth factors for 21 different areas from the Energy Information

Administration’s (EIA) 2013 Annual Energy Outlook; Figure 1 shows the

different growth factors in each state;

ii.

EPA calculated the incremental demand for new electricity in 2029 by

multiplying a state’s 2029 projected electricity by expected transmission losses,17

and then subtracting projected generation from NGCC units that are under

construction;18

iii.

EPA combined the incremental demand in 2029 with the 2029 mass equivalent

generation level from existing sources (calculated in approach 1); the resulting

sum is the “mass equivalent generation level” for 2029 that includes existing and

new sources.

Similar to approach 1, EPA calculated the mass equivalent generation levels for each year

between 2020 and 2029. EPA then multiplied these values by the corresponding emission rates to

produce state-specific, mass-based, emission targets for each year. Table 1 lists each state’s 2012

CO2 emission baseline, 2030 CO2 emission target, and the percentage reduction required to meet

the 2030 target.

(...continued)

technologies as another possibility.

See U.S. EPA, “Carbon Pollution Emission Guidelines for Existing Stationary Sources: Electric Utility Generating

Units,” Proposed Rule, 79 Federal Register 34830, June 18, 2014, pages 34923-34924; and U.S. EPA, “Carbon

Pollution Emission Guidelines for Existing Stationary Sources: Electric Generating Units,” Notice, 79 Federal Register

67406, November 13, 2014.

EPA assumes this to be a fixed percentage of 7.51% in each state. EPA also used this figure in its emission rate

methodology for building block 4.

EPA assumes that under-construction NGCC units will operate at 55% capacity.

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EPA’s Proposed Clean Power Plan: Conversion to Mass-Based Emission Targets

Figure 1. EPA’s Assumed Growth Factors in Electricity Demand by State

Annual Average Growth (2012 – 2029)

Source: Map prepared by CRS; source data from EPA technical support document spreadsheet (“Rate to Mass

Translation Data File”) at http://www2.epa.gov/carbon-pollution-standards/clean-power-plan-proposed-ruletechnical-documents#rate-to-mass.

Notes: EPA prepared annual average growth factors in electricity demand for each state, using Electricity

Market Module (EMM) regional demand projections from the Energy Information Administration’s 2013 Annual

Energy Outlook. For states in multiple EMM regions (e.g., Virginia and Pennsylvania), EPA assigned the growth

rate for the region that encompassed the largest portion of the state’s territory. EPA assigned Alaska and Hawaii

the average rate of the lower 48 states, because neither of these states is in an EMM region.

Observations About the Mass-Based Targets

Table 1 lists the state-specific, mass-based targets (2030) that EPA prepared using both

approaches and compares these targets to each state's 2012 CO2 emission baseline. In addition,

Table 1 provides the 2012 emission rate baseline, 2030 emission rate target, and the emission rate

percentage reduction required between 2012 and 2030.

As with the emission rate reduction requirements, the mass-based reduction targets (calculated by

EPA) vary by state. This section discusses some observations about the targets, how they compare

with one another, and how they compare to emission rate targets.

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EPA’s Proposed Clean Power Plan: Conversion to Mass-Based Emission Targets

Approach 1 (Existing Sources) vs. Emission Rate Targets

For the vast majority of states, the percentage reductions (between the 2012 baseline and 2030

targets) required by the emission rates match those required by the mass-based targets EPA

created using approach 1 (existing sources). However, in some cases the percentage reductions

differ. The reasons for these differences vary.

In nine states—California, Colorado, Florida, Kentucky, Mississippi, North Carolina, Ohio,

Virginia, and Wyoming—the mass-based targets for existing sources result in a smaller

percentage reduction requirement from the 2012 baseline than the percentage reduction

requirement for the emission rate target. The percentage reductions for these states are

highlighted in blue in Table 1. The differences in percentage reductions range from 1% to 14%.

For example, if Virginia were to use an emission rate target, its percentage reduction requirement

would be 38% between 2012 and 2030. However, Virginia’s mass-based target requires a 24%

reduction during the same time period.

The reason for the percentage differences in these states relates to EPA’s treatment of NGCC units

that are under construction. These nine states are the only ones with NGCC units under

construction. In EPA’s mass-based conversion methodology, the agency includes underconstruction NGCC units in the 2012 fossil fuel-fired generation baseline. However, in the

emission rate methodology the generation from these units is not included in the 2012 baseline.19

Thus, the baselines for these nine states are effectively higher using the mass-based methodology,

and a relatively higher baseline yields a smaller reduction requirement.

Two other states—Washington and Idaho—also have lower percentage reduction requirements

under the mass-based methodology. Their reduction percentages are highlighted in green in Table

1. These differences are the result of an adjustment EPA made to the states’ “adjusted affected

fossil fuel generation.” As discussed above (step 2 in the mass-based methodology for existing

sources), EPA calculates a state’s “adjusted affected fossil fuel generation” by subtracting

incremental renewable energy and energy efficiency values from a state’s 2012 fossil fuel

generation baseline. If EPA were to strictly apply this step for these states, the resulting values

would be negative, an impossible outcome. If a negative value were allowed (“on paper”) for the

purposes of the calculations, these states’ percentage reductions would match their emission rate

percentage reductions. EPA adjusts the calculations in these states, by holding the “adjusted

affected fossil fuel generation” at zero.

Four other states—Iowa, Maine, Minnesota, and South Dakota—have larger percentage

reductions under the mass-based targets for the existing sources approach. The percentage

reductions for these states are highlighted in orange in Table 1. The reason for these differences is

due to the treatment of renewable energy (RE) in EPA’s emission rate methodology, particularly

its treatment in building block 3.20

In the emission rate calculations, the generation from these units is not part of the 2012 baseline calculation, but

comes into play during building block 2.

For more details, see CRS Report R43652, State CO2 Emission Rate Goals in EPA’s Proposed Rule for Existing

Power Plants, by (name redacted).

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EPA’s Proposed Clean Power Plan: Conversion to Mass-Based Emission Targets

In building block 3, EPA applies an annual growth rate21 to each state's RE generation in 2012 to

estimate annual RE generation for each state from 2017 through 2030. If the growth factor results

in an individual state equaling or exceeding its 2030 RE target, the state's RE use is held constant

at the level that matches its regional target. The 2012 RE generation in these four states matched

or exceeded their 2030 RE targets, so the estimated future RE generation (for the purposes of the

emission rate calculations) in these states actually decreases to match their regional targets.

Arguably, this outcome artificially lowers the emission rate targets for these states. In the massbased methodology, RE generation is captured in the target calculations, not in the 2012 baseline.

Thus, in comparison to the emission rate reductions, the mass-based reductions in these states are

greater.22

Approach 2 (Existing and New Sources)

EPA’s second approach for converting to mass-based targets, which includes electricity generation

from both existing and new sources, provides some results that may be of interest to policymakers

and stakeholders. Table 1 lists the state-specific 2012 emission baselines, 2030 emission targets,

and their percentage changes. All of the states have lower percentage reduction requirements than

those in approach 1 (existing sources only), because approach 2 includes projected increases of

electricity generation. However, the range of percentage reduction requirements varies

considerably. In particular, three states—California, Hawaii, and Idaho—have emission targets in

2030 that are higher than their 2012 baseline (highlighted in yellow in Table 1). Three other

states—Alaska, Kentucky, and Virginia—have percentage reduction requirements that are 3% or

less.

Several factors help explain the range of percentage reduction requirements that result from

approach 2. First, as discussed above, the methodology in this approach uses a regional growth

factor to project electricity demand in future years. These growth factors vary significantly—from

0.29% in the Northeast region to 1.31% in the Southwest region. Assuming these factors hold

true, Arizona’s demand for electricity will increase by 25% between 2012 and 2029. In contrast,

the demand for electricity in Massachusetts will increase by 5% over the same time period.

Second, EPA uses electricity sales data in 2012 to calculate future electricity demand. The 2012

sales data include electricity generation from all sources, including hydroelectricity. This source

of generation is included in EPA’s emission rate methodology, but to a lesser extent than in the

mass-based methodology.23 The different accounting mechanisms appear to have an impact in

states that generate a significant percentage of electricity generation from hydropower (e.g.,

Idaho, Washington, Oregon). Moreover, these three states are located in a region with a relatively

high electricity growth factor (Figure 1).

Third, as with approach 1 (discussed above), the CO2 emissions from NGCC units that are under

construction are counted (at a 55% capacity rate) toward a state’s 2012 baseline. This is a factor

To establish the growth rates, EPA placed each state into one of six regions (Alaska and Hawaii are treated

individually). EPA then determined an RE 2030 target for each region based on an average of existing RE targets (e.g.,

renewable portfolio standards) that are required by some, but not all, states in the relevant region.

For more details about EPA’s renewable energy methodology, see CRS Report R43652, State CO2 Emission Rate

Goals in EPA’s Proposed Rule for Existing Power Plants, by (name redacted).

EPA accounts for hydropower generation in the building block 4 calculation (energy efficiency improvements) and

at-risk and under-construction nuclear power generation in building block 3.

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EPA’s Proposed Clean Power Plan: Conversion to Mass-Based Emission Targets

in nine states, particularly Virginia. In that state, under-construction NGCC units account for

approximately 20% of the state’s fossil-fuel fired generation in 2012, although these plants

generated no power that year.

Congressional Research Service

Table 1. EPA’s Mass-Based Targets and Emission Rate Targets Compared to 2012 Baselines

Mass-Based Approaches

State

CO2

Emission

Baseline:

Existing

Sources

(2012)

CO2

Emission

Target:

Existing

Sources

(2030)

Percent

Reduction

from 2012

Baseline

Emission Rate Approach

CO2

Emission

Target:

Existing and

New

Sources

(2030)

Percent

Reduction

from 2012

Baseline

Thousand metric tons

Approach 1

CRS-10

CO2

Emission

Rate

Baseline

(2012)

CO2

Emission

Rate Target

(2030)

Percent

Reduction

from 2012

Baseline

Pounds per megawatt-hour

Approach 2

Alabama

68,558

50,267

27%

59,214

14%

1,444

1,059

27%

Alaska

1,963

1,457

26%

1,912

1,351

1,003

26%

Arizona

36,709

17,734

52%

24,193

34%

1,453

702

52%

Arkansas

36,095

20,096

44%

23,527

35%

1,634

910

44%

California

43,688

35,805

18%

45,171

(3%)

698

537

23%

Colorado

38,442

25,335

34%

31,935

17%

1,714

1,108

35%

Connecticut

6,038

4,265

29%

4,661

23%

765

540

29%

Delaware

4,363

2,972

32%

3,435

21%

1,234

841

32%

Florida

107,509

68,221

37%

83,259

23%

1,199

740

38%

Georgia

57,017

31,676

44%

42,394

26%

1,500

834

44%

Hawaii

4,729

4,010

15%

4,899

(4%)

1,540

1,306

15%

Idaho

638

468

27%

990

(55%)

339

228

33%

Illinois

87,133

58,471

33%

65,574

25%

1,894

1,271

33%

Indiana

91,831

73,090

20%

79,341

14%

1,924

1,531

20%

Iowa

34,674

25,749

26%

28,496

18%

1,552

1,301

16%

Mass-Based Approaches

State

CO2

Emission

Baseline:

Existing

Sources

(2012)

CO2

Emission

Target:

Existing

Sources

(2030)

Percent

Reduction

from 2012

Baseline

Emission Rate Approach

CO2

Emission

Target:

Existing and

New

Sources

(2030)

Percent

Reduction

from 2012

Baseline

Thousand metric tons

Approach 1

CRS-11

CO2

Emission

Rate

Baseline

(2012)

CO2

Emission

Rate Target

(2030)

Percent

Reduction

from 2012

Baseline

Pounds per megawatt-hour

Approach 2

Kansas

31,156

24,081

23%

26,696

14%

1,940

1,499

23%

Kentucky

82,893

70,203

15%

81,953

2,158

1,763

18%

Louisiana

44,186

26,823

39%

32,839

26%

1,455

883

39%

Maine

1,629

1,323

19%

1,432

12%

437

378

14%

Maryland

18,300

11,613

37%

15,148

17%

1,870

1,187

37%

Massachusetts

11,910

7,414

38%

8,204

31%

925

576

38%

Michigan

63,164

43,403

31%

46,725

26%

1,690

1,161

31%

Minnesota

25,416

14,474

43%

17,218

32%

1,470

873

41%

Mississippi

23,500

16,449

30%

18,916

20%

1,093

692

37%

Missouri

70,926

55,792

21%

60,173

15%

1,963

1,544

21%

Montana

16,266

12,828

21%

15,190

2,246

1,771

21%

Nebraska

24,639

18,142

26%

20,233

18%

2,009

1,479

26%

Nevada

14,049

9,209

34%

11,396

19%

988

647

34%

New Hampshire

4,212

2,262

46%

2,392

43%

905

486

46%

New Jersey

11,774

6,741

43%

8,649

27%

928

531

43%

New Mexico

15,730

10,391

34%

13,337

15%

1,586

1,048

34%

New York

31,441

17,649

44%

19,310

39%

978

549

44%

Mass-Based Approaches

State

CO2

Emission

Baseline:

Existing

Sources

(2012)

CO2

Emission

Target:

Existing

Sources

(2030)

Percent

Reduction

from 2012

Baseline

Emission Rate Approach

CO2

Emission

Target:

Existing and

New

Sources

(2030)

Percent

Reduction

from 2012

Baseline

Thousand metric tons

Approach 1

CRS-12

CO2

Emission

Rate

Baseline

(2012)

CO2

Emission

Rate Target

(2030)

Percent

Reduction

from 2012

Baseline

Pounds per megawatt-hour

Approach 2

North Carolina

53,169

36,918

31%

45,165

15%

1,647

992

40%

North Dakota

30,274

27,069

11%

28,270

1,994

1,783

11%

Ohio

92,861

68,751

26%

75,116

19%

1,850

1,338

28%

Oklahoma

47,859

30,892

35%

35,127

27%

1,387

895

35%

Oregon

6,956

3,614

48%

5,293

24%

717

372

48%

Pennsylvania

105,184

72,272

31%

79,618

24%

1,531

1,052

31%

Rhode Island

3,389

2,924

14%

3,074

907

782

14%

South Carolina

32,565

15,816

51%

22,014

32%

1,587

772

51%

South Dakota

3,018

1,602

47%

2,000

34%

1,135

741

35%

Tennessee

37,410

22,837

39%

32,992

12%

1,903

1,163

39%

Texas

220,740

135,937

38%

158,775

28%

1,284

791

38%

Utah

27,961

20,384

27%

24,165

14%

1,813

1,322

27%

Virginia

24,914

18,923

24%

24,494

1,302

810

38%

Washington

6,617

2,862

57%

4,772

28%

756

215

72%

West Virginia

65,614

52,636

20%

54,566

17%

2,019

1,620

20%

Wisconsin

38,390

25,275

34%

28,102

27%

1,827

1,203

34%

Wyoming

45,358

37,590

17%

39,550

13%

2,115

1,714

19%

Source: Prepared by CRS; emission rate and mass-based targets from EPA technical support documents and spreadsheets, at http://www2.epa.gov/carbon-pollutionstandards/clean-power-plan-proposed-rule.

Notes: This table lists the state-specific, mass-based targets (2030) that EPA prepared using both approaches and compares these targets to each state's 2012 CO2

emission baseline. In addition, the table provides the 2012 emission rate baseline, 2030 emission rate target, and the emission rate percentage reduction required

between 2012 and 2030. The colored boxes highlight differences between the comparisons:

Blue: in these nine states, the mass-based targets for existing sources (approach 1) result in a smaller percentage reduction requirement from the 2012 baseline than the

percentage decrease for the emission rate target. The reason for the difference is EPA’s treatment of under-construction NGCC units.

Green: in these two states, the mass-based targets for existing sources (approach 1) result in a smaller percentage decrease from the 2012 baseline than the percentage

decrease for the emission rate target. The reason for the difference is due to a specific adjustment EPA made to these states’ “adjusted affected fossil fuel generation.”

Orange: in these four states, the mass-based targets for existing sources (approach 1) result in a larger percentage decrease from the 2012 baseline than the percentage

decrease for the emission rate target. The reason for the difference reflects EPA’s treatment of renewable energy, as discussed in the text.

Yellow: in these four states, the 2030 mass-based targets for existing and new sources (approach 2) are higher than the emissions in 2012. As discussed in the text,

several factors may explain this result.

CRS-13

EPA’s Proposed Clean Power Plan: Conversion to Mass-Based Emission Targets

Author Contact Information

(name redacted)

Specialist in Environmental Policy

/redacted/@crs.loc.gov, 7-....

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