carbon pollution standards

Carbon Pollution Standards

The U.S. Environmental Protection Agency's (EPA) Clean Power Plan, proposed in June 2014, would limit carbon pollution from existing power plants.

Electric power generation is responsible for nearly 40 percent of U.S. carbon dioxide emissions – making it the largest single source. Reducing power sector emissions is a key part of President Obama’s Climate Action Plan, which aims to reduce overall U.S. greenhouse gas emissions 17 percent below 2005 levels by 2020. His June 2013 presidential memorandum directed EPA to set standards for both new and existing plants.

Under the Clean Power Plan for existing power plants, each state has its own target (due to regional variation in generation mix and electricity consumption). Overall, the rule is designed to cut emissions 30 percent from 2005 emissions by 2030, with an interim target of 25 percent on average between 2020 and 2029. EPA is expected to finalize this rule by June 2015.

In September 2013, EPA released a “Carbon Pollution Standard for New Power Plants,” replacing a March 2012 proposal. EPA proposed standards for coal- and natural gas-fired plants (measured as tons of greenhouse gas emissions per megawatt-hour of elec­tricity produced) that states would apply at each regulated plant. EPA is expected to finalize this rule in 2014.

Explore the issues and options involved in EPA regulation of carbon pollution from power plants through the following resources.

C2ES Resources

External Resources

Carbon Pollution Standards Map


In its proposed Clean Power Plan to reduce carbon dioxide emissions in the power sector, EPA has set a unique target emissions rate for each state to hit by 2030. To develop this target, EPA first determined a carbon emissions baseline (using 2012 data) based on each state’s level of CO2 emissions from fossil-fired power plants divided by its total electricity generation (including fossil-fired generation, renewable generation, and nuclear generation). Targets for 2030 were then established based on the capacity of each state to achieve reductions using the following four “building blocks” identified by EPA:

  1. Make coal-fired power plants more efficient;
  2. Use low-emitting natural gas combined cycle plants more where excess capacity is available;
  3. Use more zero- and low-emitting power sources such as renewables and nuclear; and
  4. Reduce electricity demand by using electricity more efficiently.

Since there is a wide variation among states in both emissions baseline and capacity to leverage each of the four building blocks, there is a wide variation in how much each state must cut from current emissions to hit its 2030 target emissions rate. (See Table 1.)

Each state can meet its established target however it sees fit, and does not need to leverage each building block to the extent that EPA projects. States will be able to convert their target emissions rate (pounds CO2 per megawatt-hour of electricity generated) to a mass-based standard (tons of CO2 emitted per year) to enable a cap-and-trade program. States are also free to join together and work toward an aggregated regional target.

Table 1: Building Block Reduction by State

State Emissions Rate of Power System, including zero-carbon generation (lbs CO2 / MWh) (2012 Block 1 (Coal-plant Efficiency) Adding Block 2 (Natural Gas Fuel Switching) Adding Block 3 (Renewable and Nuclear Generation) Final Target by Adding Block 4 (Demand-side Energy Efficiency) Total Emissions Reduction Target by 2030
Washington 756 728 444 298 215 71.6%
Arizona 1453 1394 843 814 702 51.7%
South Carolina 1587 1506 1342 866 772 51.4%
Oregon 717 701 565 452 372 48.1%
New Hampshire 905 887 710 532 486 46.3%
Georgia 1500 1433 1216 926 834 44.4%
Arkansas 1634 1554 1058 996 910 44.3%
New York 978 970 828 652 549 43.9%
New Jersey 928 916 811 616 531 42.8%
Minnesota 1470 1389 999 1042 873 40.6%
North Carolina 1647 1560 1248 1125 992 39.8%
Louisiana 1455 1404 1043 978 883 39.3%
Tennessee 1903 1797 1698 1322 1163 38.9%
Texas 1284 1235 979 861 791 38.4%
Florida 1199 1169 882 812 740 38.3%
Virginia 1302 1258 1047 894 810 37.8%
Massachusetts 925 915 819 661 576 37.7%
Mississippi 1093 1071 809 752 692 36.7%
Maryland 1870 1772 1722 1394 1187 36.5%
Oklahoma 1387 1334 1053 964 895 35.5%
Colorado 1714 1621 1334 1222 1108 35.4%
South Dakota 1135 1067 732 900 741 34.7%
Nevada 988 970 799 720 647 34.5%
Wisconsin 1827 1728 1487 1379 1203 34.2%
New Mexico 1586 1513 1277 1163 1048 33.9%
Illinois 1894 1784 1614 1476 1271 32.9%
Idaho 339 339 339 291 228 32.7%
Delaware 1234 1211 996 892 841 31.8%
Michigan 1690 1603 1408 1339 1161 31.3%
Pennsylvania 1531 1458 1393 1157 1052 31.3%
Connecticut 765 764 733 643 540 29.4%
Ohio 1850 1751 1673 1512 1338 27.7%
Utah 1813 1713 1508 1454 1322 27.1%
Alabama 1444 1385 1264 1139 1059 26.7%
Nebraska 2009 1889 1803 1652 1479 26.4%
Alaska 1351 1340 1237 1191 1003 25.8%
California 698 697 662 615 537 23.1%
Kansas 1940 1828 1828 1658 1499 22.7%
Missouri 1963 1849 1742 1711 1544 21.3%
Montana 2246 2114 2114 1936 1771 21.1%
Indiana 1924 1817 1772 1707 1531 20.4%
West Virginia 2019 1898 1898 1687 1620 19.8%
Wyoming 2115 1988 1957 1771 1714 19.0%
Kentucky 2158 2028 1978 1947 1763 18.3%
Iowa 1552 1461 1304 1472 1301 16.2%
Hawaii 1540 1512 1512 1485 1306 15.2%
Rhode Island 907 907 907 867 782 13.8%
Maine 437 437 425 451 378 13.5%
North Dakota 1994 1875 1875 1865 1783 10.6%
Vermont No affected sources
D.C.

Source: U.S. Environmental Protection Agency, Technical Support Document (TSD) for the CAA Section 111(d) Emission Guidelines for Existing Power Plants: Goal Computation, Appendix 5.

C2ES Carbon Pollution Standards Resource Page

EPA’s proposed carbon standard for power plants is stringent and flexible

The Obama Administration today took a major step toward reducing the carbon dioxide emissions that are impacting our climate. The Environmental Protection Agency (EPA) released its “Clean Power Plan,” which leverages existing authority in the Clean Air Act to propose carbon pollution standards for existing power plants, the largest single source of U.S. carbon emissions. The proposal would cut emissions in the power sector by 30 percent by 2030, based on 2005 levels. We reviewed the basics of the Clean Power Plan with four critical questions in mind:

1. Is the standard based on emission reductions outside the power plant fence line?

The short answer is “yes.” EPA cannot require states or power plant operators to take any specific measures, but it can set the emissions target stringent enough so that it would be challenging to achieve unless certain measures are taken. EPA is proposing state-specific targets based on the capacity of each state to leverage four “building blocks.” They are:

  1. Make fossil fuel power plants more efficient.
  2. Use low-emitting natural gas combined cycle plants more where excess capacity is available.
  3. Use more zero- and low-emitting power sources such as renewables and nuclear.
  4. Reduce electricity demand by using electricity more efficiently.

Although “outside-the-fence-line” measures are not specifically required under the proposal, states would be hard-pressed to meet their targets without using programs to reduce the demand for fossil electricity, by, for example, increasing energy efficiency and encouraging renewable energy.

Looking to Figure 1, EPA has chosen the System-level Option.

Figure 1: Scope of reduction requirements

What to watch in EPA’s power plant carbon emissions proposal

On June 2, the Environmental Protection Agency (EPA) is expected to release its proposal to cut carbon dioxide (CO2) emissions from existing power plants. This proposal is a key element of President Obama’s Climate Action Plan, and will be critical to reducing U.S emissions of CO2, the most common greenhouse gas contributing to climate change.

The proposed rule, being developed under EPA’s authority under Section 111(d) of the Clean Air Act, could be groundbreaking for at least two reasons. First, it has the potential to drive major reductions in the highest emitting sector in the United States – the power sector – which is responsible for nearly 40 percent of U.S. carbon emissions.  Second, EPA has indicated that the proposal will include a number of novel policy provisions to advance low-emitting generation and energy efficiency.

At C2ES, we’ll be looking for answers to four key questions as we read through EPA’s proposal. These questions are expanded upon in our new brief, Carbon Pollution Standards for Existing Power Plants: Key Challenges.

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