American power plant CO2 emissions fall 12% from 2008-13

Power plants switching to natural gas, which emits roughly 50% less carbon when burned than coal

American power plant emissions of carbon dioxide fell 12 per cent from 2008 to 2013 even as the economy grew, according to a new study from sustainability group Ceres.

The Obama Administration announced plans last year to reduce power plant emissions by 30 per cent by 2030 and the Environmental Protection Agency is set to begin implementing the Clean Power Plan, which has been criticized in some quarters for its aggressive CO₂ reduction targets.

The new report examines CO₂, nitrogen oxides (NOx), sulfur dioxide (SO₂), and mercury emissions from the nation’s 100 largest electric power producers.

Ceres says power plants reduced emissions due to a decline in overall electricity demand, coal plant retirements, pollution controls at power plants, and low natural gas prices.

Southeast (Entergy and Dominion), Midwest (Hoosier Energy and Associated Electric Cooperatives) and Southwest/West (OGE and Xcel) power producers are among those achieving some of the highest levels of improvement in their CO₂ emission rates (pounds per megawatt hour, lb/MWh).

On a state level, between 2008 and 2013, a large majority of states (42) decreased their electric sector CO₂ emissions, by an average of 19 per cent according to a comparison with past Benchmarking reports. In terms of state-level emission rates, 40 states decreased their all-source CO₂ emission rates by an average of 18 per cent in the same time period.

While emissions overall are trending downward, the report found uneven performance across both power producers and the states.

CO₂ emissions rates vary 10-fold among the top 100 producers, from a high of 2,264 lb/MWh for Big Rivers Electric in 2013 to 200 lb/MWh or less for companies such as Exelon, New York Power Authority, PG&E Corporation, and Iberdrola.

Similarly, emissions rates range 10-fold in the states, from roughly 2,000 lb/MWh in Kentucky, Wyoming, and West Virginia to 200-300 lb/MWh in Idaho, Washington, and Oregon, based in part on their existing hydroelectric generation which is not included in the Clean Power Plan building blocks.

“Most parts of the country are firmly on the path toward a clean energy future, but some states and utilities have a longer way to go and overall the carbon emissions curve is still not bending fast enough,” said Mindy Lubber, president of Ceres. 

Key findings of the report:

• Air pollution emissions from power plants are highly concentrated among a small number of producers.  Among the 100 largest generators, five (Duke, AEP, Southern, NRG, and MidAmerican) generate 25 per cent of CO₂ emissions, though Southern has seen a significant decline in emissions (27 per cent) since 2000, and Duke has seen a 10 per cent decline in its emissions rate even after its recent merger with Progress Energy. Three (AEP, Southern, and NRG) generate nearly 25 per cent of SO₂ emissions.

• SO₂ and NO_X emissions in 2013 were 80 per cent and 74 per cent lower, respectively, than they were in 1990, when major amendments to the Clean Air Act were passed.
• Mercury emissions have decreased 50 per cent since 2000, when the industry was first required to report their mercury emissions to EPA.
• Coal accounted for 40 per cent of the power produced by the top 100 power producers, followed by natural gas at 26 per cent, nuclear at 22 per cent, and renewable power, including large hydroelectric, and other at 14 per cent.
• The utilization, or capacity factors, of coal plants continues to decline relative to natural gas plants, with coal plants’ average utilization rates declining from 73 to 61 per cent, and natural gas plants increasing their utilization from 40 to 48 per cent between 2008 and 2014.

“Entergy was the first American utility to adopt a voluntary carbon cap on emissions of carbon dioxide from its power plants and today, we have one of the cleanest generation fleets in the nation,” said Chuck Barlow, VP of environmental strategy and policy for Entergy Corp.

The report is the eleventh in a series since 1997 highlighting environmental improvements and progress in the nation’s electric sector. The 100 power producers evaluated in the report represent 85 per cent of the electric power generated in the U.S. and 87 percent of the industry’s air emissions. Based on 2013 generation and emissions data from the U.S. Energy Information Administration (EIA) and EPA, the report is a collaborative effort between Ceres, Bank of America, four power producers (Calpine, Entergy, Exelon, and Public Service Enterprise Group), and the Natural Resources Defense Council. It is authored by M.J. Bradley & Associates.