Environmental Leader reported that the US power plants cut emissions from nitrous oxides (NOx), sulfur dioxide (SO2) and CO2 in 2011 even as overall electricity generation increased, according to data from the Energy Information Administration and the EPA.
According the report, In 2011, power plant NOx and SO2 emissions were 70 percent and 72 percent lower, respectively, than they were in 1990 when Congress passed major amendments to the Clean Air Act, the report says. Additionally, since 1990, power plant CO2 emissions have increased by 20 percent, although CO2 emissions declined 7 percent from 2008 through 2011.
The emissions reductions are largely due to increased use of natural gas and growing reliance on renewable energy, the report says.
The Benchmarking Air Emissions report is the ninth in a series that analyzes the latest emissions data from the 100 largest power producers in the US. In 2011, the top 100 power producers together accounted for 86 percent of the electricity produced, the report says. These companies emitted approximately 4.1 million tons of SO2, 1.7 million tons of NOx, 25 tons of mercury, and 2.1 billion tons of CO2 in aggregate.
Ceres, NRDC, Entergy Corporation, Exelon, Pacific Gas and Electric Company, PSEG, Tenaska and Bank of America sponsored the report, which M.J. Bradley & Associates authored.
Nationwide, five power producers — American Electric Power, Duke Energy, FirstEnergy, Southern Company and Tennessee Valley Authority — generate 25 percent of overall electric sector CO2 emissions, though some of these producers and others have significantly reduced emissions in recent years. For example, AEP reduced its total SO2 emissions by 52 percent between 2000 and 2011, from 1.1 million tons to just over half a million tons, primarily by adding scrubbers to approximately 7,900 MW of coal-fired generating capacity, the report says.
Southern Company reduced total SO2 emissions by 63 percent while increasing overall generation 8 percent between 2000 and 2011 by bringing online approximately 14,000 MW of natural gas-fired capacity during the same period. Meanwhile, NextEra Energy added more than 20,000 MW of wind, solar, and natural gas-fired generating capacity between 2000 and 2011, and nearly doubled its total power generation, driving down its CO2 emissions rate from 1,023 to 603 pounds per MWh, a 41 percent improvement.
Among the top 100 power producers, Exelon had the eighth lowest CO2 emissions rate in 2011, largely due to its large nuclear and renewable energy fleet, as well as its investments in nuclear uprates. Exelon reduced its total CO2 emissions by 32 percent and its CO2 emission rate by 40 percent between 2000 and 2011, the report says.
Wyoming, Kentucky, West Virginia, Indiana, and North Dakota had the highest CO2 emissions per megawatt-hour of power produced, while Idaho, Vermont, Washington, Oregon, and Maine had the lowest CO2 emissions rates. States with the highest CO2 emission rates were heavily reliant on coal, the report says. Wyoming and Kentucky, the states with the highest CO2 emission rates, relied on coal for 86 and 93 percent of their power generation, respectively.
Coal accounted for 44 percent of the power produced by the 100 largest companies in 2011, followed by natural gas (23 percent), nuclear (22 percent), hydroelectric power (8 percent), non-hydroelectric renewables and other fuel sources (3 and 1 percent, respectively), and oil (less than 0.2 percent).
From 2000 to 2011, natural gas generation increased 69 percent industry-wide, while renewable generation increased 44 percent. Coal-fired generation dropped 12 percent over the same period.
(Sourced from Environmental Leader)