On June 2, 2014, the U.S. Environmental Protection Agency (EPA) proposed the Clean Power Plan, a plan to cut carbon pollution from power plants. The EPA aims to reduce CO2 emissions by 26% below 2005 emission levels by 2020 and 30% by 2030. Following the release of this plan, the North American Electric Reliability Corporation ((NERC) a regulatory authority that performs evaluations of proposals that may threaten the power reliability in North America) conducted their own study of the affects it may have on the bulk power system.
Specifically citing this case, NERC states that their findings are not meant to provide support for or against any one side of the Clean Power Plan, but rather to provide an unbiased report of the reliability and possible consequences of this proposed plan. NERC concluded that the grid is already at risk due to coal power plant closures, the switch to renewable energy and the spike in natural gas generation. NERC feels that the deadlines proposed by the EPA are unrealistic considering the timeframe needed for new pipeline construction that adequately replaces coal plants. They worry that such a rapid decrease in emission levels will make it harder to maintain aspects of grid reliability, leaving consumers more vulnerable. For more information about what conclusions NERC drew from their report, you can read the full report here: http://www.nerc.com/pa/RAPA/ra/Reliability%20Assessments%20DL/Potential_Reliability_Impacts_of_EPA_Proposed_CPP_Final.pdf