Although EPA’s Clean Power Plan (the Plan) is often reported as intending to cut overall carbon dioxide emissions by 30 percent below 2005 levels by 2030, the Plan actually specified state-level emission rate reductions, that is, the amount of carbon dioxide emitted per megawatt hour electricity produced. EPA estimates that on a national average level, the Plan will lead to a reduction of US power system carbon dioxide emissions of up to by 30% as compared with the 2005 level.
State-by-state emission rate reductions vary considerably. For example, as compared to the emission rate in 2012, Arizona’s rate goal is 52% lower by 2030, Texas’ is 39% lower, California’s is 23% lower, and North Dakota’s is only 11% lower. The main reason for the differences is that the design of the plan considers regional differences in the existing power systems, such as the existing capacity of coal-fired power plants and natural gas power plants, and EPA’s views of renewable potential and energy efficiency potential.