The decline in the generation of coal power is due to Obama’s regulations
Competition from cheaper natural gas is driving down coal use
Competition from natural gas is driving down coal use. In a 2011 survey of coal-fired power plants by the Associated Press, no respondents said federal air pollution regulations, specifically the Mercury and Air Toxics Standards and Cross-State Air Pollution Rule, were primarily to blame for plant closures. The AP analysis found that many studies cited by anti-regulatory groups “inflate the number of plants retiring by counting those shutting down for reasons other than the two EPA rules."
A 2011 report by the nonpartisan Congressional Research Service explained that older coal plants are being replaced with cleaner, cheaper natural gas "almost regardless of EPA rules":
The primary impacts of many of the rules will largely be on coal-fired plants more than 40 years old that have not, until now, installed state-of-the-art pollution controls. Many of these plants are inefficient and are being replaced by more efficient combined cycle natural gas plants, a development likely to be encouraged in the price of competing fuel--natural gas--continues to be low, almost regardless of EPA rules.