Electric utilities have turned to natural gas for electricity generation because of its low prices and because of onerous regulations affecting coal plants from the Environmental Protection Agency (EPA). Natural gas emits about half the carbon dioxide emissions that coal emits and is dispatchable, which means it can be turned on and off by an electric grid systems operator and thus can be used to back-up renewable technologies such as wind and solar when the wind is not blowing and the sun is not shining. Its dependability as a generating technology, its low fuel cost, and its lower emission rate make natural gas an important generating source for electric utilities. So much, in fact, that in April 2015, natural gas surpassed coal in electricity output, generating 31 percent of the nation’s electricity to 30 percent for coal.(i] Coal, in the recent past, had been generating 50 percent of the nation’s electricity.
