The coal-fired Castle Gate Power Plant sits idle and is no longer producing electricity outside Helper, Utah August 3, 2015. The plant was closed in the Spring of 2015 in anticipation of new EPA regulations. President Barack Obama will unveil on Monday the final version of his Clean Power Plan to tackle greenhouse gases from coal-fired power plants, kicking off what is expected to be a tumultuous legal battle between federal environmental regulators and coal industry supporters. REUTERS/George Frey