WASHINGTON — The Prairie State power plant, set amid farm fields and woods in southwestern Illinois, will start producing power soon, beginning a life of burning local coal that's expected to last until at least the 2040s. Prairie State is the largest coal-fired power plant built in the United States in the last 30 years. -snip- What sets Prairie State apart from most other U.S. power plants is that it sits next to its own coal mine. The company figures it has enough coal to run the plant for 30 years, providing electricity for 2.5 million households. Peabody Energy, the...