When the Arab embargoes of the 1970s threatened the country’s oil supply, the U.S. government issued an edict to the nation’s electricity producers: Start burning coal. So the local utility managers in rural Putnam County, Fla., did just that. The community-owned utility took out government loans and built its first power plant, using generators that made electricity from cheap Appalachian coal. Things were fine for more than three decades, until Washington delivered a new edict with precisely the opposite instructions: For the sake of the planet, stop burning coal . Now the little utility faces an uncertain future, and it is hardly alone. As the country’s electricity providers prepare to comply with new federal regulations that restrict the use of coal, […]