One of the Country’s 10 Largest Coal Plants Just Got a Retirement Date. What About the Rest? The largest coal-fired power plants keep on going, even as many smaller ones close. May 3, 2021 Emissions rise from stacks the Duke Energy Corp. Gibson Station power plant at dusk in Owensville, Indiana, on Thursday, July 23, 2015. Credit: Luke Sharrett/Bloomberg via Getty Images Related To survive among the shrinking fleet of U.S. coal-fired power plants, it helps to be extremely big. On April 22, American Electric Power announced that it would close the Rockport Plant in southwest Indiana by 2028, making the plant the only one of the 10 largest in the country that is scheduled to completely shut down before 2030.