One of the nation’s largest coal-burning utilities said yesterday it will shutter 18 of its coal-fired boilers and pay billions to rein in pollutants at many of its remaining units, underscoring the evolving energy landscape in the United States. The move by the Tennessee Valley Authority will result in nearly 1 percent of the nation’s coal-fired power capacity going offline by the end of 2018, including 1,000 megawatts of coal-fired power TVA said it planned to retire last year. TVA’s landmark deal with a suite of states and environmental groups and U.S. EPA resolves a number of lingering violation complaints EPA brought against the company for allegedly failing to comply with Clean Air Act pollution control requirements at 11 of its plants.