Mansfield, Ohio, is looking to turn two long-closed landfills into a source of clean energy. A city council-approved deal could bring a 25-35 megawatt solar project to the north side, but it will move ahead only if local businesses sign on to buy the electricity. What happened? The council vote authorized a development agreement with CEP Renewables for a solar array that could span as much as 196 acres at the former city and county landfill site…