U.S. renewable-energy generating capacity is not only growing, but it is beginning to erode coal’s share of the electricity-generating mix, according to new data from the U.S. Department of Energy (DOE). The agency predicts renewable energy—particularly solar power—to continue growing. At the same time, a combination of renewable energy and natural gas are expected to further decrease the amount of coal used to generate electricity. DON’T MISS: Renewable energy growth accelerating, says International Energy Agency…