In the Batuta coal mining subsidence area near Ulan Mulun in Inner Mongolia, the fields are black as they gleam under the early summer sun. Stretching out to the horizon, they are covered not with coal but with row after row of solar photovoltaic panels that lean backwards as they face the sun. The project, which aims to reach a capacity of 500,000 kilowatts, is part of a coal mining regeneration scheme that also involves the ecological restoration of the land for agricultural use and tourism. Until recently, almost all of Inner Mongolia’s electricity was generated by coal-fired power stations,...