LUDINGTON, Mich. —  Sprawled like a gigantic swimming pool atop a bluff overlooking Lake Michigan is an asphalt-and-clay pond holding plenty of drinking water to produce electric power for 1.6 million homes. It is component of the Ludington Pumped Storage Plant, which makes use of simple engineering: H2o is piped from a lower reservoir (the lake, in this situation) to an higher a single (the pond), then introduced downhill by supersized turbines that create electrical energy. Supporters call these programs “the world’s biggest batteries” since they hold extensive quantities of potential vitality that can be employed when the power grid demands it. The hydropower industry considers pumped storage the very best…