Ludington Pumped Storage Plant, Michigan

The Ludington Pumped Storage Plant is the second largest of the few dozen pumped storage hydroelectric plants in the USA. It is located in the town of Ludington, on Lake Michigan. The plant pumps water out of the lake, 360 feet up to a reservoir built on a bluff above the shore. The reservoir is two miles long, 110 feet deep, and holds 25 billion gallons of water. When water is allowed to flow back down to the powerhouse, the water level drops almost 70 feet over several hours, and the powerhouse’s six reversible pump/turbines generate up to 2,322 megawatts, enough electricity for a city of 1.6 million people. For a few hours, at least. It helps stabilize the electrical grid in the upper Midwest, which is heavily dependent on nuclear plants (five of them are along the shores of Lake Michigan itself). When it opened in 1973, after four years of construction, it was the largest pumped storage plant in the world.