Stock Photo - Pump storage electrical generating plant on the shores of Lake Michigan near Ludington, Michigan, USA The facility consists of a 27 billion gallon reservoir of water — the size of 2 million backyard swimming pools — and a set of six turbines that double as giant water pumps At night, when customer demand for electricity is low, Ludington’s six reversible pump turbines move Lake Michigan water 363 feet about 35 stories uphill through six large pipes to the reservoir During the day, when customer emand for electricity is high, water is released from the reservoir to flow back downhill through the large pipes penstocks, turning turbines in the powerhouse to make electricity