Characteristics
It consists of a reservoir 110 ft (34 m) deep, 2.5 miles (4 km) long, and one mile (1.6 km) wide which holds 27 billion US gallons (100,000,000 m3) of water. The 1.3 sq mi (3.4 km2) reservoir is located on the banks of Lake Michigan. Because impervious bedrock is more than 800 feet (240 m) below the reservoir, the builders had to line the reservoir with a layer of asphalt and clay to prevent water seeping into the ground.
The power plant consists of six reversible turbines that can each generate 312 megawatts of electricity for a total output of 1872 megawatts. Water is delivered from the upper reservoir to the turbines by six penstocks each 1,100 feet (340 m) long that taper from 28 to 24 feet (8.5 to 7.3 m) in diameter.
At night, during low demand for electricity, the turbines run in reverse to pump water 363 ft (110 m) uphill from Lake Michigan into the reservoir. The plant takes advantage of the natural steep sand dune landform of eastern Lake Michigan. During periods of peak demand water is released to generate power. Electrical generation can begin within 2 minutes with peak electric output of 1872 MW achieved in under 30 minutes. Maximum water flow is over 33 million US gallons (120,000 m3) per minute.
This process was designed to level the load of nearby nuclear power plants on the grid. It also replaces the need to build natural gas peak power plants used only during high demand. The Ludington Pumped Storage plant is connected to three 345 kV Transmission lines, all owned and maintained by METC, a subsidiary of ITC Holdings.
Read more about this topic: Ludington Pumped Storage Power Plant