Muddy Run Pumped Storage Facility was built by the Philadelphia Electric Company and is a

pumped-storage hydroelectric Pumped-storage hydroelectricity (PSH), or pumped hydroelectric energy storage (PHES), is a type of hydroelectric energy storage used by electric power systems for load balancing. The method stores energy in the form of gravitational potential ...

generation A generation refers to all of the people born and living at about the same time, regarded collectively. It can also be described as, "the average period, generally considered to be about 20–⁠30 years, during which children are born and gr ...

facility in

Drumore Township, Pennsylvania Drumore Township is a township in southwestern Lancaster County, Pennsylvania, United States. At the 2020 census, the population was 2,568. It is named after Dromore (Irish: ''Droim Mór''), County Down, now in Northern Ireland, with which it h ...

, United States. When completed in 1968, Muddy Run was the largest pumped-storage facility in the world. Muddy Run has a capacity of 1,071

megawatt The watt (symbol: W) is the unit of Power (physics), power or radiant flux in the International System of Units, International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantification (science), ...

s. The facility is operated by the Susquehanna Electric Company, a subsidiary of

Constellation Energy Constellation Energy Corporation () is an energy company headquartered in Baltimore, Maryland, United States. The company provides electric power, natural gas, and energy management services. It has approximately two million customers across th ...

. Ernest Spey was the superintendent of Conowingo Hydroelectric Dam and the new Muddy Run facility until 1989. The facility's upper reservoir is the Muddy Run Reservoir, with a full pool elevation of over , and a usable storage capacity of . Muddy Run Reservoir was created by damming Muddy Run with a long, high, rock-filled

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, a ...

. The lower reservoir is the Conowingo Reservoir, created in the

Susquehanna River The Susquehanna River (; Lenape: Siskëwahane) is a major river located in the Mid-Atlantic region of the United States, overlapping between the lower Northeast and the Upland South. At long, it is the longest river on the East Coast of the ...

by the

Conowingo Dam The Conowingo Dam (also Conowingo Hydroelectric Plant, Conowingo Hydroelectric Station) is a large hydroelectric dam in the lower Susquehanna River near the town of Conowingo, Maryland. The medium-height, masonry gravity dam is one of the larges ...

, with a normal pool elevation of . The power house uses excess grid capacity during off peak hours to pump water from the Conowingo Reservoir into the upper reservoir through four diameter, vertical shafts. During peak power demand periods, the water is allowed to flow back from the lake through the shafts to the eight turbines causing the pumps to act as generators. The Muddy Run electrical machinery was designed by the noted engineer Eugene C. Whitney of

Westinghouse Electric Company Westinghouse Electric Company LLC is an American nuclear power company formed in 1999 from the nuclear power division of the original Westinghouse Electric Corporation. It offers nuclear products and services to utilities internationally, includi ...

, who designed the machinery for the

Grand Coulee Dam Grand Coulee Dam is a concrete gravity dam on the Columbia River in the U.S. state of Washington, built to produce hydroelectric power and provide irrigation water. Constructed between 1933 and 1942, Grand Coulee originally had two powerhous ...

#3 powerhouse. Whitney "was present when the machines were first to be started. The operator was reluctant to take the first step. Gene said, 'Call your boss.' The boss said, 'If Gene says to start the machines, start them.' So they did, and water rose from the lower Susquehanna River to the upper reservoir, 400 feet above". The upper reservoir extends into Martic Township. The area around the upper reservoir is operated as a park, complementing the nearby

Susquehannock State Park Susquehannock State Park is a Pennsylvania state park on in Drumore Township, Lancaster County, Pennsylvania in the United States. The park is on a scenic plateau overlooking the Susquehanna River and Conowingo Reservoir. The park is named ...

. Susquehannock State Park has an overlook trail with a good view of the Muddy Run facility.

References

{{stack, {{Portal, Pennsylvania, Water, Renewable energy Energy infrastructure completed in 1968 Dams in Pennsylvania Hydroelectric power plants in Pennsylvania Buildings and structures in Lancaster County, Pennsylvania Pumped-storage hydroelectric power stations in the United States Exelon