Taum Sauk pumped storage plant
From Biocrawler, the free encyclopedia.
The Taum Sauk pumped storage plant is located in the St. Francois mountain region of the Missouri Ozarks approximately 90 miles (145 km) south of St. Louis. The hydroelectric plant, operated by the AmerenUE electric company, is designed to help meet peak power demands during the day. Electrical generators are turned by water flowing from a reservoir on top of Proffit Mountain into a lower reservoir on the East Fork of the Black River. The generators and turbines at river level are reversible, and at night the excess electricity available on the power grid is used to pump water back to the mountaintop.
The Taum Sauk plant is notable in that it is a pure pump-back operation – there is no natural primary flow available for generation, unlike most other pumped storage sites. It was among the largest such project when it was built. Construction of the Taum Sauk plant was begun in 1960 and operation began in 1963. The two original reversible pump-turbine units were each capable of generating 175 megawatts of power. They were upgraded in 1999 to units capable of 225 megawatts each.
The upper reservoir is has a capacity of 4,350 acre-feet (537,000 m³). The upper reservoir is 800 feet (244 m) above the hydroelectric plant, which gives it a greater head than that of Hoover Dam. The two are connected by a 7000 ft (2100 m) tunnel through the mountain.
This powerplant is a net consumer of electricity; the laws of thermodynamics dictate that more power is consumed pumping the water up the mountain than is generated when it comes down. However, the plant can still be economical to operate – the reservoir is filled at night when the electrical generation system is running at baseline capacity, and the power used for pump-back would otherwise be wasted.
That the Taum Sauk reservoir is atop Proffit Mountain and not Taum Sauk Mountain is often a source of confusion to tourists seeking to visit the site. Taum Sauk Mountain, the highest point in Missouri, is about five miles (8 km) east of Proffit Mountain and hosts a state park, not a reservoir. The reservoir is plainly visible from the lookout tower on Taum Sauk Mountain adjacent to the state park. Visitors can usually drive to the top of Proffit Mountain and walk a ramp to an observation deck at the top of the reservoir. At the entrance gate Ameren also operates a museum highlighting the natural history of Missouri. The powerplant is frequently visited by geology students because of a striking example of Precambrian/Cambrian unconformity in the rock layers exposed by the plant's construction.
In June, 2001, Ameren Development Corp, a subsidiary of Ameren Corporation, announced that it had filed for a permit from the Federal Energy Regulatory Commission in order to begin evaluating the construction of a much larger pump-back plant on neighboring Church Mountain. The upper reservoir of this 770 megawatt plant would be 130 acres (0.5 km²), and the lower reservoir would flood 400 acres (1.6 km²) of the scenic and environmentally significant Taum Sauk Creek valley. Resistance from a number of environmental groups, the Missouri governor's office, and the state's attorney general caused the company to conclude it was impossible to build the plant in both an environmentally friendly and cost-effective manner, and the permit application was withdrawn in August of 2001.
