Rocky Mountain Hydroelectric Plant facts for kids
Quick facts for kids Rocky Mountain Hydroelectric Plant |
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View of the power station
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| Country | United States |
| Location | Floyd County, near Rome, Georgia |
| Coordinates | 34°21′20″N 85°18′14″W / 34.35556°N 85.30389°W |
| Status | Operational |
| Construction began | 1977 |
| Opening date | 1995 |
| Construction cost | $1 billion |
| Owner(s) | Oglethorpe Power (75%) Georgia Power (25%) |
| Operator(s) | Oglethorpe Power |
| Reservoir | |
| Creates | Rocky Mountain Upper |
| Total capacity | 10,650 acre⋅ft (13,140,000 m3) |
| Power station | |
| Hydraulic head | 613 ft (187 m) (minimum net) |
| Installed capacity | 1,095 MW (1,468,000 hp) |
The Rocky Mountain Hydroelectric Plant is a special kind of power plant. It is called a pumped-storage power plant. You can find it about 10 miles (16 km) northwest of Rome in the state of Georgia.
This plant gets its name from Rock Mountain. The plant's upper water storage area is built right on top of this mountain. Building of the plant started in 1977. It began making power in 1995. After some big upgrades in 2011, the plant can now make 1,095 megawatts (1,468,000 hp) of electricity. Two companies own it: Oglethorpe Power owns 75 percent, and Georgia Power owns 25 percent.
Contents
How the Plant Was Built
Starting the Project
In 1972, Georgia Power wanted to build this plant. They asked the Federal Energy Regulatory Commission (FERC) for permission. FERC is a government group that gives licenses for energy projects. Once they got the license, Georgia Power started planning. They designed the plant and bought the land needed.
Construction Begins
Building the plant began in 1977. The first parts built were the tunnels, pipes (called penstocks), roads, and bridges. But in 1985, construction stopped. The project was only 20 percent finished.
Restarting Work
In 1987, another company, Oglethorpe Power, needed a pumped-storage plant. They started talking with Georgia Power to finish the project. On December 15, 1988, they made a deal. Oglethorpe Power got a large loan of $706.8 million. This deal meant Oglethorpe would run the plant and own 75 percent of it.
Soon after the agreement, construction started again. The power plant was finished in 1995. The machines that make electricity began working. The whole project cost about $1 billion. It was officially opened on October 9, 1995.
Plant Upgrades
The power station got a big upgrade in 2011. This made each turbine-generator much stronger. Their power went from 283 megawatts (380,000 hp) to 365 megawatts (489,000 hp). This increased the plant's total power from 849 megawatts (1,139,000 hp) to 1,095 MW. The pumps that move water also became more powerful. These upgrades happened because the original parts had been stored for a long time. They were bought before construction stopped and were waiting to be used.
How the Plant Works
Using Two Reservoirs
The Rocky Mountain Hydroelectric Plant is a pumped-storage plant. This means it uses two large pools of water, called reservoirs, to make electricity and store energy.
The upper reservoir is like a giant battery. It holds water (which is stored energy) for times when people need a lot of electricity. When demand for power is high, water from the upper reservoir is released. It flows down to the power plant to create hydroelectricity. After making power, the water goes into the lower reservoir.
When people don't need as much electricity, usually at night, the plant uses extra power from the grid. This power is used to pump water from the lower reservoir back up to the upper reservoir. This refills the "battery." The upper reservoir can be filled up again in just 7.2 hours. The same machines that make electricity can also work in reverse to pump water.
The Reservoirs and Dams
The upper reservoir is on top of Rocky Mountain. It is held in place by a very long dam. This dam is 120-foot (37 m) tall and 12,895-foot (3,930 m) long. It is made of earth and rock. This reservoir can hold up to 10,650 acre-feet (13,140,000 m3) of water. Its surface covers 221 acres (89 ha). The upper reservoir is at a height of 1,392 feet (424 m) above sea level.
The lower reservoir is much lower, at 710.5 feet (216.6 m). It holds water from Heath Creek. This reservoir is created by two embankment dams and one special dam. The special dam is 120 feet (37 m) tall. It has a spillway with two gates that can release water. The other two dams help hold the water in. The lower reservoir can store up to 18,800 acre-feet (23,200,000 m3) of water. It covers an area of 600 acres (240 ha).
Extra Water Storage
There are also two other smaller reservoirs nearby. They are called Auxiliary Pool I and Auxiliary Pool II. These pools provide extra water if there is a drought. Auxiliary Pool I is north of the lower reservoir and covers 400 acres (160 ha). It is held by four dams. Auxiliary Pool II is west of the lower reservoir and covers 200 acres (81 ha). It has one dam and an outlet.
Both Auxiliary Pools usually stay at 715 feet (218 m) of water. This is 5 feet (1.5 m) higher than the lower reservoir. They can add an extra 5,800 acre-feet (7,200,000 m3) of water to the lower reservoir. These Auxiliary Pools are also used to help wildlife and for fun activities like fishing.
Connecting the Water and Power
A large pipe, called a penstock, connects the upper reservoir to the power plant. This pipe is 889-foot (271 m) long. Before it reaches the power plant, it splits into three smaller pipes. Each smaller pipe goes to one of the three 365 MW Francis pump-turbine-generators.
The big height difference between the upper and lower reservoirs is important. It gives the power plant a strong water pressure, called a hydraulic head, of at least 613 feet (187 m). This pressure helps the turbines spin and make electricity.
