Helms Pumped Storage Plant facts for kids
Quick facts for kids Helms Pumped Storage Plant |
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Courtright, the upper reservoir
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| Country | United States |
| Location | Fresno County |
| Coordinates | 37°02′13″N 118°57′53″W / 37.03694°N 118.96472°W |
| Status | Operational |
| Construction began | 1977 |
| Opening date | 1984 |
| Owner(s) | Pacific Gas and Electric Company |
| Reservoir | |
| Creates | Courtright Reservoir |
| Total capacity | 123,000 acre⋅ft (151,718,266 m3) |
| Power station | |
| Hydraulic head | 1,625 ft (495 m) |
| Turbines | 3 x 404 MW Francis pump turbines |
| Installed capacity | 1,212 MW |
The Helms Pumped Storage Plant is a special power station located about 50 miles (80 km) east of Fresno, California. It sits high up in the Sierra Nevada Mountains, inside the Sierra National Forest. This plant uses a clever method called pumped-storage hydroelectricity to create electricity. It uses water from the Helms Creek canyon, which is part of the North Fork Kings River.
Planning for the plant started in the early 1970s. Construction began in June 1977, and it officially started making power on June 30, 1984. The plant can produce 1,212 megawatts (MW) of power. It is owned by the Pacific Gas and Electric Company.
How the Plant Works
This power plant works by moving water between two large lakes, called reservoirs. One reservoir is higher up, and the other is lower down.
When people need a lot of electricity, water is let out from the upper reservoir. This water rushes down to the power plant, spinning giant machines called turbines. These turbines then create electricity. After passing through the turbines, the water flows into the lower reservoir.
When there isn't much demand for electricity, like in the middle of the night, the plant does the opposite. It uses extra electricity from the power grid to pump the water back up from the lower reservoir to the upper one. This way, the water is stored energy, ready to be used again when demand for power goes up.
The machines at Helms are very special. They are called pump-generators because they can do two jobs: they can act as pumps to move water up, and they can also act as generators to make electricity when water flows down. The plant can start making power very quickly, in just eight minutes. This makes it great for meeting sudden increases in electricity demand. Even though it uses some electricity to pump water up, it does this when power is cheaper and there's a lot of it available.
Water and Reservoirs
The upper lake is called Courtright Reservoir. It can hold a huge amount of water, about 123,000 acre-feet. This reservoir is very high up, at an altitude of about 8,184 feet (2,494 meters).
The lower lake is Wishon Reservoir. It can hold even more water, about 129,000 acre-feet. This reservoir is at a lower altitude of about 6,550 feet (1,996 meters).
Water travels between these two reservoirs through long tunnels. First, there's a tunnel over 10,500 feet (3,200 meters) long that carries water from the upper reservoir. This tunnel then narrows into a strong steel pipe called a penstock, which is about 2,200 feet (685 meters) long. This penstock splits into three smaller pipes, and each one feeds water to a separate pump-generator.
After the water has spun the turbines and made electricity, it flows out into the lower reservoir through another tunnel, which is about 3,800 feet (1,158 meters) long. The total drop in elevation, or the "hydraulic head", that the water falls is about 1,625 feet (495 meters).
The main power station where the pump-generators are located is built underground, close to Wishon Reservoir. It holds three powerful 404 MW Francis pump turbine-generators.
