 |
|||
|
Hydropower Projects
Symbiotics Leads the Way in Alternative Energy Development Pumped storage hydroelectric power is currently the largest and most efficient method of energy storage available. It requires two adjacent reservoirs at differing elevations and a reversible pump-turbine unit between the two reservoirs. Electricity purchased at times of low price and demand can be used to pump water to the upper reservoir; at times of high price and demand the water is released through the turbines to create electricity. Because daily demand varies, pumped storage is often used to balance generation from power plants that produce at constant rates, and can also be used to store intermittent sources of power, such as wind and solar energy. The first pumped storage facility in the world was built in 1909 near Shcaffhausen, Switzerland. This facility had a capacity of 1.5 MW and was made with a separate pump and turbine. The first plant in the United States was built in 1929 on the Rocky River in Connecticut. Due to a reversible pump it was slightly higher in efficiency than the Schaffhausen facility. By the time the Rocky River project was constructed, over 40 pumped storage facilities had been built in Europe. In 1954 the first facility with a reversible-pump turbine was built in Colorado. This plant, the Flatiron Power and Pumping Plant, had a 71.5 MW capacity but was used mainly for irrigation. In 1956, Hiwasse unit 2 was the first hydroplant in the United States to be installed with a reversible-pump turbine solely to store electricity. Pumped storage facilities have varied greatly in mode of operation. The Rocky River power plant was seasonal, pumping water into the upper reservoir at times of high river flow. Many pumped storage plants in Europe are used to store electricity produced at night by nuclear power plants for use during peak times. Nuclear plants are run at steady rates for safety reasons and cannot respond to spikes in demand. Italy, currently without nuclear power, uses pumped storage facilities to store off-peak nuclear power purchased from neighboring countries. Many large hydroelectric dams supplement power production with pumped storage facilities. This allows them to recycle water that has passed through the dam during times of peak demand. Pumped storage facilities also vary in their design. The 1,320 MW Dinorwig Power Plant in North Wales is located inside Elidir Mountain, with the upper reservoir in the hills beyond the mountain and the other on the valley floor. On the Lake Michigan shoreline, the 1,872 MW Ludington Pumped Storage Plant pumps water directly from the lake. The 440 MW Cruachan Plant in Scotland is within Cruachan Mountain on the shore of Loch Awe. Rainwater directed to the upper reservoir by tunnels accounts for almost 10 percent of the total power generation. In 1999, the first pumped storage project to use the ocean as its lower reservoir began operation in Japan. Japan is also constructing the world’s largest pumped storage project. The Kannagawa Hydroelectric Plant will produce 2,820 MW when all units are operational. The last project to become operational in the United States was the Rocky Mountain Hydroelectric Plant, which went online in 1995. A new pumped storage facility has not been licensed and built in the United States for over 20 years. The high cost of development, coupled with environmental challenges, has limited recent development of pumped storage in the United States. They often use existing bodies of water, causing fish mortality and degrading water quality. However, the need for intermittent renewables and large-scale transmission stabilization indicates a need for additional pumped storage in the future. Closed loop pumped storage (CLPS), built without using existing bodies of water, provides a solution that will provide energy storage without degrading environmental resources.
|
||
 |
|||
