Hydropower is using water to power machinery or make electricity. Water constantly moves through a vast global cycle, evaporating from lakes and oceans, forming clouds, precipitating as rain or snow, then flowing back down to the ocean. The energy of this water cycle, which is driven by the sun, can be tapped to produce electricity or for mechanical tasks like grinding grain. Hydropower uses a fuel—water—that is not reduced or used up in the process. Because the water cycle is an endless, constantly recharging system, hydropower is considered a renewable energy.
When flowing water is captured and turned into electricity, it is called hydroelectric power or hydropower. There are several types of hydroelectric facilities; they are all powered by the kinetic energy of flowing water as it moves downstream. Turbines and generators convert the energy into electricity, which is then fed into the electrical grid to be used in homes, businesses, and by industry.
History of Hydropower
Humans have been harnessing water to perform work for thousands of years. The Greeks used water wheels for grinding wheat into flour more than 2,000 years ago. Besides grinding flour, the power of the water was used to saw wood and power textile mills and manufacturing plants.
For more than a century, the technology for using falling water to create hydroelectricity has existed. The evolution of the modern hydropower turbine began in the mid-1700s when a French hydraulic and military engineer, Bernard Forest de Bélidor wrote Architecture Hydraulique. In this four volume work, he described using a vertical-axis versus a horizontal-axis machine.
During the 1700s and 1800s, water turbine development continued. In 1880, a brush arc light dynamo driven by a water turbine was used to provide theatre and storefront lighting in Grand Rapids, Michigan; and in 1881, a brush dynamo connected to a turbine in a flour mill provided street lighting at Niagara Falls, New York. These two projects used direct-current technology.
Alternating current is used today. That breakthrough came when the electric generator was coupled to the turbine, which resulted in the world’s, and the United States’, first hydroelectric plant located in Appleton, Wisconsin, in 1882. (Read more about the Appleton hydroelectric power plant on the Library of Congress web page.)
| B.C. | Hydropower used by the Greeks to turn water wheels for grinding wheat into flour, more than 2,000 years ago. |
|---|---|
| Mid-1770s | French hydraulic and military engineer Bernard Forest de Bélidor wrote Architecture Hydraulique, a four-volume work describing vertical- and horizontal-axis machines. |
| 1775 | U.S. Army Corps of Engineers founded, with establishment of Chief Engineer for the Continental Army. |
| 1880 | Michigan’s Grand Rapids Electric Light and Power Company, generating electricity by dynamo belted to a water turbine at the Wolverine Chair Factory, lit up 16 brush-arc lamps. |
| 1881 | Niagara Falls city street lamps powered by hydropower. |
| 1882 | World’s first hydroelectric power plant began operation on the Fox River in Appleton, Wisconsin. |
| 1886 | About 45 water-powered electric plants in the U.S. and Canada. |
| 1887 | San Bernardino, Ca., opens first hydroelectric plant in the west. |
| 1889 | Two hundred electric plants in the U.S. use waterpower for some or all generation. |
| 1901 | First Federal Water Power Act. |
| 1902 | Bureau of Reclamation established. |
| 1907 | Hydropower provided 15% of U.S. electrical generation. |
| 1920 | Hydropower provided 25% of U.S. electrical generation. Federal Power Act establishes Federal Power Commission authority to issue licenses for hydro development on public lands. |
| 1933 | Tennessee Valley Authority established. |
| 1935 | Federal Power Commission authority extended to all hydroelectric projects built by utilities engaged in interstate commerce. |
| 1937 | Bonneville Dam, first Federal dam, begins operation on the Columbia River. Bonneville Power Administration established. |
| 1940 | Hydropower provided 40% of electrical generation. Conventional capacity tripled in United States since 1920. |
| 1980 | Conventional capacity nearly tripled in United States since 1940. |
| 2003 | About 10% of U.S. electricity comes from hydropower. Today, there is about 80,000 MW of conventional capacity and 18,000 MW of pumped storage. |
Benefits of Hydropower
This fish ladder on the Ice Harbor Dam on the lower Snake River provides safe passage for migrating fish
Hydropower offers advantages over other energy sources but faces unique environmental challenges.
Hydropower is a fueled by water, so it’s a clean fuel source. Hydropower doesn’t pollute the air like power plants that burn fossil fuels, such as coal or natural gas.
Hydropower is a domestic source of energy, produced in the United States.
Hydropower relies on the water cycle, which is driven by the sun, thus it’s a renewable power source.
Hydropower is generally available as needed; engineers can control the flow of water through the turbines to produce electricity on demand.
Hydropower plants provide benefits in addition to clean electricity. Impoundment hydropower creates reservoirs that offer a variety of recreational opportunities, notably fishing, swimming, and boating. Most hydropower installations are required to provide some public access to the reservoir to allow the public to take advantage of these opportunities. Other benefits may include water supply and flood control.
Learn more about hydropower technology
