Hydropower is the use of moving or falling water to generate mechanical power or electricity, making it one of the oldest and most widely used renewable energy sources.
It relies on the natural water cycle and the gravitational potential of water to produce energy, and today it remains a major contributor to global and U.S. renewable electricity generation.
Hydropower, also called water power, converts the kinetic or potential energy of flowing or falling water into usable power. Historically, this meant turning waterwheels to grind grain or operate machinery; today, it primarily refers to hydroelectricity, where water spins a turbine connected to a generator.
Modern hydropower facilities include run-of-river systems, which use natural river flow with minimal storage; reservoir (storage) systems, where dams store water and release it as needed; and pumped-storage hydropower, which moves water between two reservoirs to store and release energy on demand.
Hydropower has been used for thousands of years. Ancient Egyptians used Archimedes screws for irrigation, while the Greeks used waterwheels for milling more than 2,000 years ago. Watermills powered gristmills, sawmills, textile mills, and ore processing throughout the Middle Ages and early industrial periods.
The transition to electricity began in the 19th century. In 1880, a water-powered dynamo supplied electricity to a theater in Michigan. The following year, hydropower lit streetlights in Niagara Falls. The Redlands Power Plant in California became the first U.S. commercial AC hydropower facility.
Today, hydropower is used for utility-scale electricity generation, accounting for about 5.86% of U.S. electricity and over 27% of U.S. renewable electricity. It is also used for grid stability, providing fast ramping and dependable backup during outages. Hydropower is also used for energy storage, with pumped-storage hydropower supplying 88% of U.S. utility-scale storage capacity, as well as small-scale generation, including municipal water systems and irrigation canals.
Among the advantages of hydropower is that it is renewable and low-carbon, producing no direct air pollution or greenhouse gases; reliable and flexible (plants can start and stop quickly, stabilizing the grid); cost-effective (once built, hydropower is relatively inexpensive to maintain); and energy storage (pumped-storage systems provide large-scale, long-duration storage).
There are disadvantages and limitations to hydropower, however. Dams alter river ecosystems, affect fish migration, and change sediment flow; general environmental impacts are inferred from hydropower's known effects but are not directly cited in available sources.
Hydropower requires suitable rivers or elevation differences, and seasonal or long-term precipitation changes can reduce output.
Large dams require significant capital and long construction times, and large reservoirs can displace communities and alter land use.
Hydropower has evolved from ancient waterwheels to massive hydroelectric dams and sophisticated pumped-storage systems. It remains a cornerstone of renewable energy, offering reliability and large-scale storage, while also presenting environmental and geographic challenges that can affect its future development.
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Based in York, Pennsylvania, where American Hydro has a 123,000 square-foot facility that meets high environmental standards and supports large repairs and manufacturing. Its website emphasizes reliability, safety, and sustainability in its operations. American Hydro is a supplier and installer of large hydroelectric equipment, specializing in design, engineering, precision CNC manufacture, upgrades, and servicing of high-performance hydro turbines and large pumps.
https://www.ahydro.com/
Chilime Hydropower Company Limited
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Headquartered in Bethesda, Maryland, Eagle Creek, through its affiliate companies, owns and operates 85 hydroelectric facilities in the United States, producing enough electricity to power over 260,000 homes, while avoiding over 1.9 million metric tons of carbon dioxide emissions each year, while providing recreational opportunities and protecting historical resources and the environment. Its mission, facilities, and an overview of hydroelectric power are featured.
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Hydro One Limited is an electricity transmission and distribution utility serving the Canadian province of Ontario. Created in 1999 as a corporation under the Business Corporations Act with the Government of Ontario as sole shareholder, and in 2015, Ontario began selling shares to the public with the goal of 60% of the company being held by private investors. It operates 98% of the high voltage transmission grid throughout Ontario. Its residential and business services are highlighted.
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New England Hydropower Company, LLC
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https://www.nehydropower.com/
Headquartered in Manchester, New Hampshire, Patriot Hydro is a U.S.-based owner and operator of small- to mid-scale hydroelectric power plants focused on delivering affordable, reliable, carbon-free energy to local communities. Its website emphasizes safety, compliance, social responsibility, employee focus, and innovation as core values. Its facilities and capacity totals are highlighted on the website, along with information on shoreline development, river flows, and FERC relicensing projects.
https://patriothydro.com/
A subsidiary of Snowy Hydro Limited, Red Energy is a retail company for the Snow Mountains Hydro-Electric Scheme in Australia, a complex integrated water and hydroelectric power scheme, collecting and storing water that would normally flow east to the coast, diverting it through trans-mountain tunnels and power stations, releasing it into the Murray and Murrumbidgee Rivers for irrigation. Its residential and business plans are compared side-by-side, and bills may be paid online.
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Toronto Hydro Corporation is an electric utility that operates the electricity distribution system for the city of Toronto, Ontario. Its website provides customer account access, outage and construction maps, service and connection information, corporate reports, and customer support resources. The company delivers electricity to approximately 790,000 customers in Toronto, including residential and business customers. Featured is an outage map, a construction map, and guidance on connections.
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Founded in 1998, WPC is the national, not-for-profit trade association dedicated to representing the waterpower industry, including hydropower producers, manufacturers, developers, engineering firms, and other organizations. According to the website, waterpower provides more than 60% of Canada's electricity, and is the third-largest hydropower generator in the world. Membership benefits and an application are available on the website, which includes a glossary of terms.
https://waterpowercanada.ca/
