One of the best ways to learn more about hydropower is by visiting the National Hydropower Association’s Web site, http://www.hydro.org, which features an overview of hydropower technologies, statistical data, and much more. Another excellent source is the U.S. Department of Energy’s Energy Efficiency and Renewable Energy Web site, http://energy.gov/eere/office-energy-efficiency-renewable-energy. Other methods of exploration include reading books and magazines about the field and talking to hydropower and marine energy industry workers about their careers.

Hydropower uses the energy of flowing water to produce electricity. Water is retained in a dam or reservoir. When the water is released, it passes through and spins a turbine. The movement of the turbine in turn spins generators, and that spinning produces electricity. In "run of the river" projects, dams are not needed. Canals or pipes divert river water to spin turbines.

In addition to hydropower generated via dams or reservoirs, scientists are currently studying several other types of hydroenergy generation techniques. According to the U.S. Department of Energy (DOE), wave energy technologies "extract energy directly from surface waves or from pressure fluctuations below the surface." These waves can be turned into electricity by onshore or offshore systems. Wave energy can be only harnessed in certain areas of the world. In the United States, the northeastern and northwestern coasts offer the best prospects for viable wave-based generation.

Tidal energy involves the harnessing of tides into electricity. According to the DOE, tides can be harnessed only if the difference between high and low tides is more than 16 feet. There are only about 40 places on Earth where this is the case, including sites in the Pacific Northwest and Atlantic Northeast. Tidal energy is harvested by using barrages or dams, tidal fences, and tidal turbines.

Ocean thermal energy conversion (OTEC) involves converting the heat energy stored in oceans into electricity. According to the DOE, OTEC "works best when the temperature between the warmer, top layer of the ocean and the colder, deep ocean water is about 36 degrees Fahrenheit. These conditions exist in tropical coastal areas, roughly between the Tropic of Capricorn and the Tropic of Cancer." OTEC has been around for more than 80 years, but it is not yet cost competitive with traditional power technologies.

There are many technical, scientific, and managerial career options in the hydropower industry. Hydropower engineers and technicians design, construct, and maintain hydropower projects. They typically have backgrounds in civil (especially construction, geotechnical, hydraulic, and structural) engineering, electrical engineering, and mechanical engineering. Hydrologists study underground and surface water and its properties, including how water is distributed and how it moves through land. Power plant operators control the machinery that generates electricity. Hydroelectric production managers supervise operations at hydroelectric power generation facilities. Hydroelectric plant technicians operate and maintain equipment associated with hydropower generation such as turbines, pumps, valves, electric control boards, gates, fans, and battery banks.

Some dams and other water reservoirs have been found to harm fish and wildlife located in or near the project site. The industry has responded to these claims by hiring specialists to protect vegetation and wildlife from being adversely affected by hydropower projects. Biologists and other environmental scientists assess the effects of hydropower projects on wildlife and the environment. Fish farmers develop fish screens and ladders and other migration-assisting devices. Recreation managers and trail planners manage and preserve the land surrounding the reservoir or dam.

Support workers are also needed to perform clerical duties; manage workers; manage computer databases; maintain records; educate the public; and do many other tasks. Secretaries, receptionists, customer service representatives, media relations specialists, personnel and human resources specialists, lawyers, accountants, information technology workers, and educators are just some of the types of support workers who are employed in this industry.