Hydroelectric power stations convert the kinetic energy of flowing water into electrical energy. A dam or weir stores water which then flows through pipes or penstocks to drive turbines connected to generators, transforming the mechanical energy into electricity. Modern turbines can achieve over 95% efficiency. Wave power stations similarly use the motion of waves to drive turbines via air flow in pipes under the water's surface. Tidal power stations erect dams to trap tidal flows, generating electricity as the trapped water levels drop. Hydropower remains an important renewable energy source in many countries including the United States.

1. Water Power By Carmen vdb

4. About water Power Modern "water wheels" such as the francicis or pelton turbine can convert almost all of the water power into mechanical enegy. They can attain 95 pecent efficiency.