Frequently Asked Questions

Q: Is micro hydro power renewable or nonrenewable?

A: Renewable usually implies that the power does not require an external power source, so all types of hydro power are renewable; however, some types of hydropower such as pumped storage require an extra source of power to operate. This power may come from power stored in a battery during periods of low power need.

Q: What is traditional hydropower?

A: Traditional hydropower has been the main source of renewable energy for over 150 years; however, the construction and operation of traditional hydropower has limitations that have prevented new hydropower construction in the USA for over 30 years. With traditional hydropower, water flows via gravity to turn a wheel or turbine attached to an electric generator. As the turbine turns, it rotates a series of electromagnets to produce electricity. Many hydropower plants use a dam to create a supply of water and allow control of the flow of the water to the turbine. The need for a dam may create problems. For example, the Three Gorges Dam in China flooded over 400 square miles of land, the destruction of cultural artifacts on that land, and relocation of millions of people. Many hydroelectric power dams in the USA are old, in need of repair and are therefore a danger to everyone and everything downstream.

Q: What are the types of hydropower?

A: The word “hydropower” basically means that electricity is produced by the movement of water. Traditional hydropower usually means that water falls from a higher elevation to a turbine generator of electricity either from a dam or waterfall. Pumped hydroelectric often uses the traditional approach but is limited by the amount of water so during periods of low energy need, the water is pumped back upwards to the original source to be used again. Marine hydropower occurs when moving water rotates a turbine or wheel to generate electricity but uses tides, waves, or water currents as the driving force. In contrast, Poseidon hydropower uses a passive water source such as a pond, lake, or ocean by pressurizing the water via a gravity driven pump to result in the equivalent pressure of a dam but without the dam. Titan hydropower uses the water from a dam that is too short (under 30 feet tall) to produce cost effective electricity. The water is pressurized using a gravity driven pump to allow the equivalent of a taller dam.