How Hydro Energy Works
Producing electricity from water requires controlling flowing water. By building dams, electric plants are able to guide water as it naturally flows with gravity by funneling it through channels. These channels lead water through a turbine at a speed fast enough to spin the turbine. As the turbine spins, it powers a generator. Facilities can have multiple channels and turbines for the water to flow through, increasing the energy production.
What is the difference between Small Hydro and Large Hydro?
Small hydro is classified by the Department of Energy to be between 100 KW to 30 MW; large hydro being anything above 30 MW. A popular example of a large hydro project would be the Hoover Dam. There is also a classification of micro hydro, which are plants producing less than 100 KW.
California, like many other states, has adopted Renewable Portfolio Standards (RPS). Per these standards, utilities must receive a certain percentage of their energy from renewable resources. RPS was set in place to achieve increases in the amount of renewable energy entering the grid. Since a majority of large hydro plants had already been built before the RPS was adopted, they are not considered a renewable resource. California accepts four types of hydroelectric facilities to be RPS-eligible: small hydroelectric (30 MW or less), conduit hydroelectric (30 MW or less), hydroelectric generation units that are 40 MW or less and operated as part of a water supply or conveyance system, and incremental hydroelectric systems (systems that generate over 30 MW due to efficiency improvements).
Click on any link below to learn more about that project:
>Hoover Uprating Hydro Project
>Metropolitan Water District (MWD) Hydropower Project
>Tieton Hydropower Project