Hydroelectric energy (“hydro”) produces electricity by using falling or moving water to turn a turbine generator (CEC 2008). Currently, several forms of large-scale water (“hydrokinetic”) power are in use or development worldwide: traditional dams that create a reservoir (there are several in the North Coast counties); “damless” hydro that uses kinetic energy from moving water; tidal or wave power (see “Wave Energy”); and ocean thermal energy conversion are examples (http://en.wikipedia.org/wiki/Hydropower).
Hydroelectric energy generation produces no GHG emissions locally and could significantly reduce the amount of such gasses released globally, if it was implemented aggressively. Barriers to widespread use hydro include that, with the exception of traditional dam-and-reservoir system, innovative hydroelectric technologies remain nascent; the endangered and threatened status of local salmonids; future drought scenarios and the huge physical infrastructure (and capital) required for building a dam and hydro facility. Traditionally, hydroelectric power generation was reserved for large-scale applications. However, property owners with waterfalls or permitted streams can also apply hydro principles at home to generate rural, off-grid electricity (see “Micro-Hydro Energy”).
California Energy Commission (CEC) Renewable Energy Program. 2008. Commission Guidebook, 2nd Edition. CEC-300-2007-003-ED2-CMF. Pages 16-24. http://www.energy.ca.gov/renewables/documents/index.html
Jones, W.D. 2008. How much water does it take to make electricity? IEEE Spectrum Report. http://www.spectrum.ieee.org/apr08/6182