http://en.wikipedia.org/wiki/Renewable_energy
http://www.nrel.gov/
http://www.eia.doe.gov/kids/energyfacts/sources/renewable/renewable.html
http://www.sciencedaily.com/news/earth_climate/renewable_energy/
what are the types of renewable energy alternative?
what are some challenges with using and managing these alternative, renewable energy resources?
1 answer