Renewable+Energy

http://news.yahoo.com/renewable-energy-plan-hinges-huge-utah-caverns-073757162--finance.html

http://en.wikipedia.org/wiki/Grid_energy_storage

http://physics.ucsd.edu/do-the-math/2011/11/pump-up-the-storage/

http://www.instructables.com/id/Building-a-Parabolic-Solar-Hot-Water-Heater-using-/

Ludington Pumped Hydroelectric Storage (Over 40 years old) http://www.consumersenergy.com/content.aspx?id=6985 http://energystoragereport.info/ludington-pumped-hydro/