1. California Energy Commission. california renewable energy overview and programs, 21; April 2011 [accessed 07.07.11].
2. Integration of renewable resources: operational requirements and generation fleet capability at 20% RPS, California ISO; 2010.
3. National Hydropower Association. Pumped storage, Washington DC: National Hydropower Association; 2011.
4. Cheung KYC, Cheung STH, De Silva RGN, Juvonen MPT, Singh R, Woo JJ, Clarke TJW. Large-scale energy storage systems; 2002/2003.
5. Energy Information Administration. California renewable electricity profile; April 2011. [accessed 07.06.11].