As California progresses towards its goal of 33 percent renewable electricity generation, the potential for energy storage to help integrate renewable resources and maintain a reliable and efficient electric grid takes on great significance. This report presents a strategic analysis of energy storage for California by 2020. The report assesses current energy storage technologies, discusses the diverse policies affecting deployment in California, and outlines critical technology gaps, future research needs, and policy reforms. It also provides a reference framework for the Energy Commission, CPUC, and other regulatory agencies to use as they develop solutions for how commercially ready energy storage technologies can be cost-effectively applied in California to reduce costs to ratepayers, reduce emissions from fossil fuel generation, and enable and accelerate the implementation of more renewable generation and its integration in California’s electricity system.