In a decision unprecedented in the United States, on October 17, 2013 the California Public Utilities Commission (CPUC) voted unanimously to adopt an energy storage requirement for the state’s investor-owned utilities. The decision in Rulemaking 10-12-007 implements the goals of California Assembly Bill 2514 which required the CPUC to determine appropriate targets and deadlines for California load serving entities to procure viable and cost effective energy storage systems. Since passage of this legislation in 2010, the CPUC has worked to develop a framework for policies and guidelines pertaining to energy storage including consideration of various energy storage technologies and their applicability to various end uses along the “value chain” of generation, transmission, distribution, and behind-the-meter. The decision requires regulated entities to acquire 200 MW of energy storage capability by 2014 and a total of 1.325 GW of energy storage by 2020. The CPUC identified the objectives of this requirement as promoting grid optimization, integration of renewable energy, and reduction of greenhouse gas emissions.