The Christian Science Monitor

In the cleantech sector, pretty much everyone knows the acronym RPS, for Renewable Portfolio Standards. Since the first RPS policy in the U.S., implemented in Iowa in the late 1990s, 30 states have passed similar policies to promote the installation of renewable energy projects and expedite penetration (overcoming the ambivalence or outright opposition of utilities) of renewable energy in electric power supply. 

Now, as reported in this article, California is considering the adoption of what looks to be the first Storage Portfolio Standard: requirements for utilities to install grid-scale energy storage.  Specifically, in early August, the California Public Utilities Commission (CPUC) voted unanimously to adopt a framework for analyzing the energy storage needs of each utility.  This builds upon a previous bill, AB 2514, which includes a mandate for the CPUC to "determine appropriate targets, if any, for each load-serving entity to procure viable and cost-effective energy storage systems to be achieved by" the end of 2015 and 2020.