California yesterday released a proposal for a 1.325GW target for energy storage by 2020 that could boost solar adoption rates in the state.

The proposed framework from the California Public Utilites Commission outlines specific, year-by-year energy storage procurement targets for Southern California Edison, San Diego Gas & Electric, and Pacific Gas & Electric. It also breaks down targets into three categories: transmission, distribution, and customer-sited storage.

Seth Hilton, a partner in the energy practice group at Stole Rives in Sacramento, said: "There are opportunities for storage to address the fact that we have an increasing number of PV projects at the distribution level. Utilities claim that that has the potential to create some problems with intermittency and storage can certainly help alleviate some of those concerns.

"It's a good sign if you're a storage developer in California and helpful for renewable energy developers in solar as well."

Utilities will be allowed to employ energy storage for a variety of functions, such as capacity, ancillary services, and peak shaving. Utilities may own some energy storage systems, and will procure at least 50% from independent developers across all segments of the grid. The first solicitation for new energy storage capacity will be required to occur no later than 1 December 2014.

“This is the moment we’ve all been waiting for,” said Janice Lin, executive director of the California Energy Storage Alliance. “Commissioner Peterman’s historic proposed decision provides a critically needed market signal to realize the many benefits energy storage can bring to California’s ratepayers. We’re certain that other states will follow California’s example.”

CPUC Commissioner Carla Peterman, who was appointed at the end of last year, released the proposed decision.

Even as California is on track to achieve the state mandate for 33% renewables by 2020, there may be some push back from utilities who will be required by law to procure energy storage.

"Utility resistance to energy storage legislation resulted in a mandate for the CPUC to consider setting standards and now with the proposed decision it's well on its way to doing that," said Hilton. "There certainly continues to be concerns on the part of the utilities about the cost of implementing any such mandate and resistance to that. However, there is a very good likelihood that this proposed decision in some form or another will be adopted and we'll have a storage mandate in California."

Energy storage is scheduled to appear as an agenda item for a CPUC meeting on 3 October.