California’s push to transform the market for grid-scale energy storage is working even better than expected -- at least on paper.

 

Last year, California created a mandate calling for 1,325 megawatts of energy storage projects by 2020, to be scaled up every two years. The first installment of proposals due this year adds up to 200 megawatts.

 

As of mid-2014, more than 2,000 megawatts of energy storage projects have applied to interconnect with the state’s grid, according to recent data from state grid operator California ISO (PDF). In other words, project developers have received the market signal of a 1.3-gigawatt mandate and proposed enough storage to provide nearly double that amount over the coming years.

 

The list includes 1,669 megawatts of standalone battery storage, 44 megawatts of other standalone storage, 255 megawatts of batteries combined with generation projects, and a 90-megawatt project combining solar and batteries. They are all seeking interconnection under the initiative's “Cluster 7” window, which closed on April 30, 2014. (A project-by-project breakdown of all the applications is available in PDF.)