The mandate also requires 200 MW of this storage capacity to be purchased by 2014. It affects California’s three investor-owned utilities, Pacific Gas & Electric, Southern California Edison, and San Diego Gas & Electric.
The decision dovetails with California legislation dictating that one third of California’s energy is supplied through renewable sources by 2020. Variability of flow has long been a criticism of renewable energy, with solar and wind plants dependent on weather for energy generation. Energy storage is seen as a way to remedy this issue, by storing the energy when it’s not needed, and releasing it when output falls due to weather or other events. This will also cut the wasteful practice of curtailment- dumping energy produced in excess over current need.
This mandate, the first of its kind in the nation, is in line with California’s history of leading the way on climate and energy legislation. It was heralded by groups such as the Sierra Club and the California Energy Storage Association. Commissioner Carla Peterman, speaking on the decision, remarked on “the leadership role California has and continues to play in advancing progressive energy policy.” Governor Jerry Brown further stated, “We need to bottle sunlight.”
The mandate stems from AB 2514, the “Energy Storage Systems” bill, signed into law by Gov. Schwarzenegger in 2010.