A bill recently amended in California’s Senate could open the door further to energy storage from pumped hydro. A.B. 33 requires that if the California Public Utilities Commission raises a load-serving entity’s energy-storage procurement target, any portion of the incrementally higher target could be met with pumped storage hydro.

Under California’s current energy-storage procurement targets, established by the CPUC in 2013, pumped storage hydro facilities larger than 50 MW are not eligible.