California regulators have proposed adding 11.5 gigawatts of almost completely carbon-free capacity to its grid in the next five years. This ambitious target will require a massive build-out of batteries to shift solar power to cover the state’s grid peaks as natural-gas plants close and gigawatts of long-duration energy storage and dispatchable zero-carbon resources to make up for the loss of the state’s last nuclear power plant.
Some of the state’s largest CCAs joined forces last year to seek out 500 MW of long-duration energy storage resources. This spring they formed a joint procurement authority to combine their buying power and seek out larger-scale resources than would be needed from individual members.
Girish Balachandran, CEO of CCA Silicon Valley Clean Energy and head of the joint procurement authority, said in a March interview that last year’s request for proposals for long-duration storage yielded a broad mix of technologies for consideration, though he wouldn’t disclose the companies involved.
The proposals included “chemical flow batteries, compressed air, fuel cells with hydrogen, mechanical gravity storage, pumped hydro and a variety of thermal energy storage,” from compressed liquid gases to molten salt, he said. “We’ve got it for eight-, 10- and 12-hour discharge durations.”