As of the filing of the 2017 California RPS Annual Report, San Diego Gas & Electric (SDG&E) was already getting 43% of its electricity from renewable resources. The state expects to hit 50% renewables by 2020 – a full ten years ahead of the state’s 2030 target.
In order to better maximize the intermittent nature of solar power and to meet state energy storage guidelines, SDG&E has is also going big on batteries. This week the California Public Utility Commission approved SDG&E’s plans to contract with five energy storage projects totaling 83.5 MW/333 megawatt-hours (MWh), which were originally signed and announced back in April 2017.
The five energy storage projects are:
- Fluence will build a 40 MW/160 MWh lithium-ion battery facility in Fallbrook, Calif. The project is expected to be completed by March 2021.
- Renewable Energy Systems (RES) America will build a 30 MW/120 MWh lithium-ion battery storage facility in San Diego, Calif. The project is expected to be completed by December 2019.
- Powin Energy will build a 6.5 MW/26 MWh lithium-ion battery storage facility in Escondido, Calif. The project is expected to be completed by June 2021.
- Advanced Microgrid Solutions will build a 4 MW/16 MWh lithium-ion battery storage facility in San Juan Capistrano, Calif. The project is expected to be completed by December 2019.
- Enel Green Power will build a 3 MW/12 MWh lithium-ion battery storage facility in Poway, Calif. The project is expected to be completed by December 2021.
California’s investor owned utilities are under a legal mandate to install 1,835 MW of energy storage. AS2514 requires 1,325 MW, with SDG&E’s share being 165 MW. AB2868 adds another 500 MW – with each of the three state utilities having equal 166.6 MW responsibilities. S2514 requires its volume to be installed by 2024, and AB2868 must be in process by end of 2020.
— California ISO (@California_ISO) June 4, 2018
With California in breaking records for solar generation – with in-state solar providing more power than gas in May – it is obvious energy storage is needed. But how much?
A 2016 paper by the U.S. Department of Energy’s National Renewable Energy Laboratories (NREL) found that even in a situation of high system flexibility and low-cost solar, nearly 15 GW of additional energy storage will be needed in California for the state to meet 50% of its electricity needs with solar PV.
This estimate may end up being overly conservative. The state of California is expected to hit 50% renewable energy in 2020, but will not have anywhere near 15 GW of installed energy storage. And while a balance between wind and solar will help to reduce the need for storage, California’s renewable energy mix is tilting heavily towards solar.
And these values are before we consider that California has 6+ GW of distributed solar power, and is now setting growth records for residential energy storage.