California has passed 5GW of grid-scale battery storage energy storage (BESS) projects, grid operator CAISO has revealed.

California utility SDG&E has commissioned two projects totalling 171MW of battery storage, while system integrator Ameresco has secured contracts to deliver 379MWh for at four gas plants in the state.

Leyline Renewable Capital has provided loans to developers RAI Energy and Grid Connected Infrastructure (GCI) for solar and storage projects.

RWE has brought its biggest utility-scale BESS project in the US closer to the start of commercial operations.

Some 710MW of battery storage came online in the US in the first three months of the year, of which around 70% was in the ERCOT, Texas market, S&P Global said.

Adapting transmission infrastructure and accurately valuing energy storage are the major challenges to deployments in the US today, said panellists on the Keynote discussion at Energy Storage Summit USA today.

Electriq Power, a US provider of battery storage solutions, has secured a deal that could be worth more than US$300 million.

Ameresco has nearly completed its three-site, 2.1GWh battery energy storage system project for utility Southern California Edison.

The US utility-scale battery storage sector achieved its highest-ever annual deployments in 2022, a year in which solar PV and wind underperformed against expectations.

Energy technology firm Wärtsilä completed a 125MW/250MWh battery storage project for REV Renewables in California in time to help CAISO deal with record heatwave conditions in September 2022.