California issues first tender for long-duration storage to support wind and solar

Eight Californian California Community Choice Aggregators – representing local municipalities – have taken the first step in delivering long-duration storage for the state, issuing a procurement request for up to 500MW with eight to 16 hours of storage to come online by or before 2026.

A grid planning document published by the California Public Utilities Commission (CPUC) earlier in the year made the first move in acknowledging the need for “roughly 1 GW of pumped storage, or other long-duration storage with similar attributes, by 2026.”

The planning document plans for the addition of around 11GW of new utility-scale solar, nearly 3GW of wind, and 8.9GW of new battery storage.

But the acknowledgement of a need for nearly 1GW of “pumped storage, or other long-duration storage with similar attributes” by 2026 spoke to the need for the California market to begin looking towards longer-term goals.

Long-duration storage is intended to complement wind and solar plants by storing power for many more hours than lithium-ion batteries are capable of providing at a cost-effective level.

Some obvious technologies already exist – such as pumped storage hydropower – but there have been a range of new technologies proposed and attracting millions in venture and grant funding, including flow batteries and underground compressed air.

Last Friday, eight Californian Community Choice Aggregators (CCAs) launched a Request for Offers (RFO) to procure one or more projects of up to 500MW worth of long-duration storage on a minimum 10-year contract. The RFO seeks “to cost-effectively enhance renewable energy portfolios and aid in achieving California’s aggressive greenhouse gas reduction targets.”

The eight CCAs expect the long-duration storage to be able to be charged from the grid when renewable resources are at their peak, and discharge for periods of between 8 to 16 hours when renewable production is lower.

“The addition of long-duration storage to the CCA portfolios will aid renewable integration on the grid while advancing California’s aggressive greenhouse gas reduction targets for 2030,” the CCAs wrote in their press release announcing the procurement.

Necessary for providing grid reliability to better integrate the state’s increasing levels of renewable energy, spurred by California’s goal of becoming powered by renewable and zero-carbon resources by 2045, there is already significant interest in developing long-duration storage, with an earlier Joint CCAs Request for Information for long-duration storage receiving around 60 project entries representing 14 different technologies.

“By working together, the eight CCAs are able to procure large-scale projects that would be challenging for one CCA to procure on its own,” said Girish Balachandran, Silicon Valley Clean Energy’s CEO, one of the eight CCAs.

“Collaborating on this long-duration storage solution allows the CCAs to manage financial and technology risks while still diversifying portfolios with cost-effective and innovative resources.”

“CCAs are the leaders when it comes to advancing new clean energy resources in California, having already signed long-term contracts totaling more than 5,000 megawatts with a diverse mix of new-build renewable energy facilities throughout the state,” added Beth Vaughan, executive director of the California Community Choice Association (CalCCA).

“Now CCAs are acting fast to secure the reliability resources that are needed to support a more resilient power system.”