California utility Clean Power Alliance has inked a 15-year PPA with NextEra Energy Resources for an eight-hour duration energy storage project.
Clean Power Alliance (CPA) announced the long-term power purchase agreement (PPA) with energy giant NextEra Energy’s clean power arm last week (7 April). The PPA secures the offtake from NextEra’s 75MW, long-duration Desert Sands Energy Storage facility in Riverside County, California, starting in June 2026.
A media statement said that the agreement marks CPA’s “…first executed contract incorporating eight-hour storage capabilities. CPA’s many other battery storage projects incorporate four-hour battery technologies. Compared to a four-hour battery of the same size, an eight-hour battery can discharge twice as much energy.”
It did not reveal the technology used or energy storage capacity but the stated duration and power would make it a 600MWh system. The California ISO’s (CAISO) Resource Adequacy programme, through which utilities secure capacity from generating units, only requires a four-hour duration for energy storage.
CPA is one of California’s many CCAs, smaller community-owned utilities which provide local communities an alternative to the state’s big three investor-owned utilities PG&E, SDG&E and SCE. This is its fourth battery energy storage system (BESS) PPA deal.
It was in the headlines late last year when its third, a 100MW/400MWh project, Luna came online after a ‘landmark’ debt finance deal was secured.
The PPA deals are being struck after the California Public Utilities Commission (CPUC) ordered load-serving entities to procure new resources between 2023 and 2026, to address so-called mid-term reliability concerns. As part of its share, CPA needs to procure some 59MW of long-duration energy storage which this PPA satisfies entirely.