Santa Barbara County Supervisor Joan Hartmann, left, celebrates the expansion of Monterey Bay
After inking their first power purchase agreements for geothermal energy, Monterey Bay Community Power and Silicon Valley Clean Energy, two local government-run power agencies procuring electricity for dozens of cities and counties in Central and Northern California, are considering deals for more geothermal and battery-backed solar resources.
The community choice aggregators, or CCAs, on Jan. 8 approved two separate contracts with an affiliate of Ormat Technologies Inc. for a portion of its planned 30-MW geothermal project in Mammoth Lakes, Calif., known as the Mammoth Phase IIB (CD4) Plant (Casa Diablo IV). Under 10-year agreements, the CCAs will take 14 MW starting in late 2021, split evenly between the two retail power agencies.
Ormat in 2019 signed a contract with the Southern California Public Power Authority for the plant's other 16 MW.
"Ormat Technologies is a great fit because their California project helps us and our community support renewable geothermal electricity that is available for customers 24 hours a day, with zero carbon emissions," Monterey Bay Community Power CEO Tom Habashi said in a Jan. 13 news release.
"It is more expensive on a contract cost basis but the market value makes it a good complement," added Dennis Dyc-O'Neal, the agency's director of power services, during a Jan. 8, 2020, presentation to Monterey Bay Community Power's board of directors. Such value includes the plant's ability to generate additional revenue through ancillary services and provide resource adequacy, he said.
As part of their joint solicitation for resources to help meet a state requirement to cover 60% of retail sales with renewable energy by 2030, the CCAs are negotiating long-term deals for power from one other geothermal project and four solar-plus-storage facilities, Dyc-O'Neal said.
The five shortlisted projects and the approved deal with Ormat were selected from 87 proposed projects, he added.
The largest of the projects under consideration is 8minute Solar Energy LLC's so-called Aratina solar-plus-storage project in Kern County, Calif., combining 200 MW of solar and 60 MW of three-hour battery storage. The CCAs are also negotiating with NextEra Energy Inc. for the output from its battery-backed Yellow Pine Solar project in Clark County, Nev., including 125 MW of solar photovoltaics and 35 MW of four-hour storage.
An affiliate of Samsung Electronics Co. Ltd. has proposed a contract for its Angela solar-plus-storage project in Tulare County, Calif., featuring 40 MW of solar and 20 MW of 4-hour storage, while First Solar Inc. has pitched 90 MW of photovoltaic combined with 20 MW of storage at its Rabbitbrush facility in Kern County, Calif.
If approved, all of the solar-plus-storage plants would rely on lithium-ion batteries and come online in 2022.
"The solar plus storage really is coming in at the lowest cost at the moment because solar is at an all-time low and developers have really figured out how to add batteries to those," Dyc-O'Neal said, citing solar bids ranging from the low $30s/MWh to the low $50s/MWh.
Monterey Bay Community Power and Silicon Valley Clean Energy already have power purchase agreements with two large-scale battery-backed solar projects in California at prices not to exceed $40/MWh.
The agencies also are considering agreements for 78 MW of geothermal energy from the existing Navy I Facility (Coso Geothermal) in Inyo County, currently under contract with Southern California Edison Co.
While the agencies did not disclose the actual pricing for the proposed and approved geothermal contracts, geothermal bids responding to the solicitation ranged from $65/MWh to $75/MWh, Dyc-O'Neal said.
Both CCAs operate in Pacific Gas and Electric Co.'s service area, procuring an increasing amount of power for customers in partnership with the PG&E Corp. utility subsidiary, which continues to bill retail customers and physically supply the power selected by CCAs. Monterey Bay Community Power added San Luis Obispo and Morro Bay to its growing roster of member jurisdictions after announcing 11 new cities and counties as participants in December.