Three separate cooperation agreements relating to the development of the Sonoma Clean Power Geothermal Opportunity Zone that were approved by the community choice aggregator's board of directors could eventually add as much as 600 MW of geothermal energy to the grid to meet the state's growing need for power and to satisfy emissions targets.
Agreements are being made with Chevron New Energies, Cyrq Energy and Eavor through which each company would develop its geothermal energy technology as a pilot project with the goal of scaling each to commercial operation.
Although the board at a March 2 meeting unanimously passed two of the agreements, some directors expressed concern about working with Chevron New Energies. The question arose regarding whether the company would leverage its work on renewables to "greenwash" the fossil fuel portions of its parent company's business.
That motion passed on a 7-4 vote, with staff underscoring during the meeting that SCP will own all the attributes from the development and Chevron will not be able to capitalize on the project. Staff said the agreement specifically outlines how any publicity relating to the project is to be issued, but added that Chevron's technical expertise in drilling needs to be brought to bear to make the most of the region's geothermal resources efficiently and affordably.
On Feb. 23, the California Public Utilities Commission recommended an electric resource portfolio for use in the California Independent System Operator's 2023-2024 transmission planning process [R20-05-003]. The commission said this includes a need for more than 85 GW of new resources to be on line by 2035. Of that, it suggested 2,000 MW should be from geothermal resources.
Although SCP's GeoZone initiative is targeting between 500 and 600 MW of capacity and the state needs 2,000 MW, CEO Geof Syphers said there is "no shortage of demand" throughout California, including a hearty "appetite" for geothermal from other CCAs. He noted that early geothermal procurement contracts were with Nevada-based facilities, but said the state needs its own geothermal supplies.
The three agreements—which originated with the CCA's 2021 requests for information—are designed to add 500 MW of new geothermal capacity that is "low-water, low-emission and affordable" and make the increase "in a manner compatible with community values in exchange for SCP's commitment to negotiate a purchase agreement and to support community engagement and advocacy," according to SCP staff.
Geothermal resources, according to the staff presentation, would provide year-round power reliability. Because SCP is located "next to a world-class geothermal resource," it "can't afford to not invest" in the technology, staff said. Staff and others pointed out that such developments could also help transfer technology and local workers from the oil and gas industries into the geothermal and/or renewable energy industries.
Each of the technologies proposed by the three companies is different and is not yet mature, which is why the first stage of the agreement seeks to demonstrate the technology at a scale of up to 20 MW. SCP staff is "aggressively" pursuing grants to cover the above-market costs of development and is encouraging early contracts with other CCAs to purchase that power. The engineering and capital investments needed are "complex," which is why SCP has three different contracts.
Chevron New Energies is proposing a project that would have a capacity of as much as 500 MW and would be sited over 150,000 acres in Sonoma and Mendocino counties. Tanmay Chaturvedi, representing the company before the SCP board, said permitting, land access and the technology selected will determine the scale of its project. It has begun working with landowners and is considering hydrothermal low-temperature, advanced closed-loop and enhanced geothermal systems.
Cyrq Energy's Matt Rosenfeld said his firm plans to develop geothermal-based long-duration energy storage within the GeoZone. Cyrq, a portfolio company of Macquarie Asset Management, has six power plants in the western U.S. with a combined capacity of 186 MW and another 200 MW currently in development.
The company is currently working on a demonstration project at The Geysers, Calpine Corp.'s geothermal facility in Sonoma and Lake counties. It has a technical team that includes experts from Babcock and Wilcox, the National Renewable Energy Laboratory and Ethos.
A closed-loop geothermal technology proposed by Alberta, Canada-based Eavor does not require a specific type of permeable aquifer or proximity to The Geysers, Eavor's Neil Ethier said. It relies on the construction of what he described as an underground radiator, which can be located anywhere and enables supply to be placed near demand.
Ethier said the company has geothermal projects in Alberta, Germany and New Mexico. To date, its technology has shown the potential to scale up and exceed 500 MW.
The Geysers complex provides as much as 725 MW of geothermal energy to California per hour each day. Its output supplies power to Sonoma, Lake and Mendocino counties. Calpine claims it is the single largest geothermal electrical operation in the world (California Energy Markets No. 1687).
