The advent of large-scale solar on the grid has created a different kind of challenge – over-generation at midday, followed by the need to ramp up non-solar generation quickly each evening as the sun sets and household loads increase.
To help address this regional problem, the Redwood Coast Energy Authority is building and contracting for battery energy storage projects and projects that maximize benefits by combining renewable energy generation with energy storage.
Energy storage benefits RCEA and the grid in four main ways:
- by storing energy when it is abundant, clean and inexpensive for later use when energy is expensive and carbon-intensive;
- by providing capacity that can be dispatched by the grid operator when there isn’t sufficient energy to meet forecasted demand, thereby enabling RCEA to count it toward compliance with the state’s Resource Adequacy program;
- by providing ancillary services to the grid operator to be used for frequency regulation or contingencies; and
- by reducing the need for utility curtailment of renewable energy resources, which occurs when renewable generation exceeds the grid’s capacity, a phenomenon that has greatly increased in recent years.
Tierra Buena Energy Storage
The Tierra Buena Energy Storage project is helping the state maintain grid reliability during the transition to renewables, while providing clean capacity for RCEA’s resource adequacy portfolio.
RCEA and Valley Clean Energy signed 10-year agreements with Viridity Energy Solutions, owned by Ormat, for half each of the 5 MW/20 MWh battery system located in Sutter County, which began commercial operation in June 2022.

Long Duration Storage projects
with California Community Power Members
RCEA teamed up with other Community Choice Aggregators early in 2022 on two new energy storage projects that not only help fulfill compliance requirements, but more importantly support the transition to a carbon-free energy future.
The first one, the REV Renewables Tumbleweed project, will be a CAISO grid-connected, lithium-ion battery storage resource located near Rosamond, CA with an expected online date of 2026. RCEA’s share of the 75 megawatt/600 MWh project will be 2.7 MW, or 3.6% of the total project capacity.
The second is Goal Line, a 50 MW/400 MWh CAISO grid-connected lithium-ion energy storage project with eight hours of discharge duration. It is being developed by Onward Energy in Escondido, CA with an expected online date of 2025. RCEA’s share of the project will be 2 MW or 4% of the total project capacity.
Together, these projects will satisfy RCEA’s long-duration energy storage procurement obligation to the CA Public Utilities Commission.
Redwood Coast Airport Microgrid
This project located in McKinleyville, CA pairs a 2 MW battery storage system that can provide 9 MWh of energy with a 2.3 MW solar photovoltaic array. The battery storage system, comprised of three Tesla Megapacks, coupled with the advanced controls system provides the ability to “island” from the main grid so the airport and adjacent Coast Guard facility can perform critical operations during regional power outages.
Read more about this project on our Redwood Coast Airport Microgrid page.

Fairhaven Energy Storage
The Fairhaven Energy Storage project is being developed by Broad Reach Power and EWPRC at the site of the DG Fairhaven Biomass Plant in Samoa, CA. Once operational in late 2023, the 17.25 MW lithium-ion battery system will provide local capacity for RCEA’s portfolio, and critical capacity for the state’s grid reliability.

Foster Clean Power
Foster Clean Power A is a hybrid solar plus battery storage project in Arcata, CA. More information can be found on our Power Resources webpage.