Arevon signs long-term offtake with non-profit utility MCE for 1GWh California BESS

April 17, 2024

california offtake ppa tolling — Arevon’s Saticoy BESS, another energy storage project the company owns in California. Image: Courtesy of Arevon.

Renewable energy developer-operator Arevon has entered into a long-term offtake agreement for a 250MW/1,000MWh battery energy storage system (BESS) in California with community choice aggregator (CCA) MCE.

The tolling agreement for the Cormorant Energy Storage Project in Daly City will see Arevon build and operate the BESS for the needs of MCE, a non-profit utility with 1.5 million customers across Contra Costa, Marin, Napa, and Solano counties.

A first phase of 188MW will begin construction in Q1 2025 and will become operational in 2026. Arevon didn’t reveal when the second phase of the project would come online.

Such long-term tolling agreements and power purchase agreements (PPAs) in California have helped make it the leading US state for BESS deployments, with 7.6GW online as of the end of March 2024, according to transmission system operator (TSO) CAISO. Such long-term agreements help project owners acquire financing from financial institutions that can be typically risk-averse, such as banks.

Try Premium for just $1

Full premium access for the first month at only $1
Converts to an annual rate after 30 days unless cancelled
Cancel anytime during the trial period

Start $1 Trial

Premium Benefits

Expert industry analysis and interviews
Digital access to PV Tech Power journal
Exclusive event discounts

Or get the full Premium subscription right away

Get Premium Subscription

Or continue reading this article for free

Get Basic (FREE) Subscription

For example, Arevon recently secured a US$1.1 billion debt and tax equity package for a solar-plus-storage project, also in California, which has a long-term PPA agreement with a for-profit utility Southern California Edison (SCE). In November, the firm claimed to have completed “one of the first” investment tax credit (ITC) deals using new a transferability mechanism under the Inflation Reduction Act.

“Battery storage is critical to fast-tracking the clean energy transition. Through our partnership with Arevon, we are bringing online our largest battery storage project yet to support clean, reliable, and affordable electricity service for the Bay Area residents and businesses we serve,” Dawn Weisz, MCE CEO said.

Upcoming Event

Battery Asset Management Europe

2 December 2026

Italy

Battery Asset Management Summit Europe is the annual meeting for owners, operators, investors, and optimisation specialists working with operational BESS assets across the continent. The Summit focuses on how to maximise performance and revenue, manage degradation, integrate advanced optimisation software, navigate evolving market and regulatory frameworks, and plan for repowering or end-of-life strategies. With insights from Europe’s most active storage markets, it equips attendees with practical guidance to run resilient, profitable battery portfolios as the sector scales.