Briefing on Cal Flats BESS

The Cal Flats BESS project, known as Cormorant, is a 60 MW battery storage facility in CAISO operated by Arevon Energy, facing notable operational challenges including negative generation and wildfire risks, despite an apparent conflict between its reported operating status and recent construction start announcements.

Overview

• Project Name: Cormorant (Energy-Storage.News, 2026-03-29)

• Developer: Arevon Energy (Energy-Storage.News, 2026-03-29)

• EPC Contractor: Primoris Services Corporation (Energy-Storage.News, 2026-03-29)

• Latest Milestone: construction start (Energy-Storage.News, 2026-03-29)

• Expected COD: 2027 (Energy-Storage.News, 2026-03-29)

• Status: Operating, since 2021 (Note: Operating status from data conflicts with expected COD from news enrichment.)

• Grid Operator: CAISO (California)

Fleet Details

• Technology: Batteries

• Capacity: 60 MW

• Generators: 1

• Ownership: Arevon Energy, Inc.

• Operator: Arevon Energy, Inc.

Financial Profile

• Capital Expenditure (CapEx): $1796/kW

Operational Performance and Risks

• Annual Generation: -11 GWh

• Capacity Factor: -2.1%

• Recent Monthly Generation (Oct-Dec 2025): -1 GWh, -0 GWh, -1 GWh respectively

• Commitments: Construction started for a 1 GWh California BESS by Arevon.

• Constraints/Risks: Multiple wildfire incidents reported, including a fire at the California Flats Energy Storage Project on August 30, 2025, and a possible vegetation fire at Arevon Energy's facility.

Cal Flats BESS, also known as Cormorant, is an Arevon Energy battery storage project in CAISO with a 60 MW capacity. Despite being listed as operating since 2021, recent news indicates a construction start and an expected COD of 2027, suggesting a potential discrepancy or an expansion project. The plant has exhibited negative generation values and faces significant wildfire risks.