PG&E Delays Elkhorn Battery Storage Restart to 2026

Pacific Gas and Electric (PG&E) has announced a significant delay in the recommissioning of the Elkhorn battery energy storage system (BESS), now scheduled for June 30, 2026. This postponement comes after the system was automatically shut down due to events at the nearby Moss Landing Energy Storage Facility, located adjacent to the legacy Moss Landing gas plant in California.

The Elkhorn BESS, which has a capacity of 182.5 MW and 730 MWh, is the only battery storage system owned by PG&E. All other BESS projects, including the Moss Landing facility itself, are contracted through third-party producers, specifically Vistra Energy. According to PG&E’s official statement, the company initiated a phased return to service for Elkhorn on June 1, 2025.

During the testing phase, a clamp failure and a subsequent coolant leak were discovered in one of the 256 Tesla Megapacks at the site. Fortunately, there were no injuries or related incidents such as power outages, smoke, or fire due to this issue. Tesla, which supplied and maintains the BESS, is currently formulating an inspection and repair strategy to address the identified problems.

PG&E has emphasized its cautious approach to testing, stating, “We took a conservative approach to testing and restarting the system to identify any operational issues and ensure continued safe operations.” Until the necessary repairs are completed, the Elkhorn system will remain electrically disconnected from the grid, although it will be maintained at a minimum state of charge for safety.

Local stakeholders have been kept informed about the repair process and the revised timeline for the system’s restart. PG&E is committed to maintaining clear communication with both stakeholders and the community regarding any updates and progress.

This incident follows a previous issue in September 2022, where concerns arose regarding the installation of deflagration vent shield panels. The Energy Safety Response Group (ESRG) conducted an assessment, leading to collaboration between Tesla and PG&E to resolve the matter effectively. The two companies have since been actively monitoring air and water quality throughout the cleanup efforts at Elkhorn.

In light of these developments, PG&E is focusing on ensuring all safety protocols are strictly adhered to while they work towards the eventual recommissioning of the Elkhorn BESS.