Fullmark Energy, a U.S. independent power producer (IPP) focused exclusively on energy storage, has reached commercial operation of its 20 MW/40 MWh Ortega battery energy storage system (BESS) in Lake Elsinore, California, on 2025-08-20, as part of its effort to deploy grid-scale battery storage projects across the United States. Fullmark says it holds a 4 GW development pipeline in multiple U.S. markets, including California, Texas, and the Mid-Atlantic, aimed at strengthening grid reliability and accommodating renewable energy growth.
Recent Project and Context
The Ortega project, at 20 MW power and 40 MWh energy capacity, is the third facility in Fullmark’s Redwood Projects portfolio to reach commercial operation. It follows Johanna ESS in Santa Ana (20 MW/80 MWh) and Desert-Carris in Palm Springs (20 MW/40 MWh). A fourth project, San Jacinto in Banning (65 MW/130 MWh), is nearing completion. Combined, the Redwood portfolio encompasses about 125 MW of grid-scale battery storage capacity in Southern California.
Pipeline and Geographic Spread
Fullmark reports a development pipeline of 4 GW of projects under various stages across U.S. markets, notably in California, Texas, and the Mid-Atlantic. The company is growing its portfolio of operating and in-construction BESS projects, currently totaling approximately 300 MWh across its active developments.
Function and Grid Role
The Ortega facility will participate in the California Independent System Operator (CAISO) market, providing services such as energy arbitrage, frequency regulation, and resource adequacy. These functions are central to smoothing variable renewable supply and supporting periods of peak demand. In addition, Fullmark notes that its portfolio approach allows for consolidated financing, optimized capital efficiency, and diversified revenue orftake agreements.
Development Challenges and Community Engagement
Ortega’s development involved navigating environmental regulations—including a wetland conservation approach that complies with standards from the California Department of Fish & Wildlife—and addressing landowner interconnection requirements. The project also delivered community‐oriented upgrades, such as water line improvements and site landscaping.