Double Springs Energy Storage Project

Double Springs Energy Storage LLC proposes the construction of a 100 MW utility-scale battery energy storage system (BESS) on approximately 15 acres in Valley Springs, Calaveras County, California. The project consists of up to 240 prefabricated modular outdoor enclosures containing lithium-ion batteries, power inverters for AC/DC conversion, medium-voltage transformers, switchgear, and a collector substation. The facility is designed to stabilize the local transmission grid and will interconnect at the PG&E Valley Springs Substation, with additional associated improvements planned for the Tiger Creek Powerhouse, Electra Powerhouse, and Bellotta Substation. The system will feature a battery management system for charging and discharging control, integrated cooling for temperature monitoring, and remote monitoring capabilities. The project is being processed under solicitation 2024-086 CUP with the Calaveras County Planning Department as the lead agency. Environmental review has been conducted pursuant to the California Environmental Quality Act (CEQA), resulting in a Mitigated Negative Declaration and a Notice of Determination approved on September 14, 2026. Key environmental considerations include impacts on biological resources, such as the California tiger salamander and nesting birds, as well as coordination with Caltrans regarding right-of-way encroachments and pedestrian safety. Mitigation measures include worker training, pre-construction surveys, and adherence to seasonal work restrictions to protect native plants and wildlife. Coordination involves multiple agencies, including the California Department of Fish and Wildlife and the Central Valley Regional Water Quality Control Board.