California’s geothermal reservoirs could provide a major domestic source of battery material, if extraction can be made commercially viable.
Deep beneath California’s Salton Sea region lies a substantial lithium resource that could help supply batteries for electric vehicles and energy storage. A 2023 analysis funded by the US Department of Energy, led by Lawrence Berkeley National Laboratory, estimated that the region’s geothermal reservoirs could contain more than 3.4 million metric tonnes of lithium.
DOE described that quantity as enough to support more than 375 million electric-vehicle batteries. However, the estimate assumes access to the full geothermal reservoir and extraction of its lithium resources, alongside technological advances. It represents potential rather than a confirmed quantity of commercially recoverable material.
The lithium is dissolved in hot, mineral-rich brine roughly a mile underground near the lake’s southeastern shore. Geothermal facilities bring this fluid to the surface to generate electricity before returning it underground. Direct lithium extraction, or DLE, could add a mineral-recovery stage to that process, combining electricity production with a domestic battery-material supply.
Turning that opportunity into reliable production presents technical and economic challenges. Berkeley Lab cautions that researchers cannot yet confidently predict how many years of extraction the reservoir could support. Recoverable quantities will depend on lithium concentrations, extraction costs, market prices and how production and reinjection wells are managed.
Environmental performance also requires careful assessment. The report examined water demand, air emissions, chemical use, waste disposal and seismic risks. It concluded that significant negative impacts could likely be avoided with appropriate monitoring and mitigation, while emphasising the importance of local community concerns. Lithium development would not directly improve the Salton Sea’s water quality.
The opportunity is substantial: geothermal operations could supply both power and a valuable industrial mineral. Its eventual contribution to the battery industry will depend on how efficiently, affordably and responsibly that underground resource can be recovered.
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