Ariel picture of the Salton Sea

The U.S. Department of Energy (DOE) yesterday took a huge step forward in its effort to shore up America’s domestic supply of battery-grade lithium—a substance that is indispensable to our transition to a clean-energy economy. Lithium, which, after a refining process, is used to produce cathode materials for lithium batteries, is currently produced almost entirely outside the United States. This unfortunately creates a vulnerability in the domestic supply chain for lithium batteries, which power everything from consumer electronics to electric vehicles to grid-scale energy storage systems. However, there is one largely untapped source of this critical material that presents an opportunity to sustainably harvest lithium right here in the United States: geothermal brines.  

Geothermal brine is a hot, saline fluid that flows within the Earth’s crust. Producing geothermal energy involves pumping this brine to the Earth’s surface to rotate turbines and generate electricity using natural heat. In rare cases, when geologic conditions are optimal, lithium can be extracted from brines with minimal waste and carbon pollution.  There are only a few locations where this is possible in the United States. California’s Salton Sea—which offers the greatest domestic potential for lithium extraction from brines—could produce 600,000 tons annually, according to initial estimates.  

 To secure a robust domestic supply of battery-grade lithium, DOE has announced a $12 million funding opportunity to advance the science of safe, cost-efficient lithium extraction and refining from geothermal brines. Recipients of this funding will use applied research and field demonstrations to improve current procedures and technologies and pave the way for a nationwide surge in lithium battery production.  

This funding opportunity from DOE’s Advanced Materials and Manufacturing Technologies Office (AMMTO) is the latest in a series of investments in America’s untapped potential for domestic lithium production. AMMTO has supported prior research and development through its Critical Materials Institute, the Geothermal Technologies Office incentivized innovation through the American-Made Geothermal Lithium Extraction Prize, and the new Manufacturing and Energy Supply Chain Office launched a $675 million critical materials program funded by President Biden’s the Bipartisan Infrastructure Law.  

Although geothermal brines account for only a small portion of domestic lithium reserves, a recent DOE-funded study found that the rapidly expanding market for electric vehicles will make lithium extraction a profitable enterprise—with the added benefit of making clean geothermal energy generation more cost-competitive. Through initiatives like today’s investment in brine extraction, DOE will help ensure that our private-sector partners have the resources and expertise they require to make the most of this promising opportunity.