California geothermal plants in the Imperial Valley may be on the cusp of becoming major sources of lithium for batteries to store energy in electric cars and on the grid, that is, once a major project that won permits late last year is completed. The proposed project entails EnergySource building its 49 MW Hudson Ranch II geothermal plant near the Salton Sea. It would link to a planned Simbol Materials plant nearby to feed it brine that comes up geothermal wells that go deep to tap the earth’s heat for power production. Simbol Materials would recover lithium—a key ingredient of advanced batteries—and manganese and zinc, used in batteries too. The metals occur naturally in the salty groundwater around the Salton Sea, which some geologists believe contains one of the biggest deposits of lithium in the world. Energy Source vice president Vincent Signorotti discussed the project before the State Senate Select Committee on California’s Energy Independence on June 27. However, both his company and Simbol did not comment for this story, which is based on publicly available records. Simbol won a $3 million grant from the Department of Energy in 2009 to demonstrate its process of using reverse osmosis filtration to recover the metals from geothermal brine, company president Luka Erceg told the U.S. Senate Energy and Natural Resources Energy Subcommittee in 2011. It raised additional capital from investors, including Japan’s ITOCHU Corp., and built a demonstration plant in the valley. It is recovering about 500 tons a year, according to U.S. Geological Survey paper in 2012. Lithium is considered a critical material for making advanced batteries needed to power electric cars aimed at cutting greenhouse gases and air pollution and to store intermittent renewable power from the wind and sun, more of which is feeding into the state’s power grid. Yet, the U.S. imports almost all its lithium, most of which is produced in places like Argentina, Chile, and other nations by drilling in areas where there is lithium rich brine in the ground and letting it evaporate in surface impoundments. Then the salt is collected from the impoundments and the lithium is refined in the form of lithium carbonate, lithium hydroxide, or other compounds. Similarly, zinc and manganese, and other metals can be recovered from brine fields in the ground. Lithium also is mined out of the earth as a solid, but brine evaporation has become the dominant means of production because it’s cheaper, according to the Geological Service. Late last year, Imperial County approved construction of the geothermal plant and lithium production facility. The permit authorizes construction beginning in 2015, which is expected to take two years. However, construction may still be uncertain. Erceg told the Senate panel that even though his company raised $43 million after getting the DOE grant and was set to grow to 60 people by early this year, financing remains a challenge. The problem is that the market for lithium batteries still is nascent and the company needs to enter “offtake” agreements to finance its project. It’s similar to a power plant developer generally needing to enter a power purchase agreement before it can successfully complete financing for a project after it’s been permitted. If things go as planned, Simbol could become the nation’s biggest domestic producer of lithium by the end of 2016, producing up to 40,000 tons/year of lithium compounds.