"We are building the foundations for a truly sustainable battery materials and clean energy campus that will close the gap between upstream, midstream and downstream activities and set new standards for battery supply chain integration in the United States," said firm CEO Rod Colwell.

The plant will integrate a geothermal power plant with lithium production, making it the world's first facility to combine these two processes. The first phase is expected to produce about 25,000 metric tons of battery-grade lithium hydroxide monohydrate annually, sufficient to support production of about 415,000 electric vehicles each year.

Major automakers have already seized the opportunity to invest in the project. In 2021, General Motors became the first private investor, contributing an undisclosed "multi-million" dollar amount. Additional support arrived in August 2023 when Stellantis invested $100 million.

Upon full operation, the site is set to produce up to 300,000 metric tons of lithium carbonate equivalent annually. Under a 10-year contract, the developer will supply Stellantis with up to 65,000 metric tons per year of battery-grade lithium hydroxide monohydrate.

Innovative Methods

The direct lithium extraction method to be at the plant operates through two main steps. Initially, the geothermal power plant generates clean power and steam. Lithium is then extracted from geothermal brine brought to the surface during the power generation process.

Instead of discarding the surface brine, it is reinjected into the geothermal reservoir. Lithium extracted through the filtration process is then used to produce lithium carbonate or hydroxide.

The direct extraction process "is not a new technology ... and has actually been employed for several decades in Argentina, albeit in a hybrid manner," explained Michael McKibben, professor emeritus of geology at the University of California, Riverside.

CTR isn’t the first company to attempt utilizing the Salton Sea’s geothermal brines for lithium either. Berkshire Hathaway received a $14.9 million grant to study the extraction process in 2021, but the DOE rescinded the money just weeks later (in an apparent mutual decision). 

The method offers significant environmental advantages over hard rock mining, which involves blasting rock, followed by crushing, soaking it in sulfuric acid and ultimately roasting it at high temperatures to release the lithium.

The process "applied to both geothermal and oil field brines is a much more environmentally friendly technique because the infrastructure is already in place, and the brine is already being brought to the surface in the case of geothermal power generation,” McKibben added. “So, you're simply selectively filtering out lithium from the brine flow that is already being produced. There's no need to construct extensive infrastructure.”

The method also boasts a comparable extraction rate to hard rock mining, about 95%, without need for evaporation brine ponds, open pit mines and fossil-fueled processing while simultaneously generating its own power to drive the extraction process.

With anticipated growth in electric vehicle production in the coming years, demand for lithium is also expected to surge. 

A report released last year by the U.S. Dept. of Energy Lawrence Berkeley National Laboratory revealed that production in the Salton Sea region could yield over 3,400 kilotons of lithium, sufficient to manufacture more than 375 million electric vehicle batteries.

“We could eventually, out of this geothermal reservoir, produce enough lithium to meet all of our domestic needs and perhaps even have some leftover for export,” remarked McKibben, who has studied the Salton Sea geothermal field since the 1970s. “If we could produce lithium at the Salton Sea, manufacture, and recycle batteries locally, we would essentially have a completely internal supply chain, which would ... create jobs domestically and generate tax revenue.”

Government Support

At the state level, research and development efforts have been ongoing for years. 

According to Gov. Gavin Newsom’s office, California has allocated over $27 million to support nearly 20 research projects aimed at advancing innovations for lithium recovery from geothermal brines and related endeavors since 2017. He signed legislation in 2022. allocating $5 million to Imperial County to bolster Lithium Valley, and established the Lithium Extraction Tax law to ensure local communities share in industry’s growth.

“We’ve been fully committed to Lithium Valley, establishing a global hub for clean energy and ensuring that local communities benefit from this unique opportunity,” Newsom stated after the Lawrence Berkeley National Lab report. “This further validates California's potential to become the leading source of batteries for our vehicles, homes, and businesses worldwide.”

The initiatives are built on a 2022 report from the Lithium Valley Commission, established in 2020 to explore opportunities and risks in lithium recovery from geothermal brines of Imperial Valley. It recommended accelerated transmission planning, improved permitting processes and secure funding for infrastructure investments and economic incentives to support industry growth and job training.

Just before the plant groundbreaking, the California Energy Commission announced a grant opportunity on Jan. 18 to fund projects aimed at reducing scaling and corrosion impacts at geothermal power plants in California or enhancing recovery of lithium and other valuable minerals from geothermal brine at the Salton Sea field. Submission deadline for proposals is April 15.

While direct lithium extraction is an established technology, "its application to geothermal and oilfield brines is relatively recent,” said McKibben. “The challenge ahead will be scaling up these processes to commercial levels, and that will be the key area to monitor.”

This article was corrected May 31, 2024 to show that Stellantis is not parent company to GM.