Salton Sea Lithium: What's Real and What's Still a Target

By Geothermal Insider · Updated September 10, 2026

The Salton Sea lithium story usually gets told backwards. The headline version says California is sitting on an extraordinarily rich lithium deposit that will supply the American battery industry. The measurements support the scale of the resource, but not the claim that the brine itself is extraordinarily rich.

Produced brine from the Salton Sea geothermal field carries lithium at approximately 198 ppm — the average composition LBNL published in November 2023 and repeated to the California Energy Commission in 2025. Among geothermal brines it is exceptional — the CEC and SRI report describes the Salton Sea KGRA as believed to hold the world's highest lithium concentration of any geothermal brine, though individual published values elsewhere, such as Campi Flegrei in Italy, run higher. Among commercial lithium brines it is thin. Salar de Atacama in Chile reported an average of 2,041 mg/L across its 2024 measured-plus-indicated resource in Albemarle's SEC technical report summary, and against the USGS range for major brine deposits — "the grade ranges from 0.015 to 0.125 percent lithium" — Salton's 0.0198 percent sits near the bottom. (Because mg/L and mass-based ppm are not directly comparable without the brine's density, the gap is best described as roughly an order of magnitude rather than an exact multiple.)

Its commercial appeal comes from the volume of brine already circulating through the power plants. Existing geothermal power plants at the Salton Sea have been circulating "just over 120 million metric tons per year since 2004" of that brine to the surface and back down again, according to LBNL. That pumping happens for the electricity, whatever becomes of the lithium. As LBNL's Lithium Resource Research and Innovation Center puts it: "Before the brine gets reinjected, there is an opportunity to recover some minerals from it." A weak solution you are already handling by the hundred-million tonnes is a very different proposition from a weak solution you would have to go get.

The Lithium Is Not in the Salton Sea

LBNL's LiRRIC FAQ states it flatly: "The lithium is not in the Salton Sea." It is dissolved in a deep geothermal reservoir beneath the Imperial Valley, not in the lake water you can see from the highway. The proposed projects do not filter water from the lake.

The fluid in that reservoir is hot enough to run power plants. The CEC and SRI International's March 2024 pilot report describes "super-heated natural geothermal fluids present in the Salton Sea KGRA" that "can reach temperatures exceeding 250°C." KGRA stands for Known Geothermal Resource Area — a federal designation, under the Geothermal Steam Act, for an area known or believed to have geothermal-resource potential. If you want the underlying physics of why hot rock produces usable fluid at all, we cover it in our explainer on what geothermal energy is.

The Blue Ribbon Commission on Lithium Extraction in California was created by Assembly Bill 1657 (Garcia), Chapter 271, 2020, with 14 members appointed by a combination of the CEC, other state agencies, the Assembly Speaker and the Senate Committee on Rules. Its report describes the fluid simply: "the brine is rich in many minerals including manganese, zinc, and lithium." The Commission released 15 recommendations covering, in its own summary, "financial investments, infrastructure development, environmental studies, community initiatives, and collaboration."

The Power Side: 11 Plants, 414 MW

The lithium conversation only exists because the electricity business got there first. The Commission counted "11 geothermal power plants producing electricity from the geothermal brine in the Salton Sea KGRA with an installed nameplate capacity for these facilities of approximately 414 megawatts (MW)."

The 414 MW figure comes from the Commission's December 2022 report, and it is installed nameplate capacity — the plants' rated output, not electricity actually generated. These are flash plants, using the design described in our guide to how geothermal power plants work: hot pressurized brine comes up a well, flashes to steam, the steam turns a turbine, and the leftover liquid goes back down an injection well.

"Experts estimate the geothermal resource of the Salton Sea KGRA is robust enough to support development of between 2,330 and 2,950 MW of additional geothermal power plants, six (6) times the current installed capacity." That is a resource estimate, not capacity under construction. The Commission calls the capacity "additional", but its six-times comparison appears to treat 2,330–2,950 MW as the total. For how this field fits into the rest of the state's geothermal picture, see our California geothermal guide.

How Much Lithium Is Down There

The estimates can be converted into the same units, but their different reservoir assumptions prevent a like-for-like comparison.

The Blue Ribbon Commission's report carried the earlier estimate, attributed by the Commission to McKibben, Elders and Raju (2020), Chapter 7 of the UC Riverside Salton Sea Task Force report Crisis at the Salton Sea: Research Gaps and Opportunities: "It is conservatively estimated that there are 2 million metric tons of lithium available in the reservoir at a depth of up to 1.2 miles deep from ground level, with a reasonable expectation that the amount is at least three times higher." The figure is in tonnes of lithium metal, not lithium carbonate equivalent, and the "three times higher" clause is described as an expectation, not an estimate. The phrase "at least three times higher" corresponds to at least six million tonnes.

The Commission itself expected better numbers: it recorded that "A current project among Lawrence Berkeley National Laboratory (Berkeley Lab), UC Riverside, and Geologica Geothermal Group, Inc. seeks to better quantify and characterize the quantity of lithium in the Salton Sea KGRA." That work was published in November 2023.

The newer LBNL numbers

LBNL published that work in November 2023 as LBNL-2001557, "Characterizing the Geothermal Lithium Resource at the Salton Sea." It puts total dissolved lithium in the well-characterized portion of the reservoir at 4.1 million metric tons of LCE, and "as much as 18 million metric tons of LCE" for the probable resource extent.

LCE means lithium carbonate equivalent. As the Commission's report explains, "Lithium carbonate equivalent is often used as a standard unit to easily compare across different lithium products." It is a different unit from tonnes of lithium metal, and the Commission gives the conversion: one tonne of lithium metal equals 5.32 tonnes LCE. On that basis the earlier 2-million-tonne estimate is roughly 10.6 million tonnes LCE — larger than LBNL's newer 4.1 million. Different reservoir assumptions, rather than a downward revision, explain why the newer estimate is the lower one.

LBNL calls its two dynamic reservoir models "preliminary" — a caveat that applies to the production forecasts, not to the resource-in-place calculation — and the high case is assumption-driven rather than a reserve statement: in its 2025 presentation to the CEC, the 18 Mt case comes from "Adjusting assumptions for porosity and total reservoir size." The method is a resource-in-place calculation, described as "Pore Volume ... x Brine Density ... x Concentration ... = kg of Li in reservoir brines." That counts lithium physically dissolved in pore water. Recoverable output would be lower once extraction losses, well access and project economics are counted.

The decline curve

LBNL also modeled what happens over time. Under a 30-year scenario recovering 95 percent of the lithium from produced brine, "lithium recovery declines by more than half, from 0.8 to 0.3 kilograms per second." The reservoir is not a fixed tap you open and leave open.

Projected Annual Lithium Production

The Commission's report gives two annual-production projections. A CEC-funded research project by SRI International "found that the Salton Sea KGRA can produce more than 600,000 tons per year of lithium carbonate equivalent (LCE) if fully developed." Using only the geothermal plants that exist, "Some estimates indicate that Current geothermal power capacity at the Salton Sea KGRA is able to support recovery of roughly 127,000 metric tons of LCE."

For context, the Commission reported that "global production of lithium primarily through mining and evaporation ponds in 2020 was less than 500,000 tons LCE but is expected to increase significantly." So the SRI projection for a fully developed Salton Sea alone exceeds the sub-500,000-tonne LCE figure the Commission gives for global lithium in 2020. The two are not directly comparable: one is measured global production in 2020, the other a projection for a fully developed Salton Sea resource.

How Direct Lithium Extraction Works

Direct lithium extraction, or DLE, is the family of processes that selectively pull lithium straight out of a brine — here, out of the stream between the power plant and the injection well. Footnote 16 of the Commission's report describes it: "DLE technologies are designed to recover lithium and other minerals as the geothermal brine flows through pipelines and tanks and over a surface or substance that removes the lithium and other minerals before returning the brine deep underground. The environmental impacts of each project are assessed during the permitting process."

The Commission's December 2022 report names three recognized families: adsorption, ion exchange, and solvent extraction. Adsorption and ion exchange both appear in Salton Sea work. The CEC/SRI pilot report of March 2024, prepared by Materials Research LLC, describes a sorption route — "absorption onto a custom sorbent, followed by lithium desorption driven by carbon dioxide in water" — though its full pilot skid ran on synthetic brine, with actual Salton Sea brine tested only at bench scale. Controlled Thermal Resources describes designing for a "stable, high-quality brine feed for DLE via an adsorption process," a company-reported characterization. Berkshire Hathaway Energy's first demonstration used "ion-exchange media," specifically lithium-titanate. The Commission also recognizes solvent extraction, though the Salton Sea projects discussed use adsorption or ion exchange.

How DLE Compares Environmentally

The Commission compared DLE favorably with hard-rock mining and evaporation ponds, but framed its advantages in prospective terms: "The environmental impacts of the lithium recovery technologies proposed for use in Imperial County, direct lithium extraction (DLE) from geothermal brine, have a much lower environmental impact than hard rock mining and evaporation ponds. DLE is designed to be a more sustainable and environmentally beneficial approach to lithium recovery in terms of factors such as land use, water use, time to market, and carbon intensity."

The phrase "is designed to be" signals an intended advantage, not performance measured at an operating plant. The contrast the Commission draws with the alternative is more concrete: evaporation ponds "require ... square miles of land, and are environmentally destructive." Squeezing lithium out of a pipe that is already flowing avoids that footprint by construction. The remaining claimed advantages need data from operating commercial plants.

Why Ore and Brine Grades Are Not Directly Comparable

Hard rock is not even measured the same way: one analyzed spodumene concentrate came in at "2.14 wt.%" lithium — a percent-grade material, not a ppm-grade one, and a specific analyzed sample rather than a universal ore grade.

The case for Salton Sea lithium therefore rests on recovering it as a by-product of geothermal generation. Drilling and pumping 120 million tonnes of 198 ppm brine a year purely to chase lithium would be a hard case to make. The plants pump it for electricity regardless, and the lithium question is only what you do with the stream on its way back underground — the same co-production model discussed in the 2025 U.S. geothermal market report.

What the First Demonstration Plant Taught

In its August 2024 final report to the CEC, BHER Minerals described why its own demonstration plant did not work.

The plant was built at one-tenth scale and tested. The report's assessment is that it was "unable to perform as expected," with a specific cause: "failure of the selected media to perform under field conditions." The ion-exchange medium that had worked in the lab did not hold up in the real stream, and the original technology provider's contract was ended. BHE went on to other technology routes, including the TerraLithium joint venture formed in 2024.

The report identifies a central problem for lithium pilots: "actual flowing brine, can produce a very different result" than laboratory work with synthetic or stored brine. Unlike laboratory brine, the field stream is hot, pressurized, chemically complex and continuous.

Materials were part of the problem. Standard duplex stainless steels were incompatible with the very-low-pH process fluid, and components were replaced with Inconel 625 — a nickel alloy that costs many times what stainless does. BHE also calls effective removal of minerals such as "iron and silicon" critical to its recovery process. On the silica side more broadly, the Blue Ribbon Commission's report mentions "Iron-silica material" in a waste-handling context and sets a research goal to "demonstrate improved processes to remove silica and heavy metals," which establishes silica handling as a recognized technical challenge the state is funding work on.

BHE publicly detailed the trial's failure, including the material substitutions required during testing. BHE also states that commercial-scale performance "has not yet been proven commercially."

The Water Problem the Commission Quantified

The Imperial Irrigation District, or IID, controls water allocation in the valley. Per the Commission: "IID has set aside 25,000 acre-feet per year (AFY) for new, nonagricultural uses, which includes new lithium recovery and geothermal projects." Some is spoken for: "One additional non-lithium project has received an allocation of 1,200 AFY, leaving 20,400 AFY for future lithium recovery and geothermal projects." Those allocation figures are stated "Through September 2021"; the Commission does not give a later balance. EnergySource's own filing gives a number: "The EnergySource Minerals Project ATLiS EIR identified that roughly 90,000 gallons per hour or about 3,400 AFY of water will be purchased from IID for cooling water and additional process water."

The Commission estimated how much lithium production the remaining allocation could support: "if the 3,400 AFY water use of the EnergySource Minerals Project ATLiS were used as a representative amount of the water demand required for the production of approximately 16,700 metric tons of lithium carbonate equivalent products, the entire remaining balance of the IID nonagricultural set-aside could support roughly 100,200 metric tons of lithium carbonate equivalent production per year, including associated lithium chloride recovery. Planned facilities have projected as much as 210,000 metric tons of lithium carbonate equivalent production with expansions in the future. This rough comparison indicates the potential new project requirements for water are greater than the water available for new uses."

On the Commission's own numbers, planned production runs at roughly twice what the available water set-aside could support. The Commission's two stated water-use figures do not convert to the same annual total: the Commission states ATLiS's water use as "roughly 90,000 gallons per hour or about 3,400 AFY", and those two are not the same quantity — 90,000 gallons an hour run continuously is nearer 2,400 AFY. Taking the lower figure, the same method would support around 141,000 tonnes and the overshoot becomes about 1.5 times rather than 2. Either conversion indicates a shortfall, but its estimated size ranges from about 1.5 to 2 times. The Commission cautioned that other facilities may use different amounts of water: "this rough comparison assumes that water use in all new facilities would be comparable to that identified for the EnergySource Minerals Project ATLiS which may not be an accurate assumption. The comparison provides a potential scenario and actual water use will be better understood when each project completes permitting and CEQA activities."

Two water percentages, two different denominators

LBNL published a regional water scenario in which proposed geothermal plus lithium development would need "~3% of historically available water supply." That sounds like a rounding error beside the Commission's shortfall, and both are true, because they are fractions of different things. LBNL's 3 percent is measured against the region's historically available water supply as a whole, most of which is agricultural. The Commission's shortfall is measured against IID's 25,000 AFY non-agricultural set-aside — the pot new industrial projects are actually allowed to draw from. Whether the larger regional pool ever reaches lithium projects is a water-rights question, not an engineering one.

Who Is Actually Building

Three developers dominate the field.

Controlled Thermal Resources (Hell's Kitchen)

CTR says its Stage 1 long-lead equipment is "built and staged for construction." It has operated an onsite Demonstration and Optimization Facility — a demonstration unit, not the commercial plant. In issuer-reported results filed with the SEC, that facility logged "770 hours of steady DLE operation at 1/15th commercial scale," greater than 97 percent DLE recovery, and "Produced lithium chloride suitable for downstream processing."

Permitting is listed on the federal permitting dashboard as "ENVIRONMENTAL REVIEW AND PERMITTING STATUS IN PROGRESS," with federal completion then estimated for November 20, 2026.

CTR has automaker agreements, though they are not the same kind. GM, on July 2, 2021, made a strategic investment under which it "will have first rights on lithium produced by the first stage." Stellantis signed a binding agreement on August 17, 2023 for "up to 65,000 metric tons" of battery-grade lithium hydroxide monohydrate "each year over a 10-year contract term" — a hydroxide tonnage, not elemental lithium. Neither agreement documents a commercial delivery.

EnergySource Minerals (Project ATLiS)

On January 15, 2025 the Department of Energy announced a "conditional commitment ... up to $1.36 billion" for the project. A conditional commitment is neither a closed loan nor evidence that funds have been disbursed.

A DOE environmental assessment from March 2025 describes ATLiS as a company that "is proposing to build a commercial lithium production plant" — proposing, not operating. The capacity target depends on who is stating it: DOE cites "up to 20,000 metric tons of lithium hydroxide annually," while EnergySource's own project page says 22,000 metric tonnes, with a "FIRST YEAR OF DELIVERY 2H 2028." CTR separately targeted 2027 for the start of deliveries to Stellantis.

EnergySource is not a paper company on the power side. It "developed and began operating a 50MW geothermal plant."

Berkshire Hathaway Energy Renewables / CalEnergy

BHE's approach contemplates feeding a lithium operation from "brine flowing through 10 existing geothermal plants" it already runs.

Its 2025 investor presentation puts the effort "Currently in demonstration phase, with pathway to decision on commercialization in 2026," and states a "Potential to produce approximately 90k metric tons of lithium carbonate equivalent annually." That 90k figure is a target attached to a commercialization decision that had not been made when the presentation was issued. As of a June 22, 2026 update with TerraLithium, the company was still described as "pursuing commercial lithium production." BHE remained in the demonstration phase, with no announced commercialization decision.

What Has Actually Been Produced

Battery-grade lithium has been made from Salton Sea brine. On June 22, 2026, TerraLithium (a wholly owned Occidental subsidiary) and BHE Renewables announced they had achieved "Production of lithium chloride using their DLE process at BHE Renewables' geothermal facility in Calipatria, California, followed by the manufacture of battery-grade lithium carbonate," plus "Direct conversion of lithium chloride into lithium hydroxide using a commercial-scale electrolyzer" at Brawley. BHE's own Senior Vice President for Mineral Development calls these "testing milestones," and the joint venture's stated aim is still "to demonstrate that commercial application is both technically feasible and economically viable at-scale." The tests establish technical production; commercially viable production at scale is what remains.

CTR and EnergySource remain at earlier stages. CTR's demonstration facility produced lithium chloride "suitable for downstream processing" at one-fifteenth commercial scale, per its SEC filing, and its Hell's Kitchen project remains in federal environmental review. EnergySource holds a conditional DOE loan commitment and a permit-stage proposal. Among the developers examined here, the earliest currently stated delivery target is EnergySource's second half of 2028.

No developer has reported selling and shipping lithium at commercial scale from a Salton Sea plant. The available records describe demonstrations, testing milestones, conditional financing and permitting in progress.

The wider context needs its date. As of January 2022, the Commission reported: "Although the United States has large reserves of lithium in all forms, in January 2022 the only operational U.S. supply of lithium is a brine facility in Nevada using lithium evaporation ponds," citing the USGS Mineral Commodity Summaries 2022 for the reserves context. That is a January 2022 statement, not a description of today.

Globally, the Commission put global lithium "at about 86 million tons" — identified resources in the ground rather than annual supply — broken down as "Bolivia, Argentina, and Chile (estimated at 50 million tons); the United States (7.9 million tons); Australia (6.4 million tons); and China (5.1 million tons)." On actual capacity, Australia "has a capacity to supply 1.27 million tons of lithium per year" — a figure that actually describes the Greenbushes mine's spodumene concentrate capacity, not contained lithium and not a national total. The Commission appears to have mislabelled it. The United States has the resource and, at the date of that report, almost none of the production.

Frequently Asked Questions

Is there lithium in the Salton Sea itself?

No — it is dissolved in a deep geothermal reservoir beneath the Imperial Valley, not in the lake. LBNL's LiRRIC FAQ says so directly: "The lithium is not in the Salton Sea."

How much lithium is down there?

LBNL's November 2023 study estimates 4.1 million metric tons of LCE in the well-characterized portion of the reservoir, and "as much as 18 million metric tons of LCE" for the probable extent. LBNL calls its dynamic reservoir models "preliminary." Both figures are resource-in-place — dissolved lithium, not lithium anyone has shown can be recovered and sold. The Commission's earlier 2016-sourced figure of 2 million metric tons is in a different unit, tonnes of lithium metal rather than LCE.

Is the Salton Sea brine especially rich in lithium?

Among geothermal brines it is exceptionally concentrated — the CEC and SRI describe the Salton Sea KGRA as believed to have the world's highest lithium concentration among geothermal brines, though single published values elsewhere run higher. As a lithium ore it is thin: about 198 ppm, or 0.0198 percent, against a USGS range for major brine deposits of "0.015 to 0.125 percent," and well under Salar de Atacama's reported 2,041 mg/L average. Its advantage is that geothermal operations already pump the brine to the surface.

What is DLE?

Direct lithium extraction — recovering lithium from the brine as it flows through surface pipework, before reinjection, rather than concentrating it in evaporation ponds. The Commission names adsorption, ion exchange and solvent extraction as the recognized families, and judged DLE to have "a much lower environmental impact than hard rock mining and evaporation ponds" while wording the sustainability claim as design intent: DLE "is designed to be a more sustainable and environmentally beneficial approach."

Why hasn't a commercial plant been built yet?

Commercial development has been held up by technical failures, financing and permitting. BHER Minerals' August 2024 report to the CEC describes a one-tenth-scale demonstration plant "unable to perform as expected" because of "failure of the selected media to perform under field conditions," and reports that "actual flowing brine, can produce a very different result" than lab work. Duplex alloys 2205 and 2507 could not handle process fluid below pH 1.0; headers, laterals and media screens in three contactors were replaced with Inconel 625. BHE's own summary of the technology is that it has "not yet been proven commercially."

Do the automaker deals mean lithium is being delivered?

An offtake agreement is a contract to buy future output. CTR signed with GM on July 2, 2021, giving GM "first rights on lithium produced by the first stage," and with Stellantis on August 17, 2023 for "up to 65,000 metric tons" of battery-grade lithium hydroxide monohydrate "each year over a 10-year contract term." Neither agreement has produced a documented delivery.

When could commercial production actually start?

EnergySource states a "FIRST YEAR OF DELIVERY 2H 2028", and CTR said in 2023 that supply to Stellantis was scheduled to begin in 2027 for Project ATLiS — a company target; DOE still described the plant as proposed in March 2025. BHE's 2025 investor presentation put its own effort in the demonstration phase with a "pathway to decision on commercialization in 2026."

Is water a real constraint?

The Commission thought so and did the arithmetic. IID set aside 25,000 AFY for new non-agricultural uses. Through September 2021, after about 3,400 AFY for Project ATLiS and 1,200 AFY for a separate non-lithium project, 20,400 AFY remained. Extrapolating from Project ATLiS's filed use of about 3,400 AFY for roughly 16,700 tonnes of LCE, the Commission calculated the balance "could support roughly 100,200 metric tons" a year against planned facilities projecting "as much as 210,000 metric tons" — while flagging that the extrapolation "assumes that water use in all new facilities would be comparable to that identified for the EnergySource Minerals Project ATLiS which may not be an accurate assumption."

How can I invest in Salton Sea lithium?

There is no simple public-market route: the major Salton Sea projects remain at the demonstration or permitting stage rather than commercial production. For how geothermal companies are structured, see our overview of geothermal stocks and investing.