By Allison Proffitt
August 13, 2021 | “Let’s be honest, there is a global battery race going on right now worldwide and China is eating our lunch. We are losing,” said Jonathan Weisgall, vice president for government relations for Berkshire Hathaway Energy. “To develop a domestic source of lithium could be the best way to jump start a lithium battery economy in the country.”
This is the goal of a new U.S. Department of Energy Geothermal Technologies Office award: the American-Made Geothermal Lithium Extraction Prize, which is designed to de-risk and increase market viability for direct lithium extraction (DLE) from geothermal brines.
Weisgall, along with nine others, serves on the Industry Advisory Panel for the award. He, Derek Benson from EnergySource, and Dan Hoyer from Veizades and Associates gave a webinar in April outlining the current state of the technology. The three know well the challenges of extracting lithium from geothermal brines—but they also know the market opportunities.
The Prize is focused on new technical solutions for economic extraction of lithium from geothermal brines in the Salton Sea, a site in California on the San Andreas fault with a shallow, landlocked sea and deep geological wells of geothermal brines.
The area has been a source of geothermal energy for decades. Geothermal brines—extremely hot mixes of water and other metals and minerals—are drawn from deep geological aquifers, some at temperatures up to 500C. When the brines are released from pressure, they “flash” or turn immediately to steam. This steam spins turbines, which creates energy. Unused brine can be returned to the reservoir to re-heat, re-pressurize, and be used again. In the more than 35 years we’ve been using these reservoirs, we’ve seen no reduction in pressure, Weisgall said.
Lithium makes up about 250 parts per million of the brines at the Salton Sea, but, of course, it’s not the only thing dissolved in the mix. The brines are full of other metals and minerals including iron, silica, zinc, manganese, potassium, and more. “If it’s on the periodic table, chances are, it’s in the brine,” Benson quipped.
Weisgall calls the mix, “complicated and unstable”. For instance, high iron content causes corrosion in the wells. And Benson pointed out, “There are a couple of things we’d just as soon keep in suspension: that’s barium, and strontium, and things that ultimately add to a naturally occurring radioactive material.” The challenge is getting lithium out while leaving as much of the rest of the elements dissolved in solution to return to the geothermal wells.
Lithium is the most promising of the brine components because of the current and growing market. Geothermal energy plants can process 50,000 gallons of brine per minute. For the Salton Sea brines, at 250ppm lithium, Weisgall said a plant could theoretically produce 90,000 tons of lithium per year.
For a major component in batteries for electric vehicles, tablets, phones, and other consumer devices—this yield is tantalizing. Currently the US is almost entirely dependent on imported lithium; only 1% of U.S. lithium supply is being sourced domestically. Additionally, the global demand for lithium is expected to increase by 500% by 2050 due to widespread adoption of electric vehicles and grid-scale battery storage.
There are other reasons beyond just the market opportunity to seek an efficient and economic way to extract lithium from geothermal brines: the other methods of lithium extraction and extremely costly environmentally.
In South America lithium is extracted from salars, large dry salt flats with lithium-rich water just below the surface. Brines from beneath the salty crust are pumped to giant evaporation ponds—some half the size of San Francisco. Dry and windy conditions do the rest. The concentrated salts are left behind after evaporation from which lithium carbonate and other materials can be extracted.
But the environmental costs are high; the approach requires tremendous amounts of both land and water. Weisgall reports that salars use about 500,000 gallons of water to produce a ton of lithium, and he estimates that a lithium extraction process from geothermal brines would use 90% less water.
The approach also uses massive amounts of land—and it’s increasing. Dan Hoyer, from Veizades and Associates, also runs a geothermal energy facility in the Salton Sea, and his mineral extraction facility uses a comparatively small 30 acres.
In Australia, lithium is mined from open pits, also accounting for vast land areas. Mined rock must be sent to China for the final lithium extraction step and 95% of the bulk is discarded.
Theoretically, extracting lithium from geothermal brines would avoid much of these environmental impacts. Lithium extraction from geothermal brines could be, “Essentially a closed-loop system, a bolt-on technology to existing geothermal plants,” Weisgall said, “A very small, minimal footprint, much less water use, and renewable energy to provide the electricity.”
Perhaps the American-Made Geothermal Lithium Extraction Prize will deliver a solution.
“This prize is really looking at trying to both de-risk that space—lithium extraction from geothermal brines—as well as increase the market viability for direct lithium extraction technology,” Dr. Alexis McKittrick, program manager within the DOE’s Geothermal Technologies Office, explained to Battery Power.
The prize is open to teams led by U.S. academic institutions, though teams can include small businesses or groups within university technology incubators. The submission period was opened April 1, 2021, and the deadline for phase 1 submissions is September 2, 2021.
Through three escalating challenges, competitors will work to develop technical solutions that can create a safe domestic supply of lithium while minimizing environmental impact and expanding the technical workforce, McKittrick explained.
The three-phase structure begins the Idea and Concept phase—for which submissions are due at the first deadline of September 2. “We’re really looking for teams to show us in paper form that they’ve identified and developed an impactful idea or solution that addresses some of the technical challenges,” she said.
Entries for this first phase of competition can be very theoretical. “We really do mean we’re looking for a concept. What’s very important is that the concept is tied to solving some of the technical challenges we’re seeing in the lithium extraction from geothermal brines space… We’re not even looking for them to have substantial designs in place! It’s just a concept: I have an idea for how to solve this, and I can provide some background as to why it would make sense to design and move forward with it.” Up to fifteen semifinalists will be chosen, and those winners will share a $600,000 award.
That pool of up to 15 semifinalists will be invited to participate in Phase II—Design and Invent – over three months, when they will develop in depth designs for their solutions. Up to 5 finalists will then be chosen and will share a $1.4 million prize. Starting in Phase II, semifinalists will have the help of the Industry Advisory Panel on which Weisgall, Benson, and Hoyer sit. The IAP will not be involved in choosing the projects that will advance through the Prize challenges, but will instead provide participants with real-world, mentorship, technical insight, marketing expertise, product validation, and more. The IAP’s role is to, “ensure that folks are developing something that then can be hopefully directly scaled up and used in the Salton Sea,” McKittrick said.
Finally, the 5 finalists from Phase II will take on Phase III—Fabricate and Test—a 12-month phase that will produce up to three winning teams from these promising entrants. “It’ll take some time to pull those technologies together and test them,” McKittrick said. The Phase III winners will share a $2 million prize.
Solutions Wish List
During their initial webinar, Weisgall, Benson, and Hoyer encouraged all solutions, no matter how incremental or modest. Benson used a baseball analogy. “Home runs may be fun, but they are hard to come by,” he said. Single base hits still earn runs.
Each of the IAP members had a favorite area of focus. “The challenges with geothermal have a lot to do with impurities and that would be my focus,” Benson said. Weisgall encouraged teams to look at water use reduction—both for environmental and cost benefits. Hoyer—who has been running a lithium extraction pilot for ten years now—encouraged teams to focus on a variety of lithium concentrations, seeking solutions that would work for both high and low concentrations of lithium in the brine.
But they also had hopes for the fruit of multidisciplinary collaboration. “I can’t appreciate all the potential cross-pollination that can happen whether it’s in the oil and gas space, whether it’s in the water treatment space—you name it,” Benson said. “There are technologies that are transferable. It’s just a matter of having exposure and understanding the challenge.”