The Salton Sea, which lies roughly in the middle of the massive geological trough, isn’t actually a sea at all. The largest inland lake in California, it is 51 miles long from north to south and 27 miles wide, but gradually shrinks as less and less water flows into it. It was once a thriving entertainment and recreation spot, a business that has also largely dried up. It has left abandoned buildings and shallow, gray beaches. The highways that surround the lake are now mainly crossed by passing trucks.
In recent years, companies have come here to mine a valuable metal, lithium, that the auto industry needs as it moves towards making electric cars. Lithium is the lightest naturally occurring metallic element on Earth, and that is one of the reasons why it is important for batteries of electric cars, which have to store a lot of electricity in the smallest possible package.
What’s more, with the unique geography of the Salton Sea Basin, engineers and technicians can get the lithium with minimal environmental destruction, according to companies working there. In other places, lithium is extracted from the earth using freestone mining that leaves huge, unsightly scars across the land. Here it naturally exists in liquid form, so extraction requires no mining or explosion.
Over thousands of years, floodwaters from the Colorado River, carrying minerals drained from the Rocky Mountains, Ruby Canyon, Glen Canyon, Grand Canyon, and more, have washed into these lowlands. Time and again the water has come and evaporated, leaving behind metals that have gone deep into the ground.
Lithium is in abundance in the Salton Sea Basin. In fact, those working on it say there could be enough to make batteries for all the electric cars expected to be built in this country over many years, eliminating the United States’ reliance on foreign lithium suppliers. That was a priority for the Biden administration.
The crust here is thin and there is water deep underground close to the boiling hot liquid rock in the earth called magma. Trapped in that naturally occurring furnace, that water has become an overheated mineral stew.
Geothermal power companies have been drilling down here for decades into the water at nearly 700 degrees, allowing it to instantly boil out of the ground. Steam from the hot brine — so named for its high mineral content — spins turbines and generates electricity. It is then pumped back to Earth where it is reheated to start over. This type of energy is considered clean and renewable because it relies on: heat that occurs naturally in the earth.
“It’s one of the largest geothermal energy fields in the world,” said Derek Benson, chief operating officer of EnergySource Minerals.
Energy source Mineral wax was spun off in 2018 from EnergySource, a geothermal energy company that has been generating electricity from hot brine from the Salton Sea for a decade. EnergySource Minerals is now trying to extract lithium from the brine it used for energy.
Exactly how much lithium there is and how much can be extracted are questions a research team at Lawrence Berkeley National Laboratories is trying to figure out.
About a quarter of the water taken from deep underground here is made up of dissolved rock, a much higher mineral concentration than you’d find in ordinary seawater, according to Patrick Dobson, a Berkeley Labs geologist who led the study. Lithium makes up about 200 parts per million, he said, which is comparable to about 10 parts per million in some other hot geothermal fields.
“That’s why this is interesting,” he says. “It’s not just any geothermal brine. There are certain places where lithium is enriched in the brine, and the Salton Sea is the place in the US that we’re really focusing our attention on.”
People who have worked with this brine have long known about its contents, but it makes no sense to use masses of undifferentiated minerals, and selectively extracting them was not economical. But that was before electric cars became a big deal and the price of lithium started to rise. So companies have invested in new technologies to extract lithium from the brine.
“We use what we call lithium selective adsorption,” Benson said. “So we’re going to pass the lithium-containing brine over one of our proprietary adsorbers. It has a chemistry that has an affinity for lithium and really only for lithium.”
One of the challenges is how efficiently these technologies can extract lithium from the brine, said Dobson of Berkeley Labs. Although there is a lot of lithium in the brine, these extraction techniques probably won’t be able to get 100% out of every drop.
And if the lithium is taken from the brine and the brine is then pumped back deep underground, will lithium levels be significantly depleted or will the levels be replenished as more lithium is leached from the rocks?
“We know from measurements of rocks still in the reservoir that not all the lithium is in the brine,” he said. “There’s still lithium in the rocks.”
Collecting lithium now seems like a bigger money-maker for companies like EnergySource than their original company of just generating electricity from the steaming soup. In fact, other companies are largely starting with geothermal energy to get lithium. In their case, electricity is just a bonus.
Not far from EnergySource’s tawny geothermal plants, a company called Controlled Thermal Resources has its own small power plant. It is currently in the testing phase, but CTR has already entered into a partnership with General Motors, which will purchase the lithium produced here for its electric vehicles. More recently, Italian EV battery company Italvolt announced plans for a spin-off company to partner with CTR. According to the plans, Statevolt, as the spin-off is called, is to build a nearby battery factory, using both energy produced by CTR’s generators and lithium extracted from brine there. According to Italvolt, the plant could one day produce enough batteries for 650,000 electric vehicles per year.
Placing battery production on site eliminates the shipping costs for materials and the carbon dioxide emissions from all the ships, trains and trucks needed to transport the lithium to battery factories, which are today mainly located in Asia, said Rod Colwell, CEO of CTR.
This new interest could mean good things for a community in need of some help. Decades ago, the Salton Sea was… a tourist destination, with people flocking to the California desert oasis to enjoy boating and water skiing. That was before evaporation dried up the lake and concentrated pollutants in the shrinking water.
“You’d find people from Hollywood, the celebrities from Southern California coming to the boat and enjoying the good restaurants, playing golf,” said Frank Ruiz, Salton Sea program director for the National Audobon Society. “That was the life of the Salton Sea in the ’50s and ’60s and just 50 years later this is what we have,” he said, looking around a largely deserted beach on the lake.
“You went from the western Riviera to one of the worst environmental and public health nightmares,” he said.
The lake is shrinking due to a lack of natural inflow, combined with years of drought and rising temperatures due to climate change. As the lake continues to retreat, it leaves behind sand and sticky mud with many pollutants. That, combined with the area being a natural basin that tends to trap and trap smoke and smog from surrounding areas, contributes to high asthma rates, he said.
Today, the area feels almost deserted, save for some clearly thriving date farms with rows of thick-trunked palm trees. Artists have been drawn to the blank canvas of the area’s empty buildings and open spaces, creating a colony of wildly painted and decorated homes. Large sculptures of wire and concrete inhabit the beach.
Which has flowed into the area several times over the centuries. The lake that exists today was created around 1905 when man-made channels overflowed in the desert lowlands. The large lake that sprang from it has long been a boon to traveling birds, as well as water sports enthusiasts.
“We used to have over 400 different species of birds and pretty much all the species that we have in California, in the Salton Sea,” Ruiz said. “From an environmental standpoint, it’s one of the last standing jewels along the Pacific Flyway, especially here in California.”
The lake and its waters are not connected to the lithium-rich underground brine, but, Ruiz hopes, lithium mining could provide jobs and income to rebuild the Salton Sea region’s economy and perhaps even its damaged environment, in addition to placing more electric cars. the route.
“This could be really good for the entire region. Not just for Imperial County, for the Coachella Valley, for all Californians,” Ruiz said. “I mean, nationwide it can be a catalyst.”