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This huge drilling rig was once used for oil and natural gas. Now it's after hot, salty water. And in it, lithium. That's the stuff that goes into big, powerful batteries, and getting it this way supposedly uses way less water, creates fewer emissions, and it's cheaper. And you can use the hot water to make energy. It's like "two for the price of one". Sounds too good to be true? Only one way to find out. "That's massive. It's like a skyscraper rising from the fields." That's not the sort of thing you are used to seeing here in southwestern Germany.
Amidst all these peaceful fields, a geothermal energy company is drilling deep into the earth's crust. "Ready to go." This is Manfred Boeckmann, of Vulcan Energy. The company produces heat and electricity from hot, salty water, or "brine" that they pump up from more than 3,000 meters below the ground. And mixed into that brine is lithium. "Around 180 to 200 mg per liter. One fifth of a gram, roundabout." "That sounds very little." "It's very tiny, and it's of course dissolved in the brine. If you look at the geothermal brine, you won't see it."
Here's how it works. Below our feet, groundwater seeps down into hot rock layers, heats up, and flows back up again under pressure. That's the brine. It accumulates in reservoirs made of porous rock. Normally, geothermal companies just use that water to make power and heat. But the rock below here is packed with minerals, including lithium, and over millions of years, the water has absorbed those minerals. Overall, these are tiny amounts, but it's still enough for the company to start exploring the possibility of extracting here.
"This is where the main action happens. This is where you see the human roughnecks and the steel roughneck and the driller work." "Like, a rough neck?" "Yes, because that name comes from the old days where this used to be even harder, rougher work." "And from here, how deep does the drilling go into the ground?" "This particular well has a length of 3,400 meters." To get there, you need a rotating drill head - called the "bit". As it munches its way into the ground, the roughnecks - human and machine - add one pipe section after another.
Up to 300 meters a day. Drilling fluid is constantly pumped down to cool the bit and stabilize the borehole. "This smells like the paint you would use at home to paint your walls." The fluid also washes crushed rock up to the surface. This can indicate where the drilling is at. Once the borehole finally reaches the reservoir, it is secured with steel and cement and then cleaned. To do this, another drill head is lowered into the hole and then brought back up. That's what happened while we were there. When that's completed, the hot geothermal brine can start flowing to the surface through holes in the pipe and be tested for what Vulcan - and many others - want: Lithium.
It's an essential ingredient in manufacturing batteries for pretty much anything - like your laptop or phone - but mostly for EVs and the grid-scale energy storage that we need to store power from solar or wind. But there's a problem, and the opponents of EVs can't stop talking about it: Lithium mining isn't exactly a clean business. Two thirds of Lithium production come from hard-rock mining in open-pits and tunnels, mostly in Australia, where lithium-bearing rock is blasted, crushed and processed. This needs massive amounts of energy, often from fossil fuels, and leaves behind mountains of waste. The other third comes from salar brines in places like Chile and Argentina, where in most cases lithium-rich saltwater is pumped from underground
into huge evaporation ponds. It's then left there for months or even years until enough water has evaporated to concentrate the lithium. The problem is that these regions have little freshwater for communities, and lithium mining can pollute it. In comparison to that, extracting lithium from geothermal brines seems to be a good alternative. It needs no pit, and no pond. The machines here run on electricity, not oil or gas, and all the water comes from deep underground reservoirs that we can't use for anything else.
"We extract the energy from the hot water. We extract the lithium, and then the lithium-depleted, or the cold brine goes back into the subsurface, into the same reservoir." To see what the Lithium extraction looks like, we need to go to the town of Landau, just a few minutes from the rig. This geothermal plant belongs to the same company. It supplies heat to local households. "Hey, nice to meet you." "Hello." This pipe is where the geothermal brine comes from the ground. "You cannot see it because it has a temperature of 160°C which means it's above the boiling point."
Out in the open air, the water would simply evaporate. 160 °C is also way too hot to use for heating. Instead, a heat exchanger transfers most of the heat of the brine onto fresh water that's used for district heating in a big, closed loop. The cooled down brine goes here, into this pilot plant. "So, this column has a temperature of 70 °C. And at this temperature, the Direct Lithium Extraction takes place." Inside these columns, the now 70 degrees Celsius brine flows through this material. It basically works like a filter and makes the lithium stick to it.
You can then wash the lithium out of the powder with fresh water. This extraction process produces two things: The brine, now without lithium, is reinjected into the ground through this pipe. And a watery solution with a high lithium concentration that goes through a few more steps to increase concentration and remove impurities. "'Impurities' means all the other elements that can also be found in the geothermal brine. Like, for example, sodium, potassium, calcium, magnesium." To be honest, the whole process is a lot to take in - and I should've paid more attention in chemistry class. But what you get at the end of it is this lithium-rich powder.
It's perfect for manufacturing long-duration batteries for EVs and grid-scale energy storage. Though it could also be used to build batteries for smartphones, for example. The amount in this jar would make 100 of them. "And how much of that are you producing already?" "We have produced lithium hydroxide monohydrate in the tons scale already. However, from our commercial plants we're just building, they will have a capacity of 24,000 tons per year" "24,000?" "Yeah, and that is sufficient for 500,000 electric vehicles."
"Ok, that's a lot of cars." With only about a fifth of a gram of lithium per liter of brine, this means they'll have to process more than 50 million liters a day, the equivalent of 22 Olympic sized swimming pools. To be able to deliver that much brine, the company is building a commercial extraction plant, and several new well sites in the region. Not everyone here is happy about that. Some residents in a nearby town even petitioned against Vulcan to stop construction of a lithium extraction plant - and the company's activities in general. That's because pumping geothermal brine can change pressure underground and trigger tiny earthquakes.
A magnitude 2.7 event in 2009 was officially linked to activity at the exact place we visited, and to this day some residents are still very worried. Vulcan, who owns both the drilling rig and the plant, claims that the tech has improved, and the quake risk is now minimal. The company wants to produce as much lithium as a small hard-rock mine or evaporation pond. But at what impact, compared to them?
"Geothermal lithium doesn't necessarily mean that it is more sustainable." Vanessa Schenker has looked at hundreds of geothermal brines in the Upper Rhine area and elsewhere - and what the environmental impact of extracting lithium from them would be. "We actually found that the range of potential impacts is quite high, and it can definitely exceed the ones that are currently on the market." A lot of it depends on the brine. It contains other minerals too, which you have to remove to get to pure lithium. But more treatment means you need more energy and chemical additives, and you end up with more chemical waste,
more transportation and higher carbon emissions. Vulcan says their brine is relatively pure, which makes it easier to remove the remaining impurities. They wouldn't tell us which chemicals they use, and how much chemical waste is generated in the process but said that most of it, like salt or magnesium, is reused or reinjected into the underground reservoir with the used brine. But all of this operation - the machines here, the transportation, the drilling, building wells with lots of steel and cement - all that needs energy and creates emissions.
5 to 46 tons of Co2 per ton of lithium carbonate equivalent, according to Vanessa Schenker's research. But Vulcan argues: "We also produce the geothermal energy, which is clean, which is sustainable, in order to produce lithium chloride solution, and that's the reason why we have a CO2 footprint which is zero." Their calculation is: the CO2 reductions through geothermal energy, offset against the emissions of running all this, result in net-zero emissions. Another big plus is the reduced water use. "If I use the direct lithium extraction technology, I can recycle a lot of the process water. And with that, you substantially reduce the water consumption."
Vulcan says they use 300 liters of freshwater per ton of lithium - whereas one ton from hard-rock mining or salar brine evaporation consumes tens or even hundreds of thousands of liters. Vulcan hasn't put a price tag on its lithium yet but says to produce one ton of it will cost them less than US$4,200. That compares to more than US$6,000 for the same type of Lithium from salar brine evaporation and almost US$11,000 for hard-rock mining. The advantage of geothermal is that just one resource, the brine, generates two profits at once: from energy and lithium. And it all happens locally.
No shipping across countries and continents needed. At the same time, that's a big plus when it comes to safe supply chains. "We think, it's a good thing that, you know, that Europe tries to develop some lithium production here to be partly self-sufficient. Geothermal lithium for Europe is certainly a good alternative." Robin Francois is head of Lithium at Glencore, one of the biggest resource trading companies in the world, and one of the companies that have signed deals with Vulcan
to buy the Lithium we just saw. With the need for making powerful batteries, demand is growing quickly, and the existing sources likely can't keep up. That gap between demand and supply is where geothermal lithium could come in. Of course, it's not only found in Germany. Pilot sites have opened in the U.S., the UK and elsewhere. And there's evidence of lithium in geothermal and even oilfield brines in many more countries around the world. So far, nothing is happening on a commercial scale, yet. But that could change within the next 20 years or so. "We see many projects, and if these projects can really produce the volume that they claim, they could play,
I would say they could be a good part of the market. Can it be 5%, 10%, 20%? Maybe something in that range is absolutely possible." While geothermal lithium may sound like a no-brainer, it isn't "plug and play." The technology is still super young. Geology and the brine can differ a lot in each place, and that means a lot of testing and finetuning. That's way more complicated than blasting rock or evaporating water and therefore won't replace it. But if it works, it could provide a domestic lithium supply here and there, nice and steady from underground. "Over decades, it will deplete.
However, we do not expect a significant decrease of the lithium concentration over the next 30 years." "And then after that?" "We can still run our geothermal plants and further produce heat and electricity." For a mining site, that could be a really good legacy. "Are there any other 2-for-1 clean energy solutions we should check out? Let us know in the comments below, don't forget to subscribe, and check out our channel for more stories like this."
