A geothermal power plant in the UK has discovered the highest concentration of lithium ever found in geothermal fluid, opening the door to a new business model for the renewable energy source.
Third-party tests carried out this summer revealed more than 250 milligrams of lithium – a critical metal for the green transition – per litre of the fluid used to transfer heat from under the Earth.
“It’s really become a game-changer for the industry to be able to say we don’t just produce power, don’t just produce heat – we will produce lithium as well, particularly zero carbon lithium,” the founder of Geothermal Energy Ltd Ryan Law told EURACTIV.
The Cornwall-based company has plans for four new geothermal sites across the county, which together will power 45,000 homes. Each plant is expected to take 18 months to complete and all are expected to be running by 2026.
Once these are online, the company expects to extract 4,000 tonnes of lithium annually, with United Downs – the geothermal plant already constructed – possibly producing 1,500 tonnes by the end of 2023, depending on the technology.
Geothermal power is responsible for only a fraction of renewable energy used in Europe despite being accessible in some form across most of the continent. That is partly because it has extremely high start-up costs, making it a less attractive investment.
But now the technology is seeing more interest from investors, partly driven by the prospect of lithium extraction.
“It’s a big deal to try and get lithium that is both incredibly low carbon – in our case, zero carbon – and, geopolitically, to have it produced in your own country,” said Law.
Lithium is brought to the surface by geothermal fluid. In the case of the Cornish plant, this is water from an underground reservoir that is pumped between two wells to bring the heat to the surface. The water can reach temperatures of almost 200°C, but is under such pressure that it remains a liquid. At this high temperature, it is very good at absorbing minerals, like lithium, from the rocks around it.
Law’s company is trialling zero carbon methods to remove the lithium from the fluid, and is currently capable of achieve extraction rates of 95%, he says.
The discovery means the possibility of a big processing plant, possibly even a Gigafactory in Cornwall, he told EURACTIV. This would be a huge U-turn for the county, which is one of the poorest in England, and could see a partial return to the mining that the area is infamous for.
This history of mining has also helped engage the community, alongside efforts by the company, according to Cherilyn Mackrory, a Cornish Conservative MP.
“It’s important to say that they’ve taken the community with them on this, because I think that could have been potentially a scary project for a local, rural community. But actually, the community has been really involved and really engaged, because they see the benefits of what is coming,” she told EURACTIV.
The metal to keep Europe on the road
Demand for lithium is expected to boom in the coming years on the back of the shift to electric vehicles. According to the government-backed Faraday Institution, the UK will need to fulfil a domestic demand for lithium that could reach 59,000 tonnes of lithium carbonate equivalent per year by 2035.
Currently, the top five producers of lithium are Australia, Chile, China, Argentina and Zimbabwe but imports from those countries can have issues related to human rights or carbon footprint because of the transportation distances involved.
This is why having a lithium supply in Cornwall could be crucial to form a domestic supply chain in the UK, according to MP Mackrory.
“Lithium is a mineral for the future – a crucial component for electric car batteries among other high tech uses – hence mining and manufacturing it locally will be a big driver in the energy transition and make Cornwall a key contributor towards realising the UK’s climate targets,” she said.
As part of its ambition to hit net zero emissions by 2050, the UK plans to end sales of new petrol and diesel cars by 2030 and rule out sales of new hybrids by 2035.
Europe too is expected to see a huge increase in demand for lithium, with a stated aim to create a fleet of 30 million electric vehicles by 2030.
Alongside this, the European Union will soon adopt policies to introduce traceability into the supply chains of lithium batteries and Law expects a similar rule to be introduced in the UK.
“Some of the big car manufacturers, not just Tesla, but Renault and others, are already signing agreements about how they source their low carbon lithium because they can see what’s coming – you won’t be able to produce a high carbon lithium battery within Europe fairly shortly,” he said.
[Edited by Frédéric Simon]