UK company Geothermal Engineering (GEL) has announced what it claims is a technological breakthrough in the production of onshore lithium in the country.

GEL said on September 2 that independent analysis had shown the firm’s lithium carbonate produced from deep geothermal brine now exceeds the 99.3% purity specification — and can be classified as ‘technical grade’ material.

The development at the United Downs site in Cornwall gives a direct route to market as the lithium carbonate does not need further refining before onward sale to battery manufacturers, GEL claimed.

Production at the site started in February 2026 and GEL’s plant has a production capacity of 100 tonnes per annum of lithium carbonate.

However, GEL said production at the site is now forecast to hit around 2,000tpa by 2029. As other sites are added, anticipated total production will increase to 30,000tpa by 2033, meeting over 60% of the UK’s lithium target alone, the company said.

GEL’s CEO Ryan Law said: “We are demonstrating that it is possible to produce a high-quality, saleable lithium product in the UK with the highest environmental standards, creating the potential for a more secure and sustainable domestic supply of this critical battery material.”

Julian Hetherington, director of automotive transformation at the Advanced Propulsion Centre, which is supporting the UK government’s Driving Research & Investment in Vehicle Electrification (Drive 35) programme, said: “United Downs shows the huge opportunity the UK has to build a domestic supply of lithium carbonate in a sustainable way.

“It will strengthen the UK’s critical minerals supply chain and reindustrialise the country. Drive 35 is proud to have supported the project with a £1.8 million ($2.5 million) grant through our Automotive Transformation Fund, to help reach this important milestone.”

The UK has set a target of meeting 10% of critical mineral demands from domestic production by 2035, including at least 50,000 tonnes of lithium carbonate.