Kiwi firm to help power EV batteries

A Taupo company has discovered a way to extract near battery-grade lithium from geothermal fluid, which could soon be put to use in electric vehicles (EVs).

Geo40 chief executive John Worth says the earth mineral is highly sought after and can sell for US$10,000 (NZ$15,600) a tonne. 

Lithium is usually mined from hard rock and used to produce lithium ion batteries, the technology that underpins EVs. 

Geo40, which was founded in 2010 to find ways to extract minerals from geothermal fluid, is now racing to get the substance into the global market.

A commercial demonstration plant at Contact Energy's Ohaaki geothermal power station, pictured, was originally built to extract silica from geothermal brines that blocks up pipes, Worth says.

Silica had to be removed before the lithium in those brines could be extracted, but the breakthrough in lithium extraction offers new commercial potential for the firm, he tells Stuff.

“We have the technology to successfully extract lithium in an environmentally sustainable way and will now focus on commercialising lithium extraction from geothermal fluid, aimed at the fast-growing electric vehicle battery market,” Worth says.

He adds that commercial quantities of battery-grade lithium could be sold in 12 to 18 months. Geo40 is planning a multimillion-dollar expansion to enhance its silica business and a lithium module will be added to the existing demonstration plant. 

With geothermal fluid the hard work of dissolving the lithium from the rock has already been done, Worth explains. Other firms are targeting similar extraction and Geo40 is striving to be first in the global race and to do it cost effectively, he says.

“If we can get the process right, here in little old New Zealand, it suddenly looks very interesting globally.”