For the past few years, direct air capture has been seen as a potential silver bullet to the climate crisis. But now a startup originally from the snowy wastes of Iceland is taking a new approach: removing carbon from seawater. 

The industry standard for removing carbon with direct air capture methods costs anywhere between $230 to $630 (approximately €210 to €570) per metric ton, according to the International Energy Agency. However,  Amsterdam-based Brineworks, a company specializing in seawater electrolysis technology, says its innovative method is expected to cost under $100 per ton of CO₂ at scale. This would put it in a pretty efficient space compared with other methods. 

It recently secured $2.2 million (approximately €2 million) in funding led by Nordic VC firm Pale Blue Dot.

It’s by now widely accepted that the planet must keep global warming below 1.5° C, otherwise cataclysmic weather events will be unleashed. We’ve already seen, for instance, the devastation wrought on Florida, Georgia, South Carolina, North Carolina, and Tennessee, as a result of Hurricane Helene. In order to reduce this warming, we must remove the enormous amount of carbon that have been thrown into the atmosphere since the Industrial Revolution. 

So-called direct ocean capture (DOC) technology could be “sustainable, scalable, and cost-effective” said Brineworks CEO Gudfinnur Sveinsson, over a call with TechCrunch. 

Brineworks’ seawater electrolyzer not only extracts CO₂ from seawater but also produces green hydrogen (H₂) as a result of the process, creating a revenue stream. And because it can run on solar or wind and the hydrogen stored in tanks, the process can be conducted off-grid.

“What if any nation in the world could make sustainable oil from renewable electricity and seawater alone? We think Brineworks found the key to that,” said Hampus Jakobsson, general partner at Pale Blue Dot in a statement. 

Oceans are far more dense compared to the atmosphere, meaning the concentration of marine CO₂ is about 150 times higher than its is in the air. That means the energy required for DOC to capture carbon dioxide is proportionally far less compared to using DAC.

Brineworks might well be part of a new wave of sea-borne carbon capture. Caltech-founded Calcarea is a carbon-sequestration startup developing a technology that captures ship-board carbon dioxide and converts it to safe, durable ocean salts. Also playing in the DOC space is startup Captura, which has raised $34.5 million from investors including Maersk Growth and Freeflow Ventures.

Meanwhile, Brineworks is now starting its first pilot on the Canary Islands and hopes to capture a metric ton per week of carbon, according to Sveinsson.