A record-sized carbon capture plant has launched in Iceland, in what advocates say is another “proof point” for the climate-change-tackling technology.
The Mammoth direct air capture and storage (DAC+S) plant run by Climeworks is 10 times bigger than the Swiss company’s previous plant, Orca. Both are based inside the Hellisheiði geothermal park, which holds a large power plant.
Once fully operational, the modular Mammoth will suck up to 36,000 tonnes of CO2 from the surrounding air a year using giant fans. By contrast, carbon capture is carried out at the point of emissions - before they can reach the atmosphere.
"Starting operations of our Mammoth plant is another proof point in Climeworks' scale-up journey to megaton capacity by 2030 and gigaton by 2050," says co-founder and co-CEO Jan Wurzbacher.
“Constructing multiple real-world plants in rapid sequences makes Climeworks the most deployed carbon removal company with direct air capture at the core."
How does the direct air capture and storage tech work?
The plant makes the most of Iceland’s geothermal might, with renewable energy supplied by Hellisheiði power station operator ON Power.
To draw down CO2, Mammoth uses huge fans to suck air into a collector with filter material inside. Once full, the collector is closed and the temperature is raised to release the carbon dioxide from the material, after which the highly concentrated gas can be gathered.
Another Icelandic firm enters the equation then; storage partner Carbfix. The company has found a way to mix the CO2 with water and inject it 1,000 metres deep where it naturally reacts with basalt rock, turning to stone. Carbfix says this mineralisation process takes around two years.
Climeworks verifies and certifies the whole process by independent third parties.
What’s the catch with carbon capture?
DAC and other forms of carbon capture and storage (CCS) are often touted as a solution to the climate crisis.
While the tech does have a role to play in reducing industry emissions, experts caution that it can’t be considered an alternative to the rapid and large-scale emissions cuts needed to avert the worst impacts of climate change.
Chief of the International Energy Agency (IEA), Dr Fatih Birol, has said that meeting our targets "means letting go of the illusion that implausibly large amounts of carbon capture are the solution".
A recent IEA report estimated that - based on current oil and gas consumption \- the world would need to capture or remove around 32 billion tonnes of carbon to keep global heating under 1.5C.
Only 45 million tonnes of carbon is currently captured worldwide each year, and scaling up so significantly will put unfeasible pressure on electricity supplies.
Other experts have specific issues with DAC+S methods.
Marine conservation organisation OceanCare, for example, is troubled by the large quantities of water required. If seawater is used - as Carbfix is reportedly testing - it claims extraction could have a negative impact on ocean habitats.
“Promoting such technologies could be likened to a misguided scientific experiment to revive a long-extinct species,” OceanCare adds. “In the case of Climeworks' mammoth, everything indicates that time has already run out.”
Where else is Climeworks rolling out megatonne carbon removal hubs?
Critics of the technology also point to the huge expense.
OceanCare says that Climeworks' Orca plant sequesters CO2 at a cost of over $1,000 (€929) per tonne.
The company has not detailed the cost per tonne of removal at Mammoth, but says it is seeking to reduce costs of the technology to $400-600 (around €450) per tonne by 2030.
And it has big plans to scale up in order to make its technology effective.
Beyond Iceland, the company is developing multiple megatonne hubs in the US, it says, using valuable experience from its two commercial plants in Iceland.
It is part of three megatonne DAC hub proposals in the US, all selected by the US Department of Energy for public funding. Climeworks is also developing projects in Norway, Kenya and Canada.
