Climeworks, a Swiss company specialising in air capture technology, has launched "Orca" – the world's largest carbon capture and storage plant. The facility, located in Iceland, could be replicated at other sites across the country and beyond, helping to reverse global warming.

Climate change is arguably the greatest challenge facing humanity this century. Even with a mass deployment of solar, wind and other renewables, we are still likely to exceed a 1.5°C global average temperature increase – and probably 2°C too – with disastrous consequences for ecosystems, human health and geopolitical stability. In recent years, it has become increasingly clear that other solutions will be needed, besides clean energy.

Since trees absorb carbon dioxide (CO2), reforestation programs are being undertaken in many countries. However, trees can take decades to fully mature and are susceptible to droughts, wildfires and so on.

One technological solution now emerging is direct air capture (DAC), a process of capturing CO2 directly from the ambient air (as opposed to capturing from industrial point sources, such as a cement factory or biomass power plant). This can generate a concentrated stream of the gas for sequestration underground or be utilised for other carbon-neutral purposes.

Several companies have attempted to commercialise DAC systems. Climeworks, founded in 2009 as a spin-off from Swiss university ETH Zürich, is the most advanced in terms of getting its technology to market.

After receiving capital from investors in 2011, Climeworks went on to develop a prototype facility. Rapid scaling then followed, leading to a module system and the first commercial project to filter CO2 from ambient air. Completed in May 2017 and located in Hinwil, Switzerland, this consisted of 18 DAC modules filtering 900 tons of CO2 each year. The gas has been sold to a greenhouse operator for use as fertiliser.

Climeworks then began a demo project at Hellisheiði Power Station, Iceland, the world's third largest geothermal plant. Although capturing less CO2 than the previous facility in Switzerland, it could inject 50 metric tons of the gas below ground each year, where it became mineralised – replicating in two years the natural process that normally takes millennia.

Credit: Sandra Snæbjörnsdóttir

In September 2020, Climeworks raised CHF 100m ($110m) – the largest ever private investment into direct air capture – intended to drive forward its roadmap for scaling up and expanding its carbon removal capacities.

In July 2021, the Swiss and Icelandic governments agreed to jointly develop "negative emission technologies" involving the extraction of CO2 from ambient air and its storage underground, using the system developed by Climeworks.

This week, the company launched "Orca" – its largest and most powerful DAC yet. This is now capturing 4,000 tons of CO2 per year, which will be removed from the air and stored permanently through the natural mineralisation process, developed in partnership with Iceland-based Carbfix. The new facility has 80 times the capacity of the earlier prototype and is 100% powered by clean energy. Orca provides immediate impact: every ton of carbon dioxide removed from the air is a ton immediately not contributing to global warming.

The Climeworks system is a two-step process. First, ambient air is sucked into the collector with a fan. CO2 is then captured on the surface of a highly selective filter material that sits inside. Second, after the filter material is full, the collector is closed. The temperature inside is then increased to between 80 and 100°C, releasing high-purity, high-concentration CO2 for collection and removal. The collected CO2 can either be mixed with water and pumped underground to begin the mineralisation process, or upcycled in commercial applications such as the production of beverages, fertilisers, or synthetic fuels (to name just a few).

Credit: Climeworks

Compared to the roughly 35 billion tons of CO2 emitted by worldwide human activities each year, the amount being captured by Orca may seem trivial. However, modern technologies tend to follow an exponential trend – and indeed, Climeworks has big plans for expansion. It hopes to reach megatons of removal capacity in the second half of this decade and is forecasting a more than fivefold reduction in the cost per ton of extracting carbon from the atmosphere by 2035. In the longer term, analysis shows that direct air capture could be a multi-gigaton per year industry by the 2040s, potentially playing a very significant role in the stabilisation of climate change.

The global capacity to store carbon dioxide is estimated at between 5 and 30 trillion tons – easily enough to sequester the entirety of historical emissions of greenhouse gases. What makes DAC a unique approach is that it has the smallest land and water usage of all carbon dioxide removal approaches.

"Orca, as a milestone in the DAC industry, provides a scalable, flexible and replicable blueprint for Climeworks' future expansion," said Jan Wurzbacher, co-CEO and co-founder of the company. "With this success, we are prepared to rapidly ramp up our capacity in the next years. Achieving global net-zero emissions is still a long way to go, but with Orca, we believe that Climeworks has taken one significant step closer to achieving that goal."

To accelerate the progress towards net zero, Climeworks now offers a subscription service for those wishing to reduce their carbon footprint. This has already gained 8,500 subscribers who are funding the effort. The packages are highly flexible, ranging from $1/month (14 kg of annual CO2 removal) up to $2,000/month (22,000 kg of annual carbon removal): https://climeworks.com/subscriptions