Swiss direct air capture company Climeworks has become the face of the global carbon removal industry, moving further and faster than most of its peers. That’s thanks in large part to its access to abundant clean, firm power in Iceland, where the company currently operates the world’s two largest DAC projects.
That said, Climeworks is still a startup, with a still-evolving business model, trying to deploy expensive infrastructure projects in an industry that lacks a clear market. And like many other companies looking to build in the United States, Climeworks has struggled in recent months in the face of growing policy uncertainty in the U.S. — uncertainty that contributed to the company’s decision to lay off around a quarter of its workforce last month.
But in addition to these President Trump-induced challenges, as well as DAC-specific challenges like high costs and energy intensity, Climeworks is navigating one of the oldest startup problems: their technology doesn’t always perform in the field the way it did in the lab.
That problem has been on full display in southwest Iceland, where the hulking grey form of Mammoth, Climeworks’ largest project to date, sits across a dirt road from the country’s largest geothermal plant, blending into the volcanic landscape.
Mammoth’s nameplate capacity is 36,000 tons of removal per year. Climeworks has been transparent that nameplate capacity does not equal actual tons captured for any project, thanks to things like downtime and repairs, weather, and small losses at each stage of the capture extraction, and storage process. But last year, as Icelandic outlet Heimildin reported in May, Mammoth captured just a sliver of that potential, at just over 100 tons of carbon removal.
Bottom line: The company is not yet even removing enough carbon to cover its own footprint.
Of Mammoth’s 72 planned-for collector containers — modular units that house the fans and filters used to draw in air and chemically bind carbon dioxide — only 12 are fully operational today. That’s a pretty serious delay, given that the original plan was for Mammoth to be fully operational, with 72 containers installed and running, by now.
The collector containers they installed last year aren’t operating as efficiently as prototype testing had indicated, plant manager Maxim Willemse explained, so Climeworks stopped installing them while the team figured out what to do next.
“The first containers have shown us that we have some [technical] difficulties that need to be remedied,” he told Latitude Media on site at Mammoth last week. “It doesn’t make sense to now rapidly put all those other containers out there and see them fail in the same way.”
As for the climate impact of Climeworks’Icelandic operations, Willemse said the company estimates via a lifecycle assessment that it could take up to 10 years to “pay off” all of the emissions associated with the project. That includes emissions generated during construction and manufacturing of the plant, as well as the production of the sorbent it uses to absorb CO2.
In the case of Mammoth, the plant’s connection to Iceland’s renewable energy grid means its direct operational emissions from energy use are minimal. The overall emissions from the plant must be subtracted from its net removal capacity, meaning of course that Climeworks can’t sell credits for the tons it removes to cover its own emissions. To really monetize Mammoth, the company hopes the plant can operate for at least 20 years.
Barriers to scale
Removing carbon dioxide from the atmosphere via direct air capture is essentially a massive infrastructure project. Even demonstration-scale projects have high capex costs — and can also have high up-front emissions, even if they have access to carbon-free power. They require clear demand signals, immense quantities of energy, a technical workforce, and extensive supply chains for specialized materials and high-temperature industrial equipment.
But by the time Climeworks built Mammoth, its second commercial-scale plant in Iceland, the company had already worked through many of those hurdles.
Mammoth was funded with Climeworks’ own equity, rather than with traditional project finance, and by the time the project was officially announced, around a third of its nameplate capacity had already been sold. And, like the startup’s previous project, Orca, Mammoth is built on site at Hellisheiði Power Station, Iceland’s largest geothermal power plant.
The biggest challenge, COO Doug Chan explained on The Green Blueprint podcast earlier this year, always came down to the technical risk of the collector containers themselves, rather than any wider influences.
Although both Orca and Mammoth were slated to deploy the company’s “Generation 2” tech, the latter was intended to incorporate updates to things like the filter elements inside the containers and the physical container arrangement, and thereby bring down cost and energy intensity.
Climeworks deployed prototypes of these updated containers at Orca in 2023, before Mammoth was fully constructed, Chan explained. During those tests, he added, the containers were failing earlier than expected, meaning the new and improved filters weren’t working well. Instead of delaying Mammoth indefinitely, the company opted to deploy a “Band-Aid fix” in the form of a retrofit or patch.
It’s those same filter issues from the 2023 prototypes, Chan explained, that are still plaguing Mammoth in 2025.
Listen to Doug Chan’s full interview on The Green Blueprint:
In many ways it’s a classic startup paradox, Willemse added. Growing quickly and taking risks may be key to cornering a market or maintaining funding, he added, in part because direct air capture projects get closer to profitability the larger they are. Orca, for example, with a 4,000-ton nameplate capacity — that it also hasn’t yet reached — had to be subsidized by the company because that smaller size just isn’t profitable.
As Climeworks CFO Andreas Aepli explained to investor Shayle Kann last year on an episode of the Catalyst podcast, that profitability threshold has been central to the company’s deployment strategy.
Climeworks raised a $650 million equity round in April 2022 to help finance Mammoth, which, though significantly larger than Orca, still leverages tech that isn’t mature enough for more traditional project finance, he explained.
“We are of the fundamental opinion that it doesn’t really work to deploy in the lab or at very small scale, at pilot scale, and then go from that straight to the size that is required for the plant to be profitable, because that’s a huge technological risk,” Aepli said.
Looking at the challenges that have prevented first Orca and now Mammoth from reaching nameplate capacity in the planned time period, he added: “That was a good strategy to have…you can de-risk the technology at lower amounts of capital deployed.”
At the same time, the company’s iterative approach — building consecutively larger projects with slightly different technology — has meant that not all problems are solved from one project to the next.
“We were in such a hurry with Climeworks to become bigger and bigger, that you have a lot of overlapping timelines, unfortunately,” Willemse said. “The moment that you learn something at Orca, you’ve already designed your first version of Mammoth.”
What’s next for Mammoth?
The problems with Mammoth’s collector containers has forced Climeworks to deploy much more slowly than they had hoped. But there’s a silver lining to that, Willemse said, as it creates some wiggle room for the team to test “even newer and better things.”
There are 72 slots total at Mammoth, he explained. “Why would you do [the same thing] 72 times? Why not diversify?”
That diversification could include filling up some of the available slots with the company’s Gen 3 containers, which have an entirely different sorbent than those deployed at Orca or Mammoth so far, Willemse said.
Climeworks’ Gen 3 containers, slated for use at a facility the company had planned to build in Louisiana, represent a difference not only in the chemical structure of the sorbent material, but in how it is physically arranged to optimize for contact surface between the air and the material itself.
In the company’s Gen 2 containers, Willemse explained, the sorbent is contained in solid beads, held within a mesh structure. Gen 3, meanwhile, uses laminated sheets that have the sorbent embedded within them.
Climeworks has already been testing the Gen 3 containers in Switzerland, Willemse explained, but additional testing during “ramping mode” to ensure the filter material works properly and has a secure supply chain will ultimately make it easier to deploy at scale.
“It’s definitely worthwhile to do a second step here [at Mammoth] before you deploy even bigger,” he said.
That said, it’s unclear whether that Louisiana plant will ever get built. In March 2024, Climeworks, alongside Battelle and Heirloom, won up to $600 million from the Department of Energy to build “Project Cypress,” a direct air capture hub designed to remove 1 million tons of CO2 every year.
The hub was supposed to come online in 2029, but the second Trump administration’s slash and burn approach to federal funding has already thrown a wrench in those plans. Project Cypress initially appeared on a draft list of projects the administration planned to terminate, alongside a second direct air capture hub operated by Occidental subsidiary 1PointFive. Following an immense effort by the project’s stakeholders, Cypress managed to snag a new designation in April: “requires further evaluation by the Office of Clean Energy Demonstrations.”
This lack of clarity about the future of that project, Climeworks founders Christoph Gebald and Jan Wurzbacher wrote in May, contributed to the company’s need to downsize.
As to whether Climeworks will deploy its Gen 3 technology more quickly or more widely at Mammoth if the Louisiana funding is ultimately canceled, Willemse said there has been “no decision taken yet.”
