Scaling DAC? It's complicated, says Climeworks CFO

It’s a precarious moment for scaling direct air capture, and carbon removal more broadly. The sector has had a few successful deployments but is very much still proving the technology. And the hurdles on the path to full commercialization are many.  

But startups will lose the public’s trust if they aren’t transparent about the challenges of scaling their technologies, said Andreas Aepli, chief financial officer of Climeworks, on an episode of the Catalyst podcast. The company operates the world’s largest direct air capture facility, a carbon removal method that is expensive but popular among corporate buyers because it is far easier to measure and verify than the highly criticized carbon avoidance credits that dominate the voluntary carbon market.

“If people are not transparent about the challenges…people will lose faith at some point,” Aepli told host Shayle Kann, adding that they’ll come to believe that “this is just an industry that makes a lot of promises, but doesn't really keep them.”

And the voluntary carbon market has certainly struggled with broken promises. Avoid deforestation credits, in particular, have faced criticism of over-crediting and fraud. But unlike carbon avoidance, durable carbon removal using technologies like DAC, biochar, and bio-oil is often easier to measure and verify; in 2023, those approaches accounted for just 3% of the market.

As the market scales, though, Aepli stressed that carbon removal startups need to be open about challenges. For instance, Climeworks opened Orca, its first commercial plant, in 2021. It has a nameplate capacity of 4,000 tons of carbon removed per year, but over two years into operation Orca has reached a net capacity of about 2,500 tons per year, according to a Climeworks blog post.

“We turned on the switch in Orca after sort of a two year build time,” Aepli said. “And as we went into the first weeks and months of operations, we figured out a lot of things that we didn't know before.” Aepli said the company applied lessons from Orca to its next facility, Mammoth, which began operation in August with a nameplate capacity of 36,000 tons.

Climeworks is several years ahead of other DAC companies on the market, most of which are still working to get their first plant up and running. Climeworks’ troubles reflect how difficult that initial path to commercialization may wind up being for the slew of first-of-a-kind carbon removal startups that have emerged recently. 

“Over the last three years, there have been a lot of tech companies that have popped up…[with] a lot of new approaches.” Aepli said. “But we think sometimes there's a real danger in the industry over promising.”

Learning from the challenges of a first-of-a-kind plant

The problems at Orca included the extreme weather of Iceland, where the plant is located. 

“You have to take it how it is with all the snow and hail and horizontal rain that you have in Iceland with all the impurities that you have and operating in this type of environment,” Aepli said. The weather and other factors caused operational downtime, reducing the capacity of the plant, according to a Climeworks blog post on the realities of deploying in the field.

When the plant was operating, though, fluctuations in the quality of equipment also caused challenges.

“Sometimes [equipment] is purpose-built and sometimes it's repurposed from other industries and these other industries might have very different quality requirements,” Aepli said. “So for example, one thing that we experienced is on the filter side. There were quite high quality fluctuations over time from our supplier, which didn't matter to that supplier originally, but which had quite a big impact on the efficiency of our operation.”

And in the early days, once Orca had collected carbon dioxide, it was losing up to 30% of what it captured, because it was below the high-quality requirements for storage.  

“The carbon dioxide had to be vented off into the atmosphere, as it did not meet the purity standard for the post-capture liquefaction process at Orca,” according to the blog post. “As a mitigation, we installed additional equipment that allows us to decrease these losses by around 90%.”

The last factor was the lifecycle carbon emissions of Orca’s supply chain, which is deducted from the total carbon removal of the plant. Ultimately, at about 2,500 net tons removed per year, the plant reached about 63% of its nameplate capacity.

Aepli emphasized the need for an incremental strategy to address these sorts of scale-up challenges. For example, building on its experience with its first commercial plant, Climeworks used different designs to build its next plant, Mammoth, which has nine times the capacity of Orca.

“That has been a pretty steep learning curve, to be honest with you,” he added. “It's one of the reasons why we're very happy that we made the decision to move in the smaller and faster steps so we can learn along the way.”

Aepli advocated for de-risking a new technology by deploying a series of incrementally larger projects; for instance, each facility would be five to 10 times larger than the last.

“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,” he said, “because that's a huge technological risk.”

This story borrows from an interview that appeared on Catalyst with Shayle Kann, a Latitude Media podcast.