Climeworks Increases CO2 Removal at Mammoth as Operating Costs Fall
Climeworks has reported a significant improvement in the performance of its Mammoth direct air capture facility in Iceland, offering new evidence that operational experience can help reduce some of the technical and economic barriers facing engineered carbon removal.
The Swiss carbon removal company said Mammoth produced 675 tons of net carbon dioxide removal during the first six months of 2026, compared with 119 tons during the same period in 2025. That represents an increase of more than fivefold and is close to six times the previous year's level.
The increase comes after Climeworks spent roughly 18 months testing changes to the facility's proprietary sorbent material, mechanical systems and operating processes. According to the company, upgraded collector containers are now capturing more than twice as much CO2 as the original configuration under real-world conditions.
Climeworks also said the operating cost per ton of carbon removal at Mammoth has fallen by more than 50% over the past year. The company did not disclose the resulting cost per ton, meaning it remains difficult to compare Mammoth's economics directly with alternative carbon removal technologies or emerging direct air capture projects.
Improvements Focus on Sorbents and Plant Reliability
Direct air capture, commonly known as DAC, uses chemical materials to selectively capture the relatively low concentrations of CO2 present in ambient air. The captured carbon can then be released from the material in a concentrated form before being transported for utilization or permanent geological storage.
At Mammoth, Climeworks identified the sorbent and the mechanical operation of its collector units as two major areas for improvement.
The company refined both the formulation and manufacturing process of its sorbent, which influences the quantity of CO2 captured, energy efficiency, and how frequently the material needs to be replaced. It also modified equipment and operational procedures to improve plant reliability.
Two collector containers equipped with the upgraded systems have been operating for more than six months. Climeworks says they are now reaching the original design rate of approximately 1.37 tons of captured CO2 per container per day, roughly double the performance of the original units.
The upgraded collectors are currently achieving a capacity factor of around 40% to 50%. This metric accounts for factors including plant downtime, maintenance, weather conditions, and emissions associated with constructing and operating the system.
Climeworks plans to deploy the upgraded sorbent and mechanical systems across all 12 collector containers in one Mammoth plant module by the end of 2026. The company also intends to begin testing its next generation of DAC technology at the site in early 2027.
Mammoth Remains Far Below Nameplate Capacity
Despite the improvement, Mammoth's current carbon removal volumes remain substantially below the facility's theoretical capacity.
The plant began operating in May 2024 and was designed for a nameplate capture capacity of up to 36,000 tons of CO2 annually once fully deployed. Mammoth is approximately ten times larger than Climeworks' earlier Orca facility and was developed as a step toward much larger carbon removal projects.
Producing 675 tons of net removals during the first six months of 2026 therefore represents only a small fraction of that 36,000-ton annual design figure.
Climeworks says this reflects its current emphasis on optimizing performance and reliability rather than maximizing production during the plant's ramp-up period. Nameplate capacity also measures theoretical capture potential rather than net carbon removal after energy use, operational emissions, downtime, and other factors are considered.
The distinction is important for companies purchasing carbon removal credits, as the climate value of DAC depends on the quantity of atmospheric CO2 that is permanently removed on a net basis rather than simply the gross amount processed by capture equipment.
Cost Remains Central to DAC Expansion
Reducing costs is one of the biggest challenges for the direct air capture industry.
DAC is generally more expensive than capturing carbon from industrial exhaust streams because CO2 represents only a small fraction of the atmosphere. Large quantities of air must therefore be processed, requiring energy, equipment, and specialized capture materials.
Previous International Energy Agency analysis has estimated costs for direct air capture and storage at roughly $600 to $1,000 per ton of CO2 for existing projects and transactions, although future costs could fall substantially as technologies mature and deployment expands.
The reduction reported at Mammoth therefore matters not only for Climeworks but for the broader commercial viability of engineered carbon removal. Improvements in sorbent lifetime, energy efficiency, equipment utilization and plant reliability can reduce the amount of infrastructure and replacement material required for every ton removed.
Climeworks says laboratory testing of its next-generation technology has already demonstrated a tenfold improvement in sorbent lifetime and a fourfold increase in process density within the same module size. These improvements have not yet been demonstrated across a commercial-scale plant, but they point to potential avenues for further reductions in capital and operating costs.
Carbon Removal Still Faces a Major Scale Gap
The broader carbon removal industry remains far from the scale anticipated in climate scenarios.
A 2026 State of Carbon Dioxide Removal report estimates that approximately seven to nine gigatons of carbon dioxide removal could be required annually by mid-century in pathways consistent with limiting long-term warming to 1.5°C. Existing carbon removal is dominated by conventional land-based approaches such as afforestation and reforestation, while newer durable technologies including DAC and bioenergy with carbon capture currently represent less than 0.1% of total removal.
BloombergNEF reported that more than 100 DAC startups have emerged and that announced projects could represent around 4.5 million tons of annual capacity by 2035, although many projects may not ultimately be built.
For businesses considering durable carbon removals as part of long-term net-zero strategies, Mammoth's latest results illustrate both sides of the DAC market. Engineering improvements are beginning to increase output and reduce costs, but operational volumes remain small relative to both announced capacity and potential future demand.
The next phase will depend on whether improvements demonstrated in individual collector units can be replicated across complete facilities and, eventually, across projects operating at hundreds of thousands or millions of tons per year.
For Climeworks, the performance gains at Mammoth represent progress toward that goal. For the wider carbon removal industry, the more important test will be whether those improvements translate into consistently lower costs and substantially larger volumes of independently verifiable, permanently stored CO2.
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