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The combined cost of direct air capture needs to drop below $100/tCO₂ to be considered economically viable

Summary​

The combined financial cost of Direct Air Capture systems needs to fall below $100/tCO₂ to be economically viable for large-scale climate mitigation. At this target price, removing the required amounts of CO₂ to limit atmospheric concentrations to 450 ppm by 2100 would cost $86.64-$352.26 trillion depending on emission scenarios. Current operational plants by Climeworks ($600/tCO₂) and Carbon Engineering ($98-$232/tCO₂) show promising but mixed progress, with costs influenced by technology choices and energy sources. The scale of required investment highlights both the potential and challenges of DAC deployment, while operational plants demonstrate varying approaches using solid vs. liquid sorbents and different storage/utilization strategies.

It is generally accepted that the combined financial cost (capital, operational and energy) of a DAC system must be below $100/tCO₂ to be considered economically viable under current circumstances to be competitive with other forms of carbon dioxide removal 1 2 3. However, even if this cost is achieved, the financial cost of DAC systems would still be in the magnitude of trillions of dollars.

Combined costs to meet climate goals at $100/tCO₂​

Using the value of $100/tCO₂, it is possible to roughly estimate the combined costs of DAC systems to meet an arbitrarily chosen climate goal of "limiting the atmospheric concentration of CO₂ to 450 ppm by 2100" using the International Panel on Climate Change (IPCC) Representative Concentration Pathways (RCPs). From these previous calculations, we estimated the amount of carbon dioxide (CO₂) that would need to be removed from the atmosphere for the three main RCPs is shown in table 1.

Table 1: Atmospheric CO₂ removal required to achieve 450 ppm or less for each RCP scenario

ScenarioProjected 2100 CO₂ concentrations (ppm)Estimated average global temperature rise range (°C)CO₂ removal required (Gt)
RCP 2.64000.9 – 2.41300
RCP 4.55251.7 – 3.3866.4
RCP 8.59003.2 – 5.73522.6

In order to estimate the total cost, we can use the following formula resulting in the values shown in table 2:

Total cost≈Amount of CO2 removed [Gt]×109×Combined cost per tonne of CO2 [$/tCO₂]\begin{align*} \text{Total cost} &\approx \text{Amount of CO}_2 \space \text{removed [Gt]} \times 10^9 \times \text{Combined cost per tonne of CO}_2 \text{ [\$/tCO₂]} \\ \end{align*}

Table 2: Estimated combined costs for critical cost target of $100/tCO₂

ScenarioCombined cost (USD trillion)
RCP 2.6$130
RCP 4.5$86.64
RCP 8.5$352.26

How does this compare to currently operational DAC plants?​

There are two main DAC plants in the world that are currently operational and have shared their costing data with the public to better understand the cost of DAC systems: the Climeworks plant in Iceland and the Carbon Engineering plant in Canada.

Climeworks​

Climeworks is a company that has operated pilot plants all across Europe since 2015, with these pilot plants mainly capturing carbon for utilization in the agriculture and food and beverage industry. Climeworks utilizes a solid sorbent system with thermal energy supplied by geothermal energy, which is more abundant in northern Europe. In 2021, Climeworks opened a commercial plant in Iceland that has a capacity of 4,000 tCO₂/year with a focus on CO₂ storage instead of utilization. Climeworks has reported their combined capture costs to currently sit at around $600/tCO₂ 1.

Carbon Engineering​

Carbon Engineering, which utilizes a highly optimized liquid sorbent system, has operated a pilot plant in British Columbia, Canada, since 2015 with a capacity of 350 tCO₂/year and is currently constructing the world's largest liquid sorbent DAC plant in the Permian Basin of Texas known as the 'STRATOS' plant with a quoted capacity of 1,000,000 tCO₂/year. However, as of recently, the owners of the plant have stated that the plant will operate to 500,000 tCO₂/year with a capability to 'scale up' to 1,000,000 tCO₂/year 1 4 5. The STRATOS plant, a joint venture by oil company Occidental and Blackrock, is located in the oil-rich Permian Basin. Carbon Engineering has access to cheap and readily available natural gas and depleted oil wells that can be suitable sites for carbon storage. Carbon Engineering has estimated their combined cost to lie between $98 and $232/tCO₂ however, it is not stated whether these costs represent the 'net removal cost', which accounts for CO₂ that is released through the burning of natural gas for heat in the liquid sorbent system 1. It is also unclear whether the removed carbon will solely be stored, or whether it will be utilized for Enhanced Oil Recovery (EOR) and the production of synthetic fuels 6.

Sources​

Footnotes​

  1. Ozkan, M., Nayak, S. P., Ruiz, A. D., & Jiang, W. (2022). Current status and pillars of direct air capture technologies. iScience, 25(4), Article 103990. https://doi.org/10.1016/j.isci.2022.103990 ↩ ↩2 ↩3 ↩4

  2. National Academies of Sciences, Engineering, and Medicine. (2019). Negative emissions technologies and reliable sequestration: A research agenda. Washington, DC: The National Academies Press. https://doi.org/10.17226/25259 ↩

  3. McQueen, N., Gomes, K. V., McCormick, C., Blumanthal, K., Pisciotta, M., & Wilcox, J. (2021). A review of direct air capture (DAC): Scaling up commercial technologies and innovating for the future. Progress in Energy, 3(3), 032001. https://doi.org/10.1088/2516-1083/ac1d6c ↩

  4. Carbon Engineering. (2022, June 7). 1PointFive & Carbon Engineering announce direct air capture deployment approach to enable global build-out of plants. Carbon Engineering. https://carbonengineering.com/news-updates/deployment-approach/ ↩

  5. 1PointFive. (2025). Stratos: Direct Air Capture facility in Ector County, TX. 1PointFive. https://www.1pointfive.com/projects/ector-county-tx ↩

  6. Stoefs, W., Hernández, M., & Liekens, I. (2024). "Net zero" oil company: Climate action or oxymoron? Assessing the climate strategy of Occidental Petroleum (Oxy). Carbon Market Watch. https://carbonmarketwatch.org/wp-content/uploads/2024/04/04-24-Oxy-report-1.pdf ↩