Paper - Belfer Center for Science and International Affairs, Harvard Kennedy School

Prospects for Direct Air Carbon Capture and Storage: Costs, Scale, and Funding

| Nov. 30, 2023

Key Takeaways

  • Direct air carbon capture and storage (DACCS) remains at an early stage of deployment and realizing its full emissions reduction potential will take many decades. 
  • By 2050, DACCS appears likely to achieve removals equivalent to at most about 1% of current emissions of fossil carbon from energy and industry. It will thus make at most only a small contribution to meeting 2050 net zero targets. This illustrates the importance of focusing on emissions reduction wherever possible.
  • Costs of DACCS (including transport and storage costs) may fall to around $200-400/tCO2 sometime in the 2050s. However, the lower part of this range will only be achieved if costs of early plants are close to the bottom end of the currently estimated range of $400-1000/tCO2, there is rapid large-scale deployment of DACCS, and learning rates are moderate to high.
  • DACCS may have a major potential role in the second half of the century, including in achieving net negative emissions.

Abstract

Direct Air Carbon Capture and Storage (DACCS) has the potential to contribute to meeting long-term climate goals. An ambitious deployment scenario shows DACCS growing rapidly to remove about 400 MtCO2 per annum (p.a.) by 2050, the equivalent of a little over 1% of 2022 emissions from the energy and industry sectors, and reaching one Gigatonne p.a. of removals before 2060. 

However, achieving this scale of deployment will be enormously challenging, requiring strong, long-term policy support, and commitment of very large-scale physical and financial resources. Reaching Gigatonne scale is likely to require cumulative funding globally into the trillions of U.S. dollars. As part of this, a Gigatonne of DACCS will need 1400-4200 TWh p.a. of low carbon energy, which compares with U.S. utility scale power generation of 4240 TWh in 2022, and enough geological storage capacity to accommodate an amount of CO2 more than an order of magnitude greater than is captured each year for storage at present. 

DACCS is currently in the early stages of deployment and uncertainties on costs are correspondingly large. Removals from early full-scale plants coming online towards 2030 currently appear likely to cost $400-1000 per tonne of net CO2 removed from the atmosphere. Costs may fall to around $200-400/tCO2 sometime in the 2050s if large-scale deployment is successful. However, costs towards $200/tCO2 only appear achievable if costs of early projects are towards the bottom of the expected range and there is large-scale roll-out of DACCS. Aspirational goals of DACCS costs of $100/tCO2 seem unlikely to be achieved even in the longer term. Costs of DACCS may nevertheless be below the costs of abatement in some applications. 

Early deployment of DACCS is essential for reducing costs to enable timely deployment at scale. This outcome would probably best be supported by a combination of capital subsidies and contractual payments or tax credits. In the medium to longer term, removals may realize value by inclusion in emissions trading systems. 

The challenges of implementing DACCS at very large scale further emphasize the need for urgent and widespread action to reduce emissions, which should continue to be the main priority for meeting climate goals. Such action includes decarbonisation of electricity grids and, where appropriate, use of CCS with high capture rates for industrial emissions.

For more information on this publication: Belfer Communications Office
For Academic Citation: Al-Juaied, Mohammed and Adam Whitmore. “Prospects for Direct Air Carbon Capture and Storage: Costs, Scale, and Funding.” Paper, Belfer Center for Science and International Affairs, Harvard Kennedy School, November 30, 2023.

The Authors