Cost of direct air carbon capture not decreasing as fast as hoped

In this paper, ISTP researchers and Carbon Removal Lab members Katrin Sievert, Tobias S. Schmidt, and Bjarne Steffen introduce a new method to project future costs of novel technologies. This study provides researchers with a methodology to derive component-level experience rates for emerging low-carbon technologies, enabling cost projections without requiring historical deployment data.

Context

In order to meet the Paris climate targets, rapid emission reductions through both transitioning to low-carbon energy sources as well as utilising carbon dioxide removal (CDR) technologies will be needed. While several low-carbon technologies, including solar photovoltaics or batteries, have experienced massive cost reductions over recent years, the cost of novel technologies, like direct air capture (DAC) technologies, remains highly uncertain. To address this issue, the authors developed a novel method to project future costs, applying it to three DAC technologies combined with CO2 transport and storage (DACCS) to provide probabilistic estimates of the cost of CO2 net removed.

Summary

The authors projected the future costs of DACCS considering technology characteristics. Based on historic cases, they developed a novel cost projection approach, particularly valuable for technologies with limited historical deployment, leveraging the strengths of experience curves to expand the toolkit for technology forecasting. Using this new method, they analysed how three DAC technologies and their individual components compare with mature technologies in terms of design complexity and the need for customisation, thereby estimating their cost reduction potential as expressed in experience rates.

Using multi-component experience curves they performed probabilistic extrapolations of the cost of CO2 net removed in a mature technology state.

Capturing 1 gigaton of CO2 per year, the projected costs for the three DACCS technologies are at $341 for a high-temperature liquid solvent process, $374 for a low-temperature solid sorbent process, and $371 for a calcium oxide (CaO) ambient weathering process, exceeding previous estimates. Nevertheless, the authors conclude that provided deployment accelerated, DACCS could be a key tool in emission reductions as a backstop technology.