The cost of direct air capture and storage: the impact of technological learning, regional diversity, and policy.

Direct air capture and storage (DACS) is a carbon dioxide removal technology that is necessary to reach our climate targets. However, huge question marks remain regarding the cost. In contrast to previous studies, we use a costing methodology that is truly consistent with the technology readiness level of DACS to calculate cost trajectories for four example DACS technologies. Our analysis demonstrates the cost of DACS is unlikely to reach the $100 t-CO2-1 target, as costs fall to $100-600 t-CO2-1 at the Gt-CO2 year-1 scale. Rational siting and energy source selection will be critical, and importantly, coupling DACS to low capacity factor intermittent renewable electricity is uneconomical. Although, sites with high renewable capacity factors do exist. Furthermore, strong, holistic, technology-catered policy support is needed to aid market creation, scale-up, and long-term cost reductions. The results and conclusions outlined in this work have significant implications for academics, industry, policymakers, and investors alike.