Potentials of direct air capture and storage in a greenhouse gas-neutral European energy system

Negative emission technologies will likely be needed to achieve the European Commission's goal of greenhouse gas neutrality by 2050. This article investigates the potential of reducing greenhouse gases in the atmosphere via the DACCS pathway, i.e., to capture CO2 from the ambient air and permanently store it in geological formations. Since the capture of CO2 from ambient air is energy-intensive, this study particularly models the integration of DACCS plants into a greenhouse gas-neutral European energy system. The model results show that DACCS in Europe 2050 could cost between 160 €/tCO2 and 270 €/tCO2 with very conservative techno-economic assumptions and between 60 €/tCO2 and 140 €/tCO2 using more progressive parameters. Annually capturing 5% of Europe's 1990 emissions with a fully electric DACCS system would increase the capacities of onshore wind by 80-119 GWel and PV by 85-126 GWel. In the model results, Sweden, the Iberian Peninsula, Norway, and Finland incorporate the essential characteristics for a successful deployment of capturing and storing CO2 from ambient air: Sufficiently large geological CO2 storage capacities and relatively low-cost, vacant renewable power generation potentials. The low DACCS costs could minimize the cost of combating climate change and prevent the implementation of more expensive mitigation strategies. On the other hand, a DACCS-based climate protection strategy is fraught with the risks of CO2 storage leaks, acceptance problems for the additional required expansion of renewable energies, and premature depletion of global CO2 storage potentials.