Techno-economic assessment of direct air capture using curtailed wind power as a niche application: A prospective outlook

• Assessment of integrating DAC with curtailed wind power to define concept viability. • An hourly techno-economic model links curtailed wind power to flexible DAC operation. • Concept viability is driven by capex reduction rather than energy efficiency gains. • Future capex reductions can render curtail-only DAC viable at scale from 2040. • Hybrid DAC could achieve capture costs of 200 €/tCO 2 in 2050. Direct Air Capture (DAC) developers face major early-stage challenges, including high capital costs, limited funding, and access to affordable renewable energy. At the same time, power curtailment from increasing renewable capacity is a current challenge that will intensify over time. This research evaluates whether co-locating DAC with curtailed wind power can serve as an initial niche application or a long-term deployment pathway. The study establishes a foundation for understanding current limitations and opportunities, while identifying critical factors for large-scale DAC using curtailed power. The framework consists of an hourly resolved techno-economic model that links time-series wind curtailed power to flexible DAC process operation ( curtail-DAC ). Grid connectivity is proposed in this work ( hybrid DAC ) to address curtailment-driven limitations. Implemented in MATLAB, it performs process simulation, plant sizing, cost estimation, and business model analysis. The c urtail-only configuration is economically unviable under current capital cost levels of commercial DAC systems, which penalize low operating hours. In contrast, hybrid DAC can successfully extend operating hours and reduce capital burden, bridging critical gaps in the DAC market. The prospective analysis illustrates that cost-effective deployment of the curtail-only model depends on constrained productivity and continued technological learning. By 2050, it has the potential to fully utilize curtailed power at a cost of approximately 400 €/tCO 2 . Hybrid DAC could achieve capture costs of 220 €/tCO 2 while delivering higher plant productivities. Finally, the curtail-DAC concept could provide a pathway for capturing 4 – 11 MtCO 2 /yr from Denmark’s expanding wind capacity by 2050. C urtail-DAC cannot serve as a near-term DAC application to drive deployment without significant cost reductions. Concept viability is driven by capex reduction, rather than improvements in energy efficiency. The results of this work encourage energy producers, stakeholders and governments to support early development of DAC systems that can utilise curtailed power.