Electrochemical nickel-based system targets sub-$100/tonne direct air capture costs with renewable electricity integration
Direct air capture cost reduction through electrochemical innovation
Direct air capture (DAC) technology faces a critical energy cost barrier to commercial deployment at scale. Researchers at the University of Delaware and RepAir DAC Ltd. have developed an electrochemical system using nickel hydroxide batteries that replaces traditional thermal cycling with electrical charge-discharge processes, potentially reducing energy consumption and enabling integration with renewable electricity sources.
Conventional DAC systems capture CO2 by passing air through absorbent materials, then release the gas through energy-intensive heating and cooling cycles. This thermal approach dominates current commercial deployments but consumes substantial electricity, raising operational costs and limiting viability in decarbonisation strategies. The new electrochemical approach substitutes electrical pulses for thermal energy, allowing the system to function directly with renewable power sources such as solar or wind generation.
Technical performance and scalability pathway
The nickel hydroxide battery system operates with two electrodes separated by an ion-selective membrane. Applied electrical current triggers chemical reactions that capture atmospheric CO2 and subsequently release it in concentrated form for collection or utilisation. Laboratory testing over 5,000 hours demonstrated durability in controlled conditions. A larger prototype, comprising electrochemical cells measuring 9 by 300 centimetres, achieved 0.83 MWh of electricity consumption per tonne of CO2 captured during 48-hour trials.
Capture capacity reached 75 kilograms of CO2 per square metre annually, whilst maintaining a pressure drop of 300 pascals, a critical parameter for large-scale DAC installations. This pressure specification is significant because it directly influences the energy required to circulate high volumes of air through the system. The researchers project that scaling and increased manufacturing volume could reduce capture costs to below $100 per tonne of CO2, though this remains an estimate pending further development phases.
Commercial viability and development requirements
The technology must overcome several technical and commercial hurdles before competing at scale. Equipment size must increase substantially, performance must remain stable over extended operational periods, and real-world deployment conditions must be validated. Few electrochemical carbon capture systems have simultaneously demonstrated low energy intensity, high durability, efficient CO2 capture and purification, and proven scalability to commercial installations.
If commercialised, the system would integrate with low-carbon electricity grids and permanent CO2 storage infrastructure, enabling long-term atmospheric carbon removal. This positions DAC as a supplementary tool within broader industrial decarbonisation strategies, particularly for hard-to-abate sectors and residual emissions that cannot be eliminated through direct electrification or renewable substitution.
Strategic implications for investors and operators
The $100/tonne cost target, if achieved, would represent a significant reduction from current DAC economics, typically ranging from $200 to $600 per tonne. Operators evaluating carbon removal investments should monitor this technology's progression through pilot and demonstration phases. The electrochemical approach's compatibility with renewable electricity aligns with EU climate policy objectives and Iberian renewable capacity expansion, creating potential synergies with solar and wind projects. Investors should track commercialisation timelines, manufacturing scale-up announcements, and integration partnerships with permanent storage providers or industrial CO2 utilisation facilities.