Potential and risks of hydrogen-based e-fuels in climate change mitigation

E-fuels-hydrocarbon fuels synthesized from green hydrogen-can replace fossil fuels. This Perspective highlights the opportunities and risks of e-fuels, and concludes that hydrogen and e-fuels should be prioritized for sectors inaccessible to direct electrification. E-fuels promise to replace fossil fuels with renewable electricity without the demand-side transformations required for a direct electrification. However, e-fuels' versatility is counterbalanced by their fragile climate effectiveness, high costs and uncertain availability. E-fuel mitigation costs are euro800-1,200 per tCO(2). Large-scale deployment could reduce costs to euro20-270 per tCO(2) until 2050, yet it is unlikely that e-fuels will become cheap and abundant early enough. Neglecting demand-side transformations threatens to lock in a fossil-fuel dependency if e-fuels fall short of expectations. Sensible climate policy supports e-fuel deployment while hedging against the risk of their unavailability at large scale. Policies should be guided by a 'merit order of end uses' that prioritizes hydrogen and e-fuels for sectors that are inaccessible to direct electrification.

Automated summary

E-fuels have the potential to replace fossil fuels, but there are risks and challenges involved. While large-scale deployment may reduce costs, the sustainability and availability of E-fuels remain uncertain. Therefore, policies should cautiously support the development of E-fuels while also considering their risks.