Our work

The Future of Solar Fuels: When could they become competitive?

Solar energy driven processes with H2O and CO2 as basic feedstocks can produce ‘‘solar fuels’’ that could substitute their fossil based counterparts. We analyze cost developments for technologies required to produce these solar or renewable fuels by applying learning curves. We also determine the impact of the use of CO2 as feedstock.
Current and future system to produce fuels

Although fossil fuels constitute in several ways ideal energy carriers, their combustion emits CO2 into the atmosphere. To avoid the detrimental climate change impacts from emissions of this greenhouse gas, mankind has to look for renewable energy sources that preclude the use of fossil fuels. To date, most approaches that harvest renewable energy produce electricity. However, energy carriers with a high volumetric energy density may still be required, e.g. in the transport sector, for energy storage solutions, for heavy-duty industrial processes, or as feedstocks for the chemical industry. We investigate the prospects for a fast and efficient process to produce energy carriers with the same properties as fossil fuels but on the basis of renewable energy.

Cost reductions for Solar Fuels

Solar energy driven processes with H2O and CO2 as basic feedstocks can produce ‘‘solar fuels’’ that could substitute their fossil based counterparts. This article summarizes the main findings of a technoeconomic analysis of systems that can generate different types of fuels with renewable energy as starting point. These ‘‘renewable fuels’’ could potentially play a key role in future energy systems, both as a storage medium in the power sector and as an energy carrier in e.g. the transport sector, or deliver fundamental building blocks for the chemical industry. We determine whether, how, and when renewable fuels might become competitive alternatives for fossil fuels. The technologies required to produce renewable fuels are analyzed by the application of learning curves associated with individual system components. We thereby make projections for possible decreases in investment costs and reductions in fuel production costs. In an optimistic scenario we find that competitivity could be reached between 2025 and 2048 for all renewable energy production pathways that we investigate, for hydrogen, syngas, methanol, and diesel. Two techniques yield break-even costs before 2050 even in a conservative base case scenario: H2 production through electrolysis and diesel production by Fischer–Tropsch synthesis. Both processes use solid oxide electrolysis, which profits from rapid cost reductions and high efficiency.Some routes to produce these renewable fuels already exist, but their production costs are not competitive with those of producing fossil fuels. Through a detailed learning curve analysis we show how fast these costs may go down and when competitivity can be reached with fossil fuel based incumbents. Our insights support intensified fundamental research as well as enhanced investments in demonstration plants and manufacturing facilities, which could enable the large-scale deployment of renewable fuel production technologies.

Routes to produce renewable fuels

CO2 as feedstock

Currently, the impact of the use of CO2 as feedstock for fuels, chemicals, and materials is investigated in more detail. We expect to report on our findings in the second half of this year.

Cost reductions for Solar Fuels


Part of this work has been published


Remko Detz

  • Renewable Fuels
  • Energy use
  • Fuels & Markets

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