The SUN-to-LIQUID project is developing a technology that produces aviation fuels from water, carbon dioxide (CO2) and the power of the sun.

How could this technology be explained to a high school student?

Concentrated solar radiation is absorbed in a solar reactor that converts water and CO2 into synthesis gas – a gas mixture comprising hydrogen and carbon monoxide. The synthesis gas is then delivered to a gas-to-liquid plant where it is converted into jet fuel.

The fuel production chain process in the SUN-to-LIQUID solar fuel plant.

What is the value for society?

  • decarbonises the aviation sector (reduces its emissions)
  • can be scaled up to meet global fuel demands
  • does not require arable land and does not compete with food production
  • has very high efficiency potential because of few energy conversion steps
  • offers employment opportunities.

At what stage of development is this project?

This four-year project was completed at the end of 2019. The consortium is now looking for funding for the follow-up project, which is aimed at boosting the energy conversion efficiency of the process.

What government policies could bring this from the lab to the market?

  • RD&D support
  • fuel taxes on conventional fuels
  • mechanisms to stimulate demand for sustainable aviation fuels (e.g. quotas)


  • Bauhaus Luftfahrt, Germany (co-ordinator)
  • ETH Zürich, Switzerland
  • DLR, Germany
  • IMDEA Energy, Spain
  • HyGear Technology & Services, the Netherlands
  • ABENGOA Energy, Spain
  • ARTTIC, France (project management and communication)


  • European Union under Horizon 2020 (No. 654408)
  • Swiss State Secretariat for Education, Research and Innovation (SERI) (No. 15.0330)

Established in 1977, the Technology Collaboration Programme on Concentrated Solar Power (SolarPACES TCP) supports collaboration to advance development and deployment of concentrating solar thermal technologies.