Energy is the engine of our economy and is required in various forms as electricity but also as liquid fuel, which has so far been based on fossil fuels. The Sun to Liquid project is breaking new ground and has developed the technology for producing renewable drop-in fuels based on solar energy. The core conversion technology used is a thermochemical redox cycle powered by concentrated solar energy. It works at high temperatures and processes water and CO2 into a high-quality synthesis gas. This is processed into ecological hydrocarbon fuels, which can be used in aviation, for example.