Solar receiving tower
Tower of DLR (German Aerospace Centre)
Invention – hydrocarbon fuels produced directly from solar energy. The next best thing to oil...
The idea is to use the sun to power chemical plants able to split carbon dioxide. Combine the resulting carbon monoxide with hydrogen and you have the beginnings of a solar fuel that could one day replace oil.
The key is to use both the heat and the electricity that the sun can provide to make both hydrogen (from water) and carbon monoxide (from carbon dioxide). High temperature electrolysis (HTE) is one way to split hydrogen away from water. By raising the temperature of the water to ~850°C and then adding electricity.