Swiss engineers say they can create aviation fuel out of thin air. 

It sounds like something out of science fiction, but researchers at ETH Zürich in Switzerland have demonstrated that they can produce fuel by zapping carbon and water out of the air with sunlight. 

The team has developed a device that sucks up carbon and water molecules from the air and turns them into kerosene, gasoline, or diesel, by shooting them with highly concentrated sunlight to produce syngas (a mixture of carbon monoxide and hydrogen) which can be turned into fuels. 

They say that this technology is essentially carbon-neutral because the quantity of CO2 released by burning the fuels is no greater than the CO2 removed from the atmosphere to produce it. 

The researchers have already managed to produce 32 millilitres of methanol in a 7-hour demonstration which demonstrates the technical viability of their solar fuel production process, but they say that high initial investment costs mean that significant policy support is required for widespread deployment of this technique.

They calculate that a scheme for scaling up their system that could potentially satisfy the global demand for aviation kerosene consumption (414 billion litres in 2019). 

They estimate that the total land footprint of all solar fuel production plants needed would be 45,000 km2.

The study is accessible here.