Hydro-carbon fuels from sunlight

[Just_a_fan]

In rockets, it's stored cryogenicly and the tanks are continually topped up until just before launch. Then the flight lasts a few minutes. Not really applicable to aircraft flying for many hours. Watch a liquid hydrogen rocket take off and see the ice falling off the sides. That ice would prevent an aircraft from taking off if it was on the wings.

As with all alternatives, hydrogen runs in to the simple issue that "oil" is just about the perfect energy source. It's energy dense, easy to store requiring no special systems, easy to handle, easy to control in combustion.

[Just_a_fan]

Interesting snippet about F1's carbon impact.

Of the 256,551 tonnes of carbon that F1 calculated it emitted as a sport in 2018, only 0.7% was from the cars themselves.

By far the largest proportions were from logistics, in terms of road, air and sea freight, at 45%, and personnel travel at 27.7%.

But these are issues that affect all major global sports: a football World Cup or an Olympics, while not as obvious a target, also has a significant environmental impact.

The carbon footprint of the 2010 Fifa World Cup, for example, was calculated at 2.8m tonnes - or 10 years' worth of F1 seasons.

https://www.bbc.co.uk/sport/formula1/51020847

Interesting that football is so much "dirtier" than the pinnacle of motorsport.