Last night, just down the road from me in Switzerland, aviation history was made when Solar Impulse, the solar-powered aircraft, flew throughout the night, its batteries charged from the sun during a flight yesterday. It was in the air for more than 26 hours and used exactly 0 litres of jet fuel. The pilot, Andre Borschberg, who had been squashed in a cabin the size of a bathtub for all that time, had this to say:

“I’ve been a pilot for 40 years now, but this flight has been the most incredible one of my flying career. Just sitting there and watching the battery charge level rise and rise thanks to the sun… And then that suspense, not knowing whether we were going to manage to stay up in the air the whole night. And finally the joy of seeing the sun rise and feeling the energy beginning to circulate in the solar panels again!”

Bertrand Piccard, the initiator and president of the project, which he has been working on for 11 years, said: “This is a crucial step forward, it gives full credibility to the speeches we hold since years about renewable energies and CleanTechs and allows us now to get closer to the perpetual flight without using a drop of fuel!”

While we are not expecting that we will have passengers flying on the sun’s energy any time soon (or at all), these types of experimental aircraft can actually have very practical purposes for aviation: in the use of very lightweight materials and, most importantly, the development of efficient solar cells. We may, for example, see a new generation of thin solar cells applied to the wings of commercial aircraft to power things such as air conditioning or cabin lighting. 

The flight’s take-off was captured in this video: