It seems new developments are happening in cleantech almost every day. With sustainability now at the top of everyone’s minds, it’s really not all that surprising. Though transportation has always been a huge focus for energy-efficiency researchers, one major mode has yet to be really disrupted: flight.

A Swiss pilot recently made the first intercontinental flight by a solar-powered aircraft. Though it was just from Madrid, Spain across the Strait of Gibraltar to Morocco, the trip was a test for a planned round-the-world excursion for his team. Other agencies such as NASA and the U.S. military have also been working on self-sustaining planes powered by the sun. Some even think solar energy could be used to produce hydrogen gas, which could easily run an airplane.

Though the challenges are many, the soaring cost of fuel may soon prompt even further innovation in solar-powered flight. Gleaming aircraft wings and fuselages may soon be covered with ultra-thin solar panels to help offset aircraft electricity needs. And who knows, maybe eventually there will be solar cells efficient enough and batteries light enough to let us all soar on the power of our sun.