Solar Impulse 2 Completes World Tour
Solar Impulse 2 completed the first around-the-world solar-powered flight
July 26, 2016
Flying on Sunshine
The first solar-powered aircraft flight took place on November 4, 1974, when the Sunrise I, designed by Roland Schoberl and built by AstroFlight Inc., flew autonomously at Camp Irwin in California. The unmanned aircraft flew on electricity generated by solar panels — no fuel, no engine, no emissions beyond what the sun provided. It was a short, modest flight, but it proved the concept. Serious development of solar aviation then advanced significantly with the Solar Challenger, which in 1981 became the first solar-powered aircraft to cross the English Channel, flying from France to England in roughly five and a half hours.
Solar Impulse and the Dream of Clean Flight
The most ambitious solar aviation project came decades later with Solar Impulse, a Swiss project led by Bertrand Piccard and André Borschberg. Their Solar Impulse 2 aircraft completed the first solar-powered circumnavigation of the globe in 2016, flying from Abu Dhabi around the world and returning — though not in one continuous flight. The aircraft's wingspan was larger than a Boeing 747's, but it weighed less than a family car. It flew through the night using energy stored in batteries charged during the day. The journey took 17 legs over 16 months, crossing oceans, deserts, and continents powered entirely by the sun.
What Solar Flight Promises
Solar aviation remains limited in payload and speed compared to conventional aircraft, but the technology continues to improve rapidly. Unmanned solar aircraft now serve military surveillance and telecommunications relay roles, staying aloft for weeks at a time in the stratosphere. The potential for emissions-free flight is enormous as solar cell efficiency and battery energy density improve. Solar Impulse's globe-circling journey demonstrated that clean energy technology is not just a future dream — it is here now, capable of feats that would have seemed impossible a generation ago. The question is how quickly it can scale to transform aviation more broadly.