When Solar Impulse 2 returned to Abu Dhabi in July 2016, it completed something that had never been achieved before. The aircraft had travelled around the world powered only by energy collected from the sun, finishing a journey of roughly 40,000 kilometres without using conventional fuel. It was not built to prove that commercial airliners could immediately switch to solar power. Instead, the project demonstrated that advanced engineering, lightweight materials and renewable energy could keep an aircraft flying across continents and oceans. The mission lasted 16 months, with weather delays and long stopovers shaping the route, yet it ultimately became one of the most recognised demonstrations of clean-energy technology in aviation.
How Solar Impulse 2 completed the first fuel-free flight around the world
The aircraft began its round-the-world expedition after departing Abu Dhabi on March 9, 2015. By the time it returned to the same city, it had covered approximately 40,000 kilometres while spending nearly 500 hours in the air.Rather than completing the mission in one uninterrupted journey, Solar Impulse 2 travelled in stages. The aircraft made 16 stopovers, partly because weather conditions affected when it was safe to fly. Some locations required the team to wait for extended periods before continuing, stretching the overall mission across more than a year.According to the World Economic Forum article in collaboration with Reuters, the successful return to Abu Dhabi marked “the first fuel-free flight around the world”, making the mission a milestone for renewable-energy aviation rather than a conventional speed or endurance record.
How Solar Impulse 2 worked using solar power, batteries and electric motors
Solar Impulse 2 relied entirely on electricity generated by sunlight. More than 17,000 solar cells were integrated into its wings, collecting energy throughout the day. Any surplus electricity was stored in onboard batteries, allowing the aircraft’s four electric motors to continue operating when sunlight was unavailable.Although its wingspan exceeded that of a Boeing 747, the aircraft itself weighed about as much as an average family car. That unusual combination of an exceptionally large wing and lightweight construction helped it remain airborne while using relatively little energy.The aircraft was designed for efficiency rather than speed. It cruised at no more than about 90 kilometres per hour and could reach altitudes of around 9,000 metres during the journey.Swiss explorers Bertrand Piccard and André Borschberg alternated flying duties throughout the expedition, each completing different legs of the global route. Long-distance solo flights demanded more than technical preparation. The pilots also had to manage extended periods alone in the cockpit while crossing vast stretches of ocean at relatively low speeds.Reflecting on those challenges, Bertrand Piccard said, “We were facing the oceans; we had to build up this mindset, not just the plane and technology.” His comments highlighted that endurance and preparation were as important as engineering during the project.
How Solar Impulse 2 inspired the future of electric aviation
For the team behind Solar Impulse 2, the flight represented more than a successful aircraft programme. Bertrand Piccard argued that the technologies demonstrated during the mission could have wider uses beyond aviation.According to the World Economic Forum, Piccard said, “More than an achievement in the history of aviation, Solar Impulse has made history in energy.” He also suggested that many of the technologies developed for the aircraft could help reduce carbon dioxide emissions when applied in everyday life.Looking ahead, Piccard predicted that “within the next 10 years we’ll see electric aeroplanes carrying 50 passengers on short- to medium-haul flights.” While this was presented as his expectation rather than a confirmed outcome, it reflected the ambitions driving the Solar Impulse programme.
What happened after Solar Impulse 2 completed its historic world flight
The completion of the mission did not mark the end of the project’s work. As per Reuters, Bertrand Piccard and André Borschberg planned to continue promoting renewable energy technologies after the aircraft returned to Abu Dhabi.The pair also intended to establish an international council that would advise governments while encouraging the development of new applications for clean-energy technologies. Rather than treating the successful circumnavigation as a final destination, they described it as the beginning of a broader effort to encourage wider adoption of renewable-energy innovation.
