The solar-powered plane Solar Impulse is preparing for a journey around the world scheduled to begin on May 1. It is powered by about 12,000 photovoltaic cells that cover its massive wings. They allow it to charge its batteries and enable it to fly day and night without jet fuel. Above, the Solar Impulse glides over the Golden Gate Bridge in San Francisco.
A second aircraft, completed in 2014 and named Solar Impulse 2, carries more solar cells and more powerful motors, among other improvements. On 9 March 2015, Piccard and Borschberg began to circumnavigate the globe with Solar Impulse 2, departing from Abu Dhabi in the United Arab Emirates. The aircraft was scheduled to return to Abu Dhabi in August 2015 after a multi-stage journey around the world. By June 2015, the plane had traversed Asia, and in July 2015, it completed the longest leg of its journey, from Japan to Hawaii. During that leg, the aircraft’s batteries sustained thermal damage that took months to repair. Solar Impulse 2 resumed the circumnavigation in April 2016, when it flew to California. It continued across the US until it reached New York City in June 2016. Later that month, the aircraft crossed the Atlantic Ocean to Spain. It stopped in Egypt before returning to Abu Dhabi on 26 July 2016, more than 16 months after it had left, completing the approximately 42,000-kilometre (26,000-mile) first circumnavigation of the Earth by a piloted fixed-wing aircraft using only solar power.
This is a great accomplishment. I’ve wondered about the possibility of having flying solar panels that glide above the clouds and beam down excess power to ground collectors during the day.