Solar-powered plane completes first round-the-world journey

ABU DHABI, United Arab Emirates -- The Solar Impulse 2 plane has landed in Abu Dhabi more than a year after its initial take off, completing the first round-the-world flight to be powered solely by the sun's energy.

The pre-dawn landing Tuesday by pilot Bertrand Piccard marks the end of an epic 25,000-mile journey. The plane made 16 stops, including in India, China, the U.S., Italy, Egypt and the United Arab Emirates -- where it first took off.

The Swiss-engineered single-seater aircraft is powered by 17,248 solar cells and runs on battery power at night. Its average airspeed was 46 mph, though that increased during the day when the sun's rays were strongest.

It took 70 hours for the plane to cross the Atlantic and 118 hours across the Pacific.

The solar project, which is estimated to cost more than $100 million, began in 2002 to highlight the importance of renewable energy and the spirit of innovation.

"We have demonstrated it is feasible to fly many days, many nights, that the technology works" said Andre Borschberg, 63, who piloted the plane a five-day trip from Japan to Hawaii and who kept himself alert by doing yoga poses and meditation.

The project has helped to show that "as a human being you can be sufficiently sustainable to be able to fly at least five days in such a plane."

The aircraft faced a few bumps along the way.

The Solar Impulse 2 landed in Hawaii in July and was forced to stay in the islands after the plane's battery system sustained heat damage on its trip from Japan. The team was delayed in Asia, too. When first attempting to fly from Nanjing, China, to Hawaii, the crew had to divert to Japan because of unfavorable weather and a damaged wing.