The Solar Impulse 2 is a second-generation model of the craft. It was dismantled and shipped to Abu Dhabi, the United Arab Emirates, in January. From there, the two pioneers can take advantage of good weather in March, when they will start their five-month adventure.

Compared with the first model, which flew for 26 hours without landing, Solar Impulse 2 will have to fly for 120 hours, or five days and nights without stopping. That is how long it will take to cross the Pacific and Atlantic Oceans combined.

Several countries have been chosen for stopovers, including Abu Dhabi, India, Myanmar, China and the United States.

China, the world's largest energy consumer, is expected to be the fourth country on the itinerary, with stopovers in Nanjing, Jiangsu province, and Chongqing in southwestern China.

Both cities are ideal landing sites, because they have perfect local weather conditions for flying, neither too windy nor too cloudy, said Borschberg.

Chongqing was also chosen because it plays an important role in the government's "Go West" campaign, said Borschberg, also an engineer and a fighter pilot.

"China will be leading in the world in the development of clean energy to improve the quality of life," he said, adding that the country has great potential in renewable energy.

China added more solar energy capacity than any other country in the world last year.

After stopping in China, the ultra-lightweight plane will fly over the Pacific Ocean before crossing the US, the Atlantic Ocean, southern Europe and northern Africa before returning to Abu Dhabi.

The aircraft has a wingspan of 72 meters, which is longer than a Boeing 747 commercial jet, but it weighs only 2,400 kilograms, which makes it 150 times lighter than an Airbus A380 and only slightly heavier than the average car.