A Swiss psychiatrist-turned-adventurer who circumnavigated the globe in a hot air balloon now wants to become the first to do it in a solar-powered aircraft.

Bertrand Piccard, 56, believes the flight by Solar Impulse 2 offers a chance to promote renewable energy over nuclear and other forms of power that bear a heavy environmental cost.

“The Fukushima story is not only in Japan,” he said, referring to the ongoing nuclear crisis that began in 2011 and pointing out that the United States and Europe have had to grapple with nuclear accidents as well.

“My dream is that through this flight around the world, millions of people would understand that they can reduce their energy consumption, which means that potentially a flight like that can really bring a big contribution to make a better world,” Piccard, the project’s founder, said during an interview in June.

The solar-powered plane is scheduled to take off from the United Arab Emirates next March and spend four months circumnavigating the world, making around 10 stops.

The plane is not expected to land in Japan but is scheduled to fly over it, Piccard said.

He plans to remain aloft for five consecutive days and nights during ocean crossings. Solar cells will recharge lithium batteries during the daytime to give the craft enough power to fly through the night, the Solar Impulse project team said.

The plane will fly without fuel. Its wingspan is 72 meters — greater than that of a Boeing 747 — and the wings carry around 17,000 solar cells, providing a large surface area for power generation.

Made of lightweight carbon fiber, the single-seater aircraft weighs 2,300 kg, equivalent to an average-size car, the team said.

In 1999, Piccard achieved the first-ever nonstop flight around the world in a balloon. It was the longest flight in terms of duration and distance in the history of aviation. The experience motivated him to try another historic challenge, Piccard said.

The problem in the balloon feat was the fuel. The balloon took off with nearly 4 tons aboard. When it landed, it had only 40 kg left.

“I saw much of this success depended on the fuel on board,” he said. “I thought the only way to be free is to get rid of the fuel so we can fly forever.”

Engineer and entrepreneur Andre Borschberg, CEO of Solar Impulse and, with Piccard, its co-founder, spent 12 years leading a team in the search for a design. The painstaking calculations, simulation, construction and testing resulted to the aircraft’s launch in April. In all, 80 engineers and technicians were involved.

Last month the aircraft made its maiden flight, which was a success.

It is now in the testing phase, to check its performance at high and low altitude, its resilience at high speed and how it handles sharp turns — as required for civil aviation certification, Piccard said.

The project has the backing of about 100 partners, including major Swiss companies including watchmaker Omega and ABB, a developer of infrastructure equipment such as industrial motors and power grids.

Toyota Motor Corp., the sole Japanese company supporting the project, has provided the team with more than 10 hybrid-fuel cars.

“As Toyota is a pioneer in environmental technologies, including hybrids, we sympathize with the vision and plan drawn up by Mr. Piccard and his team,” said an official with Toyota’s distributor in Switzerland.

The project is also backed by the Swiss government, which has helped to smooth arrangements with airport authorities and other bodies, an indication of how far the country will go to support technological innovation and environmental conservation.

“Solar Impulse’s round-the-world flight is expected to enhance Switzerland’s image as an innovative, creative and technologically advanced country that supports the development and use of sustainable and clean energies,” the Swiss Foreign Ministry said in a statement.