Solar-powered airplane set for takeoff

IT has the wingspan of a jumbo jet but weighs less than a small car – and is powered entirely by the sun.

Adventurer Bertrand Piccard, 51, yesterday unveiled the Solar Impulse, which aims to be the prototype for a solar-powered flight around the world.

“Yesterday it was a dream, today it is an airplane, tomorrow it will be an ambassador of renewable energies,” said Piccard, who in 1999 co-piloted the first round-the-globe balloon flight.

The plane, with its sleek white wings, will have test flights over the next two years. A new plane will be built for the big takeoff in 2012 based on the results.

In a ceremony at a military airfield near Zurich, Piccard and co-pilot Andre Borschberg were joined by numerous dignitaries, including Price Albert of Monaco and major sponsors, for the unveiling.

The project’s budget is €70 million, Piccard said.

The pilots said the plane will fly day and night using almost 12,000 solar cells, rechargeable lithium batteries and four electric motors. It will not use an ounce of fuel.

But the maiden flight around the planet will take time. With the engines providing only 40 horsepower, it will fly almost like a scooter, taking off at the pedestrian pace of 35km/h, accelerating to a flight speed of 70km/h.

For that reason, Piccard’s circumnavigation will be split up into five stages. Borschberg said the stages are five days long because of the cockpit, which was made non-pressurised to keep the weight down.

“You can see it’s really small. Thirty-six hours is already a challenge. It tests your patience,” he said.

The first test flights will be later this year, with a complete night voyage planned for 2010.

“It will be like the Wright brothers,” said Piccard, who comes from a long line of adventurers. His father Jacques plunged deeper beneath the ocean than anyone else, and grandfather Auguste was first to take a balloon into the stratosphere.

“We will start one metre above the ground, then three metres, then five metres,” he said. “When that works, we’ll be able to take it to altitude.”

One thing a solar plane cannot handle is bad weather. The solar panels are needed for day flying and for charging the 400-kilogram lithium batteries powering it by night so it relies on sunshine.

Piccard says the plane should also serve as an inspiration for inventors and manufacturers of everyday machines and appliances.

“If an aircraft is able to fly day and night without fuel, propelled solely by solar energy,” Piccard said, “let no one come and claim that it is impossible to do the same thing for motor vehicles, heating and air conditioning systems and computers.”