Yesterday it was a dream -Today it is a plane-Tomorrow it will be an ambassador of renewable energy

Swiss adventurer Bertrand Piccard has unveiled the prototype of his Solar Impulse airplane, with which he later plans to make the first ever sun-powered global flight. The sleek Solar Impulse has a huge wingspan, the equivalent of a Boeing 747, but weighs less than the average car.More than 12,000 solar cells are mounted onto the wing, supplying energy to four electric motors. During the day the cells will also charge polymer lithium batteries, allowing the aircraft to run at night. The test phase is being led by former Swiss astronaut Claude Nicollier. Nicollier and his team have designed an instrument, built by Omega that will ensure the plane does not bank too far to the left or right and that the flight direction, particularly at approach to landing, is correct.

Yesterday it was a dream. Today it is a plane. Tomorrow it will be an ambassador of renewable energy; Piccard told the 800-strong audience, which included Prince Albert of Monaco, project partners such as watchmaker Omega and Deutsche Bank, and the media. The prototype should soon make its first test flights, starting at Dübendorf and then moving to the Payerne airbase in western Switzerland. A first complete night flight is planned for 2010. Based on the results of these test flights, a new plane will be constructed for the big worldwide launch, scheduled for 2012.The total budget for the project is €70 million (SFr107 million).