Solar-powered plane flies at night

An airplane that relies entirely on solar energy has flown for 24 hours straight, cruising along happily through the darkness and emerging into the dawn with three hours left in its batteries. Once the sun rose, of course, the batteries immediately began to recharge.

The Solar Impulse is the product of the same great minds that brought you the cuckoo clock–the Swiss! The entire wingspan is covered with 12,000 solar cells that power four electric engines. Average cruising speed is 70 km/hr (43.5 mph). You can see complete stats on the plane here.

The next step for the engineers is to make the next generation of the plane, one that will fly around the world by 2013. The Solar Impulse is not the first solar-powered airplane, only the first to complete a manned night flight. Scientists and engineers have been experimenting with solar-powered planes since the 1970s and manned flights since the 1980s. This new leap forward will add impetus to a field of study that has so far received little attention from the press.

While this technology is still in the experimental stage, the potential impact for the airline industry and the environment is obvious. Airline emissions pose a major environmental threat, and G8 leaders have called for a 50 percent reduction in airline emissions by 2050. That’s a tall order, but it looks like the Swiss have shown the way forward. Of course the Solar Impulse’s slow speed and small cockpit mean the age of solar-powered 747s is a long way off, think of it as the modern equivalent of the Wright Brothers plane. It was only a generation after Kitty Hawk that passengers started flying to international destinations.