In 2010, Solar Impulse flew a solar-powered plane for 26 continuous hours, becoming the first solar-powered airplane to "Fly by Night." It completed its flight with four hours of surplus energy in its battery bank. Over the next two years, the company made improvements to the prototype, allowing it to make the first international solar-powered flight (Switzerland to Belgium to France) in 2011 and the first intercontinental solar-powered flight (Europe to Africa) in 2012. That flight also set a record for the longest solar-powered flight, traveling 1116 km (693 mi).

Always reaching higher, Solar Impulse is planning the first transcontinental solar-powered flight, hoping to fly across the United States sometime in 2013. Two years later, Solar Impulse expects to fly its plane around the world.

At the corporate helm of Solar Impulse are physician Bertrand Piccard and engineer/pilot André Borschberg. You may recognize Piccard's name - he made the first non-stop around-the-world balloon flight in 1999. While the visionary leaders don't expect to see solar-powered commercial jetliners  - at least not in their lifetimes - the research and engineering behind this project will lead to improvements in materials, photovoltaics, and energy storage systems. These technologies will be used in the next generation of electric cars, trucks, trains, and even aircraft. 



Solar Impulse has a wingspan of 63 meters and weighs in at 1600 kg. It's made from carbon-fiber composite, using a honeycomb structure for strength. Its wings are reinforced by 120 carbon-fiber ribs placed at 50 cm intervals. Solar Impulse is covered with nearly 12,000 monocrystalline solar cells, chosen for their light weight, flexibility, and high efficiency. To enable night flying, the plane includes four banks of Lithium-polymer batteries with a total storage capacity of 96 kWh. The batteries drive four 10 HP motors. Taking into account the efficiency of the system and the average sunlight that it receives, Solar Impulse runs on roughly the same amount of power as the original Wright Flyer in 1903, while sustaining a considerably longer time in the air and using absolutely no fuel! 

^{Images and video courtesy of Solar Impulse}