"The solar powered aircraft weighs a mere 506 pounds fully loaded, sports a seventeen feet wingspan and measures up to twenty-three feet long. Four lithium polymer batteries provide power to an 8 horsepower motor for takeoff and climbing, and once the plane hits a cruising altitude of around 3,000 feet the solar power kicks in -- with a maximum of 40 mph (or twice that with the batteries)." - Evan Parker

I didn't see the propeller in the picture. It is actually stored in the body to reduce the drag, and the video on the page shows it. It is pretty cool. - Gaku