U.S. Department of Energy

    Solar-Powered Plane Embarks on Cross-U.S. Journey

    May 8, 2013

     A plane with a wide wingspan flies over lakes and land.

    The Solar Impulse takes off near San Francisco on the first leg of its planned trip across the United States.
    Credit: Solar Impulse, F. Merz

    The Solar Impulse, a solar-powered airplane traveling across the United States, on May 4 completed the first leg of its journey after a 20-hour flight from Mountain View, California, to Phoenix, Arizona. The remainder of the itinerary will take the Swiss-made craft from Phoenix to Dallas, Texas, St. Louis, Missouri, Washington D.C., and finally New York City. Venture co-founder Bertrand Piccard piloted the craft. His partner in the venture, Andre Borschberg, will also pilot the plane during the final leg of the U.S. trip, from Washington, D.C. to New York.

    The venture was launched in 2003. On its inaugural flight in 2010, the Solar Impulse HB-SIA, a lightweight prototype with the 208-foot wingspan of a Boeing 747-400, climbed to just under 4,000 feet during its 87 minutes aloft. The ultra-light glider-like craft weighs about as much as a car and travels at an average speed of about 45 mph, reaching a maximum height of 28,000 feet. The aircraft has nearly 12,000 silicon mono-crystalline solar cells on its wings and on its horizontal stabilizer, and those solar cells provide power to the craft's four electric engines. In 2011, the aircraft flew from Brussels, Belgium to Paris, France. To further test its range, the HB-SIA Solar Impulse prototype completed the first intercontinental solar flight in 2012, going from Europe to Africa. The project's ultimate goal is to fly around the world, a journey scheduled for 2015. That expedition is planned for the second generation of the aircraft, HB-SIB, which is currently under construction. See the Solar Impulse website and the April 14, 2010 edition of EERE Network News.