Alltrikes

The Duo has a big but not inordinately so wingspan of 22 meters.  At just over 600 pounds empty weight, it doesn't have to work that hard at lifting itself.  With more than 1500 solar cells on the wings and tail, the Sunseeker Duo can put out 25kW of power and stay aloft for as long as 12 hours.

http://www.flyingmag.com/aircraft/lsasport/electric-airplane-makes-major-advancements