Solar Impulse 2 flies over the Golden Gate Bridge in San Francisco on April 23, 2016

The Solar Impulse 2, a solar-powered airplane piloted by Swiss national Bertrand Piccard, successfully flew out of Dayton, Ohio in the dark early Wednesday en route to Pennsylvania, according to a live online feed of the departure.

The slow-moving, single-seat plane with the wingspan of a Boeing 747 contains 17,000 that power the aircraft's propellers and charge batteries. The panels provide the plane's sole source of energy for the flight.

The flight to the Lehigh Valley International Airport is expected to take 17 hours, organizers said.