It is a larger, upgraded version of the aircraft that flew across America last year.
It climbed to just over 6,000ft (1,800m), conducting a number of manoeuvres to prove the handling of the aircraft.
Early vibrations were reporter, but overall the mission outcome appeared very positive.
For the first time in history, an aeroplane flyes with no fuel day and night, showing the potential of the clean technologies.
The carbon-fibre aircraft has a huge wingspan, which at 72m is wider than a Boeing 747 jet. The vehicle weighs only 2.3 tonnes.
The tops of the wings are covered by 17,000 solar cells, which drive four brushless electric motors at speeds of up to 140km/h (90mph).
The first Solar Impulse plane set a number of world records, including the longest manned solar-powered flight at 26 hours, the first inter-continental flight in a solar-powered plane, and the greatest distance covered on a piloted solar-powered flight.
bbc.com
