A solar-powered aircraft left the Moroccan capital on Friday for Madrid on its return journey to its home port in Switzerland, an AFP correspondent reported. Piloted by Bertrand Piccard, the Solar Impulse, an experimental plane which flies without fuel, took off shortly after 6:00 am (0700 GMT), heading towards Barajas airport in Madrid. The hi-tech aircraft, which has the wingspan of a jumbo jet but weighs no more than a medium-sized car, is fitted with 12,000 solar cells feeding four electric motors driving propellers. Strong winds had grounded the Swiss-made aircraft in Morocco on Tuesday, after it arrived in Rabat a week ago following a successful flight over the Moroccan desert. It is not known exactly when it is due to return to Switzerland -- capping its first round-trip between Europe and North Africa. Last month, the solar-powered plane made the 2,500-kilometre (1,550-mile) journey from Madrid to Rabat, its longest to date and its first between continents, after an inaugural flight to Paris and Brussels last year. The flights are intended as a rehearsal for the goal of a round-the-world trip in 2014 by an updated version of the plane.