June 5th, 2012, became a red-letter day for solar energy, as Bertrand Piccard landed the Solar Impulse solar-powered airplane under a full moon in Rabat, Morocco. The flight, which started in Madrid, marked the first intercontinental flight for a solar airplane. And its next jump will take the Solar Impulse to Ouarzazate, Morocco, where workers will soon begin building the world's largest solar thermal electricity generation complex. The Solar Impulse has Airbus-size wings, but its weight is only that of an average car. The wings carry 12,000 photovoltaic solar cells, which make electricity to store in the plane's lithium batteries, and to power the brushless motors for its four propellers. It can take off at a speed of just 22 mph (35 km/h), and cruises at an average speed of 43 mph (70 km/h). It flew day and night during its 19-hour Madrid-to-Rabat trip, and landed with fully-charged batteries. Piccard, who made the first non-stop round-the-world balloon flight, founded the Solar Impulse project along with engineer and pilot Andre Borschberg. Piccard drummed-up backing for the project, and Borschberg assembled and led the project team. The team has now begun work on the next Solar Impulse model, which would fly an around-the-world tour in 2014 -- the same year the Ouarzazate plant would begin operation. Looking further ahead to the development of lighter batteries, yet another Solar Impulse model may be built to carry two pilots for a non-stop around-the-world flight.