Bertrand Piccard has just completed the first traversal of the Atlantic Ocean in an entirely solar-powered airplane. The story is fascinating. Merrit Kennedy of NPR writes:
Piccard had to try to avoid clouds, or fly above them, so that the plane could use the sun's power to charge its batteries. The plane also climbs to higher altitudes during the day, collecting potential energy, and then uses that stored energy to descend to lower altitudes as night falls. As the team explains, that's "a time of approximately one hour when the solar generators do not need to be switched on."
The success of this flight hints that a successful circumnavigation of the entire planet might be soon in the offing--but the larger picture points to a much larger trend than that of solar-powered airplanes finding success. Solar power is finally starting to find success in practical applications, and we think a tipping point is just around the corner.