"Developed by a student team from the National University of Singapore
(NUS), the drone is built mainly from carbon fiber, tipping the scales
at just 2.6 kg (5.7 lb). It has no onboard battery or other
energy-storage system, but is instead equipped with an array of 148
silicon solar cells, giving it a total surface area of approximately 4
square meters (43 sq ft).
So far, it has been flown by remote control up to an altitude of over 10
meters (33 ft). As it's equipped with a GPS system, it can reportedly
also fly autonomously. "
This is cool mainly because a copter could potentially fly all day long without having to come down for more energy.