Have you ever flown a quadcopter? If so, you must have noticed its dismal flight time – an average of 30 mins. The hassle of having to continually change batteries throughout an afternoon, and the fear of losing the drone midway through flight as a result of insufficient battery for return flight, are problems often faced by users. In view of this, our team’s objective was to create the world’s first 100% solar powered drone – a remote-controlled drone that does not require a battery for its flight and can fly high off the ground in a controlled way.

The main challenge stems from the inefficiency of the rotary-winged quadcopter, which results in the need for large amounts of power consumption for flight as compared to fix-winged planes. Given that solar cells generate power in proportion to their surface area, there is hence the requirement of a large surface area to harness sufficient solar power. This leads to further challenges, as the increase in surface area (size) of the quadcopter leads to a corresponding increase in weight, which causes the quadcopter to require even more power for flight. Furthermore, an increase in the size of the quadcopter can also lead to adverse impacts on its stability. All in all, it is a delicate balance among size, stability, and weight, all of which have strong interdependencies.

Our two-year journey designing the quadcopter brought us through four different prototypes, inculcating in us along the way the values of failing fast and learning fast as engineers. Steadily and progressively nonetheless, each prototype became more power efficient than the previous version. Finally, in April 2018, we manged to achieve the world's first 100% solar-powered quadcopter flight.