Solar Drones Are Filling the Skies, But There's Still No Clear Winner

These are exciting times for the solar aircraft industry. Airbus and Boeing have carried out high-profile launches, as have technology giants Facebook and Google – but not all still in the race. So who is in, who is out, and who is on top? And what are they competing for?

When Sunrise 1, the world’s first solar-powered aircraft, took off in 1974 it was a demonstrator with no practical use. As solar cells and batteries become more efficient, flights became ever longer, raising the possibility of an eternal aircraft that could stay aloft indefinitely.

Circling solar drones could provide high-speed communications or survey the ground below cheaper than satellites. That’s a prize worth competing for. Building one that works has proven challenging though. Solar power needs the wingspan of an airliner but provides the power of a motor scooter. The resulting huge, lightweight aircraft are apt to disintegrate when they hit turbulence or land hard. One such accident ended NASA’s Helios program in 2003.