In the discourse about the all-solar-powered aircraft, Solar Impulse and its round-the-world trip, one aspect has been less appreciated: it has flown as much on battery power as it has on solar.  Can such electric-flying be up-scaled to commercial flights? Yes.

 Last week, the US aeronautics and space research agency, NASA, said that an official designation had been given to an experimental electric-powered aircraft. The X-57 (also nicknamed Maxwell) is one of the several kinds of experimental aircraft that NASA is toying with under its $790 million, New Aviations Horizons mission.

 The X-57 will be a piloted vehicle, powered by seven battery-powered electric motors on each wing. NASA says today’s aircraft fly at lower speeds than they can to get the optimum fuel efficiency at cruising, but the electric planes eliminate this penalty for high speeds.

 Assuming that the batteries are charged by electricity produced from clean and renewable sources, the electric propulsion aircraft could be the Teslas of the skies. The X-57 might be claimed by NASA as the “first step in opening a new era of aviation," but that ‘first step’ has already been taken by Airbus. In July 2015, it unveiled a two-seater battery-powered ‘E-Fan’, which made an epoch hop over the English channel, completing the journey in 35 minutes.  The E-Fan 2.0, light enough to be towed around by a few men, is soon to have a sibling, the E-Fan 4.0, a four-seater. This, Airbus hopes, could be sold to private aircraft owners. But even that is for starters.

 If its plans go true to schedule, in only three years from now, Airbus will start producing its first battery-powered aircraft, a 100-seater capable of flying short hauls of 1,500 km. It may not be fully battered-powered, though. It could be a hybrid, where conventional engines will be used while take-off and landing, and batteries while cruising.

But even Airbus cannot claim to be the first in electric propulsion. A clutch of private-owned sports and recreational aircraft companies have dabbled successfully in this area. One of them is the US-based Sonex Aircraft LLC, which sells aircraft in kits that you can assemble at home into a flying machine. Another is Pipistrel, which makes light aircraft (and has sold 194 of those to Indian Air Force, Indian Navy and National Cadet Corps.) Flying enthusiast Hughes Duval flew his Cri-Cri, the world’s tiniest aircraft in 2011 Paris Air Show. Cri-Cri was battery-powered.  

All this bodes well for the global aviation industry, which is facing a demand to bring down emissions. Aviation was responsible for 12 per cent of transportation’s carbon footprint. In February, the International Civil Aviation Organisation agreed to follow emission limits. Aircraft will need to consume 4 per cent less fuels by 2028 than they did in 2015. With efforts of the likes of NASA and Airbus, while bio-fuels could offer some help for the larger aircraft, electric propulsion could be a reality for the smaller ones.