Stephen Shankland/CNET

FARNBOROUGH, England -- Although battery weight may keep electric planes from becoming mainstream in the near future, Airbus believes its E-Fan 2.0 will find a real market: pilot training.

It hopes to begin selling the E-Fan 2.0 in late 2017 for pilot training. That's only one fraction of the plane market. A later planned E-Fan 4.0 with space for four passengers, however, will be aimed at the general-aviation market.

Earlier this year, the company started publicly flying a prototype of the E-Fan 2.0, which weighs just 500kg (1100lbs). For the first time, the France-based aircraft maker showed it off this week at the Farnborough International Airshow here, one of the highest-profile aviation events on the annual calendar and a destination for many top executives and buyers in the industry.

Even though today's model is impractical, Airbus believes electric aircraft will become important in coming years as a way to cut greenhouse-gas emissions from conventional aircraft exhaust and to offer quieter planes. Noise isn't just an issue for people living near airports; quieter planes could be flown at hours that noisier conventional craft are prohibited, so airlines could schedule more flights, Airbus argues.

The E-Fan 2.0 has dual electric motors with a total power of 60kW; they drive two ducted fans with blades whose pitch can be adjusted. With a 120-cell lithium polymer battery, it can fly for one hour before a 15-minute reserve.

Its batteries are passively cooled -- in other words, they rely ultimately on air, not a powered cooling system, to keep them from overheating as they discharge power.

Mounting the fans inside ducts increases their thrust and decreases their noise, Airbus said. More noise reduction comes from a powered drive wheel that can accelerate the plane up to 60kmph (37mph) silently. That technique also improves the power efficiency during takeoff, Airbus said.

Efficiency is important for an electric vehicle of any kind, but especially for aircraft, where weight is a critical limiting factor to flight time, range, and operating costs. And batteries, unlike conventional fuel, don't get lighter as a flight progresses.

The prototype has two seats, one in front of the other, but the production version will have side-by-side seats.

Airbus is also researching hybrid designs, demonstrated in its DA36 E-Star 2.0 two-seater plane collaboratively built with Diamond Aircraft and Siemens and shown at Farnborough. Ultimately, Airbus believes it's possible to build an all-electric helicopter and an all-electric or hybrid 90-seat passenger plane.

Electrically-powered aircraft have major engineering challenges, but the European Commission's Flightpath 2050 plan has a goal of reducing aircraft carbon dioxide emissions by 75 percent from 2000 levels.

Airbus plans to build 100 E-Fan test aircraft to gather data for the program.