[科技前沿]电动车之后，电动飞机问世

First electric cars, now electric planes

GM (MTLQQ) has earned high praise this summer – and deservedly so – for its announcement that the forthcoming Chevy Volt electric car will get as much as much as 230 miles per gallon for in-town driving.

But while Detroit was stealing headlines on the ground, a little-known Chinese company was doing something even more incredible in the skies.

At the OshKosh AirVenture show a few weeks ago, Beijing startup Yuneec International took the wraps off the world’s first commercially produced electric aircraft, the E430.

Powered by lithium polymer batteries, weighing close to a thousand pounds, and sipping about $2.50 worth of electricity per hour of flight, the E430 has completed more than 20 hours in test runs during the last couple months, including one in Camarillo, CA, that can be seen here.

Little more has been revealed about the E430, other than some technical specifications and that it can operate for up to three hours without a charge.

Today: adding electricity-powered systems

And while the E430 may be the aircraft equivalent of an auto show concept-car, there’s a good deal of progress being made in the advancement of electrical aeronautics on the whole. “What’s going on with modern aircraft is a revolution, whether you’re thinking about commercial or military aircraft,” says Bob Smith, VP of advanced technology at Honeywell Aerospace, a unit of Honeywell (HON).

Smith doesn't mean fully electric-powered aircraft – at least not yet. In aeronautic jargon, he’s talking about developing More Electric Architecture (MEA). Enabled by much larger and more sophisticated next-gen aircraft and more efficient generators, Honeywell is replacing the pneumatic and hydraulic power transference systems of with new electric versions.

“If you look at how much power a Boeing 777 generates, it’s on the order of 200-300 kilowatts. If you look at the 787, a next-gen aircraft, it’s 1.5 megawats,” he says. “That’s a massive change, because the generator technology has improved so much.”

Moving power around aircraft has always been cumbersome. In last-gen aircraft, high-pressure gas is taken from the engine and transported through bleed valves to the auxiliary power system, which controls air-conditioning, for example. This is a massively inefficient process due to the energy required to heat and cool the gases and because of the weight of the systems. “If you can put a more efficient generator in there, you have a power station as opposed to a boiling room,” says Smith.

Electrical systems are now being used to power reverse-thrusters – air brakes, essentially - in aircraft like the A380 – and for de-icing wings.

The upside: gains in fuel efficiencies

But two of the greatest benefits electrical systems provide are simplicity and merely lightening the load. Eliminating hydraulic systems reduces the complexity of repairing leaks and eliminating hundreds of pounds of tubing.

This can lead to as much as 30% gains in fuel consumption. For military aircraft, such a system is revolutionary. In the F35 Joint Strike Fighter, Honeywell’s system carved 1,000 pounds off the weight and 11 inches off the length of the plane.

Does Honeywell have its own E430 read for prime time? Not quite, but Smith suggests the real near-term potential for fully electric aircaft comes in the form of unmanned drones. Think about light-weight drones that travel constantly, their electric systems being continually replenished by advanced technologies like super capacitors, fuel cell systems and solar power.

“Once you have large power-generating systems, you have the capability of moving the power around a lot of different ways,” says Smith. “Then things get pretty interesting, allowing you to get into very long surveillance periods.”