Thursday, August 9, 2012

Electric skies

Aircraft are the new frontier in electric vehicles, according to a new study. More energy-dense batteries, lighter components and more efficient power electronics are making plug-in airplanes a reality. In what is a record manned electric air speed of 202.6 mph in a 16 minute flight was achieved recently.
Though only small companies and entrepreneurs are currently making fully electric airplanes, larger manufacturers such as Boeing Co. and Airbus are investigating how to electrify portions of aircraft operations as the push for bigger, faster and farther yields to cheaper, quieter and greener. Among the tweaking being tried is the auxiliary power unit in commercial aircraft. The device, usually located in the tail, is a generator that provides electricity to the plane when it's on the ground and gives power to start the main engines. It usually runs off a small turbine, but airline manufacturers are developing battery and fuel cell auxiliary power units to reduce their emissions and curb fuel use on the ground.

Another target is electrifying how planes move on the ground. Most aircraft taxi using thrust from their engines. At low speeds, this is tremendously inefficient; jet engines on an airliner can use 5 megawatts of energy, but a comparable electric drive system would use 2 kilowatts while producing no pollution and minimal noise.
Boeing and Airbus are experimenting with electric landing gear that allow aircraft to turn, taxi and reverse on their own power without a truck to push the plane back from the gate. These systems can also integrate regenerative braking so that the energy from slowing a landing aircraft could charge batteries.
But yes, as a new technology, there are the hurdles. For instance, storing the electrons needed to power an airplane also carries its own unique risks, as poorly cooled high-technology batteries can catch fire or explode. Well, for a race that has come a long way from flintstones and bullock carts, nothing seems impossible.

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