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[trikester]

More movement toward electric flight. The big guys are getting more involved.

http://www.nasa.gov/centers/armstrong/Features/leaptech.html

Trikester

[Justin Andrews]

Solar Impulse is making progress on her round the world flight as well.

http://www.bbc.co.uk/news/science-environment-32110747

[trikester]

Solar Impulse is making progress on her round the world flight as well.

http://www.bbc.co.uk/news/science-environment-32110747

Way cool!

Trikester

[Doug S]

I'm not sure there's any real benefit to be had with an electric airplane. Where EVs show real superiority is in maintaining high efficiency over a wide range of operating conditions. Specifically, they don't lose their efficiency in stop-and-go usage the way an ICE vehicle does. But airplanes aren't operated that way. They run very briefly at low power while they're taxiing, then a brief period of high throttle while they're taking off and climbing, followed by a long cruise, then lower power again as they put down and taxi home. Airplanes spend 95% of their time at cruising speed, which presumably they're designed to be very efficient at. Since fuel has so much higher energy density than batteries, and since weight is so critical to aircraft, I wouldn't think any battery-powered aircraft could ever compete.

The site says that "The...project will test the premise that tighter propulsion-airframe integration, made possible with electric power, will deliver improved efficiency and safety, as well as environmental and economic benefits." I don't think I'm buying it....sounds too much like weasel words to me.

[trikester]

It sure works well in RC model aircraft.

Trikester

[lolachampcar]

Doug,
My bet for the "killer" airplane application is going to be flight training.  If you can get 40 minutes at cruise plus VFR reserves then you will nail 90% of the flight school hours.  Most of their time is spent in the pattern or in the nearby practice area. 

Assuming the above usage pattern, you'll be discharging at 1C.  If you can charge at 1C, that will effectively give the plane a 50% utilization which dove tails nicely with pre-flight, flying and post flight school activity.  Dropping the fuel costs and maintenance associated with aircraft engines should bring the cost of learning to fly down which, we all assume, is the primary driver for fewer learning to fly.

[NoiseBoy]

I've always thought that if ever there was an application for electric drivetrains it's boats. Weight is a non issue as you can replace ballast with cheap lead acid or second hand lithium. You have an infinite supply of cold water to cool the motor and power electronics and the wide torque range means an efficient fixed screw can be used.

The environmental benefits of doing away with diesel is huge especially on inland waterways. Plus anyone who has sailed knows how wonderful silent cruising is (and what a downer it is firing up the engine to motor back into port).

I'm not an experienced boater but I assume the on off ability of a motor would be a big help when maneuvering too.

However boats are a hole in the water you pour money into so it won't be me building one!

[lolachampcar]

I live on the coast so my primary concern with electric wiring and boats is constant deterioration from corrosion and that is with 12V potentials.  I can not imagine what it would be like with 100 to 400 volt potentials.  I suspect it would take some serious engineering to make that work.

Also, like aircraft, boats spend a good bit of time at better than 50% power cruise which would make battery capacity a concern.  Of course, sailboats are a completely different matter.

[Cortezdtv]

I'm not sure there's any real benefit to be had with an electric airplane. Where EVs show real superiority is in maintaining high efficiency over a wide range of operating conditions. Specifically, they don't lose their efficiency in stop-and-go usage the way an ICE vehicle does. But airplanes aren't operated that way. They run very briefly at low power while they're taxiing, then a brief period of high throttle while they're taking off and climbing, followed by a long cruise, then lower power again as they put down and taxi home. Airplanes spend 95% of their time at cruising speed, which presumably they're designed to be very efficient at. Since fuel has so much higher energy density than batteries, and since weight is so critical to aircraft, I wouldn't think any battery-powered aircraft could ever compete.

The site says that "The...project will test the premise that tighter propulsion-airframe integration, made possible with electric power, will deliver improved efficiency and safety, as well as environmental and economic benefits." I don't think I'm buying it....sounds too much like weasel words to me.

60% of flying is fuel cost..... This is coming straight from someone who works with that plane.


They have been working on this a long time!!!