I'm one of those guys that likes to dream about living in the future, all the while harboring a passion for classic aircraft. While I own an airplane built in 1953, my roots in aviation and my primary interest are heavily dominated by light sport aircraft, which is currently one of the most rapidly developing sectors of general aviation from a technology standpoint.

If you follow any kind of aviation tech news, one of the hot (but novel) topics has been the electric airplane. Long dreamed of and always just out of reach, the concept of the electric aircraft powerplant is slowly becoming a more plausible reality with ever-improving battery technologies emerging.

For pure horsepower output, there is hardly a replacement for a gasoline or kerosene-- for now. Development is taking place in the LSA weight category generally. It's just cheaper and easier to develop on lighter, cheaper craft. There are motorglider hybrid projects out there that utilize high aspect ratio wing designs and are focused on a primary goal of efficiency, but what if the goal was simply to replace your current piston engine with a comparable electric of similar power output? It doesn't seem that outrageous when you consider that a Rans S7 or Just Highlander come in well under 700 lbs empty. We'll have to keep dreaming for everything else.

I don't claim to be someone who's thought about this for more than 15 minutes at a time, but for philosophical purposes consider this:

Pros:

• Zero local emissions (consider the "longer tailpipe" concept though, where the actual emissions from electricity generation might take place 1000 miles away at a coal-fired generation facility.)
• Equal power output at all elevations, temperature-related battery performance notwithstanding
• No mixture or fuel delivery issues
• Fewer controls (single thrust lever-- Basically, shares many of the FADEC pros.)
• Electricity to charge can be generated a variety of ways (dog in a squirrel cage, solar, wind turbine, burning stuff, nuclear, hydro, etc). Electric motor output is a great aggregator of possibly a variety of energy sources.
• Quieter (most aircraft noise comes from the prop.)
• No fuel to burn in an accident.

Cons:

• Immediate refueling not currently possible, time to charge required.
• Adjustment of gross aircraft weight not possible with fuel management.
• Short endurance (1-3 hrs currently possible)

For the sake of comparison, I choose to ignore the "what if's" or other catastrophic errors, because the same is possible with any IC engine, which in reality are a much more complex beast with induction and ignition and fuel delivery systems.

No matter your theory or opinion on the outlook for availability of petroleum, the concept of electric powered flight is valid.

Check these out:









There's potential for irony from the environmental angle, as so much of our domestic electricity is produced from gas-burning turbines, but I think the truly fascinating thing about electric power is that it can be generated so many ways. Once auto fuel and avgas become scarce, which is certainly possible in a Mad Max world, those Lycomings and Continentals are boat anchors.

I'm too in love with gas-powered things that go vroom to be a serious environmental crusader, but it never hurts to have an eye on the future. One bike ride along highway 26 near downtown Portland and your lungs will tell you that combustion emissions aren't something that can be ignored forever-- they're pooling in that corridor and I breathe them daily. Yuck. Bring on the nuclear power plants and electric motors.

I'm with you Z, some exciting prospects there. I like to periodically geek out with r/c planes and helos, battery technology has completely changed what's possible in that realm. No doubt we'll see viable electric real aircraft sometime soon.

Not to turn this political, but I don't understand why the left has such disdain for nuclear - I don't think the electric future will be viable without it. Solar and wind are good local supplements to the grid, but if we all start plugging in our Teslas we're going to need more juice. I realize that most people in San Francisco and Portland probably couldn't even find Kentucky on a map, but at some point their alternative energy smugness will have to fade when they finally realize that their power comes from a coal plant there.

One way or another electric will be a mainstay in the alternative energy solution. In the near term (next 10-20 years) I'd be happy with a Continental diesel so I could switch to using Jet-A. If our supply of diesel dries up we'll have bigger problems than how to power our planes, if our global transportation network loses its fuel source life as we know is over.

That e-spyder looks pretty fun to me. Would love to have one to scout for weeds in the field.

Something like the E-Spyder would be cool for a local flight in the evenings just for fun, then plug it into a solar panel for some "free" fuel.
I see something like that in my future.
Thanks Z.

Dale

I have been following this also, especially as I am currently (pun intended) producing more electricity then I consume. The excess is shown as a credit on my Idaho Power "bill", or earnings statement as I like to call it! With the soaring ridge behind my place on the right day I only need a short burst of power to get up to the ridge....the technology is there and has been for a while for that. It is nice to know I have the option for that, it would truely be zero cost flying for me, forget the initial expense of course.

Hybrid aircraft are also being worked on, and I think they, like hybrid cars, will sooner mature as a technology and offer the performance/range we are used to. Think of the torque of the electric motor right when you need it, on take off. Once aloft and cruising it is all done on a much smaller gas engine optimized for the lesser power requirements of level flight. This makes perfect sense when you get passed by a Prius hauling ass as has happened to me, the performance is there if needed. In descent, the prop will act as a wind turbine and regeneratively recharge partially the battery, like stepping on the brakes in a hybrid car does! The benefits could be: increased take off performance, better economy at cruise, and longer range on a given amount of fuel, all of which hybrid cars now do. Sign me up for that....I'll save the mnoey an ALL electric would cost for the first aircraft hybrid power system.

One last advantage, if the gas engine craps out on takeoff, the much more reliable electric motor may help extend the glide to the crash site.

Good insight, Vick. It's usually difficult to divorce politics from an issue as core to our existence as energy, but I'd argue that unlike social issues, most people regardless of their position, just want energy. They want to be able to power their stuff. Few people have any idea how the electricity that powers their homes and office is generated, much less where it originates, and when you consider that most resistance to nuclear and coal power stems from NIMBY opposition, I think there exists less fodder to fuel a left vs right debate. The diesel-burnin' rancher would probably quickly side with environmental opposition to nuclear plant if it bordered his property. The inner city bicycle commuter with a new Nissan Leaf would probably sign up for nuclear energy as long as it remained out in the wasteland outside his or her realm.

I don't want to spark a whole energy debate, but it might be inevitable. I just wanted to add that the political spectrum becomes a lot less clear when you start dealing with something that everyone wants, and isn't religious.

Excellent point, you're absolutely right. I could have made my point more diplomatically by wondering why widespread opposition to nuclear persists, NIMBY notwithstanding.

Wow Zane when are you running for office , you got my vote.

This is the start of a great thread.

One more con to electric power is when you get to the end of a battery the available amperage draw (power) also drops, that might not be fun if doing touch and goes at the end of a flight. I have switched all of my RC planes to electric because I.C. engine power is not even comparable anymore, the things that electric RC helicopters can do are amazing compared to the glow powered counterparts.

courierguy,
I know you love to fly your plane to your jobs, I am looking to convert my house to solar and wind power, you could get some serious hours flying to Indiana...

I could have made my point more diplomatically

Screw that- your way leads to more interesting conversation!

After watching the videos I was confused, was the runway the E-Spyder used paved or grass...

Here's my electric bush planes - I'll get something bigger when I grow up

given the torque-iness you hear about with electric motors, would they be better suited to a prop application or a turbine application?

1SeventyZ wrote:[list][*]Zero local emissions (consider the "longer tailpipe" concept though, where the actual emissions from electricity generation might take place 1000 miles away at a coal-fired generation facility.)

I'm all for it. We just got to make more electricity. As to your statement above....it's a win-win either way. Number one, you are shifting the pollution load but you are shifting an Otto cycle efficiency to a Rankine cycle (greater than 30%) thermodynamically. Also, if you are making all the pollution in one spot it's easier to engineer controls for those emmissions. Even if it is coal....it's still more efficient. Nuclear/solar/wind/waves/hydro would be further icing on the cake. Just a thought.

Last year I attended a forum in Tehachapi, CA held by the E-Soaring group, formerly the "Sailplane Homebuilders Association"

I can guarantee that most of the best and brightest minds were there, in the fields of low power flight, electric flight, alternate aircraft power, etc. etc. When you see people like Paul MacCready and Burt Rutan at these events (previously), and they are taking notes wildly when listening to these new generation aero engineers... you realize that there is something to all of this E stuff.

The big eye-opener forme was one presentation given by someone, who postulated that the new tech electric stuff could actually be the one thing that saves private aviation in America. Not by obsoleting all of our existing aircraft either! The idea is that using small personal aircraft for daily transportation will create more pilots, more aviation friendly voters, and more pro-aviation government.

This fellow pointed out that we are not building roads or rail lines anywhere near fast enough to keep up with the population growth. We don't have the !($*^ money to build roads fast enough to keep up with projected populations. Roads are expensive, train tracks are expensive. And they don't move to change with new needs or growth patterns. And building roads and tracks pollutes like hell. The cities are exploding with people and the city infrastructures are not growing fast enough either.

So this fellow pointed out that living 50 or even 75 miles away from the city and commuting by an efficient electric or hybrid aircraft is absolutely do-able, even with today's technology. Battery improvements will only get better. The big push from this presentation was that you could live more cheaply and peacefully out in the country 50 or 75 miles out from the city, and (with proper pilot licensure and GPS/nav ability) commute to work in the city a LOT faster than a two hour drive. No gridlock, no expensive road projects (funded by higher taxes).

The aircraft would charge overnight by plugging it in to the power grid at home. Most low-speed personal aircraft can operate from 1000 strips inside the city, the same way as our Cubs, T-crafts and Aeroncas can already operate safely from a thousand foot strip. More glider-like light airplanes with full span camber changing (full span flaps) can easily operate from less than 1000 feet. Electric motors can create plenty of torque with a reasonably sized prop to have 500 foot takeoff performance.

The idea was that we will substitute free airways for expensive asphalt and concrete roadways. Zillions of dollars saved immediately on construction, zillions of tons of pollution saved, many years of time saved. Those savings are easily large enough to justify teaching more people to fly. Obviously, new idiot-proof flight controls, computerized anti-collision widgets, autopilots, and some new infrastructure would be needed. But nowhere near the cost of building freeways and rail lines.

It makes sense that there would be altitudes and corridors for these semi-amateur-pilots who are not lifelong aviators. Maybe 500 AGL to 2500 AGL. Speeds would have to be standardized for given flyways, to minimize overtaking. But compared to a 50 foot wide road, you could have many many "passing lanes" or different speeds in a five mile wide flyway.

Anyway, as far-fetched and "Popular Mechanics" as this all seems now, the truth is that this fellow giving the presentation is correct: The sky is probably the only viable and low-cost alternative to spending and taxing ourselves into oblivion with building millions of miles of new roads and rails. Nuclear power is a lot safer and more environmentally friendly than dead dinosaurs, so distributing electricity to rural homes for charging vehicles is a good prospect - better than many others.

Anyone who is interested in this sort of thing, please feel free to check out http://esoaring.com/ and start taking personal sized electric airplanes a little more seriously. They're flying NOW, you can buy one NOW, and just like your VCR and DVD they will only get cheaper in the near future.

EZ,

That presentation sounds oddly like the aviation manufacturers' claims that the 2-place and 4-place aircraft of the late 40's and 50's would revolutionize personal travel in the US on a grand scale, but we know how that went. Don't get me wrong, I LOVE that there are people thinking like this, but there's much more to the personal air travel equation than the power source.

The one reason that aviation is still not a viable larger scale personal travel solution is simply: Airmanship isn't trivial. Dumb down the aircraft all you want, but it still takes a pilot to control the thing, and adding that 3rd dimension is, sadly, too much for most people, not to mention all the other factors like weather, aerodynamics, procedures, etc. It takes a dedicated person who wants to be a pilot no matter how you dice it.

I love all the dreamers and schemers. Too bad most of it won't happen in the next twenty years. I'm really glad some folks are willing to work on stuff that stuffy engineers "know won't work". Now and then they actually hit a home run.

That said, electric propulsion in an airplane has all the problems of an automobile, plus extreme sensitivity to weight. Dead dinos are still the most dense power source readily available to mass markets. Some specialty vehicles that serve the short range mission are possible, and the rest is waiting for the proverbial "better battery".

It is fantastic that some early adopters are willing to buy stuff with lesser capability, for a higher price, because those sales fuel further development. I just replaced my ten year old laptop with a new one. It will run an honest 6 hours on a battery charge, compared to the old one at about 1-1/2 hours. Batteries are getting better. All sorts of machines are getting more efficient. It takes a lot of development dollars to do this.

It is too bad that the money that has been spent on wars over the last thirty years or so couldn't have been spent on developing better energy systems for all kinds of uses.

tom

I've daydreamed about using the powerplant and ECU from the Tesla roadster with a PSRU to power an aircraft. Electric motors are torque monsters, use the PSRU to swing a huge prop for max thrust, and a guy could cut back on the battery weight by using a small turbine generator for extended flights.

My friend Dave Morss loved the one he tried out. He is a test pilot, you may have heard of him.

http://www.davemorss.com/work3.html

He told me he would like to convert his motor glider to electric because it is better to know it's going to start, and it's just a single switch and you have power.
I however worry about in flight fires, and would like a way to dump the batteries in case (um, like need a fire proof chute.) I worked for a company that did a lot of battery work in lap tops, and sometimes they burn up. You could also quick change them out on the ground for a second set this way I guess.

Get a beer and watch this. Check out the burnout at the end!

http://www.vholdr.com/node/89135

This is why we are not going to stop flying anytime soon, but we better get some engineers on it, and stop messing around with fame.
Engineering rocks!

Electric engines for airplanes are highly unlikely to be a practical powerplant in our lifetimes. You just can't store enough 'trons, chemically speaking, in a light enough package to come anywhere near the capabilities of the oldest, creakiest, most ancient internal combustion engines powered by hydrocarbon fuels.

Nothing wrong with dreaming, but that's all it will be for the foreseeable future, unless some geniuses figure out how to store a whole lot more chemical energy in a lighter weight package that recharges anywhere near as rapidly as hydrocarbon fueled engines do.

Hell, I'd be excited if the GA engine manufacturers would develop and market a replacement unleaded fueled, liquid-cooled, high-horsepower-to-weight, electronic ignition, computer controlled FADEC engine, with a 5,000 hour TBO that operates anywhere near the efficiencies (hp/weight and fuel consumption) of the cheapest modern small car engines out there, and get it STC'd by the FAA to retrofit the entire legacy fleet. The technology is already developed, and if they brought the prices down to anywhere near car engine prices, even the legacy aircraft owners - like me - would rush to buy the new engines and put them in our airplanes.

The reasons we don't have engines like this already have mostly to do with economics, marketing, and other non-technical constraints on the GA engine manufacturers. A number of high tech GA engines have been designed, announced, and then promptly failed in the marketplace in the last 10 years. Thielert, for example. Maybe all it takes is a smarter business plan for this dream to finally come true - a replacement for the early-20th century-design aircooled opposed piston aircraft engine.

Who wouldn't want an engine that would virtually NEVER fail? That gets near double the current fuel efficiency, using standard unleaded mogas? And that doubles or triples the horsepower-to-weight ratios of our old-tech, mageto-fired, 100LL-sucking aircooled engines with TBOs of only 1,400-2,000 hours?

That's dreaming, but it is a helluva lot more achievable than electrically powered aircraft that have anywhere near the capabilities of even the oldest, crappiest legacy GA aircraft in the fleet today.