# X Prize Clean Aviation: $10 million by mheslep Tags: aviation, clean, million, prize PF Gold P: 3,021 An MIT collaboration with the X Prize foundation may soon release a proposal for a fastest coast to coast flight using only electric power. Reporter’s Notebook: How to spur energy storage innovations I am thinking some of the electric ducted fan technology discussed here, and some very high end battery technology is the key, probably primary batteries if they allow it. I'll follow up later.  Imagine flying all the way from coast to coast, completely guilt-free, in an airplane that doesn’t emit a single particle of greenhouse gas or air pollutants. That could happen someday, perhaps brought to reality thanks to the incentive of a$10 million prize that has been proposed by a team of MIT students. [...] The X-Prize Lab@MIT, a collaboration between the Institute and the X-Prize Foundation aimed at creating concepts for new prizes, led by instructor Erika Wagner of the Deshpande Center for Technological Innovation, just completed its third semester-long class devoted to developing new prize ideas. This time, the subject was energy storage, and the final presentations by the four teams of students in the class were held on Friday, Dec. 11. Graduate students Daniel Codd (mechanical engineering), Wendelin Michel (AeroAstro), and Paul Tu (MIT Sloan School of Management) proposed the “Clean Aviation” X-Prize. The concept, they explained, would be to hold a race from California to New York, in which all the competing planes would have to be powered entirely by electricity and produce no emissions. The planes would be allowed two stops during the journey, which would have to be completed within 24 hours. The first to cross the finish line would get a $7.5 million prize, while the plane that covered the longest distance on a single leg of the flight would win$2.5 million. [...] this is not the first proposal for a green-aviation challenge, it’s the only one requiring an all-electric, emissions-free system. The plan calls for holding the race three years after the contest is announced, and then if no team is able to complete the challenge, holding a second contest two years later for a reduced prize. “It would be open to all possible entrants, from people working in a garage to Boeing.” [...] Ultimately, the decision about which, if any, of these proposals will be launched as X-Prize competitions rests with the X-Prize Foundation itself. The foundation was created and is run by Peter Diamandis ’83, SM ’88, who initially set it up to administer the first X-Prize, which led to back-to-back flights into space by the one-person rocket called SpaceShipOne, in 2004. The successor to that craft, the eight-person SpaceShipTwo, was unveiled last week and is expected to begin carrying ordinary citizens (and quite a few celebrities) into space in about two years, ushering in a new era in space transportation. [...]
 PF Gold P: 3,021 From earlier pondering, I considered a Bombardier CRJ900, modified with ducted fans, at 12 kWh(41k BTUs) per mile based on its gross range data given a full load of fuel. Perhaps that could be cut that in half for a more efficient, slower, jet aircraft appropriate for this contest, or 6 kWh (21k BTUs )per mile? Distance for the contest is ~2500 miles, with two stops allowed, or ~850 miles per leg, 5100 kWh (17.4 million BTU )per leg. Zinc-air non rechargeable batteries achieve about 0.5 kWh per kg, giving ~11 metric tons of battery per trip leg. However, power density of metal air batteries is low, at least for commercial models. This 11 m ton pack would provide only 1.1 MW. Ducted fan concept:
 P: 4,780 This prize seems to ignore the realities of energy storage issues. Everyone under the sun in the UAV world is trying to get high energy electric systems. I do not see what this prize is supposed to do, it's certainly not going to 'start' people thinking about electric. As for your post above, does a 'superconducting motor replaces turbine' exist outside of the imagination?
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## X Prize Clean Aviation: \$10 million

This source shows aviation fuel efficiency topping out at about 1MJ / seat-km in the large jumbos, or 2 seat-miles per kWh. I'm curious as to how that metric would scale down for smaller jet aircraft - fewer seats, more overhead.
PF Gold
P: 3,021
 Quote by Cyrus This prize seems to ignore the realities of energy storage issues. Everyone under the sun in the UAV world is trying to get high energy electric systems.
Why, what's wrong w/ petroleum for the UAV crowd?

 I do not see what this prize is supposed to do, it's certainly not going to 'start' people thinking about electric. As for your post above, does a 'superconducting motor replaces turbine' exist outside of the imagination?
? That's not my sketch. AFRL built a 3MW motor. It's out of the paper in the link I referenced in the other thread.
http://www.masbret.com/asc08/ASC08_T...c_Aircraft.ppt
 P: 4,780 Why would you want a loud, vibrating engine on a UAV?
 P: 4,780 I'm looking at that ppt, and I have to ask: why would you use an electric motor to power a ducted fan, and not just use a more efficient propeller??? Also, where are you going to get adequate energy storage?
PF Gold
P: 3,021
 Quote by Cyrus Why would you want a loud, vibrating engine on a UAV?
Ok you're talking about military applications. Doubt that matters for the higher altitude aircraft.
PF Gold
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 Quote by Cyrus I'm looking at that ppt, and I have to ask: why would you use an electric motor to power a ducted fan, and not just use a more efficient propeller???
Sorry I don't follow. What source of power are you suggesting, if not an electric motor? Edit: Perhaps you are asking: why use an electric motor instead of a traditional gas turbine? Electric motor can be >95% efficient, is quiet, as you mentioned above, and can run on electric charge that may have been generated on the ground and stored in the aircraft.

 Also, where are you going to get adequate energy storage?
Post #2, for purposes of this prize. 11 metric tons of battery per 850 mile leg.
 Sci Advisor P: 5,095 Spurring on innovation is nice. That is what makes the world go round and improve. However, this, like every other electric application, is doing nothing more than shifting the sources of pollution. Most forms of clean electricity production are pretty much fixed. What's going to happen if this electric dream comes true with millions of cars and now aircraft. Crank up the coal plants. We certainly aren't doing much in nuclear and dams are pretty much fixed output. It's short sightedness at its best. Back on topic....there is no way to make current energy sources viable and thus useful. Like the other X prize, it is nothing more than a stunt.
P: 4,780
 Quote by mheslep Sorry I don't follow. What source of power are you suggesting, if not an electric motor? Edit: Perhaps you are asking: why use an electric motor instead of a traditional gas turbine? Electric motor can be >95% efficient, is quiet, as you mentioned above, and can run on electric charge that may have been generated on the ground and stored in the aircraft. Post #2, for purposes of this prize. 11 metric tons of battery per 850 mile leg.
No, i'm saying why would you power a fan, instead of a prop. Larger rotors are more efficient.
P: 4,780
 Quote by mheslep Ok you're talking about military applications. Doubt that matters for the higher altitude aircraft.
Why do you doubt this? The purpose of a UAV is to be a sensors platform. The formula for arc length is $$s=r d \theta$$. The higher you are......
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 Quote by FredGarvin Spurring on innovation is nice. That is what makes the world go round and improve. However, this, like every other electric application, is doing nothing more than shifting the sources of pollution. Most forms of clean electricity production are pretty much fixed. What's going to happen if this electric dream comes true with millions of cars and now aircraft.
At least regarding the cars you must know that the power plants, even the worst of them, are much more efficient that any internal combustion engine going down the road. In moving cars to electric, conservative figures say CO2 pollution improves by almost a third on average. SO2 may increase, if coal picks up all the additional load. In metropolitan areas pollution drops dramatically across the board, and the really bad stuff (benzene, etc) goes away completely. For me the biggest win is it does away with imported oil.

Edit: Last, how did I forget: electric ground vehicle transport is 1/3 the cost per mile of petrol based. It's break even amortizing in the cost of the batteries - at today's price of a gas, and that's only going up.

 Quote by FredGarvin Crank up the coal plants.
Or the natural gas. Just as much gas electric power capacity in the US as there is coal; gas is more expensive but much cleaner. And local.

 Quote by FredGarvin We certainly aren't doing much in nuclear and dams are pretty much fixed output. It's short sightedness at its best.
Nuclear uprates and turbine upgrades are going through - another US 4GWe while nobody was looking. Also add another 5-10GWe a year wind - useless for baseload but fine for charging batteries.

 Quote by FredGarvin Back on topic....there is no way to make current energy sources viable and thus useful. Like the other X prize, it is nothing more than a stunt.
Maybe so. First X prize didn't advance the art in any areas?
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P: 3,021
 Quote by Cyrus No, i'm saying why would you power a fan, instead of a prop. Larger rotors are more efficient.
Oh. Prop aircraft are more efficient that turbofan jet aircraft? Still? I wouldn't know. This is a contest so speed matters, so my first hunch was to go with the fan. I was guessing something under 200-300 knots would be required to keep the losses to drag down, but I am vaguely aware that the altitude, lift, and air speed couple together in matter (that's beyond me) that complicates the energy efficiency issue.
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 Quote by mheslep Oh. Prop aircraft are more efficient that turbofan jet aircraft?
At these low speeds, yes.
P: 5,095
 Quote by mheslep At least regarding the cars you must know that the power plants, even the worst of them, are much more efficient that any internal combustion engine going down the road.
Are we talking efficiency or polluting/going green?

 Quote by mheslep Maybe so. First X prize didn't advance the art in any areas?
Nope. Not a bit.
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 Quote by FredGarvin Are we talking efficiency or polluting/going green?
Improving the first usually means improving the second, though 'going green' is not on the top of my to do list. I'm primarily after getting off imports and spending less on energy per mile. Electric transportation does that nicely, probably in aircraft too from what I can see.

 Nope. Not a bit.
Hmm. Do you believe that's specific to the X Prize and its particulars, or every such contest: Lindberg crossing the Atlantic, etc?
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 Quote by Cyrus No, i'm saying why would you power a fan, instead of a prop. Larger rotors are more efficient.
At what size aircraft operating at what altitude and for what distance? Why do highly efficient puddle-jumpers side with turboprops while highly efficient medium and long-haul aircraft side with turbofans?

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