I can't wait for electric/hybrid aircraft.
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I wish I could go to this, but travel there is too difficult for me at present. Somebody else might like to go, however:
"Following function in real time
Kavli Medal Lecture by Professor Clare Grey FRS
6 October 2011, 6.30pm - 7.30pm
The Royal Society, London
"This talk will describe existing battery technologies, their use in transport and grid applications, and research being performed at Cambridge and elsewhere to help develop improved batteries for these applications. Doors will open at 5.45pm. No ticket or advance booking required and seats are allocated on a first-come-first-served basis."
Chris N
"Following function in real time
Kavli Medal Lecture by Professor Clare Grey FRS
6 October 2011, 6.30pm - 7.30pm
The Royal Society, London
"This talk will describe existing battery technologies, their use in transport and grid applications, and research being performed at Cambridge and elsewhere to help develop improved batteries for these applications. Doors will open at 5.45pm. No ticket or advance booking required and seats are allocated on a first-come-first-served basis."
Chris N
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Given the already-mentioned favourable operating profile of the motor car compared to your typical light aircraft, we will be waiting and waiting until long after EVs become accepted in the motor car. I guess battery energy densities will need to improve to about half the energy density of hydrocarbon before they get a decent look-in. That's a factor of about 22; that figure allows for some on board power plant weight reduction to be offset against battery weight.
What density improvements have batteries achieved since the introduction of say Nickel metal hydrides? About a factor of six I think, based on what model Lipo batteries are capable of. We are not near ready for the infrastructural cost of recharging either.
I would put money on it that electric will never compete with hydrocarbons in aircraft for at least 30 years. Also leave out distorting tax incentives. What I would bet on is that solar bioengineering will harness microbes to produce hydrocarbon feedstock much sooner, making AFO fuel the best solution especially when distribution costs are factored in.
What density improvements have batteries achieved since the introduction of say Nickel metal hydrides? About a factor of six I think, based on what model Lipo batteries are capable of. We are not near ready for the infrastructural cost of recharging either.
I would put money on it that electric will never compete with hydrocarbons in aircraft for at least 30 years. Also leave out distorting tax incentives. What I would bet on is that solar bioengineering will harness microbes to produce hydrocarbon feedstock much sooner, making AFO fuel the best solution especially when distribution costs are factored in.
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I would put money on it that electric will never compete with hydrocarbons in aircraft for at least 30 years.
Well, change comes to all things, even aviation. The changes we predict don't always happen and the ones that catch us out are often completely unexpected. There's another law of futurology, which is that we tend to overestimate the impact of R&D in the short term, and underestimate it in the long term.
All progress, it's said, is due to unreasonable people. In aviation one might say that all progress is due to people who are rich, brave and unreasonable. I'm neither rich enough nor brave enough to be a pioneer myself, but in the meanwhile I see no harm in throwing ideas around, and daring to believe that one day the problems already mentioned on this thread may be solved or sidestepped.
Anyway, there's no reason either not to hope for improvements in technology, or to diss those people who are unreasonable enough to try to make them reality.
This news story just took me completely by surprise:
http://web.mit.edu/newsoffice/2011/a...leaf-0930.html
Don't yet know what to make of it, if anything.
All progress, it's said, is due to unreasonable people. In aviation one might say that all progress is due to people who are rich, brave and unreasonable. I'm neither rich enough nor brave enough to be a pioneer myself, but in the meanwhile I see no harm in throwing ideas around, and daring to believe that one day the problems already mentioned on this thread may be solved or sidestepped.
Anyway, there's no reason either not to hope for improvements in technology, or to diss those people who are unreasonable enough to try to make them reality.
This news story just took me completely by surprise:
http://web.mit.edu/newsoffice/2011/a...leaf-0930.html
Don't yet know what to make of it, if anything.
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As I'm sure you know, the electric Pipistrel Taurus G4 won the CAFE Foundations Green Challenge prize for the most efficient aircraft in the world. The 4-place aircraft managed to fly to the equivalent of 400mpg/person! That's obviously less gas/person than any aircraft has ever done before (and it relegated the former high scorer Boeing's 787 Dreamliner to the back row). But what's even more impressive is that it's less than any hybrid or electric car has ever managed as well! The G4 flew almost 200 miles and still had to have an equivalent of a "reserve" charge left when they landed. It averaged about 100mph.
Even with batteries so low in capacity as they are, it shows that you can still achieve almost usable performance. Today. What will happen when batteries double, quadruple?
BTW, I just recently learned a new fact - who is the biggest single user of electricity? Oil refineries. They need tremendous heat to be able to crack and refine crude oil. Apparently, just putting the electricity they use back into the grid would cover any electric vehicle recharging programs. So the efficiency if this gets factored in, is even less for fossil fuel engines. Maybe below 20%, even. So if the energy density of 12Kwh/kg for gas only in real life is closer to 2.4kwh/kg, then today's batteries with 0.5kwh/kg are not so far off. Even with a doubling of capacity (1kwh/kg), it will start to be a real contender due to the low weight of electric propulsion systems. The bell is tolling for fossil fuels...
But the most exciting fact for me personally, is that in the near future we'll start to see technology that's accessible and cheap enough for multiple developers to use. This means that the future might hold a true revolution in personal transport. It also means that there's a potential to reverse the decline in GA and the decline in pilots. It might just be that in 50 years time, the cheapest way to get from London to Paris might be in your own electric aircraft that you tow to your garage and charge there. Isn't this exciting?
Even with batteries so low in capacity as they are, it shows that you can still achieve almost usable performance. Today. What will happen when batteries double, quadruple?
BTW, I just recently learned a new fact - who is the biggest single user of electricity? Oil refineries. They need tremendous heat to be able to crack and refine crude oil. Apparently, just putting the electricity they use back into the grid would cover any electric vehicle recharging programs. So the efficiency if this gets factored in, is even less for fossil fuel engines. Maybe below 20%, even. So if the energy density of 12Kwh/kg for gas only in real life is closer to 2.4kwh/kg, then today's batteries with 0.5kwh/kg are not so far off. Even with a doubling of capacity (1kwh/kg), it will start to be a real contender due to the low weight of electric propulsion systems. The bell is tolling for fossil fuels...
But the most exciting fact for me personally, is that in the near future we'll start to see technology that's accessible and cheap enough for multiple developers to use. This means that the future might hold a true revolution in personal transport. It also means that there's a potential to reverse the decline in GA and the decline in pilots. It might just be that in 50 years time, the cheapest way to get from London to Paris might be in your own electric aircraft that you tow to your garage and charge there. Isn't this exciting?
Last edited by AdamFrisch; 5th Jan 2012 at 01:47.
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Abgd - no, it did not as far as I know. It was competing with 3 other aircraft who did the same routing. The E-Genius came in second place, which is another electric airplane:
e-Genius flies into the record books, averages 100 mph over 211 miles
The two other ones were gas or hybrid powered and ended up last. Here's the full list of the performances:
http://cafefoundation.org/v2/gfc_2011_results.html
Yes, Pipistrel is a very interesting company. Their Panthera looks to be a real killer when it gets out. Will be available with IO-390, hybrid, or full electric. The electric version has considerably lower performance and only a range of 250nm or something, but it's a start. As batteries improve, you can just upgrade.
e-Genius flies into the record books, averages 100 mph over 211 miles
The two other ones were gas or hybrid powered and ended up last. Here's the full list of the performances:
http://cafefoundation.org/v2/gfc_2011_results.html
Yes, Pipistrel is a very interesting company. Their Panthera looks to be a real killer when it gets out. Will be available with IO-390, hybrid, or full electric. The electric version has considerably lower performance and only a range of 250nm or something, but it's a start. As batteries improve, you can just upgrade.
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Yes, I am really looking forward to the Panthera as well. If they can really acheive 200 knots on 10gph, even the avgas will be a huge step in mpg for high speed SEPs
One should rightly be sceptical and some will probably point to the wildly overestimated speed of the DA42 before it was released, but Pipistrel has good track record of creating some very efficient aeroplanes. Virus SW will apparently cruise at 140 knots on 75% power from a Rotax, sipping just 5gph
If their claim holds, I'll queue up
One should rightly be sceptical and some will probably point to the wildly overestimated speed of the DA42 before it was released, but Pipistrel has good track record of creating some very efficient aeroplanes. Virus SW will apparently cruise at 140 knots on 75% power from a Rotax, sipping just 5gph
If their claim holds, I'll queue up
Here's something that's been bothering me for a while... The unreasonable effectiveness of aircraft at holding altitude. You set your power, you trim, then after a moment or two to settle an aircraft will hold +- a few hundred feet with no further intervention.
It just doesn't seem feasible to me that you can trim an aircraft to fly so precisely level that it flies for 50 nm and only gains 200 feet. My theory is that it's partly to due with power loss at altitude - if you gain altitude because of a slight mis-trimming, then the engine produces less power; conversely if you lose altitude then the engine will produce slightly more power, and you'll regain it.
I'd be interested to hear whether this mechanism is at least partly responsible for aircraft being so good at holding altitude, but also wondered whether it has repercussions when it comes to electric aircraft, where power output is linked much less strongly to altitude. Will this make them difficult to fly accurately... Will people need to build an altimeter into the control circuitry?
It just doesn't seem feasible to me that you can trim an aircraft to fly so precisely level that it flies for 50 nm and only gains 200 feet. My theory is that it's partly to due with power loss at altitude - if you gain altitude because of a slight mis-trimming, then the engine produces less power; conversely if you lose altitude then the engine will produce slightly more power, and you'll regain it.
I'd be interested to hear whether this mechanism is at least partly responsible for aircraft being so good at holding altitude, but also wondered whether it has repercussions when it comes to electric aircraft, where power output is linked much less strongly to altitude. Will this make them difficult to fly accurately... Will people need to build an altimeter into the control circuitry?
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400 wh/kg
More battery power:
See: Envia Batteries Improve Use of Electric Cars | Bangstyle :: A Global Network Promoting Independent Artists
Chris N
See: Envia Batteries Improve Use of Electric Cars | Bangstyle :: A Global Network Promoting Independent Artists
Chris N
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12 kWh/kg
This could be the breakthrough we're waiting for:
IBM Creates 'Breathing' High-Density Lithium-Air Battery - Slashdot
IBM creates breathing, high-density, light-weight lithium-air battery | ExtremeTech
IBM - The Battery 500 Project - United States
IBM Creates 'Breathing' High-Density Lithium-Air Battery - Slashdot
IBM creates breathing, high-density, light-weight lithium-air battery | ExtremeTech
IBM - The Battery 500 Project - United States
The main thing, though, is that lithium-air energy density is a lot higher than conventional lithium-ion batteries: the max energy density of lithium-air batteries is theorized to be around 12 kWh/kg, some 15 times greater than li-ion — and more importantly, comparable to gasoline."
Well, I'll be delighted if and when they arrive. The idea of Lithium-Air batteries has been around for a while though. The proof of the pudding is in the eating.
The Volta Voltare:
The Chevy Volt of airplanes, the Volta Volare GT4, is ready to fly | ExtremeTech
High-Performance Efficient Aircraft With GT4|Volta Volaré
If they really have one ready to fly, it would have been nice to seee pictures of the prototype.
The Chevy Volt of airplanes, the Volta Volare GT4, is ready to fly | ExtremeTech
High-Performance Efficient Aircraft With GT4|Volta Volaré
If they really have one ready to fly, it would have been nice to seee pictures of the prototype.
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I seriously hope for solar-powered ultra-lightweight motorgliders. A bit like this one:
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I don’t see the ultra-light weight motor glider electric power as very likely – the weight of batteries demands strong and hence heavy wings.
I think the Arcus approach – batteries spread along the wings to minimise bending moment at the root – as the optimum concept. Retrofits like my FES, with all the added weight in the non-lifting fuselage, are less optimum (but all that was available to me).
As always, battery capacity (absolute, and per unit weight) is the limiting factor, but getting better over time. There is also a fire risk factor from batteries, but then there is too with internal combustion engines and, perhaps, with small gas turbines.
Chris N
I think the Arcus approach – batteries spread along the wings to minimise bending moment at the root – as the optimum concept. Retrofits like my FES, with all the added weight in the non-lifting fuselage, are less optimum (but all that was available to me).
As always, battery capacity (absolute, and per unit weight) is the limiting factor, but getting better over time. There is also a fire risk factor from batteries, but then there is too with internal combustion engines and, perhaps, with small gas turbines.
Chris N