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#1
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Here is a link to an article about the first manned fuel cell flight.
It has been in the works for some time, and wonderful to see it coming to fruition: http://www.gizmag.com/first-manned-f...e-flight/9117/ For those who don't know, Boeing converted a Dimona motorglider to have an electric motor, and on board proton exchange membrane (PEM) hydrogen fuel cells (integrated with L-ions) that generate enough juice to power the aircraft during powered level flight. Neat stuff! Paul |
#2
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While I congratulate that team on a fine engineering accomplishment, I
really have to question the whole Fuel-Cell thing. The problem is Hydrogen. It is abundant in nature, but it *loves* to bond to everything. So you have to reclaim it from other things and separate it out. That takes time and energy to do. In fact, it can take a *lot* of energy to break the chemical bonds that hydrogren has with many things. And what about the environmental aspects of removing Hydrogen from the ecosystem? I made a post about this awhile back on RAS (regarding tow-planes) - but really the only cost-effective solution with today's technology is to use Nuclear power to generate really cheap electricity, and then use electrolysis to separate Hydrogen from Oxygen in water (like the ocean or a large fresh-water sea). How many Nuclear plants will the public allow to be built? My dad has worked as an engineer at a Nuclear power plant for 25+ years so I am totally comfortable with the system... But the American Public, at least, has been motivated by fear and ignorance on this topic for decades. Even if you get Nuc plants built for the electricity and the electrolysis, you still have only solved the production side of the equation. What about storage and shipping and distribution? Gasses are inherently less dense than a solid or a liquid, so you either have to expend energy to cool and condense the gas; OR you have to transport it inefficiently in a gaseous state. And the material and systems to keep an explosive gas safe during transport add a lot of weight and complexity to the situation. As you can see, every single step along the production & distrubution line "costs" you energy and materials. Sure you have a non-polluting system at the very end of the chain - but how inefficient is the system in total? You are *already* generating a lot of electricity at the very early stages of the sequence I described above. Why not use efficient electrical distribution networks (which we already have), and efficient electric motors (which we already have), and run things that way? The weak link is the battery technology - but that is seeing steady improvement, and there have been some genuine breakthroughs lately. Lots of hype, too - but a few things have been truly world-changing recently... For example, how about this new twist on Lithium-Ion/ Lithium-Polymer batteries: http://news-service.stanford.edu/new...re-010908.html They think they are only 2 - 3 years from mass production, and even if the batteries are only half as effective as the prototypes, that would still increase capacity by 5 times the current levels. Wow! To put that in perspective: An Apis-E (electric-launch Apis 15m glider) battery pack would go from weighing over 100 lbs to weighing maybe 20 lbs, yet could still provide enough power for a couple of 3000' launches. OR, the Tesla Roadster ( www.teslamotors.com ) could go 1000 miles per charge, instead of 200. ...And remember, I'm quoting conservative numbers based on 50% effectiveness of mass-production models. I'm not saying that electric power is here _now_ or that its the ultimate solution for the world; but for many applications it is just as close (if not a whole lot closer) to being a suitable large-scale solution than fuel cells are! Take care, --Noel |
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On Apr 9, 5:25*pm, "noel.wade" wrote:
While I congratulate that team on a fine engineering accomplishment, I really have to question the whole Fuel-Cell thing. The problem is Hydrogen. *It is abundant in nature, but it *loves* to bond to everything. *So you have to reclaim it from other things and separate it out. *That takes time and energy to do. In fact, it can take a *lot* of energy to break the chemical bonds that hydrogren has with many things. *And what about the environmental aspects of removing Hydrogen from the ecosystem? I made a post about this awhile back on RAS (regarding tow-planes) - but really the only cost-effective solution with today's technology is to use Nuclear power to generate really cheap electricity, and then use electrolysis to separate Hydrogen from Oxygen in water (like the ocean or a large fresh-water sea). How many Nuclear plants will the public allow to be built? *My dad has worked as an engineer at a Nuclear power plant for 25+ years so I am totally comfortable with the system... *But the American Public, at least, has been motivated by fear and ignorance on this topic for decades. Even if you get Nuc plants built for the electricity and the electrolysis, you still have only solved the production side of the equation. *What about storage and shipping and distribution? *Gasses are inherently less dense than a solid or a liquid, so you either have to expend energy to cool and condense the gas; OR you have to transport it inefficiently in a gaseous state. *And the material and systems to keep an explosive gas safe during transport add a lot of weight and complexity to the situation. As you can see, every single step along the production & distrubution line "costs" you energy and materials. *Sure you have a non-polluting system at the very end of the chain - but how inefficient is the system in total? You are *already* generating a lot of electricity at the very early stages of the sequence I described above. *Why not use efficient electrical distribution networks (which we already have), and efficient electric motors (which we already have), and run things that way? The weak link is the battery technology - but that is seeing steady improvement, and there have been some genuine breakthroughs lately. Lots of hype, too - but a few things have been truly world-changing recently... *For example, how about this new twist on Lithium-Ion/ Lithium-Polymer batteries: http://news-service.stanford.edu/new...re-010908.html They think they are only 2 - 3 years from mass production, and even if the batteries are only half as effective as the prototypes, that would still increase capacity by 5 times the current levels. *Wow! *To put that in perspective: *An Apis-E (electric-launch Apis 15m glider) battery pack would go from weighing over 100 lbs to weighing maybe 20 lbs, yet could still provide enough power for a couple of 3000' launches. *OR, the Tesla Roadster (www.teslamotors.com) could go 1000 miles per charge, instead of 200. *...And remember, I'm quoting conservative numbers based on 50% effectiveness of mass-production models. I'm not saying that electric power is here _now_ or that its the ultimate solution for the world; but for many applications it is just as close (if not a whole lot closer) to being a suitable large-scale solution than fuel cells are! Take care, --Noel EXCELLENT reply Noel. Tell me, where can I get in touch with Mr. Cui .... I want to but stock in his new company. Mike J. |
#4
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On Apr 9, 4:25 pm, "noel.wade" wrote:
While I congratulate that team on a fine engineering accomplishment, I really have to question the whole Fuel-Cell thing. The problem is Hydrogen. It is abundant in nature, but it *loves* to bond to everything. So you have to reclaim it from other things and separate it out. That takes time and energy to do. In fact, it can take a *lot* of energy to break the chemical bonds that hydrogren has with many things. And what about the environmental aspects of removing Hydrogen from the ecosystem? I made a post about this awhile back on RAS (regarding tow-planes) - but really the only cost-effective solution with today's technology is to use Nuclear power to generate really cheap electricity, and then use electrolysis to separate Hydrogen from Oxygen in water (like the ocean or a large fresh-water sea). How many Nuclear plants will the public allow to be built? My dad has worked as an engineer at a Nuclear power plant for 25+ years so I am totally comfortable with the system... But the American Public, at least, has been motivated by fear and ignorance on this topic for decades. Even if you get Nuc plants built for the electricity and the electrolysis, you still have only solved the production side of the equation. What about storage and shipping and distribution? Gasses are inherently less dense than a solid or a liquid, so you either have to expend energy to cool and condense the gas; OR you have to transport it inefficiently in a gaseous state. And the material and systems to keep an explosive gas safe during transport add a lot of weight and complexity to the situation. As you can see, every single step along the production & distrubution line "costs" you energy and materials. Sure you have a non-polluting system at the very end of the chain - but how inefficient is the system in total? You are *already* generating a lot of electricity at the very early stages of the sequence I described above. Why not use efficient electrical distribution networks (which we already have), and efficient electric motors (which we already have), and run things that way? The weak link is the battery technology - but that is seeing steady improvement, and there have been some genuine breakthroughs lately. Lots of hype, too - but a few things have been truly world-changing recently... For example, how about this new twist on Lithium-Ion/ Lithium-Polymer batteries: http://news-service.stanford.edu/new...re-010908.html They think they are only 2 - 3 years from mass production, and even if the batteries are only half as effective as the prototypes, that would still increase capacity by 5 times the current levels. Wow! To put that in perspective: An Apis-E (electric-launch Apis 15m glider) battery pack would go from weighing over 100 lbs to weighing maybe 20 lbs, yet could still provide enough power for a couple of 3000' launches. OR, the Tesla Roadster (www.teslamotors.com) could go 1000 miles per charge, instead of 200. ...And remember, I'm quoting conservative numbers based on 50% effectiveness of mass-production models. I'm not saying that electric power is here _now_ or that its the ultimate solution for the world; but for many applications it is just as close (if not a whole lot closer) to being a suitable large-scale solution than fuel cells are! Take care, Noel With my post, I was not promoting hydrogen as a magic bullet for the world's energy needs as you seemed to have reacted to it as. I really do think it is a good thing that alternative methods are being developed in the arena of aviation. Even if Boeing never gets it past this phase, it sets a tone that other manufacturers/independent inventors can follow; the doors are opening. It's one thing when relatively unknown companies (Aerovironment, Lange, Apis, Sonex, etc) dabble in electrics, but when a big name like Boeing gets in on it it reduces the risk of such ventures for other designers to follow suit. An electric motor in a motorglider is not cool enough because it also has some obsolete technology? I'm sure glad the Wright brothers continued with their experiments with inefficient, crude, unrefined etc flying contraptions, paving the way for proper aircraft. Walk before you run right? Boeing's fuel cell demonstrator provides another platform for knowledge on electric aircraft to be amassed. Do you not see that as a byproduct, bugs are being worked out of electric flight? The electric power source on that plane can be changed to whatever the energy of the month is, and it would probably still have the same motor/prop/wiring/etc, which in this process also becomes more refined. Yes, of course getting the silicon nonowire batteries on the market will be a revolution, so much so that the powers that be probably will not allow us to have such technology, since it's revolutionary enough to actually threaten the power structure of the world's energy monopolies whom seem to have an awful lot of say in our lives, but that's another story...Anyone/group spending money that could be spent on other things to try to find a sustainable future for aviation has MY respect at least. Paul Hanson |
#5
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On Apr 9, 4:25 pm, "noel.wade" wrote:
...The problem is Hydrogen... Absolutely! Didn't we have this conversation at that restaurant in ABQ? Anyhow, my favorite treatise/screed/rant on this topic is that of Don Lancaster of www.tinaja.com fame (.pdf format): http://www.tinaja.com/glib/energfun.pdf My favorite quote: Electrolysis for bulk hydrogen energy is pretty much the same as 1:1 converting US dollars into Mexican Pesos. Don's somewhat peculiar definition of what constitutes a "fuel" that excludes hydrogen seems to rankle some folks, but his nomenclature seems to hold at least internal consistency. I think it's worth a look. In other odd news, somebody on another forum was telling me about an interesting research program to use algae to liberate electrons, basically a biofuel cell: http://en.wikipedia.org/wiki/Microbial_fuel_cell Thanks, Bob K. http://www.hpaircraft.com/hp-24 |
#6
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![]() "Bob Kuykendall" wrote in message ... Don's somewhat peculiar definition of what constitutes a "fuel" that excludes hydrogen seems to rankle some folks, but his nomenclature seems to hold at least internal consistency. I think it's worth a look. On this (and other things) Don is exactly right. Looking at the big picture, hydrogen is not a fuel. It is best to think of hydrogen as just a way of packaging and transporting energy...a damn inefficient way of packaging and transporting energy. Vaughn |
#7
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![]() "Vaughn Simon" wrote in message ... "Bob Kuykendall" wrote in message ... Don's somewhat peculiar definition of what constitutes a "fuel" that excludes hydrogen seems to rankle some folks, but his nomenclature seems to hold at least internal consistency. I think it's worth a look. On this (and other things) Don is exactly right. Looking at the big picture, hydrogen is not a fuel. It is best to think of hydrogen as just a way of packaging and transporting energy...a damn inefficient way of packaging and transporting energy. Vaughn Hydrogen is to big oil what nuclear fusion is to the coal industry. The advantage to these industries is that the technology doesn't work - at least right now. Big coal will tell you that the future of electric power generation is fusion reactors which, while true, is at least 50 years in the future which means that we continue burning coal in electric plants and they keep making profits. The "hydrogen economy" is two things. First, it's a stalking horse for the nuclear industry which will be needed to produce the vast quantity of hydrogen needed to fuel an entire economy. (Nukes are VERY efficient at making H2 since ionizing radiation splits water as does the electricity they produce.) Second, it's a politically attractive solution that is far enough in the future that we continue burning oil - and big oil keeps making enormous profits. Dr. Yi Chi's carbon nanowire breakthrough in lithium battery anodes is, if it works out, a classic "disruptive technology". It means that plug-in electric vehicles will have a range of many hundreds of miles and recharge in minutes. The surprise is that he just got 10 million dollars to commercialize his invention from....wait for it....a Saudi university. See: http://news-service.stanford.edu/new...ui-040208.html Another potential disruptive technology converts simple radioactive decay directly into electricity. These devices are generally considered as safe as the smoke detectors you have at home. Add them to Dr. Yi's nanowire lithiums and they will slowly charge themselves - for 20 years or so. Just put your electric glider in its trailer and next weekend, it's charged up ready to go. Bill D |
#8
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The problem is Hydrogen. It is abundant in nature, but it *loves* to
bond to everything. So you have to reclaim it from other things and separate it out. That takes time and energy to do. Indeed. A professional aerodynamicist friend tells me that the best efficiency you can achieve from a solar charged "eternal plane" depends a lot on the storage system. FYI the "eternal plane" is solar powered. During the day it flys on solar power while storing energy to keep it flying overnight. If you use a fuel cell, splitting water during the day, storing the hydrogen and dumping the oxygen and then using the fuel cell for night power while collecting the water from it to recycle the next day, your best energy storage efficiency is about 66%. If you just charge a Li-poly battery the storage efficiency is around 85%. Bottom line: you'll need a lot fewer nukes if you use them to charge batteries than if you make hydrogen. Thats without considering the cost of transmitting the electricity to chargers versus the cost of carting hydrogen to the gas station. -- martin@ | Martin Gregorie gregorie. | org | Zappa fan & glider pilot |
#9
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![]() "Bill Daniels" bildan@comcast-dot-net wrote in message . .. Another potential disruptive technology converts simple radioactive decay directly into electricity. These devices are generally considered as safe as the smoke detectors you have at home. Add them to Dr. Yi's nanowire lithiums and they will slowly charge themselves - for 20 years or so. Just put your electric glider in its trailer and next weekend, it's charged up ready to go. Actually, electrical generators powered by radioactive decay have been around for at least 50 years. That said, the chemical reaction you suggest might represent an improvement on the concept. Of course, any chance the common man ever had to possess and use radioactive materials to generate power (slim to none at best) totally disappeared on 9/1/01, so this is unlikely to ever be a deal changer. Vaughn |
#10
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![]() "Vaughn Simon" wrote in message ... "Bill Daniels" bildan@comcast-dot-net wrote in message . .. Another potential disruptive technology converts simple radioactive decay directly into electricity. These devices are generally considered as safe as the smoke detectors you have at home. Add them to Dr. Yi's nanowire lithiums and they will slowly charge themselves - for 20 years or so. Just put your electric glider in its trailer and next weekend, it's charged up ready to go. Actually, electrical generators powered by radioactive decay have been around for at least 50 years. That said, the chemical reaction you suggest might represent an improvement on the concept. Of course, any chance the common man ever had to possess and use radioactive materials to generate power (slim to none at best) totally disappeared on 9/1/01, so this is unlikely to ever be a deal changer. Vaughn I wasn't writing about a chemical reaction or a thermionic generator - try betavoltaics. You already have this much radioactivity in your smoke detectors. Actually, a terrorist could deliver more radioactivity by throwing bananas at us. Bill D |
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