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#1
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Alternative to the Battery wows?
Ran across this short article about an interesting project at the Delft University in The Netherlands:
https://www.yahoo.com/lifestyle/dutc...153606032.html Uli AS |
#2
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Alternative to the Battery wows?
On Monday, 8 March 2021 at 18:26:28 UTC, AS wrote:
Ran across this short article about an interesting project at the Delft University in The Netherlands: https://www.yahoo.com/lifestyle/dutc...153606032.html Uli AS Easy to tell it's H-powered ... look at all the water vapour it's left behind! ;-o) |
#3
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Alternative to the Battery wows?
wrote on 3/8/2021 10:35 AM:
On Monday, 8 March 2021 at 18:26:28 UTC, AS wrote: Ran across this short article about an interesting project at the Delft University in The Netherlands: https://www.yahoo.com/lifestyle/dutc...153606032.html Uli AS Easy to tell it's H-powered ... look at all the water vapour it's left behind! ;-o) The article startles with the announcement the aircraft will have a 164 foot wingspan! Better to use the developers' website at ... https://aerodelft.nl/project-phoenix/ .... where you learn it is an 18M wingspan. Hydrogen aircraft have flown before, but I don't know if any used liquid hydrogen. I did see recently that Toyota is offering the hydrogen fueled Mirai sedan for 2021. For our electric gliders, batteries will remain the best choice because energy density is not critical, as it is for airplanes. -- Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me) - "A Guide to Self-Launching Sailplane Operation" https://sites.google.com/site/motorg...ad-the-guide-1 |
#4
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Alternative to the Battery wows?
https://www.ebay.com/itm/40271384237...d2e50c37173811
How about just scale this up a bit. Already available technology , it works great! Available right off the shelf. No fire problem. No carbs or FI to fiddle with. I think you can buy a folding nose prop today. Just run a piece of 6" PVC under your seat run the rubber band nose to tail and wind it up. Nick T |
#5
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Alternative to the Battery wows?
I recommend doing a bit of research into how hydrogen is produced (mostly) from fossil fuels. Methane (or "clean-burning Natural Gas") is the primary source, and the process is pretty energy intensive. Electrolysis is possible, but at lower energy efficiency.
Storage of gaseous hydrogen to the typical 5,000 to 10,000 psi used is a very real energy and safety concern. Liquefaction is more energy intensive and much less safe due to the refrigeration required to keep the hydrogen from "boiling off" and producing an extremely combustible cloud. Lose the refrigeration and you are in for a real treat. Hydrogen molecules are so small that they leak through anything. Storage by adsorption (not absorption) in metal hydrides is much safer, but requires significant energy to store the hydrogen and then release it for use. Add in the cost of building an entirely new infrastructure to produce, store and deliver hydrogen as a fuel and the "clean" benefits are quickly outweighed by the need to build the infrastructure using conventional energy sources, i.e. oil & gas. And I seem to remember hearing that water vapor is more of a "greenhouse gas" than carbon dioxide. In short, hydrogen is not the super-simple solution to all of the world's problems, and could, in fact, exacerbate them. |
#6
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Alternative to the Battery wows?
On 3/8/2021 1:53 PM, Eric Greenwell wrote:
wrote on 3/8/2021 10:35 AM: On Monday, 8 March 2021 at 18:26:28 UTC, AS wrote: Ran across this short article about an interesting project at the Delft University in The Netherlands: https://www.yahoo.com/lifestyle/dutc...153606032.html Uli AS Easy to tell it's H-powered ... look at all the water vapour it's left behind!Â* ;-o) The article startles with the announcement the aircraft will have a 164 foot wingspan! Better to use the developers' website at ... https://aerodelft.nl/project-phoenix/ ... where you learn it is an 18M wingspan. Hydrogen aircraft have flown before, but I don't know if any used liquid hydrogen. I did see recently that Toyota is offering the hydrogen fueled Mirai sedan for 2021. For our electric gliders, batteries will remain the best choice because energy density is not critical, as it is for airplanes. "Hydrogen is kept in a cryogenic tank at -253°C and warmed to 0°C using a complex tubing system." The hydrogen may be light, but the cryogenic tank isn't. Hydrogen is notoriously difficult to store in a dense form. If you can make a fuel cell affordable (big if), there are better fuels for the purpose, that store as a liquid in ambient conditions or mild pressure, e.g., methanol, ammonia... (All of which can in theory be produced using solar power, but don't hold your breath, it's makes no sense economically.) |
#7
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Alternative to the Battery wows?
Mark Mocho wrote on 3/8/2021 11:34 AM:
And I seem to remember hearing that water vapor is more of a "greenhouse gas" than carbon dioxide. Not so much when it comes to climate change, because as water vapor increases (primarily due to global warming), it forms more clouds, which reflect the heat, tending to reduce global warming - all part of a natural cycle that's be going on since the earth began. CO2 does not condense, and we are adding it to the atmosphere at a far higher rate than natural carbon sinks can remove it. -- Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me) - "A Guide to Self-Launching Sailplane Operation" https://sites.google.com/site/motorg...ad-the-guide-1 |
#8
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Alternative to the Battery wows?
On Monday, March 8, 2021 at 1:42:45 PM UTC-7, Eric Greenwell wrote:
Mark Mocho wrote on 3/8/2021 11:34 AM: And I seem to remember hearing that water vapor is more of a "greenhouse gas" than carbon dioxide. Not so much when it comes to climate change, because as water vapor increases (primarily due to global warming), it forms more clouds, which reflect the heat, tending to reduce global warming - all part of a natural cycle that's be going on since the earth began. CO2 does not condense, and we are adding it to the atmosphere at a far higher rate than natural carbon sinks can remove it. -- However, using hydrogen as an alternative fuel WILL add to the amount of water vapor in the atmosphere. Note the following statement: "...water vapor is the largest contributor to the Earth’s greenhouse effect...However, water vapor does not control the Earth’s temperature, but is instead controlled by the temperature...If there had been no increase in the amounts of non-condensable greenhouse gases (like carbon dioxide), the amount of water vapor in the atmosphere would not have changed with all other variables remaining the same." (from the American Chemical Society's ACS Climate Science Toolkit) The key phrase is the last one: "with all other variables remaining the same." Imagine that instead of seeing "normal" contrails behind a high flying airliner, there is a huge plume of water vapor that results from burning hydrogen. That definitely adds to atmospheric water vapor, independent of the natural evaporation/condensation cycle that forms clouds. Of course, the "Chemtrails" paranoids will get a corresponding boost in popularity. |
#9
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Alternative to the Battery wows?
Mark Mocho wrote on 3/8/2021 3:10 PM:
On Monday, March 8, 2021 at 1:42:45 PM UTC-7, Eric Greenwell wrote: Mark Mocho wrote on 3/8/2021 11:34 AM: And I seem to remember hearing that water vapor is more of a "greenhouse gas" than carbon dioxide. Not so much when it comes to climate change, because as water vapor increases (primarily due to global warming), it forms more clouds, which reflect the heat, tending to reduce global warming - all part of a natural cycle that's be going on since the earth began. CO2 does not condense, and we are adding it to the atmosphere at a far higher rate than natural carbon sinks can remove it. -- However, using hydrogen as an alternative fuel WILL add to the amount of water vapor in the atmosphere. Note the following statement: "...water vapor is the largest contributor to the Earth’s greenhouse effect...However, water vapor does not control the Earth’s temperature, but is instead controlled by the temperature...If there had been no increase in the amounts of non-condensable greenhouse gases (like carbon dioxide), the amount of water vapor in the atmosphere would not have changed with all other variables remaining the same." (from the American Chemical Society's ACS Climate Science Toolkit) The key phrase is the last one: "with all other variables remaining the same." Imagine that instead of seeing "normal" contrails behind a high flying airliner, there is a huge plume of water vapor that results from burning hydrogen. That definitely adds to atmospheric water vapor, independent of the natural evaporation/condensation cycle that forms clouds. Of course, the "Chemtrails" paranoids will get a corresponding boost in popularity. Again, the water vapor will condense, and restore the natural balance; CO2 does not condense, but remains in the atmosphere for hundreds of years. The CO2 in the atmosphere is measurable, and has been increasing for many decades wherever it's measured around the world; water vapor comes and goes with the weather. -- Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me) - "A Guide to Self-Launching Sailplane Operation" https://sites.google.com/site/motorg...ad-the-guide-1 |
#10
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Alternative to the Battery wows?
On Mon, 08 Mar 2021 15:10:08 -0800, Mark Mocho wrote:
On Monday, March 8, 2021 at 1:42:45 PM UTC-7, Eric Greenwell wrote: Mark Mocho wrote on 3/8/2021 11:34 AM: And I seem to remember hearing that water vapor is more of a "greenhouse gas" than carbon dioxide. Not so much when it comes to climate change, because as water vapor increases (primarily due to global warming), it forms more clouds, which reflect the heat, tending to reduce global warming - all part of a natural cycle that's be going on since the earth began. CO2 does not condense, and we are adding it to the atmosphere at a far higher rate than natural carbon sinks can remove it. -- However, using hydrogen as an alternative fuel WILL add to the amount of water vapor in the atmosphere. Note the following statement: "...water vapor is the largest contributor to the Earth’s greenhouse effect...However, water vapor does not control the Earth’s temperature, but is instead controlled by the temperature...If there had been no increase in the amounts of non-condensable greenhouse gases (like carbon dioxide), the amount of water vapor in the atmosphere would not have changed with all other variables remaining the same." (from the American Chemical Society's ACS Climate Science Toolkit) The key phrase is the last one: "with all other variables remaining the same." Imagine that instead of seeing "normal" contrails behind a high flying airliner, there is a huge plume of water vapor that results from burning hydrogen. That definitely adds to atmospheric water vapor, independent of the natural evaporation/condensation cycle that forms clouds. Of course, the "Chemtrails" paranoids will get a corresponding boost in popularity. If H2 was to replace hydrocarbons as the main fuel type, where would it come from? Electrolysis of water? Stripping carbon out of hydrocarbons? ow would the cost compare with other power sources once transport to the point of use is included in the price? It appears that the last two are the current favourites in the form of steam reforming of natural gas, partial oxidation of methane, and coal gasification, with extraction from carbon compounds providing 96% and are not particularly green because they all produce a lot of carbon oxides as a waste product - and we don't have a good way of using them or keeping them out of the atmosphere. Bottom line: hydrogen has good energy capacity per kilogram, but this tends not to look so good once you consider the cost of carrying it around in compact, multi-kilogram quantities. Pipes should be fine, provided somebody manages to invent a reasonably light pipe material that H2 can't leak through, but you can't power road/rail vehicles or aircraft with piped hydrogen! -- Martin | martin at Gregorie | gregorie dot org |
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