![]() |
Originally Posted by MAN Pax
(Post 27498152)
When I was studying Computer Science in the 80's the very idea that a passable video stream over a copper phone line was science fiction - both with bandwidth and the compression technology required at both ends.
As it was correctly pointed, current limitation is with fundamental laws of physics and chemistry and with material science as well. 10x increase of battery density with the same weight would be sufficient to transfer most passenger cars to electric ones. But it won't be sufficient for heavy-duty trucks (25x increase required) and planes (50x increase required). Considering battery efficiency\density increase in last 30 years, unless there are fundamental discoveries in physics\chemistry, chances that you will see electric power replacing fuel is quite slim in next 50-100 years.
Originally Posted by Dieuwer
(Post 27502885)
What is the energy density of liquid hydrogen or liquid ammonia compared to Jet-A?
Originally Posted by Dieuwer
(Post 27502885)
Also, if you can find a way to store a lot of hydrogen/protons in a safe matrix at higher densities than the liquid itself, would be a breakthrough.
https://en.wikipedia.org/wiki/Liquid_nitrogen#Safety https://en.wikipedia.org/wiki/Liquid...cal_properties https://en.wikipedia.org/wiki/Liquid...gen#Properties |
Originally Posted by YVR Cockroach
(Post 27502421)
What is the cost, not just monetary but also energy, of making such fuel? I am not a physicist but I imagine you can't disobey the laws of thermodynamics or other laws of physics.
Originally Posted by invisible
(Post 27503643)
Originally Posted by Dieuwer View Post
What is the energy density of liquid hydrogen or liquid ammonia compared to Jet-A? About 3x for liquid hydrogen. H2 gas is very bloated in volume, so that requires monstruously large aircraft. LNG is even a better option, but far more flammable, so the sky is filled with flying bombs, just like H2 powered planes. Remember the Hindenburg airship in 1937 ? |
Originally Posted by airsurfer
(Post 27504170)
No I am not violating these laws. It costs energy to make synfuel as energy to be used plus the losses in the process has to be input. And I think that over the longer term (decades) I think it will be economically feasible to use renewable energy for powering this process. The sources are mainly water and CO2, so actually one is recycling CO2. Mankind will be forced to do this for survival on this planet.
|
Originally Posted by YVR Cockroach
(Post 27505299)
On the environmental cost, I agree. On the economic and/or energy cost, I suspect it will cost more than 100% of energy produced. The question is if the solar or whatever renewable energy can be put to better use.
And, as said (unless a miraculous battery or hydrogen storage technology emerges), jet fuel has the best energy density, so there is no choice for another propulsion source. And an economy without aviation is also impossible (unless for shorter distances < 500km which might be replaced by high speed train or Hyperloop). |
Originally Posted by airsurfer
(Post 27502344)
Batteries are not radioactive and that is the danger.
Look what happens to this (tiny) lithium battery Then try imagining what happens if we don't have a few Wh (e.g the iPhone 5 battery has 5 Wh (14,000 mAh @ 3.8V) but a couple of GWh. (1 GWh = 1,000 MWh = 1,000,000 KWh =1,000,000,000 Wh) |
At least the resulting contamination from a large lithium battery fire int likely to be anywhere near as toxic and devastating as radioactive material contamination.
I wouldn't want to be anywhere near either of the two catastrophic events though. |
Originally Posted by YVR Cockroach
(Post 27505919)
At least the resulting contamination from a large lithium battery fire int likely to be anywhere near as toxic and devastating as radioactive material contamination.
|
Originally Posted by WorldLux
(Post 27505889)
I didn't say that they were. You said (correctly) that a nuclear reactor would be a great safety hazard. Well, stuffing a commercial airline to the brim with batteries is a great safety hazard too.
|
Originally Posted by WorldLux
(Post 27505889)
Then try imagining what happens if we don't have a few Wh (e.g the iPhone 5 battery has 5 Wh (14,000 mAh @ 3.8V) but a couple of GWh. (1 GWh = 1,000 MWh = 1,000,000 KWh =1,000,000,000 Wh)
Assume an aircraft loaded with 180 tons of fuel, that makes (180000 kg *43.7 MJ/kg) / 3.6 kWh/MJ = 2185000 kWh is indeed 2GWh. The damage is not different from exploding Li-ion with the same capacity. |
How about directed energy beams?
Instead of aircraft being burdened with carrying their energy source onboard, planes fly along prescribed routes populated with ground-based energy beam stations that continually shoot the planes with directed energy beams (insert magical process here) providing thrust and onboard power. Similar to current-day VORTAC stations and published airways. |
Originally Posted by airmotive
(Post 27512755)
How about directed energy beams?
Instead of aircraft being burdened with carrying their energy source onboard, planes fly along prescribed routes populated with ground-based energy beam stations that continually shoot the planes with directed energy beams |
Originally Posted by airmotive
(Post 27512755)
How about directed energy beams?
Instead of aircraft being burdened with carrying their energy source onboard, planes fly along prescribed routes populated with ground-based energy beam stations that continually shoot the planes with directed energy beams (insert magical process here) providing thrust and onboard power. Similar to current-day VORTAC stations and published airways. If we are going to dream, let's dream big! Even heavier-than-air flight was once thought to be a magic process, now thousands of aircraft take to the sky each day. Bring on the energy beams I say! |
Originally Posted by airsurfer
(Post 27509663)
Nothing different than a crashing planeload of Jet-A1.
If the plane crash, he doesn't matter what happens: Both the passengers and the people on the ground will almost certainly perish. The batteries would however be a constant danger. A faulty battery cell could have horrible consequences. Given how highly reactive lithium is, I wouldn't wanna sit on thousands of batteries, that are needed to generate the couple of GW/h needed for a flight. Filling up a plane with lithium batteries (which are considered to be so dangerous, that they may no longer travel as air freight on board of passenger aircrafts), seems to me to be equally idiotic than filling up an airship with hydrogen. Add to that multiple other issues:
|
Originally Posted by WorldLux
(Post 27513063)
:rolleyes:
If Add to that multiple other issues:
But you are right: Li batteries are not an option at all. The energy beams sound very science fiction to me. But maybe somday in the 2080s it might be feasible....? Then a 'magic' battery technology which does not have the big disadvantages of Li batteries is more probable. In the 1970s we also never thought that within 50 years an electric car was possible. |
Originally Posted by airsurfer
(Post 27515033)
Then a 'magic' battery technology which does not have the big disadvantages of Li batteries is more probable.
Originally Posted by airsurfer
(Post 27515033)
In the 1970s we also never thought that within 50 years an electric car was possible.
|
| All times are GMT -6. The time now is 1:09 am. |
This site is owned, operated, and maintained by MH Sub I, LLC dba Internet Brands. Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Designated trademarks are the property of their respective owners.