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Originally Posted by HABBERDABBER
Good luck with hydrogen fueled vehicles. Hydrogen is a medium for energy storage, but it has to be created.
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True! Just like the chemical energy storage in a charged battery.
Unfortunately, the efficiency of producing hydrogen from water by electrolysis, compressing or liquefying it, and making electricity from it, is much lower than the efficiency of battery storage.
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Originally Posted by HABBERDABBER
Simple enough...we can get all we want from water. But it takes energy, usually electricity, and a lot of it, to produce electrolysis to get the hydrogen produced.
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That's the dream, but most hydrogen is currently produced from methane (from natural gas).
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Originally Posted by HABBERDABBER
And then there's the quirks of hydrogen. In piping it, hydrogen chews up metal by embrittlement. It is the smallest and simplest element, and even metal does not stop it's movement out of a pipe. In practical terms, that doesn't matter. My point is, it is a much different animal than fossil fuels. You HAVE to MAKE it, (not pump it out of the ground like oil) and then compress it enough to store it. And storage of hydrogen in a vehicle is another problematic issue. You just can't plop some hydrogen gas or liquid into a tank.
It can all be done technically, but its use in mass consumer markets, it will be an interesting experiment..
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All (or at least mostly) valid concerns, but all can be handled, although at significant cost. Toyota has had its hydrogen fuel cell car (the Mirai) in the hands of thousands of consumers for years; like other similar vehicles, it carries about 5 kilograms of hydrogen at 700 times atmospheric pressure in tanks the size of a pickup truck fuel tank, but made of carbon fibre reinforced resin, lined with a polymer, and with a protective fiberglass outer layer, weighing about 80 kilograms. Not as heavy or bulky as a battery storing the same energy, but substantial and expensive.
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Originally Posted by HABBERDABBER
We do use it to power rocket ships effectively.
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Some, notably the Saturn V that launched Apollo, the Space Shuttle (but not its boosters), and the coming Artemis program.
Rockets are fueled by cryogenic liquid hydrogen; hydrogen fuel cell cars carry the hydrogen as a highly compressed gas.
Kerosene is the more common rocket fuel. The company founded by the founder of Tesla Motors uses kerosene, and is switching to methane for the next series of rockets; maybe he doesn't mind burning fossil fuels after all.
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Originally Posted by HABBERDABBER
Maybe there's some gee whiz solution.
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There are lots, such as materials that absorb the hydrogen, but none are really solutions.
It only takes a brief examination of alternatives like this to see why the problems of battery-electric vehicles might not be so bad.