A kilogram of hydrogen holds 39.4 kWh of energy — the highest chemical energy density you’ll find, at least by mass — but typically costs around 52.5 kWh of energy to create via current commercial electrolyzers:
Australian company Hysata says its new capillary-fed electrolyzer cell slashes that energy cost to 41.5 kWh, smashing efficiency records while also being cheaper to install and run. The company promises green hydrogen at around US$1.50 per kilogram within just a few years.
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A reservoir at the bottom of the cell keeps the electrolyte out of contact with both the anode and the cathode until it’s drawn up through a porous, hydrophilic, inter-electrode separator using capillary action. The electrolyte thus has direct contact with the electrodes, but only on one side, and both the hydrogen and oxygen gases are produced directly, without any bubbling to get in the way.
This is a good development, but at 95% efficiency it is likely near the theoretical efficiency limit. The Second Law requires the efficiency to be under 100%.
Then there is the issue of the source of the electricity for electrolysis. If it is nuclear, then those plants have an efficiency of something over 40%. Deduct transmission losses from that.
There is also the issue of hydrogen storage and transmission, which is complicated by hydrogen embrittlement of steel.
By the way, that embrittlement would also occur in the fuel storage tank and fuel lines of the vehicle. There would have to be regular safety inspections for all hydrogen vehicles.
Most likely, hydrogen would be generated at the point of sale, and this raises the question of how fast it can be made. But it does eliminate the transportation and storage issues.
Had the luck during my college years to have a Physical Chemistry professor who as a post-doc worked on the first actual nuclear power reactor project for the US Navy. The unwanted hydrogen production was a significant problem discovered during development of the reactor and was solved by driving the reaction to the left by high system pressurization. I started grad school in 1963 and the three semesters with him were as high a quality and level as I found at the Ivy League university classes I encountered there. What I learned about hydrogen from my college professor was that it is nasty stuff. It is impossible to contain as it leaks through everything. It embrittles as Bob Sykes says. It explodes over a wide range of percentages in air — a really wide range. If one thinks natural gas is a dangerous fuel, one hasn’t seen anything until you embrace the hydrogen economy.
The “Hydrogen Economy” is scientifically absurd — which is why it gets promoted by the same scientific illiterates that push Catastrophic Anthropogenic Global Warming.
Hydrogen does not occur naturally on Planet Earth. It has to be manufactured, using an external source of energy — these days, mostly natural gas. Hydrogen is more akin to an electric cable, moving power from where it is generated to where it is used. And burning hydrogen generates water vapor which is — you guessed it! — a “Global Warming Greenhouse Gas”.
Hydrogen is simply another waste of taxpayer subsidies.
Gavin Longmuir says, “The ‘Hydrogen Economy’ is scientifically absurd — which is why it gets promoted.”
Yep.
Every since I heard of this stuff I really favor it.
https://en.wikipedia.org/wiki/2,5-Dimethylfuran
https://news.wisc.edu/engineers-develop-higher-energy-liquid-transportation-fuel-from-sugar/
This is great stuff. I wonder what it would take to set this up to be produced by solar. The electricity could be solar cells and the light left over as waste could maybe be used to break down plant matter with yeast to make sugar.
Gavin, hydrogen solves an energy storage problem. Put these electrolisers next to wind turbines, use them to store curtailed energy as H2, then win.
There is the opportunity to hit 5p per kWhr of generation even without this new every tech announced today.
Check this out showing hydrogen production cost per type of energy you use to make it:
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1011506/Hydrogen_Production_Costs_2021.pdf