this post was submitted on 15 Jul 2024
134 points (94.1% liked)
Climate - truthful information about climate, related activism and politics.
5245 readers
375 users here now
Discussion of climate, how it is changing, activism around that, the politics, and the energy systems change we need in order to stabilize things.
As a starting point, the burning of fossil fuels, and to a lesser extent deforestation and release of methane are responsible for the warming in recent decades:
How much each change to the atmosphere has warmed the world:
Recommended actions to cut greenhouse gas emissions in the near future:
Anti-science, inactivism, and unsupported conspiracy theories are not ok here.
founded 1 year ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
It's always important to remember that hydrogen is not harmless.
First, it normally comes from natural gas since it's less energy-intensive to produce it that way.
Second, even if we were to produce hydrogen from water, the cycle of electrolyzing, transporting and using hydrogen is associated with enormous energy losses, and we still have to get that extra energy from somewhere.
Third, even if renewables will fully cover the demands of such production, they are not completely harmless, either. They need to be manufactured and then discarded; they require intermittent energy storage, which either relies on batteries which are not eco-friendly, or again something like hydrogen which would necessitate a much more powerful source and commonly requires rare metals. Also, even in use, solar farms and windmills affect local ecosystems by the construction process, shadows, and, in case of windmills, noise pollution.
That's not to say renewables are bad - they are the best we've got - but any extra energy always comes at a cost, both financially and environmentally.
An air taxi is normally not a wise use of said energy.
Regarding transportation and storage, have a look into "LOHC", there's a lot of promising tech that is already beginning to solve these problems.
Will check out, thanks!
What are the advantages over compressed hydro on one side and metal hydride storage on the other?
Also, if I understand right, that does not address the issues of conversion efficiency.
So as far as I know, the benefit of LOHC is that compression/cooling is no longer required. Transporting/storing hydrogen becomes as easy as transporting any oil. There is an energy cost in the binding reaction, which is endothermic, but the unbinding reaction is exothermic so you get some of that energy back.
Unless you mean some other conversion?
I mean obtaining and using. You have energy losses converting water to hydrogen and hydrogen to energy, and those two compound nastily, even while using the most efficient tech.
Also, safety is a concern that can be addressed, but that was beyond my point. You still need to transfer hydrogen from point A to point B, and it is way more expensive and eco-unfriendly than moving electricity around. Or, if you want to put electrolyzers on each petrol station, you need to make sure the water supply is adequate and hydrogen storage is large enough to supply for peak demand, and that your station gets enough electricity, too (and you'll need more of it compared to a regular charging station).