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the dark side of cobalt

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langwadt:

--- Quote from: tszaboo on July 11, 2023, 09:05:21 pm ---
--- Quote from: langwadt on July 10, 2023, 01:17:03 pm ---
--- Quote from: nctnico on July 10, 2023, 12:54:19 pm ---
--- Quote from: Nominal Animal on July 09, 2023, 07:32:29 pm ---Why is it that activists are always telling others what to do, instead of doing it themselves first [snip]

--- End quote ---
Because if they do that, they'll end up living in caves or huts made from tree branches.

--- End quote ---

freezing, hungry, in th dark ...

--- End quote ---
I believe the plan goes: No meat, no heat, no air-conditioning, no cars, no flying, no babies. Sit at home, alone, poke your phone in the dark. Eat those bug burgers, that simultaneously make you fat and provide protein that you cannot digest. Cut off some body parts, and pay the lifetime subscription to hormones and insulin. Own nothing and be happy.
And if you think this is conspiracy theory, just go on the website of the WEF and this is their mission statement.

--- End quote ---


wood phone power by hand cranking?

Infraviolet:
Ofcourse hydrogen is less energy efficient than batteries, generating energy as electricity to power electrolysis to make hydrogen, and then putting that hydrogen in a fuel cell to convert back to electricity to produce kinetic energy is always going to be less efficient than storing the electrical energy directly in a battery, but I'd say this isn't such a problem really.

Why?

Well, in the sort of ideal future grid we should be working towards there will be ample energy to spare. Nuclear fission power can't be throttled back easily, it runs at close to full power all the time, (fusion power would perhaps be the same once available?) so there would be excess energy in the grid much of the time. Energy efficiency is not the top priority, sure it is nice to have, but the future we should be planning for is one of cheap plentiful energy, exactly as the original hopes for atomic power suggested. When you've got energy to spare, the chemical nature of H2 fuel, and its energy density makes it superior to batteries (not to mention speed of refuelling as vs time to charge up batteries) even if you lose a large proportion of energy in the conversion steps. Futures planning for electric cars optimised for a grid too feeble to supply the true needs of a place are completely missing the point, the only type of grid which can usefully supply an industrialised civilisation is one which is producing the sort of levels of excess power that energy efficiency is no longer the top concern.

Siwastaja:

--- Quote from: vad on July 11, 2023, 07:06:22 pm ---Forget lithium-ion batteries; their energy density is laughable.

--- End quote ---

I don't know if that was an ironic comment or not, but you realize the the energy density of current li-ion, already exceeding 300Wh/kg at cell level, is just fine for wheel-based mobility? It's not like it's making electric vehicles significantly heavier anymore. Of course new improvements are welcomed, but their importance is dropping. I remember the analytical discussions from 2009 or something when the conclusion was that energy density needs to double and cost needs to halve. From 150Wh/kg to 300Wh/kg, that's what happened except the cost is at one quarter from around $400/kWh to around $100/kWh (even better inflation-adjusted actually). It was a gradual breakthrough with no any single big jump, but small improvements accumulating.

Infraviolet:
Batteries, 300Wh/kg, hydrogen fuel 33000Wh/kg.

Siwastaja:
And your mother's ass, 3300000000000000Wh/kg.

What matters in engineering is if a specification is good enough, not "bigger is better". For example, we use 25V rated capacitors on 12V systems, not 450V even when they are available, because those come with other compromises.

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