But most Bitcoin mining is not that. I feel like Joni Mitchell in the Big Yellow Taxi: "They paved paradise and put up a parking lot" [2] Why are we allowing this to happen? (Well, at least outside China)
The aluminum analogy is apt, but at least I can cook eggs on aluminum pans and wrap my leftovers in tinfoil, even if I can't turn it back into electricity. Bitcoin and other PoS schemes have no such upside.
1. If you spend energy to produce, say, charged batteries or aluminum or biodiesel, that allows you to do something useful with those resources without needing corresponding energy consumption later. When you spend energy to mine Bitcoin, there's no way to use it to decrease your future energy needs; you can only use it to pay others and induce them to produce something you want, spending even more energy in the process.
2. With most energy production methods, you can get at least a bit of extra efficiency by scaling up. But the Bitcoin economy in aggregate can't produce coins at a higher rate; the best you can do is compete for a larger slice of the fixed pie. So even though each individual miner is incentivized to spend more and more energy, the economies of scale are negative.
I don't like the energy wastage of Bitcoin anymore than anyone else. This needs to be fixed and firing up old fossil fuel plants, for example in upstate New York, needs to be outlawed.
I just thought the Bitcoin as battery was interesting and I stand by it. I can imagine cases where abundant renewable energy sources are not being utilized because they are geographically remote and Bitcoin mining is a way to get some value out of it.
[1] https://news.ycombinator.com/item?id=26609247 [2] https://www.nbcnews.com/science/environment/some-locals-say-...
If you use energy to move bits in a computer at the end you have heat and the result of a calculation. If that calculation was just to proof that you did the calculation, well, that doesn't sound very efficient to me but that's just my opinion.
What I'm pretty sure is that it's not a battery.
But the extra money is of no help to the climate. From an Iceland's point of view, the alternative to using excess geothermal to Bitcoin mine is (i) build smaller geothermal power plants which have even smaller carbon footprints to build/maintain or (ii) reduce the carbon footprint of other countries by courting their energy-intensive industries with low cost renewable electricity.
The bitcoin network (and all PoS) schemes incentivize waste beyond merely throwing away power: they incentivize e-waste, frivolous cooling and refrigerant use, &c. It's strictly better to just dump excess capacity than it is to use it on PoS schemes.
Edit: to make the analogy more complete: a bitcoin is, in effect, proof that energy has been wasted. Using a bitcoin to purchase renewable power from a windfarm is tantamount purchasing that power with empty batteries or empty oil drums.