It can’t be turned off at will if you’ve got a huge investment in mining infrastructure that needs to pay for itself and the margins are so thin you can’t afford downtime.

Aluminium smelting.

So, trying in good faith to understand, isn't the problem that the output in this case is physical, while Bitcoin's energy-to-money output is digital?

Why is that a problem? The price for Aluminium is more stable than the price of bitcoin.

I mean, you tell me. I don't mean to sound snarky. But it seemed to be your point that existing processes which turn energy into money are a hindrance to clean energy investments. The previous commenter offered an example of aluminum smelting. Which is not exactly what I meant, because I was being more literal when I was talking about an energy-into-money process, and that example appears to really mean energy-to-aluminum-to-money. I understood this example to mean that the reason other existing "energy-to-money" processes have been a hindrance to clean energy investments is that they have byproducts which negate clean efforts. In contrast to this, renewable crypto mining has no physical byproducts. Dunno if I misunderstood something.