Bitcoin is not a battery because the conversion from negentropy to hashes + waste heat is thermodynamically irreversible.

In this case bitcoin is acting as dispatchable demand, similar to how aluminum smelting is dispatchable demand.

A useful product is made on demand. https://twitter.com/balajis/status/1351214402167578626

The counterintuitive part is that the production of bitcoin security will eventually feed back into the creation of more renewable energy, just like aluminum or lipstick eventually helps to make more renewable energy.

It's intuitive that aluminum makes energy which makes aluminum which makes energy, etc.

But the same is true for lipstick, since more lipstick makes people happier and therefore more able to work, and that labor eventually feeds into making more renewable energy.

Well, the same is true for bitcoin.... at least that's the theory!

In some ways, cryptocurrency can actually make us worse off (ransomware, assassination, etc), but the hope is that the positive applications will win out.

Another example is AC units that make ice during the night when electricity is cheap, and use it to cool buildings during the day when electricity is expensive.
The useful product (coolness) is made at a time when electricity is cheap.

Dispatchable demand makes intermittent primary energy sources more profitable, and because they are more profitable more of them will be built.

So in a very roundabout way, cryptocurrency mining is like a battery: it absorbs power now, and makes more power later.