Haha, ok the long version:

it means bitcoin the money is backed by the fact that you can 100% verify everything about it, so you don’t need to have it “backed” by anything, you already have proof. The whole point of “backing” is proving that it can’t be arbitrarily created, that it has a meaningful and incorruptible monetary policy behind it. And of course you have that on your full node, better than any other monetary good in human history.

While bitcoin *transaction settlement* is backed by energy. Because when you do a transaction, the number of confirmations are undeniable proof as to how much energy is needed to reverse it.

So the bitcoin itself has nothing to do with the energy, the bitcoin is defined by the monetary rules, which are software. But the finality of your transactions *is* backed by energy, and has an open and measurable amount of assurance that it has been completed and will not be undone.