Less than the Bitcoin network would use if the entire world switched to it.

At it's current usage where maybe 2-3% of the global population has ever actually performed a transaction on the bitcoin network, and next to no one uses it as their primary network for transacting, it used the equivalent energy of the entire country of Brazil, which has half the U.S. population (though less than half the energy usage)

To be clear, the energy usage is a function of price more directly than it is of actual usage, it just so happens that the price would continue to increase if people actually used it for real-world transactions.