Reminder: a currency's "backing" is whatever you can exchange it for to ensure scarcity. Bitcoin doesn't inherently let you exchange it for anything in particular (including energy), it has its own scarcity.

I used to go along with "Bitcoin is backed by energy" until I realized the dollar is actually backed by energy, and it's a huge problem for the dollar, which needs to be backed by a hard money like gold or silver. #Bitcoin just doesn't have that issue