Energy is most definitely not fungible. The availability of energy and demand for energy can vary by greatly location. For it to be fungible, energy would need

Energy is most definitely not fungible. The availability of energy and demand for energy can vary by greatly location. For it to be fungible, energy would need to be free to transport, or demand for energy would need to be location insensitive. Bitcoin actually does a lot of good things here because it is location insensitive. For stranded energy, say methane flare gas, there is not an economical way to use the energy of this gas because transport is too expensive and demand is too far away. In this way, the bitcoin mining is consuming energy that wouldn't actually otherwise be marketable. It is also greatly reducing greenhouse emissions without demand for the energy, the methane would be burned, which has much worse emissions than when consumed in a generator.