The Bitcoin network is a global energy buyer with properties unlike any other. It will continue to bid for stranded and excess energy that cannot be used for other applications. With last year's Chinese mining ban the network has become more distributed than ever and is likely to be very resilient to US domestic energy-price swings.

PoW is the solution to an important set of interconnected problems, and as long as the network has value, PoW will keep bidding for energy to secure that network.

It's been said, correctly IMHO, there is only Proof-of-Work and obfuscated Proof-of-Work. Rephrased, nothing is cheaper than Proof-of-Work: https://www.truthcoin.info/blog/pow-cheapest/