Replace any currency with any power generation you want.
In prison, its the work of smuggling that stores economic value in cigarettes. In a gold based system, its the work of mining elements out of the earth that stores economic value in base metals. In a peer to peer network, its the work of electricity(of any kind whatsoever, clean or polluting) that stores economic value on a fair distributed ledger.
Money is about storage of work, and quite frankly the weaker the money used to store energy, the more lethargic and rusted the whole economic system gets. Fiat, i.e. "proof of wasted energy" just does a lot of work and lets it evaporate in economic terms leaving the entire society that uses it in constant need of more and more fiat because that energy, that work done, keeps dissipating.
It doesn't matter what money is: seashells, carved rai stones, arrowheads, cigarettes, ramen, non-livable apartment homes sold solely for wealth storage, luxury cars, art, gold, printed paper with your uncle sam's face and "guarantee" stamped on it, centralized entry in a private database, decentralized entry on a public blockchain. Society needs money in order to achieve higher levels of cooperation. Might as well use the strongest form of money that exists. And as far as I know, it aint proof of wasted electricity, i.e. fiat.