I've only recently begun to understand how Bitcoin works. My comments regarding the unsustainability and unsuitability of it as a currency seem to be confirmed by others who know a lot more about how it works.
Here's a Cleantechnica article.
https://cleantechnica.com/2018/01/12...p-drastically/
Distributed ledger is a superior idea, but the currency also needs to have a relatively stable, inflating value, and consume small amounts of power.