Regarding the Bitcoin, it is true to say that it generates a tremendous electrical energy consumption.
The amount of electricity that is spent to get the Bitcoin protocol going  is indeed enormous,
but you have to understand, it is absolutely vital for the future development of blockchains
this characteristic of the Bitcoin is not general at all.
Blockchains do not have, generally speaking, the obligation to have a system,
what we call the Bitcoin mining system, which generates a large electricity consumption.
It's a mistake to believe that it will be a hindrance to the development of blockchains.
That is totally wrong.