But blockchain at its core is just a distributed database. One that has no central authority, can not be tampered with, cannot be altered, nor taken down if parametrized accordingly.
Which is completely useless if the data that goes into that blockchain isn’t guaranteed to be correct. And if there’s money in it you can bet your ass that someone will try to game the system.
You’re also glossing over the existing grid that needs money to be maintained while complaining that energy companies want money. Yes, there’s a general problem where society allowed (and partly encouraged) sociopaths to be unrestrained greedy assholes that needs some kind of solution, but not all companies are useless leeches, it’s “just” an all-pervading corruption that needs to be dealt with - and as long as that hasn’t happened, every idealistic solution faces the threat of being corrupted itself.
Still useless for anything that depends on external data, since there can be no guarantee that what has been entered is correct. What’s the point of a consistent record of garbage?