It seems the Blockchain tech won't be something to invest in to make money, but it does seem to be a technology that will be useful in the future to help spread and maintain renewable energy. This is from RMI, which is a very respectful organization:
Blockchain Is Reimagining the Rules of the Game in the Energy Sector - Rocky Mountain Institute
Interested in blockchain implementations and read through the paper. Green energy and blockchain are very often pitched together nowadays, but I still fail to understand what is the use case for blockchain mentioned in the paper. The biggest issues with blockchain implementations start where blockchain meets a real world - it is hard to avoid centralization here which is the whole point of the blockchain.
For example, you can perfectly track electricity usage/generation with blockchain, but at the end of the day, it is the utility company sending electricity to your outlet, you can not deliver electrons within the blockchain. Same happens with money - at the point where paper money transfer into real money, the centralization happens and that usually kills the whole idea.
You can notice these points easily - they usually have some kind of "oracle" or third party arbiter. The solution in the paper still looks centralized, so it looks like internet connected smart meters would be sufficient without the whole blockchain infrastructure. I might be wrong and ready to discuss is someone has ideas on that.