When looking at Power Ledger and what they are trying to accomplish you ask yourself where would they fit into the puzzle that is Elon Musk. For instance: Elon Musk dreams to colonise Mars his ultimate challenge, however with this ambition he needs some key factors to fall into place before it could eventuate.
These key factors would be a

self sustainable energy system run on solar energy (Power Ledger)
a low energy un hackable and secure perfect working system that can scale, communicate with machines and technologies, link devices and basically run itself ( Iota)
obviously the machines and devices themselves (Tesla etc)
a supercomputer to be the brain of the system( Golem)
public approval ( so it will have to be tested first in just say Australia’s dessert and solar climate)
It might be me but these projects that have already began to spring up through ICO funding cryptos seem to fit into a puzzle that are endorsed by all the billionaires that have changed the world for the future such as Elon Musk, Bill Gates, Richard Branson and so on. Either this club of elites has already began turning the wheels or they need to catch up for a beer. 🍻