Nikola Tesla thought that Radio waves worked on a 'circuit' where the signal was transmitted via the 'aether' and returned via the Earth and he believed that Electricity worked the same way and so could be transmitted through the 'aether' too. At the time people didn't know enough about how electricity worked including Tesla but that didn't of course stop him coming up with ways of using electricity after all you don't need to know how a wheel is made in order to roll one along the road. The last modern 'wireless power' transmission systems I came across were based on firing very powerful microwaves at a receiver that would then turn that energy into an electrical current. A rather different idea where electricity is turned into energy that is then turned back, with a considerable loss in the process, to electricity again. A great way to get energy to places where hard wiring isn't available but far from cheap, solar would probably be a better option, plus I believe that anything that happened to pass through the focused microwave beam might find itself somewhat toasted and of course it would depend on 'line of sight' between transmitter and receiver. When I worked with Microwave radar equipment we used to regularly have to clear away the frazzled pigeons and that is a relatively low powered microwave system. In a local area I would imagine they are using some sort of induction system where they are creating a magnetic field that will then induce a current in a receiving coil. That would mean of course that you are, yourself, surrounded by that magnetic field and there have been various complaints over the years about the effects that magnetic fields might have on the human body.
Don't get me wrong, Tesla moved a lot of things forward but he was 'of his time'. He wasn't an Alien, he didn't have access to arcane knowledge no-one else has and he was feeling his way in the dark. He had the relatively new phenomena at his hands to experiment with time and money to allow him to experiment. The guy was good at what he was doing and he was at the forefront of working with a new technology but, if he truly had discovered a way of transmitting electricity wirelessly the electricity companies would have jumped at it although the wouldn't have made it 'free' to the end users. Think of the savings they would have made not having to install pylons, cables, substations etc.
