The question is rather vague, but if you mean the ability to transfer energy from one place to another without wires between the two places, I can think of dozens of approaches off the top of my head. Solar power is an obvious example...you can plug in a lamp, shine it at a solar cell, and it's converted back into electricity. Wind power is another obvious one...plug in a fan, point it at "wind mill" style rotors connected to an electric motor, and out comes electricity. There are lots of forms of energy which can be converted to and from electric power, with energy forms that are transmitted without wires. Other examples...hydroelectric energy using water pumps to generate pressure and turbines to convert back to electricity, vibrational energy using speakers to generate and piezo transducers to receive, thermal energy using resistors or compressors to generate and peltier junctions to receive, magnetic energy using electromagnets to generate and induction coils to receive, and so on.
If you mean a way to transmit 20 kilowatts to each of 20,000 houses from a central station located two miles away, it would be really challenging, and the inefficiency would certainly make it impractical...converting between forms of energy introduces ineffiencies. Even wireless battery chargers, like
http://www.splashpower.com/vision/vision.html , which use magnetic fields to transmit power less than an inch, waste a lot of power compared to plugging in a wire.