why dont we have wireless power then?
It's hugely inefficient to transmit power wirelessly.
About 8 years ago I conceived a plan to harvest power from electromagnetic waves permeating a particular space (my house I guess). It looks like free power (but of course isn't). If you can have a wireless radio then you can use that same power to trickle charge a battery, multiply by the various frequencies with powerful signals, etc., etc.. [I'm sure many others here have had a similar idea].
On a very short range this has come out as a gadget in the form of wireless charging pads (eg http://www.powermat.com/) and reports are out of using the trick above to charge lower power devices over long distances (http://www.technologyreview.com/communications/22764/?a=f).
Haven't seen anything of this sort in the shops yet though. I suspect it might not be legal in my jurisdiction.
Just because it hasn't been done yet, doesn't mean it can't be done. There may well be physical properties of our reality which haven't been discovered yet that will allow the efficient transmission of power through the atmosphere.
If you look at it from a needs basis...the world needs much more power (every Indian and Chinese family is eventually going to buy a fridge and a TV, and ricecooker etc etc). We can't go on indefinitely building billion dollar power stations to support that need.
There are two alternatives. An efficient way of transporting power long distances (continent to continent)...or...eventually localised power harvesting will be so cheap and ubitiquious that transporting power long distances won't be necessary. (Solar panels so cheap, like newspaper, they can be put on the roof and walls of every mud brick house).
Never say never is all I'm saying.
Indubitably, implicit in my statement is "It's [currently¹] hugely inefficient to transmit power wirelessly.".
I can imagine harvesting extra-dimensional power sources or vacuum-energy or as you say ultra cheap solar power conversion.
¹ No pun intended.