If you have two resonators that are the same size -- we'll call that D -- and the distance between the coils is less than or equal to D, we can transfer 95% of the power. If you pull them further apart -- say 5D -- the percentage of power transferred is about 10%.

Generally speaking, most of the systems we're building operate somewhere in that spectrum. If you're a car charger and you're doing 3,000 watts you care a lot about high efficiency. If it's a cell phone, you don't care as much. If I'm replacing an alkaline battery, if it's only 1% efficient it will still beat the pants off of a battery because disposable battery power costs 350x grid power.

So it's largely a function of the size and distance. But you can imagine a house having a coil laid up in the ceiling to power a range of devices.

Milliwatts to kilowatts, basically. And distance-wise you can go centimeters to meters. You generally don't do kilowatts over meters.