[I want the USA back]

The amount of current that can be obtained is very small, unless this device is very close to the transmitter. (Intensity falls off in inverse proportion as the square of the distance from its source)

The principle is sound; but how do you get enough power to make this worthwhile ?

[Red Badger]

First, get rid of that Inverse Square Law.

Then get rid of the Laws of Thermodynamics.............................

[MeanWestTexan]

Have it harvest cosmic rays. Use it in deep space.