
In the last few years several projects have been proposed to collect solar power in orbit and then transmit it to Earth. Two of the possible designs are: a) generate power using solar cells in space and transmit the energy to Earth as microwaves, and b) reflect sunlight to boost power generation for Earth-based solar panels.
Several experiments have been run so far to examine the viability of the long-distance power transmission. However, up to my knowledge, direct power transmission from space to ground hasn't been tested yet. This question will resolve positively as soon as it is first demonstrated.
To distinguish power transmission from a radio or laser communication, the receiver has to have efficiency >0, i.e. it should produce more power than it uses for the reception.
Returning charged batteries in the landing modules doesn't count.
I do not bet on my own questions.