Stationary High Altitude Relay Platform (SHARP)

In the 1980s, Canada's Communications Research Centre created a small airplane that could run off power beamed from the Earth. The unmanned plane, called the Stationary High Altitude Relay Platform (SHARP), was designed as a communications relay. Rather flying from point to point, the SHARP could fly in circles two kilometers in diameter at an altitude of about 13 miles (21 kilometers). Most importantly, the aircraft could fly for months at a time.

The secret to the SHARP's long flight time was a large, ground-based microwave transmitter. The SHARP's circular flight path kept it in range of this transmitter. A large, disc-shaped rectifying antenna, or rectenna, just behind the plane's wings changed the microwave energy from the transmitter into direct-current (DC) electricity. Because of the microwaves' interaction with the rectenna, the SHARP had a constant power supply as long as it was in range of a functioning microwave array.­

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I thought this was interesting.
If this was done in the 1980's what can be done now, 20+ years on? Why are we still cluttering up space sending satellites into geostationary orbit if these things could give us many of the same advantages? Where is this technology now?

Practically, I suppose there are only so many spaces for these planes to fly and we would have to avoid them all flying in circles up there when we wanted to get into space. There is probably enough microwave energy whizzing about already to utilise this technology - if only we could find the right frequency to use it.