It was eventually determined that there were better, more efficient, and
less troublesome technologies available for broadband delivery, and dropped,
at least here, although I believe that there may still be some places in
Europe where the tests are still happening. Bear in mind also, that the
generating and distribution companies, use this, or a similar high frequency
technology, in-house to carry telemetry data around their grid distribution
network.

What over the 475 kV grid?, don't you mean via the fibre optic at the
top running along the "aerial" earth wire?....

--
Tony Sayer