Paul J Gans wrote:

The Drake equation assumes that the ETs will be blasting out
electromagnetic waves at a furious rate.  *We* started doing
that only in around 1920 or so and already we are doing less
and less of it.  By 2120 we could easily be using wired or
directed sources and no indiscriminate electromagnetic radiation
at all.

I'd look for industrial emissions, such as signals from the cross-
country electric power grid.  But maybe we will quickly improve our
efficiency and reduce energy losses, or switch to a 100% hydrogen
economy.

I'm told that the United Kingdom is unique in having power demand
surges in the evening at particular times each day.  This is because
certain television programmes have large numbers of viewers, and when
the programme breaks or ends, tea is brewed, by using electric
kettles.  With digital choices, catch-up, and services such as
YouTube, this may soon change.  (And anyway, I recently heard about it
once more from the people who broadcast the television programmes for
which claims are made.)