In article , Wanderer
writes
Not sure if it's still done, but it's quite easy. Energy is measured at
bulk supply points (i.e.where the local leccy companies get it from the
national grid). Deduct all the units billed, factor in an allowance for
unmetered supplies, like street lights, and system losses, and you have
an indication of unbilled units.

I can remember in a certain place I lived they knew from the substation
which two streets were consuming twice as much as they were paying for.

J.
--
John Rouse