On Thu, 27 Feb 2014 16:33:32 +0000, Nightjar wrote:

If the electricity supplier cut down all the trees that could hit the
lines if they fell,

How much extra would you be willing to pay for your electricity to
achieve that level of maintenance?

Nothing - because they do that now.

We've just had about a dozen trees removed by Western Power - free of
charge to us - because their proximity to lines posed a risk. Having
moved in last year, we phoned them to arrange transfer of the wayleave
for some poles, and asked about the tree clearance. A surveyor was here
in days, and went a funny colour - the lines had allegedly been inspected
a couple of years previously, but clearly not particularly well...

They aim for five metres clearance from 11kv lines, and 3m from 230v, but
if the landowner is unwilling to co-operate they can get a court order
granting them access and rights to clear 3m from 11kv and 1m from 230v.
And that's horizontal distance as well as vertical. Anything that's
further than that but may pose a risk should it fall will be glared at,
too.

They take this very seriously indeed...