National Grid margins expected to be 'lower this winter'

The National Grid is expected to confirm on Tuesday that the amount of spare capacity has decreased significantly from last year.

The operator of the national power network is publishing its yearly outlook, which predicts how energy supply will match demand.

It is expected to say spare capacity has fallen to a seven-year low, but that measures have been taken to make sure the lights stay on.

Esyllt Carr reports.