A 25 per cent increase in investment in Britain’s electricity distribution networks to £1.3bn per year over the next five years has been given the green light by Ofgem, the energy regulator, to restore crumbling infrastucture and encourage new “smart grid” technology.

The plans, set out by Ofgem in its proposals for price controls on electricity distribution for 2010-15, will add up to £20 per year to an average electricity bill by the end of the period.