Five of the six companies that own and operate Britain's local electricity network have been told they must do more to cut costs for consumers.
Energy regulator Ofgem has rejected their business plans for the period between April 2015 and March 2023, with Western Power Distribution the only company to have its price controls agreed early.
Western Power serves customers in south Wales, the UK's Midlands and the south west of England.
Western's business plans include about £7 billion sterling of expenditure of which around £3 billion is for investment to upgrade and maintain its network.
In the case of the proposals from Western Power, bills should be reduced for its customers by an average of 11.6% or around £11.30.
Around 19% of an annual electricity bill is made up of network distribution costs.
"We understand that energy costs are a big concern for consumers and we set a high target for demonstrating value for money," commented Ofgem's Hannah Nixon.
"We are pleased that nearly all companies have pledged to cut bills, but we feel that most companies can go further in cutting their costs and expect to see further improvements when they resubmit their plans in March," she added..
There are 14 million distribution networks and as they are regional monopolies customers rely on regulation by Ofgem, rather than competition, to get the service they require at a reasonable price.