UK regulators have handed the six groups that own the country's electricity networks - and by extension their shareholders including renowned investor Warren Buffett - a £24 billion bill for network improvements, and shaved £11 a year off consumers' bills.

The power regulator, Ofgem, has today signed off on eight-year business plans for the six companies - Central Networks, Electricity Northwest, Northern Powergrid, UK Power Networks, Scottish & Southern Energy and SP Energy Networks - that control regional electricity-transmission systems around the UK.