Britain on Monday sped up its work to connect soaring numbers of renewable energy projects to the electricity grid as regulator Ofgem unlocked 7.7 billion pounds of investment for Scottish network operators to modernise their high-speed grids.

Ofgem allowed utilities Scottish Power and SSE to make transmission charges of an initial 2.9 billion pounds between 2013-2021, with a further 4.7 billion pounds chargeable over the period if needed for additional projects approved by the regulator.

The charges will cost consumers 35 pence more per year as transmission charges make up around 2-3 percent of household energy bills, Ofgem said.

The regulator, which has the power to limit the amount of money operators can charge for transporting energy, sped up its so-called price control decision to help companies deal quickly with a growing amount of renewable energy projects.

The proposal is subject to a consultation period.

The fast-tracked companies can now benefit from the swiftness of the process and concentrate on delivering efficient network improvements for consumers, said Hannah Nixon, Ofgem's senior partner in charge of the price control process.

SSE will receive 5.1 billion pounds and Scottish Power around 2.6 billion pounds in revenue from transmission charges, Ofgem added.

Scottish Power said it will use the money to connect around 11 gigawatts (GW) in offshore and onshore wind power projects and to double electricity export capacity on cables between Scotland and England, among other projects.

This investment will create up to 1,500 new jobs and deliver plans to connect enough green energy for 6 million homes, said Frank Mitchell, chief executive of Scottish Power Energy Networks.

The other owner of high-voltage electricity networks in Scotland, National Grid, which was not fast-tracked, will find out about its separate allowed transmission charges for 2013 later this year, Ofgem said.

The majority of new renewable energy projects, especially wind farms, will be located in the windier regions of Scotland, while most of Britain's energy is consumed in the south, creating a challenge for electricity transmission.

Britain aims to produce 15 percent of its energy from renewable energy sources by the end of the decade, which, on the back of government incentives, has spurred a high increase in green energy projects.

(Reporting by Karolin Schaps, editing by William Hardy)