The British government has unveiled a policy white paper for a wide-scale low-carbon energy switch to help meet its ambitious 2020 emissions reduction targets.

Energy and climate change minister Ed Miliband announced targets to double the proportion of UK power generated from low-carbon sources to 40 per cent by 2020. Of that portion, more than three-quarters, or 31 per cent of all power, would come from renewables with the rest from clean-coal and nuclear plants.

Miliband flagged a wide portfolio of renewable energy sources to meet the target including a big expansion of wind energy and development of wave and tidal energy in England’s south-west.

The Low Carbon Transition Plan also entails measures to increase energy efficiency and speed the deployment of low-emission cars with alternative fuels. Along with the power generation measures, this will help Britain meet its EU target for 15 per cent of total energy needs to come from renewable sources by 2015.

The government will also fund four carbon capture and storage demonstration coal-fired power plants, although the technology may not be widely deployed by 2020.

The plan estimates the low-carbon sector growing at 4 per cent a year until the middle of the next decade and producing 400,000 new jobs.

The government has already committed the UK to lowering greenhouse gas emissions by 34 per cent below 1990 levels by 2020, among the most ambitious targets set by developed nations.

Miliband said the low-carbon energy target is designed to see the power sector deliver 230 million tonnes of emissions reductions, half of the cuts needed from current levels by 2020 to meet the emissions target.