By Alex Kirby BBC News Online environment correspondent

The energy review published by the UK Government spells out the way to a much cleaner, more efficient economy.

It is a radical vision of the sort that comes once in a generation.

Implementing it would require huge changes not only by industry but by individuals as well.

Whether or not it does become a reality will depend on the resolve of politicians.

In calling for a 40% increase in domestic energy efficiency, the review offers the prospect of ending "fuel poverty" - the inability of many people to heat their homes properly.

Some pensioners have had to choose between buying food and fuel, and campaigners say 30,000 people die annually from cold-related diseases.

Steady progress

The government's present target is for 10% of electricity to be generated from renewable sources like wind, wave, solar power and biomass by 2010.

The review recognises that the UK is far from certain to reach the target - and then doubles it.

It calls for 20% of electricity to come from renewable sources by 2020, a huge step change from today's 3%. It even thinks they could be supplying 30% by 2030.

Nuclear power remains commercially unpopular

Even so, the rate of change from fossil fuels - oil, gas and coal - to renewable sources will be far slower than in countries like France, Germany and Denmark.

So Friends of the Earth describe the review as "a welcome step in the right direction, but not a great strategic leap forward".

Some environmental campaign groups have criticised the review for not rejecting nuclear power outright.

It does leave the door open to a new generation of nuclear reactors. But it does so on terms which are unlikely to be met.

Thumbs up

Dr Paul Jefferiss, head of environmental policy at the Royal Society for the Protection of Birds, was a member of the group advising the Energy Minister, Brian Wilson, on the review.

He is also on the Department of Trade and Industry's energy advisory panel and the board of the Carbon Trust.

Renewables need to compete on equal terms with fossil fuels

Dr Jefferiss told BBC News Online: "I think the review is a very positive step forward, and I hope the government will pay close attention to it.

"The recommendations on energy efficiency and the use of renewable fuels are quite ambitious.

"The economics of nuclear power still make it unlikely that it'll be commercially viable.

"The review makes a clear recommendation to prioritise the environment and carbon reduction as objectives in energy policy.

Decision time

"But it is a pity it didn't stress more strongly the need to price carbon as the way to achieve reductions."

Many scientists say carbon dioxide is the chief human contribution to global warming. The review examined ways to achieve a 60% reduction in carbon emissions by 2050, which the Royal Commission on Environmental Pollution has said will be necessary.

So the review provides a map to a scarcely discernible low-carbon future. It is now for the politicians to decide whether and how fast the UK takes to the road.

One key indicator will be whether they are willing to help renewables to compete equally in a market that remains loaded against them.