Cameron wants us to measure up to the neighbours on energy bills

Homeowners could be told how much gas and electricity their neighbours use, under green plans unveiled by David Cameron today.

The Tory leader said information could be included on bills showing families the average consumption of homes of similar size and age.

Homes would get a free 'smart meter' to help reduce energy use, said Mr Cameron, who also came out firmly against a third runway at Heathrow.

He said he would not be diverted from his environmental agenda by the economic downturn, insisting that record oil prices showed Britain 'can't afford not to go green'.

Unveiling a 'blue/green charter', Mr Cameron said: 'When oil is moving towards $140 a barrel, when families are being hit hard every time they pay their gas bill, fill up their cars or do the weekly shop, are you telling me we shouldn't  -  we can't  -  go green? The era of cheap oil is well and truly over.'

A Tory government, he said, would 'wean' the UK off its reliance on fossil fuels, tell car makers to produce cleaner models or force gas guzzlers off the road, and block future developments of old-fashioned coal-fired power stations.

A key step would be the inclusion on bills of information letting households work out how much energy they are using compared to their neighbours.

Families would not be told how much energy other houses in their street are using, simply the average consumption for homes of similar size and age.

Mr Cameron said: 'Research in America shows that if we find out our neighbours, or households similar to ours, are using half as much energy as we are, then we're much more likely to bring our own consumption down in line.'

The Tory plans do not go as far as one American scheme, where householders get a 'smiley' face on bills if they are consuming below-average amounts and a 'grumpy' face if not.

Mr Cameron said every home would get a 'smart meter' giving a real-time reading of the amount of power being used in a home at any one time.

As well as giving a live reading, they are connected directly to utility companies, doing away with the need for meter readings and estimated bills. Tory sources said energy firms would be expected to bear the cost of installing the meters.

Experts say smart meters encourage lower energy use because they show how much it is costing to leave TVs, DVD players and other devices on standby. In the UK, appliances left on unnecessarily waste £900million of electricity a year.

The wind turbine at David Cameron's home

The meters also allow homeowners who generate their own energy  -  for example, through solar panels or wind turbines  -  to sell any excess back to the National Grid.

Mr Cameron has just got planning permission to reinstall a wind turbine on his £1million family home in West London.

Attacking the Government's plans for hikes in road tax on larger family cars bought up to seven years ago, Mr Cameron also pledged that any Tory 'green taxes’ would be designed to influence future behaviour.

Any new coal-fired power station would have to adopt 'clean coal' technology which can eliminate 85 per cent of greenhouse gas emissions, Mr Cameron said.

The policy would effectively rule out the building of coal-fired plants with no means of trapping CO2.

He also came out firmly against a third runway at Heathrow, saying the economic and environmental arguments for expanding Britain's biggest airport are badly flawed.

He said that on top of 'serious' worries about the environmental impact of a third runway, there were doubts about whether Heathrow's management could cope with the expansion after the chaos at the new Terminal 5.

And he said the key economic argument  -  making Heathrow a giant hub for transfer flights  -  was badly flawed because connecting passengers generated tiny amounts of cash.

Transport Secretary Ruth Kelly accused Mr Cameron of being 'irresponsible' in opposing Heathrow expansion, but green groups broadly welcomed his commitments.