He cut the pipe in December. No gas, no oil yet his radiators are toasty. The heat is piped from the edge of a field beyond the village.

"My old oil tank is beside the house. I try and disguise it with plants, but I can't wait to get it removed now."

Most of the green home heating debate we've heard so far has been dominated by the choice of domestic heat pumps or hydrogen boilers. The idea of piping hot water to people's homes from a central heat source feels a little alien, reminiscent of Soviet-era Berlin.

But it is a massive untapped energy resource and modern systems give householders like Mike complete control.

"It's just how you would normally heat your home. All it does is replace the heat from a boiler system to hot water that comes out of a pipe from the ground.

"There's a thermostat that sits in the living room, and we can set that like any heating system."

Most electricity is generated by burning fuel to boil water and make steam. That steam then drives a turbine, while much of the heat is wasted, lost to the air via those giant cooling towers surrounding power stations.

It's reckoned that the wasted heat from industry and power stations across Europe is equivalent to all the energy used in France, or the waste heat from the Netherlands.

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At the moment, just 2% of British homes are attached to heat networks, that figure rises to 12% for the EU. But Andrea Voight, head of public affairs for the low carbon engineering company Danfoss, says there is so much more potential.

"I think district heating has a great and bright future, and it's not being tapped into right now. Half the final energy consumption in Europe is for heating and cooling.

"But there is still a vast amount of excess heat from power and industry which is available, which is not being used and which is just being blown in the air."

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But hot water pipes can be connected to any central heat source. The most climate friendly are heat pumps like the one near Mike Brewer's place in Swaffham Prior.

Here a partnership between Cambridgeshire County Council and Bouygues Energies and Services resulted in a £12m energy centre, with both ground and air source heat pumps.

At the movement these use electricity from the grid, but by the summer they will be almost entirely fed from a nearby solar farm. Fifteen homes are connected to this so far, but they are rolling out towards 300.

Emma Fletcher, who developed the project, said: "This is a hot water system. We're taking water to 75 degrees, and then we're pumping it round the village to people's homes.

"It's a water system that makes sure that people can use their existing wet central heating system, and they've had no major disruption to their house."

Though pricey to install, heat pump based networks like this could be appealing to the 1.1 million, predominantly rural, homes off the gas grid and still dependent on oil.

But what about using the wasted heat from all those existing power stations? In southeast London, just next to the Millwall Football Club ground, sits a massive energy from waste plant.

Run by Veolia, it burns unrecycled black-bag waste to make electricity. Some of the spare heat goes to 2,000 neighbouring homes, and they want to attach 18,000 more.

Tommy Folliard, head of energy recovery operations, said: "This is a low carbon solution as it replaces the need to have fossil fuels such as gas used to heat those homes. and energy from waste plants displace the need of sending that waste to landfill."

There is no escaping the fact that while energy from waste plants do reduce landfill, they still emit a lot of CO2 and concerns over local air pollution.

But using their heat reduces emissions elsewhere as connected homes use their own boiler a lot less or may not need one at all. Domestic gas boilers are meant to be phased out in Britain, yet they are still being installed and in the European Union it is estimated that a new boiler goes in every eight seconds.

Attaching pipes to many homes and businesses is a big infrastructure task with a lot of digging and disturbance but when fossil fuels are scarce, polluting and expensive it seems odd to be letting so much of their power vanish up the chimney.