London plans to use the surfeit heat generated by the tunnels of its Underground as an environmentally friendly source of warmth for homes.

The 3.7 million pound project will see the Bunhill Heat and Power network in the north of London channel excess heat from the tubes of the city’s underground metro system to 500 homes in Islington, recycling energy that would otherwise be wasted.

The heat will be captured from the city’s Northern Line via a ventilation shaft maintained by the London Underground and a sub-station owned and operated by UK Power Networks.

The project is expected to significantly lighten the utilities bills of local residents and achieve reductions in CO2 emissions of around 500 tonnes per annum.

The Bunhill Heat and Power Centre already siphons the heat generated by secondary sources to furnish warmth to 700 homes in the area as part of a broader, city-wide initiative to promote the recycling of urban energy.

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According to a report released in July of this year, the initiative launched by London mayor Boris Johnson aspires to supply 25 per cent of London’s energy needs via “decentralized sources” by 2025, significantly shrinking the carbon footprint of one of the world’s leading cities.

These sources could include the waste heat which is generated by industrial and commercial processes as well as environmental heat which occurs naturally in the ground, atmosphere or nearby bodies of water.

In addition to heat generated by the underground rail, Islington council is also considering plans for the capture of the waste heat generated by high voltage electricity substations.

Islington Council and the European Union are jointly funding the project, contributing 2.7 million pounds and 1 million pounds respectively towards its realization.

The new scheme is also part of the EU’s CELSIUS project, which seeks to investigate methods for the recycling of wasted energy.

Martin Wilcon, UK Power Networks head of future networks, says the engineering method has tremendous potential for deployment in other parts of London, particularly given the utility’s pre-existing facilities.

“If it is successful there could be potential to replicate this and increase access to low carbon, low cost energy in other parts of the capital because we have electricity substations dotted throughout London,” he said.