Now that formal plans to tap into the deep-fried city of London's vast underground reserves of sewer-clogging cooking grease in order to help power homes and business have been unveiled, it should probably come as no surprise that another rather unsavory, subterranean element is being eyed as a source of emissions-slashing energy in the British capital: stinky, stifling subway heat (and there's more than enough to go around).

The waste heat — generated by the trains’ motors and breaking systems, lighting systems, operating equipment, and the bodies of millions of harried commuters and tourists — will be captured at a ventilation shaft on the London Underground’s Northern Line before being distributed to over 500 homes across the borough of Islington through an existing green power network. The first-of-its-kind plan, geared to ease the sky-high wintertime heating bills experienced by Islington residents while stamping out an estimated 500 metric tons of annual carbon emissions, is part of London Mayor Boris Johnson’s overall scheme to slash the city’s emissions by 60 percent while producing 25 percent of the city's energy from local, secondary sources by the year 2025.

Says Martin Wilcox of UK Power Networks, an electricity delivery and maintenance firm that owns a local electrical substation that will be providing a supplementary supply of heat to the pioneering project: “We are carrying out a feasibility project exploring the potential to capture waste heat from one of our high voltage electricity substations and use it to warm local homes for the first time. 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 which keep the lights on for millions of homes and businesses."

This new waste heat recovery plan — launched as a partnership between UK Power Networks, the Islington Council, Transport for London, and the Mayor’s office —will join Islington's groundbreaking Bunhill Heat and Power Network which, since being launched in 2012, has supplied over 700 homes with excess heat captured from a local combined heat and power (cogeneration) plant. The heat itself is distributed to local housing estates through a 1.4 mile network of pipes ("In the same way that we use heat from a car engine to keep us warm when driving, the energy centre uses the heat created from producing electricity to help heat buildings and provide hot water.") The additional heat captured at the Northern Line Tube vent and at UK Power Networks' substation will be funneled through these same pipes to reach the aforementioned 500 additional homes in the southern section of the borough.

"The expanded Bunhill Heat Network will cut energy bills for hundreds more local people. With energy prices going up and up, it's vital we do what we can to cut bills,” explains Islington Council Leader Richard Watts. “It's all part of the Council's work to help people manage the rising cost of living. Last winter was one of the coldest for decades and record energy prices meant many families on fixed incomes spent it in misery, unsure whether to heat or eat."

Funded in part by the Islington Council and the European Union, the project was launched as part of the EU's CELSIUS project, a four-year, five-city (London, Cologne, Rotterdam, Gothenburg, Genoa) pilot initiative geared to "demonstrate how the efficiency and performance of district heating systems can be improved by focusing on the opportunity that they offer for capturing and utilising sources of waste heat that are generated within cities."

Via [Wired UK]

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Matt Hickman ( @mattyhick ) writes about design, architecture and the intersection between the natural world and the built environment.

London homes to be kept toasty with Tube-harvested heat
Waste heat captured from a vent along the London Underground will be used to keep homes in the borough of Islington cozy without the horrifying heating bills.