The large amount of waste heat produced in the Northern Line, a subway route that runs from south-west to north-west London, will be channeled through tubes into up to 1000 residences and businesses in Islington.
The project is a pioneering attempt. Studies regarding the viability of such a plan have been conducted but it has never been applied before. Ramboll, the firm in charge of the heating network construction, stated that the project is the first in Europe to recycle waste heat from an underground facility providing residences with a low-cost and environmentally friendly solution.
The scheme is part of a larger UK's endeavor that aims at using renewable energy replacing fossil fuels. The government plans to ban gas boilers by 2025. Waste heat from underground lines, power plants or mines could be used to warm the buildings. Currently, 800 houses are warmed by heat deriving from the Bunhill Energy Centre through Bunhill heat network in Islington.
About 50% of the consumed energy in the UK is used for heat, producing significant emissions. According to GLA (Greater London Authority), 38% of the city's demand could be satisfied if all the waste heat produced in London was manipulated. “Almost half the energy used in the UK is for heat, and a third of UK emissions are from heating. With the government declaring that we must be carbon-neutral within 30 years we need to find a way to take the carbon out of our heating system. The opportunity that has become clear to the decentralized energy community is the idea of capturing waste heat and putting it to use locally,” Tim Rotheray, director of the Association for Decentralized Energy, stated.
The UK is currently planning to utilize its large potential of geothermal energy. In Stoke-on-Trent, a $63 million project that will use energy from hot water sources located underground to heat conventional water, is underway. When it's completed (in 2020), the annual carbon emissions in the city could be reduced by 12,000 tons. Moreover, a new project in Edinburgh suggests the usage of hot water stored in a large mine to create another heating network.