The London Underground is famous for lots of things, good and bad, but there’s no denying that the warm temperatures and muggy air down there can make it an uncomfortable place to be.
However, this week Transport for London (TfL) announced that this heat will soon be given a new purpose. By the end of 2019, it will be being used to heat up to 1,000 homes and businesses in the local area.
How will it work?
The London Underground produces heat at a temperature of 18-28°C (64 – 82F). A heat pump will capture this heat via ventilation shaft on City Road and use the heat to provide hot water and heating.
The scheme is a joint project between Islington Council, TfL and engineering firm Ramboll. Warm air from a disused station on the Northern Line, which would otherwise have been wasted, will be piped to homes and businesses in Islington as part of the heat network which is already in place there.
It is the second phase of the project which currently takes excess heat created in the Bunhill Energy Centre is channelled to 700 homes in the area while generating electricity for council housing, a leisure centre and schools.
What is a heat pump?
There are 2 types of heat pump (ground source and air source) but a specialised air source heat pump will be used in this system. It extracts latent heat from the air (even in temperatures as low as -15°C) and compresses it to increase the temperature so it can be used to heat your home and / or water for radiators, underfloor heating systems and taps.
In domestic settings it can be installed either in addition to your existing heating system or as a replacement. It uses a small amount of electricity to run but does not produce carbon when working unlike gas or oil boilers. This is not only better for the planet, but in many homes it can also reduce heating bills.
Why is this such big news?
There are many initiatives across the UK using ‘waste’ heat produced by power plants, factories, disused mine shafts and rivers to heat district heating networks. However, the Islington heat network plans to use heat from underground train lines are the first of their kind in the world.
According to estimates by the Greater London Authority, London’s waste heat could – if harnessed properly – be used to supply 38% of the capital’s demand for heating. If district heating networks continue to expand, this could cover 63% of demand by 2050.
Another potential benefit is that removing warm air from the tube lines could cool temperatures for commuters.
It is hoped that this Islington scheme could inspire more London districts to follow suit as the UK continues to look for low carbon heating solutions after the Government’s recent pledges.
What has the UK government committed to?
In March 2019 the government announced that it would be illegal to connect new homes to the gas network from 2025, and in June 2019 they committed to the UK producing net zero carbon emissions by 2050.
Tim Rotheray, director of the Association for Decentralised Energy, said: “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 decentralised energy community is the idea of capturing waste heat and putting it to use locally.”
Lily Frencham, head of operations at the Association of Decentralised Energy, said: “Using surplus heat rather than wasting it is a great way to ensure that we cut carbon emissions whilst helping people stay warm at an affordable cost.”