Bunhill 2 is the first initiative of its kind in the world, supplying cheap, clean heating by using waste heat emissions from the London Underground network. The system supplies low-carbon heat and hot water to hundreds of local homes, two leisure centres, and some commercial premises, with council tenants receiving a 10% discount on the standard heating charge – helping to alleviate fuel poverty in the borough.
The London Borough of Islington commissioned the Bunhill 2 project to expand its existing Bunhill heat network. In the original network, the hot water was supplied by a gas-fired combined heat and power (CHP) plant. With the network being expanded to supply a further 500 homes on a nearby council estate and increasing capacity for 1,000 more in a new-build development plus a primary school, a new energy centre was required. The Council was keen to expand the network in an environmentally responsible way and decided to harness waste hot air expelled by the tube system.
The new energy centre is constructed around a 1MW heat pump that harnesses warm air expelled from a disused London Underground ventilation shaft to create hot water for the network. The system is also designed to operate in reverse during summer, when warm air will be cooled by heat pump coils to reduce temperatures in London’s Underground tunnels and make journeys more comfortable on the Northern line.
The project was part-funded by the European Union through the CELSIUS project as a demonstrator of this technology. The energy centre is also designed to bring visual impact to the local community and has received multiple architectural awards.
The new energy centre is expected to reduce carbon emissions by 500 tonnes per year. This, on top of the 1200 tonne CO2 reduction from Phase 1, will go a considerable way towards helping Islington to reach its net-zero carbon goal by 2030. We believe there is huge potential to tap into further waste heat sources across the borough and for other cities across the UK and around the world to harness waste heat to warm homes and buildings.
Talk to local residents – In the design phase, we held lots of outreach meetings with local residents and stakeholders so they could find out more about the scheme and ask questions. It was also important to communicate potential building work disruption and road closures throughout the project.
Make sure you have a strong project plan – There are so many moving elements and interested parties involved in an initiative like this; it’s vital that everyone understands what’s possible, what’s happening, and what the outcomes will look like.
- Amount of carbon emissions saved by utilising the waste heat.
- Number of additional properties connected to the district heating system.
- Replication in other parts of the UK.