How a London council is using public transport to heat homes

摘要

It is probably not something you have ever thought much about, but the air in the London Underground is generally warmer than that above ground – somewhere between 18˚C and 28˚C, in fact. And now it is being put to good use to heat and provide hot water to 1,350 homes, a school and two leisure centres in the borough of Islington, north London. “As far as we know, it’s the only scheme taking waste heat from an underground system in the world,” says Lucy Padfield, director of energy for Ramboll, the engineering consultancy providing technical support on the project. The basis of the Bunhill 2 Energy Centre – Bunhill 1 is a combined heat and power plant that began operating in 2012 – is that the warm air is drawn up from the Underground via a ventilation shaft using a fan and this is then passed over water-filled pipes, heating the water inside with the assistance of heat pumps to about 80˚C. The water is transported to the homes, centres and school via 1.5 kilometres of piping.