London is sitting on an untapped and unexpected source of heat: the 'lost rivers'. A new report (PDF) suggests we could warm or cool London's buildings using waste heat from subterranean watercourses.
A new report from 10:10 Climate Action and energy consultants Scene reckons we could be making more of these invisible channels. Sewers can be sweaty places — as we can attest from personal experience. This warm air can be tapped by heat pumps and carried to the surface. Configured slightly differently, a heat pump can also be used for cooling.
For efficiency, the building to be heated must be close to the buried river. Anyone who's followed the route of the buried River Tyburn will immediately think of one high-profile opportunity: Buckingham Palace. The river passes directly beneath its grounds. According to the report, 100% of the palace's heating demands could be met by installing heat pumps in the Tyburn.
The untapped energy could also benefit us commoners. The study highlights Brockwell Lido as a potential beneficiary. Heat from the nearby River Effra could maintain the pool at a balmy 25 degrees centigrade all year round. Other examples include bewarming a school in Tufnell Park with Fleet heat, pumping hot air into Hammersmith and Fulham town hall from Stamford Brook, and using the Fleet to add extra capacity into the Somers Town Heat Network.
The report discusses how sewer-based heat pumps have already been used in parts of Germany, Switzerland and Scandinavia. It's an intriguing idea for providing low-carbon heat to London's buildings, albeit on a small scale.
Read the full report here.