A recent story picked up by multiple sources focused on the potential for hidden hydrological systems to provide heat and cut carbon emissions through tapping into underground lost rivers. The crux of the argument is that heat pumps could extract heat from these now piped subterranean waterways, and this heat could be used for buildings and other uses, offering an alternative power option for London. The Guardian offered the potential for heat to “cut capital’s emissions”, and the Times and The Londonist echoed this, focusing on Buckingham Palace as a visible example for the potential for heating buildings. Mother Nature Network and Earth.com a took a slightly different slant, focusing on helping curb carbon emissions, similar to the coverage from the Daily Mail about using heat from underground rivers to “tackle climate change”.
The specifics come from a group called 10:10 Climate Action, and a recent report highlights ‘Heat seeking in London’s lost rivers’, and looking at the variety of now-buried rivers as a source of power:
“But what if we could use them to power our city once again? Through the magic of heat pumps, London’s lost rivers could provide low cost, low carbon heating and cooling to the buildings above. They could help us solve the big challenge of decarbonising heat. There’s huge potential for London’s lost rivers to provide clean, efficient and reliable heating for the city – tackling climate change and air pollution. And of course the same technology can be used in other underground waterways like sewers in towns and cities across the country.”
y for heat pumps to transfer heat from one place (the subterranean pipes) to another, specifically buildings or other areas via refrigerant, where it is compressed to form heat at the top of the loop, and then expanded to cool down and capture more of the heat. A primer on heat pumps, as well as a video showing how heat pumps work also helps explain the concept, along with this diagram.
This is already happening in some areas, including Borders College in Scotland, tapping into local wastewater, and the State Ministry Building in Stuttgart, Germany, which is tapping into flow from the Nesenbach, a buried river. A map extracted from the report (image below) shows a number of the potential sites in London, including The Effra, Stamford Brook, The Tyburn, and the Fleet, all of which have potential sites for the use of these technologies. Specific places include Buckingham Palace (mentioned in a few of the articles above), which would tap the Tyburn, Hammersmith Town Hall which flows above Stamford Brook, and other buildings like schools and site elements like heated swimming pools, which is currently being done in Paris. [click to enlarge map below]
A video from 10:10 explains this in a bit more detail, showing an example of a London pub sits atop a lost river and uses this heat pump technology and for it’s heating and cooling.
There’s questions on the cost-benefit, and each of these systems would require some infrastructure to be viable, however it’s pretty exciting to consider the potential of these systems to contribute to energy savings and reduction of carbon emissions, giving back some of their benefits to the city, even while still being buried underground. I’m sure we’ll hear more about this process in cities around the globe, all of which could utilize similar techniques, as we search for expanded tools to battle climate change and rising energy costs.
HEADER: Image of the now subterranean mouth of the Fleet, via The Guardian