Testing the waters: how the ‘secret energy’ from rivers could heat a million UK homes

The UK government has announced plans to use "secret energy" from more than 4,000 rivers, estuaries, canals and coastal sites across the country to provide 6GW of low-carbon heat to communities.

We need to make the most of the vast amount of clean, renewable heat that lies dormant in our rivers, lakes and seas– Ed Davey, UK energy and climate change secretary

The energy will be generated using water-source heat pumps: devices that provide clean, renewable power that their supporters say could generate electricity for a million homes and businesses in the UK, and allow a typical household to halve its carbon footprint. 

The heat pumps operate by taking solar energy stored in water, extracting it using heat exchangers and feeding it into local heat networks or single buildings. 

Ed Davey, the UK’s energy and climate change secretary, said: "We need to make the most of the vast amount of clean, renewable heat that lies dormant in our rivers, lakes and seas.   

"Doing this will help contribute to an energy mix that maximises clean, reliable home-grown resources rather than relying on foreign fossil fuels.  

"It also provides a system that bolsters growth in local economies, protects the natural environment and creates resilient communities that are capable of producing sustainable power systems." 

SSE, one of the UK’s big six energy suppliers, has been appointed to carry out a feasibility study.

Energy secretary Ed Davey at Battersea Power Station

The company will also investigate the re-use of existing engineering infrastructure that was built 80 years ago to connect Battersea power station to the Thames. If a heat pump were to be installed at the site, it would provide heat to around 4,000 new homes, shops, offices and public amenities that are being built in the present redevelopment of the Battersea area.  

The UK government has unveiled an online tool for communities called "Heatmap", an interactive web-based map showing the level of heat demand across England. It can provide developers and homeowners with information to help them get their heat pump projects up and running. 

Richard Parry, the chief executive of the Canal & River Trust, the charity that cares for 2,000 miles of waterways in England & Wales, said: "We very much welcome today’s announcement, which recognises the huge potential of water-source heat pumps to deliver a low carbon solution to the UK’s heating and cooling demands." 

Image: Battersea power station (Wikimedia Commons)