Portsmouth reservoir to feed UK’s largest water-source heat network

Portsmouth Water is to provide the water to supply the UK’s largest water-source low carbon heating and cooling network, which is to be installed at Welborne, a new generation sustainable garden village in Hampshire.

The first-of-its-kind technology is being designed and built by Rendesco and will draw water from Portsmouth Water’s underground Hoads Hill Reservoir. The project partners said using water as a source will make the network significantly more efficient than if air source heat pumps were used, due to the more stable and higher average temperature of the reservoir. Moreover, by reversing the process and expelling heat back into the reservoir, the network will also be able to deliver cooling.

Phase one will see 700 new homes, commercial premises and community buildings supplied with heat, hot water, and cooling, expanding to all 15,000 residents in 6,000 new homes. The complete network has the potential to save over 272,000 tonnes of carbon in the first 25 years of operation compared with gas boilers, which adds up to the emissions of more than 33,000 average homes.

Portsmouth Water chief executive, Bob Taylor, said: “The water that supplies our service reservoir at Hoads Hill comes from an underground aquifer that has the capacity to supply natural energy to the low-carbon heat network serving the development. Longer term, the design principles here are a blueprint for future environmentally led developments right across the UK.”