Water source heat pumps working with hydorpower deliver a carbon negative system at a historic site on the Bonsall Brook in Matlock.  


Demonstrating that modern technology can work effectively and in tandem with older buildings, Cromford Mills has reintroduced waterpower to its historic site – thanks to a new turbine, water wheel and heat pump technology from Vaillant. 

Working with the team at Vaillant and as part of ongoing restoration efforts, the Arkwright Society has spearheaded a project to revitalise the historic water wheel and integrate it with low carbon heating solutions. Now, via the installation of two Vaillant flexoTHERM water source heat pumps, donated by Vaillant, Cromford Mills is harnessing the power of the Bonsall Brook to generate energy for its 16th Century buildings.  

Originally established in 1771 by industrial pioneer Sir Richard Arkwright, Cromford Mills in Matlock was the world’s first water-powered cotton spinning mill. It is now a vital part of the UNESCO Derwent Valley Mills World Heritage Site, attracting thousands of visitors eager to engage with its rich history.

Truly renewable

Simon Gill, former operations director at Cromford Mills, emphasises the importance of this initiative: “Our goal has been to harness the natural resource of the water flow for the benefit of the mill, maximising the energy we can obtain in a responsible way.”

James Boon, the architect on the project, notes: “Richard Arkwright built his mills using water power. We have been able to go back to using water power, using sustainable energy, just how it was when Richard Arkwright designed it, but in the 21st century.”

Paul Leedham from Matrix Energy Systems, who installed the system, highlights the project’s environmental benefits: “We designed a system that consumes less power than what the water mill actually generates, so what we have here is a cabin negative system that generates more electricity than what we use. There is an abundance of water on this site so it absolutely made sense to use water source heat pumps here. It allows us to take that energy, transfer it inside, and raise it to a higher temperature to use it within the building.”

Flexible solution

Vaillant’s flexoTHERM multi-source heat pump provides a versatile option that can be tailored to suit the energy source needs of the site, be that water, ground or air source when fitted with the appropriate adaptive technology. It can also be adjusted to provide optimal hot water comfort and is available in a range of sizes from 5kW through to 19kW. Silent in operation, the flexoTHERM boasts the Quiet Mark certification.