The UK’s largest ground source heat pump system

Construction work has begun on England’s largest ground source heat pump system.

A total of 400 flats over eight tower blocks in Enfield, north London, are to be retrofitted with a district ground source heat network, featuring 16 shared ground loop systems serving the blocks.

Ground source heat pump specialist Kensa Contracting, working for Keepmoat, will carry out the work. The Shoebox heat pumps are manufactured by the firm’s sister company Kensa Heat Pumps.

Each district system will typically consist of clusters of eight boreholes serving individual heat pumps installed within the flats of half a tower block.

This system architecture allows each resident to select their own preferred energy supplier to access the best available electricity tariff.

Eight tower blocks will be retrofitted

The shared nature of the ground array design also reduces drilling costs – typically the most cost-prohibitive aspect of a ground source heat pump installation – and ensures funding through the Energy Company Obligations Scheme as well as the government’s Non-Domestic Renewable Heat Incentive, securing Enfield Council quarterly payments for 20 years.

It is expected that the upgrade will result in residents’ energy bills reducing by 30-50%.

Kensa Contracting has already begun drilling the boreholes with one site’s groundworks planned for completion before the end of the year.

Dr Matthew Trewhella, Kensa’s contracting director, said: “This project is an excellent example of how district heating can be rolled out using the shared ground loop system architecture. 

“One of the great strengths of this system type is its flexibility and scalability. Shared ground loop systems can be featured in developments of just two properties (micro-district) whilst this project clearly demonstrates how the concept can be scaled up to much larger systems.

“Not only do ground source heat pumps provide the lowest cost heat, they also deliver substantial carbon savings, and landlords benefit from the exceptionally low servicing and maintenance costs.”

The project is planned for completion in October 2018.