Turning Borehole Failure into Long-Term Success

Modified Drill Rig installing a 130m borehole in a London basement

Services: Design & Build

Project Value: £500,000

Innovate Heat was commissioned to design and drill a new open-loop borehole system to serve the primary heating and cooling plant for a major building refurbishment. Our scope included the complete borehole design, drilling, testing and the development of the operational strategy, delivering a robust renewable energy source tailored to the site’s long-term requirements.

A key aspect of the project was that the site already contained two boreholes installed over 20 years ago that had failed prematurely. Before designing the new system, Innovate Heat investigated the causes of the previous failures and incorporated these findings into the replacement design. The new system comprises two 130-metre-deep boreholes, each constructed with a dual-casing arrangement to suit the challenging ground conditions. An outer steel casing provides the structural strength required during installation and operation, while an inner plastic casing offers long-term corrosion resistance in the site’s aggressive ground environment. The completed system operates by extracting groundwater from one borehole and passing it through plate heat exchangers, where energy is either extracted from or rejected to the water depending on the building’s heating or cooling demand, before the water is returned to the second borehole. To maximise resilience, either well can operate as the abstraction or rejection well, ensuring continued operation in the event of a well pump failure. The project also required drilling within a basement with less than five metres of headroom, requiring modifications to our drilling equipment and bespoke installation methods. Despite these challenging constraints, Innovate Heat successfully delivered and tested the new boreholes, demonstrating our expertise in delivering complex open-loop ground source heat pump systems.

Interested in learning more?

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