Ground source heat pump project at UHL
On Wednesday 27 May 2026 we were delighted to announce that work on a once in a generation sustainability project at University Hospital Lewisham is moving into its initial ‘test phase’.
Since funding (see below) was approved we have been working on plans to install a ground source heat pump system at the hospital, replacing the 1970s gas-fired boilers that currently heat the site.
It will completely modernise our heating system and make it fit for purpose in the 21st century. The heat pump, located at the hospital, would use low - carbon energy by drawing on groundwater from the chalk aquifer beneath Ladywell Fields and then returning it safely back underground.
An initial study, which has included engagement with both the Environment Agency and Thames Water, has identified that the hospital and Ladywell Fields are favourably situated for this type of project. The first phase - to begin on Wednesday 3 June 2026 - will involve drilling test boreholes, in the north end of the park (towards Ladywell station) and at the south end.
The aquifer beneath the park is essentially a big rock with lots of fractures in it that are full of water, and this phase is just to prove we can extract and return enough water to make the heat pump system viable.
We have conducted several surveys covering: groundwater, arboriculture (trees/roots/plant life) and ecology (animal/wildlife environment) to ensure we minimise any impact to the park. Disruption during the work will be kept to a minimum and local residents will continue to have access to the park at all times.
The test phase will involve drilling two sets of boreholes, each comprising one deep borehole and one shallower monitoring borehole (four boreholes in total). Work will be restricted to small, fenced enclosures, and a traffic management system will ensure that equipment is brought on and off site efficiently, with minimal disruption.
One set of boreholes will be located in the open field area north of the playground, with the second set at the southern end of the park. These locations have been selected to minimise impact on tree root zones. Track matting will be laid between the two work areas for the duration of the works. If the data collected during this initial testing phase (scheduled to finish on 11 August 2026) proves the scheme is technically viable, the project will work towards a second phase that would require additional drilling of up to 6 further boreholes, again, with works restricted to small, specific areas.
When work is completed, the boreholes will not be visible to park users except for a small access hatch, about the size of a standard drain cover, which will be camouflaged from view.
Work will then focus on the infrastructure on the hospital site itself, removing old boilers and pipework and replacing them with a new network and installing the heat pump.
We’re expecting all works to be completed in summer 2028 and once installed, the new, more efficient system is projected to save 4,000 tonnes in carbon emissions a year which will improve air quality in the local area.
Ladywell Fields is a much-loved local space enjoyed by Lewisham residents and many of our LGT colleagues. As well as the Lewisham Council team, our engineering consultants, the Environmental Agency and other partners, we have met with local residents’ group: ‘Friends of Ladywell Fields’. We wanted to ensure the ‘Friends’ were a part of our early conversations and to get their feedback on the project, and we’ll be making sure they and other local groups and residents are contacted and informed as we move through each stage.
Funding for this project came from a successful bidding process in June 2025 via the Public Sector Decarbonisation Scheme, through which we have been allocated: £17,790,274 of Government grant funding. Our Trust will supplement this with additional capital to deliver the scheme, which will total a £25 million investment. Several NHS Trusts around the country have also set out their plans for similar projects as the NHS works towards its overall net zero targets.
The Public Sector Decarbonisation Scheme is run by the Department for Energy Security and Net Zero and delivered by Salix. Director of Public Sector Decarbonisation at Salix, Ian Rodger: “At Salix, we are proud to deliver the Public Sector Decarbonisation Scheme and to stand alongside Lewisham and Greenwich NHS Trust on this ambitious and complex journey. The NHS has set bold and vital net zero targets, and by cutting carbon emissions, the Trust is not only creating a safer, cleaner environment for patients, visitors and staff today, but also shaping a healthier, more hopeful future for our planet and for generations yet to come.”
Dr Neil Goulbourne, Chief Strategy and Transformation Officer & Deputy CEO at LGT said: “Climate change is a real and pressing public health challenge. It exacerbates health inequalities, places additional pressure on our services and disproportionately affects the most vulnerable in our communities. The actions we take moving forward as a Trust, to reduce our emissions and costs, will make a very meaningful difference to our service users, local community and our colleagues both now and for future generations. We look forward to updating you as the project develops in the coming months.”
If you have any questions, you can contact us on: lg.sustainability@nhs.net or for media and communications questions: lg.communications@nhs.net
Visit our website to find out more about this project and the kinds of sustainability work already taking place across our Trust, including the installation of over 3000 energy efficient LED lights, improved recycling processes, reduction of environmentally harmful gasses in our operating theatres and the building of our RHS Wellbeing Garden space (the first of its kind in a hospital setting in England).
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