Money and carbon-saving benefits for OUH project

The total expenditure – including £29.8 m received from the Department for Energy Security and Net Zero’s Public Sector Decarbonisation Scheme (PSDS), was just over £38 m.

The Public Sector Decarbonisation Scheme (PSDS) is initiated by the Department for Energy Security and Net Zero, and delivered by Salix Finance. It provides grants for public sector bodies to fund heat decarbonisation and energy efficiency measures, and supports the aim of reducing emissions from public sector buildings by 75% by 2037, compared with a 2017 baseline.

NHS England’s Greener NHS programme gives a four-step approach to decarbonising the NHS Estate:

1: Make every kWh count: Investing in ‘no-regrets’ energy-saving measures.

2: Preparing buildings for electricity-led heating: upgrading the building fabric.

3: Switching to non-fossil fuel heating: investing in innovative new energy sources.

4: Increasing on-site renewables: investing in on-site generation.

The OUH bidding strategy and timeline

The OUH NHS Foundation Trust’s bid was to decarbonise the two hospitals with the most retained estate areas — the Horton General Hospital in Banbury, and the John Radcliffe Hospital in Oxford. We felt it was important to decarbonise all our retained estate in a one-off, cohesive programme. We also had to be realistic, only bid for what was achievable, and ensure that there would be a minimal impact on daily patient care, as we could not shut down clinical areas.

With only 12 weeks to prepare the bid, largely over the summer holiday period, the project team was under enormous time pressure to draft a Business Case that showed the need and potential return on investment, and to get it through the Trust’s internal governance procedures.

However, the Trust’s Executive Board recognised this project’s importance, and gave it high priority to ensure that the Business Case was properly scrutinised and not held up at any stage. Externally, the team was also given excellent support by Salix, and OUH’s bid was delivered to the Department for Energy Security and Net Zero by the October 2022 deadline.

From award to mobilisation

In January 2023, the Department for Energy Security and Net Zero granted PSDS funding of £24.1 m for the John Radcliffe, and £5.7 m for the Horton General Hospital. In addition, OUH paid £8.4 m towards the wider scheme, taking the total expenditure to £38.2m over a three-year period.

The work at the Horton had to be completed by the financial year end of 2024, and work at the John Radcliffe (JR) must complete by the financial year end of 2025. With an April 2023 start date, completing the heating works over the summer months, and just 12 months to complete all the works on the Horton site, time was extremely tight. In addition, work had to start in March to be part of the April funding draw down. The Trust advanced the project seed funding of £1 m, which formed part of the Trust contribution towards the grant to get the programme rolling, and ensure that the heating work at the Horton could be completed over the summer.

One contractor for both sites

Vital Energi was already embedded in the John Radcliffe, with an existing energy contract that still had 20 years to run, and exiting it would have cost circa £22 m. After the Horton works were competitively tendered, Vital Energi was awarded the contract for both sites because of its involvement with the John Radcliffe site, good working relationship with the Trust, and previous PSDS experience. It was also important to have one contractor for both sites.

Vital Energi swiftly prepared the planning applications for the outside works on both hospitals. Cherwell District Council in Banbury and Oxford City Council were very supportive, and both applications went through quickly and efficiently. The Horton is low rise, so High Rise Buildings (HRB) approval is not needed, and work started on the JR before the new regulations came into effect.

The key to the design of this project was to find a balance between delivering decarbonisation while achieving financial savings with minimal disruption to site operations. To allow for the integration of efficient low carbon heating systems, it was necessary to replace the original steam and high temperature distribution systems with lower temperature systems and better controls.

During the review of the Horton, one major problem superseded all others. The existing connection to the National Grid had insufficient capacity, and, as it was too old to be adapted, a new, higher capacity connection had to be installed. This would entail shutting off the entire hospital’s electricity supply for a week, leaving the hospital to rely solely on generators for power. While there were some sleepless nights in the planning phase, noone noticed when the generators took over. The operation was seamless, and patient care went on without any interruption. Even the contingency back-up generators were not needed.

At the JR, de-steaming the heating system was extremely significant, because the new heat pumps work on Low Temperature Hot Water (LTHW) at 70-75 °C, whereas our previous High Temperature Hot Water (HTHW) system ran at around 160 °C. However, the existing HTHW pipework was ‘end-of-life’, and could not work on this change of temperature, so it was all replaced. The lower hot water temperatures, and new, lagged piping were immediately more efficient, and replacing them has removed a significant backlog maintenance cost.

LTHW heating distribution improvements

On both sites, the existing secondary side LTHW heating distribution systems required improvement works to ensure the efficient operation of the new low carbon heat pumps. Digital twins of the hydraulic systems were created to help identify opportunities to improve temperature control and manage heat demand more efficiently. Improvement measures included converting inefficient constant flow heating systems to variable flow systems by installing new speed-controlled pumps and 2-Port valves, and removing any low loss headers or unnecessary bypasses in the system.

Other Energy Conservation Measures (ECMs) were implemented to help deliver energy savings and improve conditions for patients and staff. This included replacing belt-driven AHU fans with new, efficient direct drive alternatives, pipe lagging to reduce unnecessary heat loss, and BMS upgrades to improve the control of heating, ventilation, and air-conditioning equipment. We now have one control system for all the buildings, rather than the multiple ones that had grown organically over the years, and were end-of-life and obsolete.

The works ‘at a glance’

Work undertaken at the Horton included:

• Replacing obsolete equipment with new.
• Removing asbestos in some areas.
• New, upgraded, higher capacity connection to the National Grid.
• Heat pump installation.
• The fitting of 870 solar panels on 11 buildings, covering 1,699 m²,with a capacity of 357 kWp.
• Introduction of variable flow heating distribution systems through the installation of 7 new variable speed pump sets and 38 2-Port valves.
• Replacement of 20 belt-driven air-handling fan units with EC AHU fan assemblies with integrated inverter drives and BMS Modbus control units.
• Replacement of 22 chiller condenser fans with Electronically Commutated (EC) axial fan units and controls.
• A BMS upgrade (33 obsolete controllers replaced) and strategy optimisation.
• Pipework insulation.

The work at the John Radcliffe meanwhile entailed:

• Relocation and upgrading of the compactor to allow for the extension to the Energy Centre building.
• De-steaming works.
• Replacing obsolete equipment with new.
• Removing asbestos in some areas.
• Conversion of the Energy Centre from a steam to a Primary Low Temperature Hot Water Energy Centre.
• Installation of a Primary Low Temperature Hot Water link to a water source heat pump.
• 1,342 solar panels fitted to seven buildings covering 2,682 m², and with a capacity of 584 kWp.
• Installation of heat pumps.
• Replacement of 32 existing belt-driven air-handling fan units with 51 EC AHU fan assemblies with integrated inverter drives and Modbus control units.
• A BMS upgrade (173 obsolete controllers replaced) and strategy optimisation.
• Pipework insulation.
• Draughtproofing.

What the project will deliver

The installation of heat pump systems will deliver 4,000 tonnes (approx.) per annum of carbon savings towards Net Zero targets, alongside the following benefits:

• Self-power generation from solar PV panels for greener energy.
• Implementation of Energy Conservation Measures with immediate cost and carbon savings.
• Reduced backlog maintenance and future lifecycle upgrade costs.
• Replacement of steam and HTHW networks, combined with secondary side modifications provides low / zero carbon ready heating infrastructure; without these changes delivering Net Zero targets would be impossible.
• Increased resilience towards fluctuations in price and availability of different energy sources and grid capacity.

The design should save over 25,000 GWh of fossil fuel, and 4,000 tonnes (approx.) of carbon per year, which will reduce the Trust’s exposure to any future carbon taxes, and there should also be financial savings. We will only know these figures once we have a full year’s data.

Importantly, however, patients, staff, and visitors, are already feeling the comfort of improved control of the heating temperature and hot water.

Wendy Cheeseman, head of Sustainability and Carbon Management at OUH, said: “If you look at the Greener NHS’s four-step approach, our decarbonising project has delivered on all four objectives, and gives us the ability for further improvements in the future.”

Future intentions

Looking ahead, the Trust sees this project as the starting point for future carbon reduction works. On both sites, the ongoing maintenance of the new LTHW systems will be easier and quicker to manage, as the spare parts will be ‘off the shelf’, and this will significantly reduce waiting times should something need replacing.

Wendy Cheeseman continued: “This scheme is not the end-point. It is the beginning. Yes, it has been disruptive and expensive, but it lays the foundations for all the future work we must do to reduce our carbon emissions exponentially year on year.”

Chris Yeo added: “This project enables the future integration of further low carbon heating systems, and is a significant step in delivering OUH’s Net Zero carbon targets. To deliver full heat decarbonisation, a significant amount of future funding and infrastructure upgrades is still required.

“Due to the lack of as-installed design information available for older hospital sites, it is very important 
to carry out a thorough review of existing systems to ensure that any new technical solutions can be 
integrated effectively. Carrying out detailed investigations of baseline operating conditions, and the creation of virtual Digital Twins, has helped ensure that the final solution can deliver the required design conditions of the hospital.”

Disruption management

From a disruption management standpoint, we engaged with stakeholders very early on, and these changed as work progressed from ward to ward. Lyn Bennett, a former ICU matron, is our interface between the Estates team and clinicians, and she discussed the programme with clinical colleagues so that they could plan ahead, and we could all agree the mitigations needed to reduce our impact on patient care. We also have our own Estates Communications manager, who is in constant contact with all Trust staff on all the construction, facilities, maintenance, and infrastructure matters.

Many other teams have also played a significant part in this project’s success. For example, liaison between the Project team and IT teams to ensure that the new software would be compatible with other systems already in use in the hospitals was critical.

We have done this work at speed without compromising the governance, quality, and scope, of what we set out to achieve. We have now delivered the majority of the project to remove and replace the two hospitals’ hot water and heating systems without losing a day’s patient care, and will complete the outstanding work by October this year. The support we have had from Salix, all our Estates and clinical colleagues, Vital Energi, and the Trust’s Board, has been immeasurable.

I think our brave decisions will pay off as we aim to achieve NHS England’s carbon reduction targets, and we are looking forward to seeing exactly how much carbon and financial savings we achieve.