Rooftop HVAC plant surveyed by Salvis during a mechanical condition survey at Southampton General Hospitial

NHS - Southampton General Hospital & Princess Anne Hospital

3,856,050 kWh Annual Renewable Generation
832 tCO₂e Year 1 Carbon Reduction
8.3 GWh Annual Electricity Savings
98% Projected Reduction by 2040

Public Sector Heat Decarbonisation Fund.

Southampton General Hospital and Princess Anne Hospital consist of multiple large buildings ranging from the 1970s to modern facilities. Facing ageing infrastructure and high energy demand, the NHS Trust commissioned Salvis to develop a full Heat Decarbonisation Plan to cut carbon emissions and transform the estate's energy performance.

The recommendations supported a successful £29.3m Public Sector Decarbonisation Scheme (PSDS) funding application.

The Solution:

Across an eight‑phase programme, Salvis proposed:

A site‑wide ambient loop heat network and new energy centre.
Heat pumps and a 4‑pipe chiller with heat recovery.
Replacement of legacy pipework, emitters, and AHUs.
External wall insulation for older buildings.
A 4MW solar PV system.
Enhanced BMS controls, scheduling, and monitoring.

These interventions transition the hospitals away from gas-based boilers and CHPs toward fully electric, low‑carbon heating.

82% Carbon Reduction by 2032
£29.3m PSDS Funding Secured
Net Zero Estate Aligned with NHS Goals

Frequently Asked Questions

  • A Heat Decarbonisation Plan is an engineering-led strategy that maps out how a building or estate can transition from fossil fuel heating to low-carbon alternatives. Southampton General and Princess Anne Hospital have multiple large buildings dating back to the 1970s with ageing infrastructure and high energy demand. The Trust needed a clear, evidence-based plan to understand what changes were required across the estate, how to phase the work, and what it would cost, so they could apply for government funding to deliver it.

  • Yes. Most public sector funding schemes, including the Public Sector Decarbonisation Scheme, require a robust technical plan before they will consider an application. A well-prepared HDP provides the energy modelling, carbon projections, and cost breakdowns that funding bodies need to see. Without one, it is very difficult to put together a competitive application.

  • It depends on the size and complexity of the estate. For a single building, a Heat Decarbonisation Plan can be completed in a matter of weeks. For a large multi-building estate like this, the planning stage takes longer because each building needs individual assessment. The delivery of the physical works is then typically phased over several years to minimise disruption and align with available funding.