Heat Decarbonisation, Southampton

Southampton General Hospital and Princess Anne Hospital consist of multiple large buildings ranging in age from the 1970s to new buildings. The buildings differ in terms of their fabric and energy performance. The NHS Trust commissioned Salvis to undergo a Heat Decarbonisation Plan to assess the current state of equipment and reduce the site's carbon emissions and energy usage.
 
The Trust used the report and proposals produced to support an application for funding from the Public Sector Decarbonisation Scheme (PSDS), which awarded them £29,300,000 to undertake part of the work.

Our proposals included the following suggestions over 8 phases of installation:

• Introduction of an ambient loop heat network and an energy centre
• 4-pipe chiller to provide simultaneous heating and cooling with heat recovery 
• Heat pumps are used to provide additional heating to the ambient loop.
• Replace the current heat emitters and distribution pipework with a new lower-temperature infrastructure that is compatible with the low-temperature heat network.
• Replace old AHUs with newer models with heat recovery.
• Install external wall insulation on the older buildings. 
• 4MW solar PV
• Implement set points, more sophisticated schedules, and alarm monitoring for the BMS.

The proposed interventions were projected to reduce the Trust's carbon emissions from 23,971 tCO2e in 2022 to 566 tCO2e in 2040. This is a carbon saving of 98% and will require the removal of all gas-based boilers and gas-based CHPs, which will be replaced with electrically driven heat pumps. The transition will also see an 82% reduction in carbon emissions between 2022 and 2032, with a target to reduce emissions by at least 80%.