The Diocese of Guildford has taken a significant first step towards decarbonising its entire school estate, by installing low-carbon heating systems at 11 schools across Surrey. The move is part of a long-term sustainability programme supported by funding from the government’s Public Sector Decarbonisation Scheme (PSDS), which is administered by Salix Finance. 

The project – from heat loss calculations and energy efficiency audits to grant applications and management of the installations – was overseen by specialist consultancy ReEnergise. Following a competitive tender process, Viessmann Climate Solutions was selected as the heat pump technology supplier, providing air source heat pump systems tailored to each school’s requirements.  

The units ranged from the compact 10 kW Viessmann Vitocal 150-A heat pump at Newdigate Pre-School to a 384 kW system using three Vitocal 200-A Pro units at The Priory School in Dorking. In total, 15 individual systems were installed across 11 schools, with the works carried out by Aston Cord Energy Services Ltd between July 2024 and March 2025. 

Now fully commissioned and operational, the new systems are expected to save over 466 tonnes of CO2 annually due to the removal of fossil fuel heating. They will also reduce total energy use by almost 1.8 million kWh, due to the much greater efficiency of heat pumps compared to gas boilers. This equates to a 70% reduction in total annual energy consumption across the upgraded schools. 

Jonathan Grist, Commercial Sales Director at Viessmann Climate Solutions UK, said: “It has been great to partner again with ReEnergise, who are incredibly experienced and knowledgeable in school decarbonisation programmes. Besides Viessmann’s role as a technology supplier, we’ve enjoyed helping to educate children and staff at the schools in how heat pumps work. 

“Our customers know we are never far away. Now the heat pumps are installed, we’re continuing to support the Diocese and ReEnergise with remote energy and performance monitoring, ensuring the heating systems are optimised for energy efficiency.” 

Simon Hayes, Managing Director at Aston Cord Energy Servicessaid: “Delivering decarbonisation during term time in live school environments brings unique challenges, requiring meticulous planning and execution. I’m proud of the Aston Cord team for their professionalism and adaptability throughout.”

Nigel Aylwin-Foster, Director at ReEnergise, said, “The LCSF and PSDS grant allocation and administration processes are technically and commercially rigorous, such that any education authority will need expert support in developing and submitting credible and compelling applications. It fell to us to support the Diocese of Guildford with their applications, both of which were successful. At ReEnergise, we are proud of our 100% success rate in PSDS applications.”

Mike Giles, School Buildings & Estates Manager for the Diocese of Guildford said: “​​With the support of the PSDS, we have taken a vital first step toward our sustainability goals. These 11 installations are just the beginning. The heat decarbonisation plans and first PSDS grant have laid strong foundations upon which we can continue to build moving forward.” 

The PSDS installation of air source heat pumps has provided schools with vital funding to replace outdated, fossil-fuel heating systems with cleaner, more efficient alternatives. For many schools, it has been a great opportunity to make significant progress toward Net Zero, reduce energy bills, improve learning environments for pupils and encourage further pupil awareness of sustainability.  

In the future, it is hoped that the project will serve as a blueprint for other educational authorities, Dioceses and trusts embarking on their own decarbonisation journeys. 

The 11 Diocese of Guildford schools with new heat pumps are: 

• Busbridge C of E Junior School
• Chilworth C of E Infant School
• Crookham C of E Infant School
• Newdigate C of E Infant School
• St Bartholomew’s C of E Primary School
• St Matthew’s C of E Infant School
• St Peter’s C of E Junior School, Farnborough
• St Peter’s C of E Primary School, Farnham
• The Chandler C of E Junior School
• The Priory C of E Secondary School Dorking
• Wonersh and Shamley Green C of E Primary School