HEAT NETWORK | COMBERTON VILLAGE COLLEGE Comberton Village College is a large secondary school six miles to the west of Cambridge DECARBONISING COMBERTON The installation of a new heat network at Comberton Village College is set to significantly reduce the heating bill and save 248 tonnes of CO2. Andy Pearson speaks to Bouygues Energies & Services about how two 500kW ground source heat pumps replaced oil-fired boilers scattered across 16 plantrooms 24 August 2023 www.cibsejournal.com C omberton Village College provides a glimpse into a low carbon future for schools. It shows how retrofitting renewable energy technology to an existing school can help educational institutions across the country decarbonise their heating systems. In its first year of operation, the 3.1m scheme is expected to signifcantly reduce the colleges heating bill and cut carbon emissions by 70%, saving 248 tonnes of CO2. By 2050, with the further decarbonisation of the electrical Grid, that figure is predicted to increase to more than 90%. Comberton Village College is a large secondary school located close to the city of Cambridge. It is formed from a diverse collection of buildings of various ages, most of which have been constructed as selfcontained units, complete with their own plantrooms. The campus has no gas supply, so the majority of buildings were heated by fuel oil, with a few heated using liquefied petroleum gas (LPG). Bouygues Energies & Services (E&S) is a contractor under the Greater London Authority and Partnerships energy performance contracting initiative Re:fit. As part of this, in 2018 it was approached by Cambridgeshire County Council and the Cam Academy Trust to develop proposals to decarbonise Comberton Village College. Bouygues E&S energy design manager Tom McGrath describes the process: We start each project by developing an energy baseline that provides us with an overview of the current energy consumption and carbon emissions of the site. We then review potential decarbonisation options and quantify the impact of these for carbon and cost. The most effective options are then presented in a business case that demonstrates that the intervention will save X tonnes of carbon and energy annually, and will offer a financial payback of Y years. The metrics form the basis of an energy performance contract (EPC), in which Bouygues E&S guarantees that it will be achieved, says McGrath. We undertake responsibility for full design, planning and procurement, and include this in our