Bouygues Energies & Services: Award winning renewable energy and clean heat network

At a glance
Who: Bouygues Energies & Services
What: Renewable heat network scheme
When: 2023
Where: Swaffham Prior village, Cambridge
Why: To retrofit a village with renewable heat

The challenge 

Like many local authorities, Cambridgeshire County Council has a net-zero target but is currently combatting heightened fuel costs as part of inflated market prices. Any bid to reach net-zero would have to provide a reliable source of low-carbon heat and electricity that saved residents money on energy bills. 

The solution 

The Swaffham Prior Heat Network scheme, being delivered by Bouygues Energies & Services for Cambridgeshire County Council, is the first UK village to be retrofitted with a renewable heat network. 

How it works 

Cambridgeshire County Council’s net-zero goal for 2045 is ambitious, but requires wholesale transformation. 

Reliance on high-carbon stored fuels has left the village vulnerable to shortages and inflated fuel prices and will not push the Council toward its net-zero aim. Other risks also persist, including leaks which contaminate water stores impacting wildlife and drinking supplies; producing further hydrocarbons such as methane which contribute to climate change and negatively impact air quality and contaminates seeping into soils. 

Any solution needed to respond to all these issues.  

Comprising a hybrid air and ground source heat pump system coupled with a large-scale solar farm, the Swaffham Prior Heat Network scheme provides low-carbon, affordable and 100% renewable heat and hot water for the village. 

The project utilised cutting-edge heat pump technology, capable of delivering Low Temperature Hot Water (LTHW) at a temperature compatible with conventional heating systems. This was necessary, as retrofitting of buildings to become compatible with conventional LTHW was deemed unfeasible. 

The project utilised local supply chains, particularly for construction activities with the highest controllable environmental impacts such as civil or ground works. M&E works were completed using local contractors with the main civil contractor being based less than 500m from the site. 

A strong circular economy policy was implemented, particularly on works involving significant fresh water and earthworks. Electric vehicle (EV) charging points were installed onsite and a 10% net gain for biodiversity was achieved.  

The programme did encounter a few short delays due to lead times on key equipment, consequent of external market factors, but the work schedule was optimised to ensure that the availability of heat was achieved in a timely manner.  

Pressures due to the external financial climate were mitigated through expert procurement meaning the project was delivered largely on budget. As a result, residents of Swaffham Prior receive renewable heat from the network at no greater cost than their conventional systems 

The results 

This project replaces 100% carbon intensive fuel oil and fossil-based heating and hot water and will reduce CO2 emissions by 96% in the first year, rising to 99% by 2050. 

The scheme has a capacity to generate 2MW of heat for 300 homes in Swaffham Prior. Thanks to the peaking capability of thermal stores, the short-term maximum heat output of the energy centre exceeds 2.7MW. Because of the private wire connection to a 39MWp solar farm, over 95% of the electricity consumed by the energy centre is directly derived from a renewable source. 

The organisation 

Bouygues E&S is ISO 50 001-certified and has an ambition of becoming a net-zero organisation by 2050 across all three Scopes. 

The company has set ambitious carbon targets to become net-zero for Scopes 1 and 2 by 2025 and to achieve a 30% reduction in (upstream) Scope 3 carbon emissions by 2030 on the road to the wider 2050 target. 

The Judges said: 

“The judges were impressed by the full integration of multiple renewable technologies combing solar with hybrid air and ground source heat pumps, powering a comprehensive heat network. The project demonstrated exceptional community engagement, not only meeting the village’s energy needs but also increasing biodiversity and improving the overall environment. The Swaffham Prior Renewable Heat Network demonstrates a truly holistic approach to renewable energy.”