According to the London Borough of Hounslow (LBH), gas usage – primarily for heating homes and other buildings – accounts for 79 per cent of the council’s direct emissions and around 32 per cent of wider borough emissions. Reducing gas use is therefore a priority under Hounslow’s Climate Emergency Action Plan.
To tackle this, we were commissioned by the LBH to conduct a feasibility study into an ambitious new district heat network which will supply low-carbon, affordable heat to buildings across the entire borough – and beyond. When complete, it will be one of the largest district heating networks in the UK.
What is the Hounslow district heat network – and what is AECOM’s role in it?
At the heart of this initiative is a bold plan to capture waste heat from the Mogden Sewage Treatment Works in the borough – transforming what is typically a lost resource into a valuable supply of low-carbon heating.
This heat will then be used to warm homes and businesses throughout the area. Currently, there is enough waste heat available to serve over 250 individual sites within the borough, as well as some locations beyond, including Heathrow Airport.
Having already performed a heat mapping exercise to identify six possible heat demand clusters for the network in the project’s first phase, we were commissioned to conduct a feasibility study to examine these options in more detail.
First, we assessed the viability of different scales of low-carbon heat networks across the borough. We next identified a preferred option that would remove as much carbon from the atmosphere as 2.8 million mature trees annually – all while providing a more cost-effective alternative to other carbon reduction technologies.
Cutting emissions, lowering costs
The project will deliver low-carbon heat via insulated pipes from energy centres to customer buildings, replacing existing fossil fuel-based heating systems.
This will save an estimated 2.7 million tonnes of CO2 over its lifetime compared to gas boilers, reducing LBH’s emissions by 26 per cent annually from 2022/23 levels.
Customers are expected to benefit directly through lower heating costs, making the transition to low-carbon energy more affordable.
In addition to cutting carbon emissions, LBH aims to improve local air quality by reducing nitrogen oxides (NOx) and particulate matter (PM) through its Air Quality Action Plan. Switching from gas combustion to electrically powered district heating will support these goals.
Aligning with community needs: shaping the future of Hounslow’s district heat network
We’re proud to be playing a key part in the delivery of this pioneering district heat network, which is set to deliver significant environmental and economic benefits across the borough.
Construction is expected to begin in Isleworth as early as 2028, with a phased rollout across the borough over the next 12 years.
The project has now transitioned from feasibility to design, where the next critical step is to engage with potential customers to ensure that the network meets community needs while achieving its sustainability goals.
For more information about the project please visit the council’s website, or you can download the report here (please note that commercially sensitive information has been redacted).