Channa Karunaratne, district energy market sector lead at AECOM discusses how heat networks have become a key power behind the energy transition in London.

London has set itself a target to generate 15 per cent of its energy from local, renewable sources by 2030, and this includes capturing waste heat¹. 

Heat networks – though by no means a new method of heating our towns and cities – are becoming an increasingly popular way to do this. Government investment in the low carbon heating source is expected to reach up to £80 billion by 2050² which, coupled with ongoing work to develop heat network zones, will help accelerate the rollout.  

For Londoners, the benefits of these zones are many.   

When tasked with decarbonisation, people in the capital have two main options: installing a heat pump or connecting to a heat network. The latter is a much simpler, cost-effective way of decarbonising not least because it avoids issues with grid connection and capacity.  

The market is gearing up for mass adoption of heat networks and we’re already seeing the laydown of infrastructure for the future, with advanced zoning beginning to take place ahead of final consultation. Eventually, the supply from these heat networks will become a regulated utility like gas or electric, providing us with a secure, resilient and affordable source of energy for our future. 

A model for urban decarbonisation  

The government heat network fund (GHNF) is helping accelerate the rollout of new projects. Recently it’s supported the commercialisation and construction of the UK’s first-of-its-scale district heat network in London, that will harness waste heat from the cooling of a number of data centres. 

AECOM was brought onboard to design the heat network, which will act as a blueprint for how data centres and communities can coexist and collaborate. 

The heat network is set to serve more than 9,000 new homes along with 250,000 square meters of commercial space, extending across three London boroughs within the Old Oak and Park Royal Development Corporation (OPDC) region. It’s expected to deliver around 90GWh of heat across several phases between 2027 and 2040.  

New targets mean London will be expected to build 80,000 homes a year³ and projects like the OPDC are a great example of the ability of heat networks to support decarbonisation at scale.  

To meet these targets, we need to be creative in how we generate our heat. Why not take waste heat from the tube, or data centres or any other source for that matter. Recycling this heat will help our planet, facilitate growth and in the long run and be economically beneficial for the country. 

There are still challenges, especially in a busy city like London where the potential for widespread road closures during development could have serious impact on businesses. However, advanced planning, permitting, consultation and coordination with local authorities will minimise disruption as much as possible. And why stop there. On the back of these infrastructure schemes, we should be looking at electric vehicle charging, placemaking and public realm improvement. We should put back better. 

Connecting the past and future 

Retrofitting into existing homes and buildings will also have a big part to play in encouraging widespread adoption of heat networks, and we’re helping to combat this in the capital.  

We’ve been involved in the creation of Project SWAN, the largest low carbon heat network in the UK which can provide heat to Grade I and II listed buildings. The energy network would serve an area from Pimlico to the Strand Aldwych and use low carbon sources like the River Thames and TfL ventilation shafts. 

Scalability, coupled with government initiatives and funding, puts heat network technology in an ideal position to help us meet net zero targets. Upcoming zoning consultation will be essential to facilitating both a city- and country-wide rollout, enabling a future where renewable electricity is in abundance and our heating systems are in place to make the most of it. We’re building London’s future, allowing us to retain our title of somewhere people want to live, work and invest in. 

³ London's new homes target