The energy challenge for cities: could waste heat be powering the city in the future?

From your laptop (or, more specifically, the data centre providing the computing power to your search engine) to the local sewage works or the fridges in your local supermarket, sources of heat are available across our cities but the energy they produce is often simply being lost up into the air.

With nationwide ambitions to be carbon neutral in the decades to come, if we could somehow harness and recycle that energy it could keep the city’s homes, businesses and shops toasty warm without the need to generate any excess energy. According to the Greater London Authority there is enough heat wasted in London to meet 38% of the city’s heating demands.

London and Sheffield are two cities where we are exploring exactly these opportunities – looking for ‘waste’ heat sources that we can capture and use in our district heat networks supplying thousands of customers.

And it was so positive to see both cities featured in the Government’s recent announcement of millions of pounds in funding to develop some of England’s first heat network zones, with these opportunities potentially creating tens of thousands of jobs in the future.

£5.8 million has so far been allocated to pilot projects of the new heat zoning scheme – the UK’s pioneers of technology to provide low-cost, low-carbon heating to more businesses and building owners.

Sheffield has been chosen along with London, Leeds, Plymouth, Bristol and Stockport to develop the zones, with construction expected to start from 2026.

This is exactly this kind of challenge we work with every day – advising cities and helping to find solutions for their specific challenges, and we know the city of Sheffield is especially forward thinking on developing heat networks in the city.

In London, our district heating scheme in the Square Mile has gone through huge transformation in recent years to make sure we are leading the Mayor’s efforts to decarbonise heating. Our 22km of heating and chilling network now rely on heat pumps fed from geothermal energy sources 200m below the capital.

And in Sheffield, our Lower Don Valley network is powered by waste wood that would otherwise have gone to landfill – with recently announced plans to expand the network further into the city and explore new ways of generating heat – or capturing it from nearby industrial sources.

Our plans are to add about 10km to the existing 8km heat network to connect businesses and homes across the Lower Don Valley region, delivering more low carbon and cost-effective heating to the city. We've also recently announced plans to explore the potential of working with our neighbours Yorkshire Water on the energy potential coming from their Tinsley wastewater treatment works.

In both these circumstances we are looking at how we can bring our capability and experience to work collaboratively and share the ambition for change.

We don’t just work with councils, we are collaborating with businesses, residents, community groups, universities, hospitals, national government and more.

The energy transition brings huge benefits in terms of cost of living, jobs and skills, better cities and cleaner air. But we can only achieve by bringing everyone and everything together.