Heat networks: a homegrown opportunity for the UK’s energy future

Hemiko’s work with Worthing Borough Council provides an example of how heat networks can work in practice, including in places outside the major cities traditionally associated with network development.

The Worthing Heat Network has been developed over several years, with a main spine running through the centre of the town and connecting council buildings, Worthing Hospital and other major sites. The project has involved the challenges of retrofitting existing buildings and laying infrastructure through a busy seaside town, but Sarah sees it as an important demonstration of what is possible.

The network’s energy centre sits on the town’s high street and houses the equipment needed to operate the system, including large air source heat pumps, backup systems and a thermal store. This is effectively a large hot water tank that provides additional resilience and can help manage costs.

From there, hot water travels through insulated pipes buried deep underground to connected buildings, including the hospital, town hall and theatres. Existing plant rooms are refurbished and fitted with heat interface units, which provide a familiar-looking alternative to traditional gas boilers.

Sarah says the next phase will extend the network to a leisure centre and another historic theatre, while the existing infrastructure provides the foundations for further expansion.

One of the biggest opportunities offered by heat networks is that they do not have to be designed as a fixed, one-off solution.

Future expansion can be built into the network from the beginning, from the size of underground pipes to connection points that allow new branches to be added later.

Sarah adds: “Our goal is to be able to connect every building in the town if they’d like to over the next few decades.”

She compares the approach to building with Lego. “You can just expand over time, branch out to new areas, as well as adding new sources of heat for additional capacity.”

That flexibility is particularly important as the UK’s energy system changes. Networks can incorporate a range of heat sources as they develop, including air source heat pumps, river-source heat pumps, energy from waste and heat recovered from data centres.

In other words, the infrastructure being built today does not have to depend on a single technology or energy source for decades to come.

Heat networks also offer a potential alternative to requiring every individual building to install and operate its own low-carbon heating technology.

By connecting multiple buildings to shared infrastructure, heat networks can provide heating across whole neighbourhoods, towns and potentially cities.

Sarah refers to Scandinavia, where heat networks have already been used extensively to connect entire urban areas, as evidence that the model can be scaled.

“We always build in additional capacity to be able to serve surrounding buildings that want to connect to the network.”

That creates an opportunity to roll out low-carbon heating infrastructure efficiently, with individual buildings able to connect to a wider system rather than each having to develop its own solution.

The benefits are not only environmental.

According to Sarah, heat networks can also provide greater resilience against fluctuations in global fossil fuel markets.

“Heat networks are typically the lowest cost decarbonisation solution compared with something like an air source heat pump.”

Because networks can use locally sourced heat, customers are less directly exposed to the international price fluctuations associated with imported fossil fuels.

The network operator can also manage the system in ways that would be more difficult for an individual household to replicate. Thermal storage, for example, can allow heat to be generated or stored at more favourable times, helping manage periods when electricity prices are higher.

That combination of local energy, shared infrastructure and flexibility could become increasingly valuable as the UK seeks to reduce its dependence on imported energy while keeping bills under control.

For Sarah, the key message is that the UK does not need to wait for a completely new technology to emerge before making progress.

Heat networks are already being built and operated. The opportunity now is to expand them, connect more buildings and make sure the infrastructure being installed today can accommodate tomorrow’s technologies and demand.

“I think we have a huge opportunity in the UK to roll out heat networks as quite a simple solution to some of the biggest issues like energy security and customer bills and net zero targets.”

That expansion will require investment, long-term planning and public support -particularly when construction means disruption to roads, businesses and residents.

But Sarah argues that clear communication can make a significant difference.

“Having the community on board and understanding why they’re seeing construction work, why they’re feeling disruption from the outset is enormously helpful.  

“If you understand the longer-term purpose of that disruption, it’s much more digestible.”

The Worthing project illustrates the wider potential: heat networks are not a futuristic concept waiting to be invented. They are an existing piece of infrastructure that can be expanded, adapted and supplied by an increasingly diverse range of heat sources.

The opportunity for the UK is to take what is already working and build it at much greater scale, to create a heating system that is lower carbon, more locally sourced and designed to remain flexible as the country’s energy needs evolve.

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