Thanks to both innovation and government policy, heat networks are evolving rapidly. Future-proofing them with low-carbon technologies is responsible investing, argues Jarrad Bedford, Head of Sales – O&M at Insite Energy.
Serving multiple buildings from a single heat source, heat networks have been viewed by successive governments as an efficient, climate-friendly heating and cooling solution for urban centres. Now their implementation and effectiveness are increasing fast, backed up by a regulatory overhaul designed to protect consumers, encourage investors and support climate goals.
Zones are being designated within which new housing developments and certain other types of buildings are required to connect to a heat network. Starting with London, Leeds, Plymouth, Bristol, Stockport, and Sheffield, the longer term aim is to roll out to cities across England.
At the same time, the launch of the Heat Network Technical Assurance Scheme in 2026 will see detailed standards applied across the lifecycle of a system, from design to decommissioning, including aspects such as installation, carbon efficiency, maintenance, and metering & billing.
The clock is ticking for local authorities and housing associations to get their portfolios in order to avoid fines and other penalties. And, on the flipside, there are a host of new opportunities to capitalise upon, including big technical advances.
Cleaner heat
Traditionally powered by large gas or biomass boilers, modern heat networks are now increasingly being designed around renewable heat sources. Some repurpose waste heat from factories, data centres, mine water geothermal heat, or the London Underground. Others use heat pumps to capture warmth from the air, or in some cases, from the ground, rivers or lakes.
Using latent heat in this way is far cleaner and more efficient than generating it through combustion. For every kilowatt-hour (kWh) of electricity heat pumps use, they typically deliver 2-5 kWh of heat. In comparison, a gas boiler produces less than 1 kWh of heat per kWh of energy.
The Carbon Trust estimates that replacing a gas boiler with a heat pump reduces emissions by around 60 per cent. And, as the nation’s electricity supply continues to decarbonise, that figure will only grow.
Planning-friendly
In major cities like London, where robust decarbonisation policies give priority to both heat networks and heat pumps, combining the two technologies offers a clear advantage for public sector housing providers in achieving the high Energy Performance Certificate (EPC) ratings now demanded by planning authorities.
The London Plan targets a scenario in which 15% of the capital’s energy is generated locally from renewable sources by 2030*. It also aligns closely with the government’s Future Homes Standard, which is anticipated to ban the installation of gas boilers in new-build properties from 2027.
The ASHP advantage
Air source heat pumps (ASHPs) often offer the most flexible renewable heat source option because they can be installed almost anywhere, including on top of roofs or suspended from exterior walls. This opens up more retrofitting opportunities in densely populated areas than might otherwise be the case.
Although still rare in the heat network sector, ASHPs are quickly becoming more common. At a new development in Barnet, North London, for example, twelve 42 kilowatt (kW) air source units are delivering heat to 236 homes around three times more efficiently than an equivalent fossil-fuel system.
Flexibility
It’s a major advantage of heat networks that they can switch heat sources, or even combine multiple types of sources, within a single scheme. It allows obsolete or uneconomic equipment to be replaced without disrupting service or stranding assets. At the same time, public sector housing providers can align their energy strategy with policy shifts, funding cycles or technical innovations, integrating new, cleaner technologies as they emerge. And it means systems are inherently resilient, scalable and future-proofed – all hallmarks of good use of public funds – while also delivering measurable carbon savings that increase over time.
Fifth-generation systems
Another important innovation in heat network technology is the emergence of ambient loop systems. These circulate water across the network at far lower temperatures (usually 10-30oC) than conventional systems operate at. Small WSHPs in each home then raise it to meet individual households’ space heating and hot-water requirements. This dramatically reduces heat loss without the need for highly insulated pipes, increasing efficiency and lowering costs.
Known as the fifth generation of heat networks, ambient loops also simplify retrofits because existing pipework can often be retained. And they’re scalable; new properties can generally be added to a scheme in significant numbers without the need to upgrade the centralised heat source.
Skills issue
Unfortunately, the rapid advancement of the heat network sector and the wider transition to renewables is causing a growing skills gap that threatens to undermine progress. For engineers trained to install and maintain household gas boilers, switching to much larger, interconnected, low temperature systems takes specialised training that generally takes three years to complete.
Recognising the urgency, we’ve opened a fast-track route to our own experienced heat network engineers to speed an injection of expertise and talent into the workforce, alongside two apprenticeships. But equivalent training and accreditation programmes must be rolled out more widely if the UK is to fully harness the potential of this practical route to carbon reduction.