Natural gas has long been the foundation of the UK’s heating system, and around 85% of homes currently rely on a gas boiler. But our dependence on this highly polluting fossil fuel has also plunged millions into fuel poverty, stoked geopolitical conflicts, and intensified the impacts of climate change. To break this cycle, the UK needs a swift transition to affordable and sustainable heating that brings consumers along for the ride.
One key solution is connecting homes to district heat networks. They currently provide around 3% of UK heating, but recent studies project they will need to supply up to 60% to achieve our net-zero target. These underground piping systems can leverage various low-carbon heat sources, including electric heat pumps, renewable energies, and combined heat and power plants. Additionally, when connected to long-distance heat transmission highways, heat networks can utilise clean, low-cost heat from across an entire region, such as commercial and industrial waste heat and geothermal heat from abandoned coal mines. This diversified approach can ensure heat networks always use the cheapest and greenest heat available.
However, to reach net zero and eradicate fuel poverty once and for all, connecting to a heat network can’t just be possible – it needs to be highly attractive. As Denmark has proven successfully, District Heat-as-a-Service (DHaaS) can help regain consumer trust while delivering a host of financial, social, and environmental benefits.
Delivering Hassle-Free Heat, Street by Street
The core objective of DHaaS is to make converting to a heat network fast, simple, and affordable. The subscription model enables households to replace their gas boiler with a heat interface unit (HIU) at no upfront cost. Instead, they pay a simple monthly fee covering all hardware, monitoring, maintenance, and heating costs, spread over 15 to 20 years.
In Denmark, around 65% of homes are connected to district heating, including around 95% in its four largest cities. According to Næstved, one of the country’s leading district heating companies, around 99% of its new customers connect via the DHaaS model. This subscription-based approach has been fundamental to accelerating heat network conversions – reducing heating costs and emissions while virtually eliminating fuel poverty.
High-Quality HIUs with Digital Monitoring
The heart of a heat network connection is the heat interface unit (HIU), which transfers hot water supplied by the network into the dwelling’s space and water heating systems. Unlike electric heat pumps that require a large physical area, the HIU’s footprint is typically equal to or smaller than that of a gas boiler. Their compact nature supports fast and simple conversions, making them ideal for the UK’s abundant and ageing stocks of terraced housing.
With incoming legislation bringing UK heat networks under utility regulation, the performance and accuracy of HIUs will soon face far greater scrutiny. Therefore, installing the right HIU and monitoring combination is essential to maintaining accurate, reliable, and compliant operation. On a commercial level, it’s also crucial to making heat networks investable assets that can be aggregated into profitable, large-scale heat utilities.
An optimal customer setup features a mechanical HIU with a separate digital energy monitor. A high quality self-acting thermostatic and mechanically controlled HIU can operate reliably for over 20 years, while a standalone digital monitor ensures the system remains compliant with evolving regulations and communication technologies.
Ensuring Accurate Metering and Billing
The type of digital energy meter installed directly influences the scope and accuracy of system monitoring. Wired and wireless M-Bus systems (such as those from Germany’s OMS-Group) remain the gold standard. Their open protocol guarantees network operators have continuous access to metering data and avoid being limited by closed systems.
Digital monitoring ensures more transparent billing and can significantly improve customer engagement. Network operators can leverage this data to produce more user-friendly heating bills and populate online portals and monitoring apps – key steps in building strong consumer loyalty.
The Value of Five-Year HIU Performance Data
Collecting real-world HIU performance data over five or more years provides valuable insights and benchmarks that can help optimise the entire network. For example, this data can reveal trends such as efficiency drops, maintenance frequency, and the most common points of failure. It accurately reflects dynamic operating conditions and user behaviour – offering a precise snapshot of the HIU’s long-term value.
For network operators, real-world HIU data also delivers substantial financial benefits. It highlights the true cost of ownership – including OPEX, REPEX, and energy consumption – and helps operators make more informed decisions. This data-led approach ensures HIUs meet their practical needs while providing comprehensive insights into their quality and efficiency. Ultimately, these factors ensure heat networks fulfil their promise of delivering reliable, clean, and affordable heating to all users.
Building Lean and Green Heat Utilities
Streamlining operational performance is important for individual heat networks – but it’s critical as they evolve into large-scale heat utilities. Digital monitoring and historical performance data can minimise OPEX and REPEX costs by enabling targeted maintenance and eliminating unnecessary servicing. These factors also boost customer satisfaction, reinforcing that their HIUs are being continuously monitored and when performance starts to drift, re-calibrated and optimised to reduce heating costs.
With heat networks coming under stricter regulations, digital monitoring also supports the demanding requirements of enterprise-scale energy management systems. This data can assist heat utilities in their ESG performance and climate reporting, ensuring they align with the UK’s net-zero goals.
DHaaS: The Key to Clean and Affordable Heating
As heat networks gain momentum across the UK, a consumer-centric approach is needed to accelerate conversions and build successful heat utilities. As we’ve seen in Denmark, DHaaS eliminates many of the common barriers to entry, allowing customers to make a simple transition without up-front costs or complicated renovations. This approach empowers consumers to play a direct role in our national energy transition and break the stranglehold of expensive and polluting natural gas.
By combining quality mechanical HIUs with digital monitoring, network operators can ensure accurate and transparent billing, streamline operational efficiency, and build strong customer loyalty. These factors can ultimately make district heating a cornerstone of the UK’s energy system, supplying millions of homes with green, low-cost heat – and making fuel poverty a thing of the past.