Heat Networks: What are they and how are they regulated in the UK?

What is a heat network? 

Heat networks are systems in which heating, hot water, or less frequently cooling, is generated centrally and supplied to multiple properties – either domestic or commercial - over a local area. 

These systems leverage a central heat source to power an energy centre, which then distributes that heat to properties as hot water through a network of pipes. The cooled water is returned to the energy centre via another set of pipes. As such, individual properties within the network do not need to have their own traditional boiler.

The UK government defines two main types of heat network: 

• Communal heating – in which heat and hot water a supplied to multiple consumers within one building (for example, in a block of flats). Often, the energy centre is a large boiler in the basement. 
• District heating – in which a local energy centre provides heat and hot water to consumers spread across multiple buildings. These networks can be large, serving thousands of customers. Heat networks are run by suppliers and operators; customers typically interact with the supplier, who provide them with heating, cooling, or hot water. Operators are responsible for maintaining and ultimately controlling the network. 

Because heat networks are fuel agnostic – i.e. they can use any source to generate heat centrally – they are a useful tool to support decarbonisation efforts. While most existing heat networks currently use a fossil fuel source, newer networks often use lower-carbon sources. It is also possible to retrofit existing networks with lower carbon technologies, therefore reducing the carbon footprint of all associated properties simultaneously.

How widespread are heat networks in the UK? 

Typically, heat networks are located in areas with high population density, as their economies of scale depend on properties being in close proximity. Government data shows that even until recently, over 90% of heat networks in Great Britain were located in England, with a significant proportion of those in London. However, with various government funding schemes available for new heat network development, and new areas for potential development to be identified, this regional pattern could soon evolve into a more widespread distribution. 

Overall numbers for heat networks are anticipated to increase dramatically over the next two decades. In fact, the government ambition is to increase the proportion of heat provided by heat networks from 3% today (14TWh in 2020) to 20% by 2050 (80TWh).