Heat Networks Delivery Plan Review Report 2026

2. Progress against target

44. Whilst the data we currently have about heat networks has significant limitations (see Box 2 for more information), our previous best estimate was that in 2022, 1.36 TWh^[11] of heat was supplied via heat networks in Scotland. Our current best estimate is that 1.57 TWh of heat^[12] was supplied via heat networks in 2025. 1.57 TWh equates to over 2% of non-electrical heat consumption in Scotland.

Box 2: Data sources, considerations, limitations and analysis approaches

The Heat Networks Metering and Billing Regulations (HNMBR) 2014 require heat networks to notify and provide certain data to the regulator, and to submit an updated notification within four years of the previous notification.

Taking a similar approach to the previous report, our best estimate of heat supplied via heat networks for 2025 is based on HNMBR notification data spanning from 2014 to September 2025, aiming to provide an estimate of the whole known heat network sector in Scotland, including networks that have not provided updated notifications. Our estimate relies on limited data with concerns about its quality. This includes poor data coverage in key areas which required modelling to fill in the gaps, lack of information around decommissioning of networks, and issues surrounding enforcement of notifications. All the above factors limit our ability to estimate the true size of the heat networks sector in Scotland or the total amount of heat supplied.

Changes in non-electrical heat consumption will have an impact on how the percentage - over 2% - changes over time. Using the 2024 provisional figure for non-electrical heat consumption, the estimate is 2.3%. Energy consumption figures for Scotland are derived from sub-national consumption figures produced by the Department for Energy Security and Net Zero. To calculate total non-electrical heat consumption, we combined gas consumption figures for 2024 and other combustion fuel consumption figures (petroleum, coal, bioenergy and wastes, and manufactured fuels) from 2023, producing a provisional figure of 68.6 TWh for 2024. Consumption of fuel used for transport and agriculture are not included in this estimate. This figure is provisional because the other combustion fuel consumption figures for 2024 will be confirmed in July 2026.

45. Noting the limitations of the data, caution should be applied in using these data for wider purposes. However, we think there is value in providing a broad overview of the current state of the heat networks sector in Scotland.

46. There are over 1,380 known heat networks supplying heating and cooling to domestic and non-domestic properties and industry in Scotland. Across these networks:

• 67% (929) were communal heating schemes and 30% (415) were district heating networks (3% unknown).
• 39% (606 GWh) of the heat supplied was by communal heating, and 61% (955 GWh) supplied by district heating.
• over 36,000 homes and 3,000 non-domestic properties are connected to heat networks.

47. More accurate data is expected to be collected over time about heat networks via the UK consumer protection and authorisation scheme, as well as via HNTAS. We continue to work with the UK Government and Ofgem so that Scottish Ministers have access to such data for statutory reporting purposes and to support evidence-based policy making. In doing so, we aim to reduce the risk of operators being asked for the same data via different processes and of data being required by two sets of regulations (under the Energy Act 2023, and the 2021 Act).

48. One of the limitations of the data currently available to us is that it does not provide the detail needed to allow an estimate of the emissions reductions associated with the growth in heat networks. For this, we would need more information about the buildings connecting to new and expanding heat networks (for example their previous heating systems and connection dates) and more reliable information about the heat network energy centres (for example the energy sources).

49. Additionally, we expect emissions reductions from existing networks, the majority of which use natural gas, will come from their decarbonisation (which is planned to be tackled as part of the developing regulatory regime). As such, our emissions reductions during this reporting period are unlikely to be significant. Efficiencies driven by the introduction of HNTAS will also contribute to emissions reductions.