Low carbon district heating with Cardiff Council

Cardiff bay

How can local councils decarbonise their heat systems?

The UK needs to decarbonise its heating system — where carbon-intensive gas meets up to 73% of heat demand—to make Net Zero a reality. A solution? Heat networks. Seen as a cost-effective, low carbon, and reliable alternative in high heat density areas by the government, heat networks can help the UK drive down both emissions and energy bills.

Cardiff Council wanted to investigate the feasibility of heat networks as a means to cut emissions and close in on the city’s carbon neutrality goal.

However, the nature of heat networks requires significant planning and upfront investment. This can sometimes force local authorities to shelve these projects. To prevent this from happening, Cardiff Council sought a partner who could help them turn ideas into reality.

Heat networks

Heat networks, also known as district heating, offer the promise of supplying domestic and non-domestic buildings with low carbon heat from a central source. A heat network can derive its heat from sources, including energy from waste schemes, industrial waste heat and water sources. Its carbon-saving potential rises as the network becomes more connected.


From idea to implementation: Making low carbon district heating a reality

From concept through to start of construction, we guided Cardiff Council throughout this process. As part of this, we helped the local authority spend the development grant it had received from the Heat Network Delivery Unit (HNDU) run by the UK government and get the ball rolling. 

Here, an energy reclamation facility situated 600 m from the council’s county hall was identified as an appropriate very low carbon heat source that could be harnessed to transport heat to facilities in and around Cardiff Bay, with the potential to further expand the heat network into the city centre. Together, we:


Developed the specifications of the feasibility study, providing clear guidance for tenders on determining the project’s practicality.


Brought a range of stakeholders who could provide long term commitments to the project to the table. This included each customer connected to the network, the owners of the energy from waste plant, funders and landowners.

Business case

Established the business case of the heat network. As part of this, we submitted capital funding applications and underlined how a council-owned heat network made both commercial as well as environmental sense.

construction jobs

Procured contractors, supporting the council throughout its Design, Build, Operate and Maintain (DBOM) procurement process to ensure construction at scale.


Commercialising heat networks

By bringing this project to fruition with construction beginning in early 2022, Cardiff Council is establishing the first large-scale city heat network in Wales. Situated in Cardiff Bay, it will connect some of Cardiff’s most iconic buildings, from the Senedd to the city’s home of performing arts, the Wales Millennium Centre. The first phase is already making an impact, which will grow as the network expands:  

heat networks

Build confidence and establish stakeholder buy-in in the feasibility of heat networks. The project gave the local authority the tools and knowledge to build a scalable scheme that can expand and connect many more buildings to its heat network.

government funding

£15.2 million

The council secured an additional £6.6m grant from the UK government and an £8.6m loan from Welsh government, financing the project's first stage and bringing it to fruition. Read more.

carbon removal etc_DACC

2,197t CO₂e

The city will save 2,197 tonnes of CO2e emissions per year at the project's current stage. This will increase to 5,600 tonnes of CO2e savings as the network expands.

The commercialisation of the heat network has meant that Cardiff Council can go a step further. Future phases will connect housing developments and businesses to the network, providing them with a highly cost-effective, low carbon heat solution.