Cardiff landmarks switch to low-carbon heating

30 October 2026

Three of Cardiff’s most prominent public buildings have replaced gas-fired heating with a low-carbon network that uses surplus heat from a nearby energy recovery plant.

The Senedd, Tŷ Hywel and Wales Millennium Centre are now connected to Cardiff Heat Network, which transports heat from Viridor’s Trident Park Energy Recovery Facility to buildings across Cardiff Bay.

The council says the connections will reduce carbon emissions from heating at the three buildings by up to 80%. The network captures surplus heat produced during electricity generation that would otherwise be lost, distributing it through insulated underground pipes to provide heating and hot water.

Cardiff Council cabinet member for climate change Dan De’Ath comments:

“These three buildings are at the heart of Welsh public and cultural life. Their connection to the heat network sends a real signal that Cardiff, as the capital city of Wales, is serious about playing its part in tackling climate change and increasing its energy resilience while continuing to serve communities.”

The new connections follow those made by Cardiff and Vale College, Butetown Community Centre and several other council and public buildings, including a social housing development at Scott Harbour.

The £15.5m network was funded through a UK government grant and a loan from the Welsh Government. It was delivered by Cardiff Council through its arm’s-length company, Cardiff Heat Network Ltd.

The council says carbon emissions per person in Cardiff have fallen by 21.6% since 2019.

Further expansion is being considered, with the network operator in discussions with potential customers near the existing pipes. Funding options are also being explored for a second phase that could extend the network into the city centre and further across Cardiff Bay.

Although the network currently relies on heat from the energy recovery facility, its design allows other sources to be connected in future. These could include groundwater or deep geothermal heat beneath the city.

Matthew Jones, The Senedd’s head of FM services and sustainability:

“Joining the heat network is a good opportunity to secure a resilient, locally-produced heat supply for the Senedd estate.  We expect joining the scheme to lower both our operating costs and carbon footprint.  As such, this is a key part of the Senedd Commission’s Carbon Neutral Strategy and we’ve been very pleased to work with Cardiff Council on this project.”

Wales Millennium Centre. Image credit: Cardiff Council