3.4.25

Construction of a low-carbon district heating network that will reduce carbon emissions from connected buildings in Cardiff by up to 80% is nearing completion, with the first heat expected to be supplied to customers in the coming months, once final commissioning and testing has taken place.

The £15.5 million Cardiff Council project, delivered with support from a UK Government grant and a loan from Welsh Government, will be the first of its kind in Wales. The network, which forms part of Cardiff Council's One Planet Cardiff response to climate change, will supply a range of buildings in Cardiff Bay including, the Senedd, Wales Millennium Centre, Cardiff and Vale College, the Butetown Hub, the Scott Harbour flats and a range of other Council buildings.

Cabinet Member for Climate Change, Strategic Planning and Transport, Cllr Dan De'Ath and Council Leader Huw Thomas on a recent visit to the Heat Network. Image credit: Cardiff Council

Cabinet Member for Climate Change, Strategic Planning and Transport, Cllr Dan De'Ath, said: "Switching on the heat network for the first time will be a significant milestone on the road to achieving our carbon neutral ambitions. It's a major green infrastructure project, the first of its kind on this scale anywhere in Wales, and will instantly eliminate the need for connected buildings to have gas boilers, reducing their carbon emissions by up to 80%. Over the course of a year that's going to save over 10,000 tonnes of carbon emissions once it's complete - roughly the amount of carbon produced from heating 3,700 homes."

Construction of the network of pipes and the new energy centre required for the system has taken approximately four years. During that time the council's main contractors Hemiko, employed a network of local sub-contractors, providing employment opportunities that saw approximately 30 local people working on site, for every day of the construction period.

The installation of a new ‘pipe bridge' was one of the final stages of construction. Image credit: Cardiff Council

Ken Hunnisett, Programme Director for Triple Point Heat Networks Investment Management who manage and administer the UK Government's heat network funding programme, said: "It's fantastic to see the benefits of the Heat Networks Investment Project (HNIP) funding being realised, having first been awarded to this scheme in 2020. As the project nears completion, the delivery of first heat later this year will mark a major milestone in Wales' transition to sustainable energy. We look forward to seeing the positive impact this network will have on Cardiff, providing low-carbon, cost-effective heating for years to come."

How will the Cardiff Heat Network work?

Cardiff Heat Network will use excess steam, already generated in the process of burning non-recyclable waste at Viridor's Energy Recovery Facility, to provide sustainable heat and hot water.

The incinerator burns non-recyclable waste to produce steam. The high-pressure steam created powers turbines which generate 250 GWh (gigawatt hours) of electricity. The heat from this steam is currently lost. A new Heat Exchanger and Energy Centre will capture the heat from this steam after the electricity generation process, and will   transport it to connected buildings via a network of highly insulated pipes, where it will be used to provide heat and hot water. 

Where is the network?

The current network of pipes runs from a newly built energy centre close to Viridor's Energy Recovery Centre, and along Hemmingway Road where it splits, with one branch running south towards Wales Millennium Centre and the Senedd and a second branch running through Butetown and up through Butetown to Callaghan Square.

How can this be low carbon when it relies on burning non-recyclable waste?

The heat network itself creates no carbon emissions, and it means that connected buildings no longer need to use traditional boilers which rely on fossil fuels.

Although carbon emissions are released when non-recyclable waste is burnt at the Energy from Waste Plant, this is not the same as burning gas or coal purely as an energy source. The only current alternative is sending non-recyclable waste to landfill. This also creates carbon emissions, as well as causing other long-term environmental issues.

The carbon impact of burning waste in Cardiff is already mitigated to some extent through it being used to generate electricity, which can replace electricity generated through the burning of fossil fuels purely for energy.

The Cardiff Heat Network takes heat which already exists as a by-product of this process, and without the Heat Network would be simply lost to the atmosphere, and harnesses it to create further carbon savings.

What happens next?

Before delivering its first heat to customers the system needs to be fully tested. Subject to satisfactory testing and commissioning, customers will be added to the network in stages, with the first heat expected to be delivered later this year.

Discussions are ongoing with further potential customers in close proximity to the network with a view to adding further connections.

Funding options are also being explored for a potential ‘phase 2' of the network, which could see it expand further into the city centre.