Leeds City Council: Low carbon heat network

Buildings in the UK use lots of energy to keep warm and we currently rely upon multiple carbon intensive production processes to meet our energy needs.

However, as councils strive to meet their net zero targets, the general population is also becoming more acutely aware of the damage burning fossil fuels is doing to our environment and the inevitability that these fossil fuels will eventually run out.

Councils need to consider the different ‘greener’ ways to create secure and affordable energy, how these can be supported locally, and how low-carbon energy can be distributed effectively to our building stock.

Lots of buildings and industrial processes produce excess heat that is currently wasted, such as factories, data centres and waste processing plants. If we can capture and utilise this excess heat effectively then it can provide an innovative and reliable local heat source that replaces our use of energy generated by burning fossil fuels.

Heat networks are often designed to use sustainable sources to provide heat directly into connected buildings using a network of insulated pipes. The ‘Leeds PIPES’ network was delivered by Leeds City Council in partnership with Vital Energi with the aim of providing affordable, reliable, and low carbon heat and hot water. The scheme uses energy recovered from the city’s non-recyclable household waste at the Leeds Recycling and Energy Recovery Facility (RERF), currently operated by Veolia.

The scheme supports the Council’s ambition to become the first net zero major city in the country, working towards a 2030 target. Part of their climate action work has seen the local authority recognise and deliver on the low carbon potential of heat networks while helping the community and local businesses to access affordable energy.

By replacing thousands of polluting, inefficient fossil fuel powered heating systems with a more sustainable alternative the network is helping to cut Leeds’ carbon footprint and improve local air quality.

Unlike the use of electric storage heating or heat pumps, buildings connecting to the network also help to reduce demand on the city’s electricity grid, freeing up capacity as they transition to an increasingly electrified transport and heating system.

The network now stretches around 26 kilometres in length and work is currently underway to extend it another 2.5 kilometres to enable more building to connect.

Over the last financial year, more than 15,000 megawatt-hours of heating was provided by Leeds PIPES which helped reduce the city’s carbon footprint by more than 2,000 tonnes.

Around 1,800 residential properties, 8 public buildings, and 2 commercial buildings are currently connected to the network. Several more customers (including the Ministry of Justice and a second major connection to the Leeds Teaching Hospitals Trust) have announced plans to connect soon and discussions are progressing well with many more potential customers.

The more buildings that do connect and take heat from the network, the greater the positive environmental impact and phase three of the main spine extension is currently underway, increasing the connection capacity. It is estimated that the scheme has the capacity to save more than 16,000 tonnes of carbon from being emitted every year once fully built out.

Alongside environmental benefits, the network is currently providing around 1,800 homes with affordable warmth, supporting efforts to alleviate fuel poverty in some areas of the city experiencing high levels of deprivation.

In addition to the generation and distribution of the heat, the team was also able to utilise time spent installing district heating in resident’s homes to deliver improved heating systems consisting of Heat Interface Units, new radiators, and controls. 

The network’s commercial customers are benefiting from competitive - and predictable - pricing of heat, supporting local economic growth. The relative stability of pricing has been especially attractive for commercial customers recently compared to the volatile prices of oil and gas.  

The project, delivered in partnership with Vital Energi, has helped employ more than 430 people in the local low carbon sector including 36 apprentices.

The network continues to expand and is regularly connecting to new buildings with the aim of becoming one of the UK’s largest heat networks in the near future.

For example, Leeds Teaching Hospital Trust recently announced plans to connect another 10 of its own buildings to the network, as part of a wider package of decarbonisation and efficiency measures using government funding. The Trust successfully connected the Beckett Wing of St James’s University Hospital earlier this year.

Leeds PIPES has received funding from a range of local, regional, national and European sources, including both grants and loans.

Unlike privately owned networks, the council isn’t driven to make a profit from the network, deliberately setting tariffs to be competitive with fossil fuelled alternatives to tackle fuel poverty and improve business competitiveness. The surpluses generated are typically reinvested in expanding the network to serve even more of the city and, longer-term, to invest in additional low carbon heating sources.

When the Council first started consulting prospective customers about connecting to the network, the clear message came back that they would only seriously negotiate once construction started. However, without a firm idea of potential customers, the risks of construction were high. The Council took a calculated risk, underpinned by connections to social housing and public sector partners, to commence construction on the assumption that new customers would connect once district heating infrastructure was available. This is now coming true but is a real barrier to many large strategic networks ever commencing. 

Resilience was also considered at an early stage. A new energy centre was created to take waste steam from the RERF and convert it into low-temperature heat and hot water for the district heating network. A second energy centre at Saxton Gardens was created to meet peak demand and add resilience to the overall system using gas boilers, ensuring continuity of supply in all circumstances.

As this changeover involved working in people’s homes, the team ensured that they liaised closely with the Council’s housing teams and their partner’s resident liaison team to ensure disruption was minimised. Whilst working in the flats, they also installed sprinklers for fire safety as part of the works package. This coordination reduced the number of visits required to each property and kept disruption to a minimum.

George Munson, Senior Project Manager: [email protected]

Vital Energi