Energy Systems Catapult has identified a range of options for reducing the capital costs of rolling out low-carbon district heat networks across the UK, laid out in a report for the Energy Technologies Institute.

District heating, where all buildings within an area share a single heat source, has the potential to play a far greater role in the UK energy system. However, work must be done to help heat networks evolve. If fully exploited, nearly half of all heat demand could be met by heat networks.

Capital costs are the main barrier to progress in this area. However, we believe these proposals could reduce capital costs by up to 40%, rendering heat networks more attractive than other forms of low-carbon heat provision.

Eight cost-saving route maps

We have suggested eight ‘route maps’ designed to cut costs for district heating network deployment in the UK.

1. Knowledge management research and training – Establish a District Heating Knowledge Centre to share learning and increase the impact of all other innovations. This knowledge centre would disseminate current best practice and outputs of other innovations, bringing together a wide group of stakeholders.
2. Low flow rate design – Develop tools to help increase the accuracy of heat demand estimates and maximise the difference between temperatures entering and leaving the building.
3. Radical routes – Reduce costs of civil engineering by running distribution pipes along the buildings themselves; either in the eaves or on the front. This is most effective in terraced housing but can be implemented cost-effectively in semi-detached areas.
4. Trenchless technologies – Drill tunnels underneath the surface, removing the need for trenching. The technology for this already exists but key products need development to make it more cost-effective.
5. Improved front-end design and planning – Demonstrate and quantify the positive impact of improved design work and surveying. This includes undertaking detailed survey and design work early, focussing on the activities that realise the greatest cost savings as well as adopting alternative contract frameworks to minimise the pricing of risk.
6. Shared civil engineering costs – Share the costs of civil engineering between utilities working in the same region. This solution includes aligned planning cycles, developing a Streetworks Partnership, and joint ventures between district heating and utility companies.
7. Direct heat interface unit system and existing hot water storage – Demonstrate the potential cost savings of replacing indirect with direct Heat Interface Units (HIUs) whilst making use of existing hot water tanks. This would include some product development to alleviate perceived risks to the consumer.
8. Heat interface unit optimisation – Innovate to reduce the cost of HIUs for retrofit schemes from approximately £1,500 to £200.

Next steps

To enable innovations to reduce capital costs within heat network infrastructure, UK central and devolved governments need to provide frameworks that support demonstration, knowledge transfer and skill development in the sector.

Elevating heat networks to be included as infrastructure within the Infrastructure and Project Authority will give impetus for stakeholders to innovate. It would demonstrate that the government recognises that the need for and scale of our heat network development is a major infrastructure project.