Project Summary
The South West Net Zero Hub commissioned a study of existing and projected heat and cooling demands near abandoned coal mines in South Gloucestershire/East Bristol.
The report identifies potential locations where a networked ambient or heat and cooling solution might be beneficial.
Four locations were identified as having potential and have been earmarked for further investigation.
Background
South Gloucestershire Council is looking at solutions to decarbonise heat in new and existing buildings, including around 20,000 buildings that are located near former mine workings.
An initial study by the Mining Remediation Authority (formerly the Coal Authority) identified some areas where former mine workings might have the potential to resource a heat network.
Our Role
The study commissioned by the Hub was the next step in determining whether demand aligned with this potential supply of low carbon heat.
The Hub designed a study to meet South Gloucestershire Council’s aspirations to consider the potential for a low carbon heat network to supply the large volume of poorly insulated housing stock in the area.
The study was aligned with the Heat Network Delivery Unit’s standard specification for a masterplanning study to ensure any resulting heat network opportunities are aligned with Government funding requirements.
Location
East Bristol and Central South Gloucestershire, including:
- Easton and Fishponds, Hanham, Cadbury Heath and Warmley, Hillfields and North Kingswood, Coalpit Heath to Westerleigh, and Pucklechurch.
Technology
The study considered networked heat and cooling (two pipe) and ambient loop systems compared with individual air source heat pumps.
Financing and Ownership
The identification of a technically and economically viable heat network is still some way off, however it is envisaged that any project would be de-risked using public funds (council, MCA, central Government) to attract commercial investment from a large heat network operator, such as Vattenfall.
The structure of any commercial arrangement has not yet been determined.
Results
The total impact from the top three potential heat networks identified in the report are:
- Peak output – 170MWp
- Carbon savings – 440,000tCO2 over 30 years
- Total capital investment required – £250M
This is based on:
- Lawrence Hill: annual demand 73GWh; peak demand 41MW; £50,000,000 capital investment; 210,000tCO2 saving over 60years.
- Fishponds: annual demand 153GWh; peak demand 93MW; £120,000,000 capital investment; 460,000tCO2 saving over 60 years.
- Science Park: annual demand 60GWh; peak demand 36MW; £80,000,000 capital investment; 210,000tCO2 saving over 60 years.
Lessons Learnt
A further conclusion was that residential housing density – even for terraced streets – is insufficient to underpin the business case for a heat network based on the analysis approach taken without a significant increase in key anchor loads.
This leaves the question of how the heating and cooling energy demands of existing fabric poor properties will be met economically without expensive and technically challenging deep retrofit, and the extent to which these could be served by individual heat pumps.
There is some uncertainty as to whether the additional benefits of a socialised system are fully accounted for in the modelling.
Benefits
The study has contributed further to the understanding of potential heat network opportunities in the area, supporting multiple organisations, including Bristol City Leap, in their commitment to building decarbonisation in the region.
The study was also used in discussions with businesses around development options using low carbon heating and/or cooling (linked to the mine water resource) and in the review of the Local Plan.
Next Steps
South Gloucestershire Council is keen to take forward the potential heat network opportunities and is seeking funding to carry out a techno-economic study at the Bristol & Bath Science Park.
Vattenfall is interested in the potential opportunity in Fishponds, and is carrying out its own investigations there.
Key Facts
| Client | South Gloucestershire Council |
| Strategic priority | Heat decarbonisation |
| Energy generation/saving | Peak output – 170MWp |
| Timeline | 2025 – TE study 2026 borehole trials 2027 onwards – detailed project development + commercialisation. |
| Carbon saving | Carbon savings – 440,000tCO2 over 30 years |
| Project value | Total capital investment required – £250M |
| Project website | Read the project report |
