It is clear that we need to get Strathbungo off gas heating sooner rather than later, but onto what? Improving energy efficiency and insulation comes first, but we need to replace the boilers. One option is air source heat pumps where each property has their own independent system. Another is a district heating system where hot water is delivered directly to properties rather than gas. District heating needs a heat source, Central Glasgow will get a network drawing heat from the Clyde, parts of Southside might be able to run a network off the White Cart, and in some areas (regrettably probably not ours) minewater heat can be used. Strathbungo does not have an obvious heat source but there are still options.
Ground Source Heat Pumps which draw energy from under the ground (1.5-250m) can work better than Air Source Heat Pumps as underground is at a pretty constant temperature year round. They can use pipes laid in trenches if you have lots of space (we do not) or boreholes otherwise. However, the cost of drilling a borehole can be high, partly due to the cost of bringing in the equipment. Drilling lots of boreholes in one go is much cheaper per borehole than drilling them one off. Therefore a network of boreholes in Strathbungo’s back lanes might supply the needs of Strathbungo’s heating.
There are other advantages: such heat pumps can be run in reverse to provide cooling. While Glasgow has historically not had much need of cooling, we don’t live in that world any more. Heatwaves can kill large numbers of people. Consequently ensuring that at least some properties have cooling is an essential matter of life and death as well as increased comfort. We can invite neighbours round to lie next to cold radiators and wait for the weather to turn, as it surely will. Running the pumps in reverse also helps recharge the boreholes, increasing their capacity and efficiency in the winter.
One of the key constraints is the rate at which the ground cooled by the boreholes warms up again as heat moves in from the centre of the earth and surrounding ground. Draw energy out too fast and the ground will slowly cool over the years and the system become less efficient. Charging the boreholes in the summer from cooling radiators/solar thermal panels etc. can enable more homes to be heated off the same borehole network.
The main difficulty is likely to be organisational and financial rather than technical as there is a significant capital cost, complexities around running costs, title deeds etc. and it would only work financially if enough households made a firm commitment.
Kensa has a video of how ground source district heating systems can work.
Strathbungo Eco Group and Loco Home Retrofit are talking to one manufacturer about the possibility of a Bungo Borehole Network. We hope that developing this idea and assessing feasibility can form part of future back lane funding proposals. Loco Home Retrofit will also apply to the new Heat Networks Development Fund to develop this idea. We are looking for people to help manage this project, do get in touch: email@example.com