Plans to turn former coal mines in Glasgow into a large scale geothermal laboratory could get underway next year.
Geothermal has potential to provide a sustainable energy source that could help end fuel poverty in some urban areas in the UK. Sounds simple – and it could be – but there are a lot of unanswered questions and a planned facility in Glasgow could hold the key to unlocking these. This £9M research laboratory is being developed by the British Geological Survey (BGS) as part of the Natural Environment Research Council’s (NERC) £31M Geoenergy Observatories Project. The aim of the work is not to provide Glasgow with a geothermal resource at this stage, but to provide greater understanding of the challenges and benefits of such schemes.
The focus of the laboratory will be the geothermal energy potential of low entropy heat drawn from groundwater in flooded coal mines. BGS director of energy systems and basin analysis David Schofield, who is leading the project, says: “A lot of cities that grew up in the industrial revolution were based around a fuel source, which was mostly coal, so we have a lot of UK cities on top of disused coal mines so you have this convergence of new resource – the groundwater in abandoned coal mines – and a need for that resource – densely populated communities in fuel poverty.”
The research in Glasgow could have a wide reaching benefit for other UK cities, such as Sheffield, Manchester, Stoke-on-Trent, Swansea, Leeds and Bradford.
“There are two aspects that make coal mines attractive – one is that they have a flux of groundwater through them to create recharge and the second is that they go down to depth so you have access to the geothermal gradient at shallower depths,” explains Schofield.
“It is the drilling to depth that makes geothermal expensive, but by using the mine structure you don’t need to drill as deep to get the benefits.
“Normal groundwater temperature is usually 11°C. Mines in South Wales, which are up to 800m deep, have water coming out at 20°C, but there are not large urban communities close by.
However, in Glasgow, the mine workings are shallower at 300m to 400m deep so the water may not be as warm, but there are communities in fuel poverty concentrated nearby.”
The laboratory will primarily aim to tackle the technical issues around exploiting this potential geothermal resource, but Schofield hopes that the research will also address how the economics stack up as well. “There are engineering and sociological challenges that we hope to address,” he says.
Work on the Glasgow project started 18 months ago with a geological overview of the area for the feasibility study to create this geothermal laboratory. The work included building partnerships with
Glasgow City Council, Clyde Gateway Project and other relevant regulatory bodies and authorities.
“This kind of project needs the buy-in from others in the area from the start,” says Schofield.
“The main challenges so far have been relationship building. The next stage will focus on the technical challenges.”
A public meeting in early September presented details of the potential sites identified and presented the BGS’s plans for them to local people before work on gaining planning consent started.
“We ruled out some potential sites based on issues such as contaminated land and lack of space for future development,” explains Schofield.
“Surface development may be small initially, but we could need room for expansion.
“The fundamental issue is that the problems we have encountered so far in Glasgow are the same as the problems such a project would find elsewhere, so the knowledge gained will be transferable.”
According to Schofield, the challenges to get the facility up and running are the normal ones that face most geotechnical projects: getting a ground investigation carried out, procurement and getting a contractor on board. “All the typical challenges,” he says.
Schofield hopes that the planned 350m drilling depth of the 20 to 30 borehole array at the site will mean that the planning application will not be overly complicated as he describes the holes as “relatively shallow”.
The current hope is to start borehole drilling on site in the first half of 2018, and for research projects to be starting from 2020.
“This is a laboratory rather than a project, so focus is for others to come and do research,” adds Schofield.
“There are other geothermal laboratories in Europe, but not others that look specifically at low entropy heat. Most other geothermal labs focus on deeper geothermal and particularly power generation. This lab will focus on producing heat and storing heat.”
NERC will develop funding calls around the use of the facility so universities and other groups will be able to make bids to carry out research but it is hoped there will also be international interest.
“Outcomes from the laboratory are not known at this stage but the aim is to gain understanding of the technology needed to use low entropy heat in the UK,” says Schofield.
“Some of the questions we expect the research to address would include how much heat can be extracted, what is the best way to do it, how much can you store, what happens when you re-inject heat into the ground, the use of heat exchangers and so on.
“Not all the knowledge we need to gain is under the ground. Some of it is about the social and economic issues of setting up networks to use this resource at surface.
“From a personal perspective, I am really excited by this as I think it is the first time that we have had the opportunity in the UK to get to grips with some of these questions.
Previous research to answer these questions has been done on a small scale, but this is going to take it to a bigger scale where we have the opportunity to look in more detail at the scientific questions, and I think that is really exciting.
“What will hopefully come out of it – more than anything – is building confidence in our ability to deliver this kind of geothermal solution. If the research programme over the next decade builds our ability, our confidence in rolling this kind of project out, we will really have achieved something.”
Plans for development of several potential sites in Glasgow were presented to local residents in early September. The BGS hopes to select one site and gain planning consent to allow work to start on site next year with research starting in earnest in 2020.