Welsh Government maps abandoned mines for heating schemes
The Welsh Government has published a new map detailing all the former coal mines in Wales which could potentially be used for heating schemes.
The government commissioned the Coal Authority to investigate the water heating potential from disused mines, and produce a “mine water heat opportunity map” to inform local authorities and developers on potential locations for heating schemes.
Mine water is a low carbon, sustainable heat source, which could compete with gas prices and deliver carbon savings of up to 75% compared to gas heating.
Flooded mine workings
Heat from the mine water is extracted by pumping water from flooded mine workings underground and bringing it to the surface.
In some abandoned mines this water will have been heated by geothermal energy.
Heat exchangers and heat pumps on the surface then recover this heat and boost the temperature further to heat up a clean loop of water, which can be used to transfer the heat into buildings for everyday use.
Heat pumps are key to taking advantage of mine water heat, as their efficiency means for every unit of electricity used to recover the heat from the mine water they output between three and five times the amount of heat.
After heat recovery, the cooled mine water is returned underground, and the water then slowly filters back through the flooded mine system and warms back up ready to be used again.
Ken Skates, Cabinet Secretary for the Economy, Transport and North Wales said in a written statement: “Disused coal mines are a legacy of Wales’s mining past. Where suitable, our historical underground coal mine network may now offer a renewable, secure, low carbon source of heating for buildings in coalfield areas.
“With heating accounting for 50%of energy use in the Wales, mine water heat could improve the sustainability of the places where we live and work.
“Mine water heat could also play a part in our necessary efforts to tackle climate change and support decarbonisation.”
Opportunities
The Coal Authority’s work included assessing all known coal mine workings in Wales which might now hold water that is warmed by natural processes.
Subsequently they created the map, covering all 22 local authority areas, categorising coal mine workings as “Good”, “Possible” and “Challenging” opportunities for mine water heat developments.
Additionally, they produced a map, illustrating locations where mine water is already brought to the surface via controlled gravity-driven discharges and mine water treatment schemes.
Such locations offer particularly cost-effective potential for heating schemes.
Technical reports have also been prepared for 11 local authorities, highlighting mine heat opportunities.
These will be published on the Welsh Government’s website and link to DataMapWales.
The reports will provide information and data, for developers who are interested in exploring the decarbonisation and economic opportunities offered by mine heat resources.
The mine heat reports are part of a package of information that will be published over the coming months as part of the Welsh Government’s wider commitment to decarbonisation and what it describes as “sustainable economic growth”.
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More bluster from WG, the mine water heating project Seren was raising this over 20 years ago, from work at Cardiff Uni
https://core.ac.uk/reader/42492440
I worked with consultants from the Carbon Trust at the time looking at possibility of a new school being built at New Tredegar using mine water heatpump as form of heating the school, which is adjacent to Elliott’stown colliery shaft.
Never got support from WG to pursue further although initial survey was promising, now it seems it’s back on agenda.
I’d imagine that the increase in gas prices along with the increased push to reduce CO2 outputs have made this idea more financially viable. A step in the right direction at last!
This sort of project is long overdue. For far too long we’ve gone down the route of the polluting and finite oil and gas to replace coal for heating. Having worked in the coal industry I know from experience how hot in can be even at the modest depth of mine workings.
Hopefully now they’ll stick with it.
This sort of mapping just points out the bleedin obvious although I think they are missing a trick with some of the deeper mines such as Llay near Wrexham which have far higher temperatures than older near surface workings.