How Defunct Coal Mines Could Heat UK Homes
The title of this post, is the same as that of this article on Mining Technology.
This is the introductory paragraph.
In a country with no operational coal mines, the UK Coal Authority has proposed to once again turn these operations to heating homes and businesses. But this time, they will not provide coal for burning. The plan, to take warm water from flooded mines, would turn an environmental problem into a community solution, and the idea is spreading.
The reason, I’m posting this is two-fold.
There was a report on this edition of Countryfile, which should be available until the end of 2022. The relevant section starts at 38.5 minutes into the program.
Charlotte Adams is featured in this report and the Countryfile program. I first came across Charlotte and her fascinating work at a lecture in 2018, which I wrote about in Can Abandoned Mines Heat Our Future?
Mine Water Heat
The title of this post, is the same as that of this press release from the Coal Authority.
This is the introductory paragraph.
The Coal Authority is working with partners to unlock the heat within our historical coal mine network, to transform the homes and workplaces of the future.
The Coal Authority doesn’t have much of a historic product, so selling the heat from the mines could be an environmentally-friendly revenue scheme.
These four paragraphs are the heart of the press release.
As part of our work to make a better future for people and the environment in mining areas, we’re exploring opportunities to use mine water to heat and cool homes and businesses.
Water within the mines is warmed by natural processes and can, if sustainably managed, provide a continuous supply of heat. Mine water temperatures are not affected by seasonal variations and, subject to the right support, mine water can provide renewable, secure, low carbon heating for buildings in coalfield areas.
With heating accounting for 40% of energy use in the UK, mine water heat could improve the sustainability of the places where we live and work. Mine water heat could also play a part in the UK’s efforts to tackle climate change and support its net zero future.
The Coal Authority are working with academics, local authorities, central government and others to help realise the potential of mine water heat. We’re supporting the delivery of mine water heat projects and working with others to make them happen.
The press release then adds more details and describes specific projects.
Mines For Storing Electricity
We also mustn’t forget other uses for abandoned coal mines.
I particularly like Gravitricity’s idea of used abandoned deep mines to store energy, that I wrote about in Gravitricity Explores Czech Coal Mine For MW-Scale Storage.
I hope the Coal Authority has its eyes on this ball.
Conclusion
I first became aware of the ability to extract heat from abandoned coal mines at a lecture at the Geological Society of London, after which I wrote Can Abandoned Mines Heat Our Future?.
I believe that for some parts of the country, this could become the preferred technology for heating homes and businesses.
The technology was even featured on the BBC tonight.
Eden Project: Geothermal Heat Project ‘Promising’
The title of this post, is the same as that of this article on the BBC.
This is the first paragraph.
A three mile-deep (4.8km) borehole has shown “promising” prospects for a geothermal heat plant in Cornwall.
Eden estimates the borehole can produce enough heat for 35,000 homes.
Geothermal energy is only at the beginning in the UK, but just because we don’t have any active volcanoes, we shouldn’t discount it.
On the other hand, we do have a lot of water-filled abandoned coal mines, which in former mining areas of the UK can and will provide a substantial amount of district heating, as I wrote in Exciting Renewable Energy Project for Spennymoor.
And then there’s one-off project’s like Bunhill 2 in Islington, which I wrote about in ‘World-First’ As Bunhill 2 Launches Using Tube Heat To Warm 1,350 Homes.
Conclusion
The UK may not be an Iceland, Indonesia, Italy, New Zealand, Philippines or the USA, but according to Wikipedia we have a good potential.
- Deep geothermal resources could provide 9.5GW of baseload renewable electricity.
- Deep geothermal resources could provide over 100GW of heat.
I think my most significant post on geothermal energy is Schlumberger New Energy And Thermal Energy Partners Form Geothermal Development Company STEP Energy.
Schlumberger and the other oilfield services companies have a very serious problem.
With countries abandoning oil and gas, they have lots of engineers, geologists and other staff, who will not be needed by the oil and gas industry.
But their expertise and skills can be transferred to the geothermal heat and power industry. This will benefit the staff, the companies and the world!
The other place there expertise can be used is in the storage of captured carbon dioxide.
Scotland’s Mines To Be At Centre Of Green Energy Renaissance
The title of this post, is the same as that of this article on the Glasgow Herald.
The article is a good explanation of the pros and cons of using the heat stored in disused coal mines, to heat hones and businesses.
Funding To Develop Geothermal Energy Plans For Disused Flooded Coal Mines
The title of this post, is the same as that of this page on the University of Strathclyde web site.
This is the introductory paragraph.
Researchers at the University of Strathclyde have won early stage funding to develop plans to tap into the geothermal energy contained within disused, flooded coal mines in Scotland.
I have talked about this technique before in Can Abandoned Mines Heat Our Future?, which I wrote after I attended a public lecture at The Geological Society.
This page on the Geological Society web site, gives a summary of the lecture and details of the speaker; Charlotte Adams of Durham University.
This paragraph indicates the scale of the Scottish project, which has been called HotScot.
Heat trapped in 600 km3 of disused mine-workings in the Central Belt of Scotland could meet up to 8% of Scotland’s domestic heating demand.
It looks to be a very comprehensive project.
Conclusion
As this appears to be the second project where disused coal mines are used as a source of heat, after one in Spennymoor, that I wrote about in Exciting Renewable Energy Project for Spennymoor. I wouldn’t be surprised to see other projects starting in other mining areas.
And not just in the UK, as techniques developed by engineers and scientists get more efficient and more affordable.
Fruit And Veg Self-Sufficiency Ahead Thanks To Heat From Sewage Farms
This headline caught my eye on an article in today’s Times.
This is the introductory paragraph.
Britain will become far more self-sufficient in tomatoes, cucumbers, peppers and other produce under plans to tap heat from sewage farms and pipe it to giant greenhouses.
The idea of using waste heat to grow fruit and vegetables is not new.
The technique is used at Drax power station and at various Scottish distilleries.
Low Carbon Farming just intend to do it with heat from sewage works.
- They have identified 41 sites in the UK.
- The greenhouses will be larger than the O2.
- The first two sites are in East Anglia and are being built near two of Anglian Water’s sewage works.
- Fully developed, they could make the UK self-sufficient in tomatoes, cucumbers and peppers and for most of the year.
- It would be a £2.67 billion investment, that would create 8,000 jobs.
Intriguingly, if they need more heat, they’ll use a fossil-fuel combined heat and power unit. The carbon dioxide produced will be fed directly to the fruit and veg, as it makes them grow faster.
Another Source Of Heat
In Exciting Renewable Energy Project for Spennymoor, I wrote about a Durham University project to use the waste heat in old coal mines to heat housing.
Could this heat be used to grow fruit and veg?
Exciting Renewable Energy Project for Spennymoor
The title of this post is the same as that of this article on the Durham University web site.
This is the first paragraph.
In January 2016, local residents Alan Gardner, Cllr Kevin Thompson and Lynn Gibson from the Durham Energy Institute at Durham University, met a team of academics to explore the advantages renewable energy and specifically the use of geothermal resources could bring to Spennymoor.
And this is the last.
Durham University is one of the world leaders in this research field. Spennymoor now has an opportunity to be at the forefront of that research. What the outcomes will eventually be is unknown at this stage but being able to explore the opportunity by the best in the business is encouraging.
Charlotte Adams mentioned in the article is the academic, who did the presentation I saw yesterday and talked about in Can Abandoned Mines Heat Our Future?.
Everybody, who lives in a mining area, should read this article and show it to everyone they know.
Can Abandoned Mines Heat Our Future?
The title of this post, is same as that of the title of a public lecture I attended at The Geological Society this afternoon.
This page on the Geological Society web site, gives a summary of the lecture and details of the speaker; Charlotte Adams of Durham University.
The Concept
The basic concept is simple.
- Abandoned coal mines had their pumps turned off when they are closed and the worked areas have flooded with water, that is now at temperatures of around 12 to 20°C.
- As fifteen billion tonnes of coal have been extracted from UK coalfields, that is a lot of space to flood. An estimate of around two billion cubic metres is given.
- This means that the water holds somewhere between 27.9 and 46.5 GWH of energy in the form of heat.
- Heat pumps would be used to upgrade the temperature of this water, to provide hot water at useful temperatures for space heating.
For those unfamiliar with the concept of a heat pump, Wikipedia gives a good explanation, of which this is the first paragraph.
A heat pump is a device that transfers heat energy from a source of heat to what is called a heat sink. Heat pumps move thermal energy in the opposite direction of spontaneous heat transfer, by absorbing heat from a cold space and releasing it to a warmer one. A heat pump uses a small amount of external power to accomplish the work of transferring energy from the heat source to the heat sink.
In connection with this project, the heat source is the warm water in the mines and the heat sink is the water that is circulated to heat the buildings.
Wikipedia goes on to say this.
In heating mode, heat pumps are three to four times more effective at heating than simple electrical resistance heaters using the same amount of electricity. However, the typical cost of installing a heat pump is also higher than that of a resistance heater.
Wikipedia also has a section, which descries the use of heat pumps in district heating.
It should also be noted, that as with lots of technology, heat pumps are much improved, from the one I installed in a swimming pool in the 1980s.
Gas Is Replaced By Renewable Energy
The electricity to drive the heat pumps could be derived from renewable sources such as hydroelectric, solar, wave or wind.
Effectively, the system is using intermittent sources of electricity to create a constant source of heat suitable for space heating.
Would The Mines Run Out Of Heat Or Water?
As I understand it, the water in the mine will continue to be heated by the heat in the mines. The father of a friend, who came with me to the lecture was a coal miner and my friend confirmed it was hot in a coal mine.
The water will of course continue to flood the mine and the water pumped to the surface will probably be returned.
So the system will continue to supply heat for space heating.
How Long Will The System Supply Heat?
The system has the following characteristics.
- It is electro-mechanical.
- It is powered by electricity.
- Water is the heat transfer medium.
- Additives like anti-freeze will probably be applied to the water used for heat transfer.
There is no reason the system can’t be designed, so that it supplies heat for many years with regular maintenance and updating.
How Does The System Compare To Bunhill 2 Energy Centre?
In Bunhill 2 Energy Centre, I described Islington’s Bunhill 2 Energy Centre which uses heat generated in the Northern Line of the London Underground to provide district heating.
I am fairly sure that a lot of similar technology will be used in both applications.
This page on Wikipedia is entitled London Underground Cooling.
There is a section, which is entitled Source Of The Heat, where this is said.
The heat in the tunnels is largely generated by the trains, with a small amount coming from station equipment and passengers. Around 79% is absorbed by the tunnels walls, 10% is removed by ventilation and the other 11% remains in the tunnels.
Temperatures on the Underground have slowly increased as the clay around the tunnels has warmed up; in the early days of the Underground it was advertised as a place to keep cool on hot days. However, over time the temperature has slowly risen as the heat sink formed by the clay has filled up. When the tunnels were built the clay temperature was around 14ºC; this has now risen to 19–26ºC and air temperatures in the tunnels now reach as high as 30ºC.
So one big difference is that the Underground is warmer than the mine and this should make it a better heat source.
I feel that engineers on both projects will benefit from the ideas and experience of the others.
Would Infrastructure Funds Back This Technology?
In the UK, there are several infrastructure funds set up by companies like Aberdeen Standard, Aviva, Gresham House and L & G.
In World’s Largest Wind Farm Attracts Huge Backing From Insurance Giant, I explained why Aviva had invested nearly a billion pounds in wind farms to support pensioners and holders of their insurance policies.
Comparing the risk of using abandoned mines to heat buildings and that of offshore wind turbines generating electricity, my engineering knowledge would assign a greater risk to the turbines, providing both were built to the highest possible standards.
It’s just the onshore and offshore locations and the vagaries of the weather!
I think it is true to say, that infrastructure funds will back anything, where there is an acceptable long-term income to be made, commensurate with the costs and risk involved.
But then Government or any public or private company or organisation should not pay over the odds for the energy delivered.
Conclusion
Charlotte Adams in her lecture, asked if abandoned mines can heat our future.
The answer could well be yes, but there are other sources of heat like the London Underground, that can also be used.
The Anonymous Widower 