Abandoned Coal Mines

Abandoned coal mines providing cheaper, clean energy for homes
Water in flooded shafts and tunnels, heated by the Earth's crust, promises a green revolution, with around six million households close to former pits.

when the mines shut down, the shafts and tunnels tend to flood and that water is warm - anything from 15 - 40C (59-104F) and generally hotter with greater depth as a result of geothermal energy from the Earth's crust.

In Gateshead, they are now piping the water into a heat pump - an industrial version of what's being recommended for homes as a replacement for gas boilers.

Hot water is then circulated to local homes and businesses through a network of pipes.

https://news.sky.com/story/gateshead-abandoned-coal-mines-providing-cheaper-clean-energy-for-homes-13085012

Plenty mines in Wigan

Sounds like a really sound idea for cheap but more importantly green energy.
Round here in the Wigan area and more widely the Lancashire area we must have untold miles of underground passages filled with geologically warmed water.
The technology at Gateshead has been proven, so can we expect a similar venture over here?
Two things that I wonder, on the negative side, will it cause subsidence as the mine workings empty of water, on the positive side, will the passages refill with water to be processed again?

ramiejamie wrote:Sounds like a really sound idea for cheap but more importantly green energy.
Round here in the Wigan area and more widely the Lancashire area we must have untold miles of underground passages filled with geologically warmed water.
The technology at Gateshead has been proven, so can we expect a similar venture over here?
Two things that I wonder, on the negative side, will it cause subsidence as the mine workings empty of water, on the positive side, will the passages refill with water to be processed again?

They don't pump the water out of the mine, they pump it up to a heat exchanger, and then return the cooled water to the mine, to be heated up again by the hot rocks.

Thanks for the explanation TTS,  I wasn't aware of the technology involved, of course it makes sense now that you've explained it
Best thing is it is a continuous ongoing process.

This article shows just how farbehind the UK is in Green Energy!

Starting in early 2005, I worked as a Project Manager researching into Geothermic energy. At that time, it was a well known source in Scandinavia. So well known that several private houses used it as a heating system.

From that project, I can state this. Even if there are several ways of using underground water, two stand out. The first one is to pump out the water, extract its heat, then put it back in the ground. The two disadvantages with this us that heat energy is lost bringing it up to the surface, and then it must be put back in the ground a distance away. It cannot be put back in the same hole! The quantities needed are also ridiculously high.

The second way, and now more or less universal, is to use a sealed pipe that is filled with a kind of antifeeze mix. The liquid goes round and round, picking up heat as it does so. This heat is removed in a specialised kind of heat pump. As long as the minimum temperature of the water the pipe goes into never falls below exactly 9,5C, it works quite well. at least, it does until air temperature starts to fall below zero. A big advantage of the low water temperature requirements is that shallower holes are needed. Typically, these will be btween roughly 100 and 200 metres in depth. Its often better to use 2 x 100 metre bore holes, rather than 1 x 200 metre.

So impressed with what I found out working on the project, I installed this in 2006. Anyone want more info?

Some good info there Uncle Joe, you are obviously well informed

ramiejamie wrote:Some good info there Uncle Joe, you are obviously well informed

Thanks for that. The info comes fromm having worked on it. Its probably a bit dated now though, as advancements have been made in the area.

One thing I could add. Canals are a huge source of geothermic energy as well. Although not as efficient as using coal mines, they are far cheaper to put into practice.

Blimey UJ, who da thought canals could be a source of energy?
I suppose they contain millions of litres of water that is non flowing, generally speaking, which is solar heated, not sure how the extraction and heat transfer works.
Let’s hope it can be used.

ramiejamie wrote:Blimey UJ, who da thought canals could be a source of energy?
I suppose they contain millions of litres of water that is non flowing, generally speaking, which is solar heated, not sure how the extraction and heat transfer works.
Let’s hope it can be used.    

To give an idea of the amount of energy in a canal. The Leigh Branch of the Leeds-Liverpool canal is 7,5 ,iles long. Assuming the pipes were correctly laid, that would produce enough energy to heat roughly 750 well insulated homes!

Thanks for that interesting info UJ.
The economics I would imagine are that it would cost maybe hundreds of thousands of pounds to put the infrastructure and technology in place, and the return would be the income from 750 houses energy bills.
I would imagine the payback would be financially unviable.
A good idea methinks but would it provide lots of cheap energy for lots of homes?

A lot depends on how this is approached. Using myself as an example.

When I first moved into the house I am living in, the annual energy use was 52 thousanf kW! That was divided into 45 000kW heating, 7 000 for the rest. Horrendous. When working on the project, I looked into how it would be if I used the technology to provide heating. It seemed viable, so I took the plunge, and installed it. Payback time due to savings was estimated at 5 years.

After installation, energy used dropped to around 16 000 total. Due to the rise in energy prices around 2007, payback time dropped to two years. So it was well worth doing. Since then, technology has moved on. On December 12th last year, the "1st. generation" pump was replaced by a new "2nd. Generation" one. Early indications are showing a 20-25% reduction in Winter energy bills. Thats despite this Winter being a bad one. Well worth it! Thats the positive side.

There is a negative one though. The house is now all electric. Thats where the infrastructure problem comes in. If one or two houses use this technology, its fine. If everyone uses it, then more Power Generating Stations will have to be built. Added to that, not every house can use it. Terraced houses, or those on small plots of land would not be able to. It would be perfect for farms though, and relatively cheap for them to install.

Thanks for the info UJ, I’m impressed with your results.
I didn’t glean from your post as to what system you installed in your house to give you these savings, I’m guessing it was a heat pump.

I had solar panels in my last abode, and was thinking about a ground source heat pump.
I moved house and now I've got neither

ramiejamie wrote:Thanks for the info UJ, I’m impressed with your results.
I didn’t glean from your post as to what system you installed in your house to give you these savings, I’m guessing it was a heat pump.

I use two bore holes, one that is 90 metres deep, the other 110. All of these systems use heat pumps, in my case "antifreeze" to water. Uts the only one that can be used with boreholes. If you wish, I'll try to find a photo of the actual pump.

Lolly wrote:I had solar panels in my last abode, and was thinking about a ground source heat pump.
I moved house and now I've got neither

Ground sourced energy is a good idea, but many British houses dont have enough space for it. Thats a big drawback in many cases.

At around £7000 a battery of 10kwph for solar panels is very expensive, no wonder that written off electric car battery's are difficult to obtain when they are being sold for around £2000 for a battery with 40/50 kwph storage

"I use two bore holes, one that is 90 metres deep, the other 110. All of these systems use heat pumps, in my case "antifreeze" to water. Uts the only one that can be used with boreholes. If you wish, I'll try to find a photo of the actual pump."

Blimey UJ, I can't think of how you could drill bore holes so deep, unless the heat pump suppliers do it for you.
I am unlikely at my age to want to fit a heat pump in my house which is detached with a fair amount of land, but it would be interesting to see what size and shape a heat pump is, but please don't bust a gut trying to find a photo.

This is the best photo I have of the pump. It was really taken to show the pipe connections. Size wise, its about as big as a washing machine. The previous one was about the size of the hot water tank to the right of the photo. Look closely, and you will see a green light in the black band (control panel)- That shows its operating as it should Red or yellow indicates a fault.

Many thanks for the info UJ, I can’t believe what a neat compact unit it is.
Sorry to ask so many questions, I assume the heat pump provides hot water to the tank and then this is pumped round the system just like a conventional gas fired system works.

ramiejamie wrote:Many thanks for the info UJ, I can’t believe what a neat compact unit it is.
Sorry to ask so many questions,  I assume the heat pump provides hot water to the tank and then this is pumped round the system just like a conventional gas fired system works.

You ask as many questions as you want. Its a pleasure answering them.

The heat generated by the pump warms up two separate systems. One is for the Central Heating, the other for shower, kitchen and so on. Whish system is chosen is controlled by a multi position valve. The positions are: Off. On, centrl heating only. On, hot water only. On, both of the previous. If the pump cant cope when its in the third position, then additional heating is provided. normally, this would only happen when outdoor temps are well below freezing. The tank that you can see to the right of the photo I posted is only for shwers, etc.

Thanks for the very clear explanation UJ.
It may be that in future years, and maybe not all that long away, that we will all have similar systems installed.
Energy efficient systems like yours are surely the answer to the country’s low carbon future needs.
Well done you.

Dont forget that there are other systems that work on similar priciples. although they are not quite as efficient, they are a lot cheaper.

In regards to carbon emmisions, a lot of new technology is being developed. One that even uses CO2 as a fuel base.

What is needed is for the scientists to find out how to generate fusion power, then there could be limitless electric production, and heating etc would be powered by electricity

Surely there are many armchair scientists elsewhere

Do you mean the coal people

Because a massive underground complex like the three connected underground Golborne, Parsonage and Bickershaw Mines, and them being deep, there would be a lot of geothermal energy down there, and I presume that because they were on different levels, you will have convection currants moving the water around the mine powered by the heat down there, but how do you get the energy from down there, up to the surface and used in a practical way, which is an economically practical way, it might sound like a good idea, but in reality it is an 'impractical' thing to do, because of the expense involved