Wind-pumped hydro electric storage

https://www.youtube.com/watch?v=Ugk2_tI6AN8

Scientists at Clausthal University of Technology are investigating whether it is possible to use inactive mines to store energy. To address the problem of supplying uninterrupted power generated from wind and water, electricity producers need new storage technologies.
The scientists say underground power plants can help. Solar and wind energy can be used to bring large quantities of water into basins above mines. At times when wind and sun is scarce, the water can be released through a shaft to drive a power producing turbine. They say it is a way to preserve the natural landscape and use decommissioned mines as rationally as possible.

easychair

Deleted User wrote: »

https://www.youtube.com/watch?v=Ugk2_tI6AN8

One doesn't need to be a scientist to come up with this, and all that is new is the idea of using old mines for pumped storage.

It sounds to me as if these particular "scientists" are more likely to be trying to drum up some publicity for "Clausthal University of Technology", (where that? ed.) rather than putting forward anything new.

One doesn't have to think too long to spot the flaws which will, probably, make this not viable economically.

Depends on how expensive & available the alternatives will be in the future!

djpbarry

easychair wrote: »

One doesn't have to think too long to spot the flaws...

Off you go then.

BryanF

seems like a perfectly good idea to me, its just a variation of this: http://web.archive.org/web/20030430003158/http://www.jcold.or.jp/Eng/Seawater/Outline.htm and its the same thing the spirit of Ireland group attempted to get going just as Ireland imploded.

easychair

BryanF wrote: »

seems like a perfectly good idea to me,

One wonders how good an idea it will be when one tries to "fill" an abandoned mine with water, only to find that it's doesn't fill and the water runs away through one of the many cracks or fissures. Mines are not reservoirs, and are more usually large and complex underground areas which are porous and not designed to hold water, but are designed to allow water to drain away.

Then, if by some miracle, you could fill a mine with water, the sheer weight of the water would be likely to burst through underground until it finds an outlet. Remember, one cubic meter of water weighs one tonne. Mines are rarely stable places, abandoned mines even less stable.

It might be possible to construct some sort of "tank" within the mine, but it would be easier to construct such a tank in a more stable environment if you were going to go to all that trouble.

djpbarry

easychair wrote: »

It might be possible to construct some sort of "tank" within the mine....

Which is exactly what this proposal entails.

easychair wrote: »

...but it would be easier to construct such a tank in a more stable environment...

Such as?

Oldtree

Pumped hydro storage is what Organic Power is trying to do in Mayo, see here:

http://www.pleanala.ie/casenum/PC0093.htm

and also had in mind for, but were unsuccessful, in another part of Mayo discussed in this other thread:

http://www.boards.ie/vbulletin/showthread.php?t=2055393679

BryanF

easychair wrote: »

One wonders how good an idea it will be when one tries to "fill" an abandoned mine

sounds like a better idea than fracking?

btw do you have any proposals on generating and storing renewable energy yourself?:rolleyes:

Oldtree

BryanF, are you suggesting the lesser of two evils approach then?

Renewable power generation and storage are a million miles away from being sustainable in this country and continue to be less financially viable as more oil, coal and gas deposits are both becoming viable to extract and new ones being discovered. Any in depth research shows them to be white elephants.

Don't get me wrong though I would like to see an end to this type of pollution, but I just can't see it happening. Subsidy is always the death knell of any industry.

BryanF

Oldtree wrote: »

BryanF, are you suggesting the lesser of two evils approach then?

I suppose I am, but that was not really where I was going with the conversation. I rarely see an proof from this poster, so i said i try a different tack and ask does easychair have a better option

Oldtree wrote: »

Renewable power generation and storage are a million miles away from being sustainable in this country and continue to be less financially viable as more oil, coal and gas deposits are both becoming viable to extract and new ones being discovered.

i think you need to divide these two issues. fossil fuels are cheap because everyone is set up to use them, any change away from this is as much bout psyche as its is about perceived extra costs. I disagree that renewable's (I'm speak primarily about wind)are less financially viable than fossil fuels, imho its more about the barriers in their way..

Any in depth research shows them to be white elephants.

can you point me to some thanks

Don't get me wrong though I would like to see an end to this type of pollution, but I just can't see it happening. Subsidy is always the death knell of any industry.

you hit on an interesting issue here, if the CC bill was implemented maybe it would have sent a message to investors that our government were serious about reducing our national reliance on fossil fuels, and were open to the renewable business.. we have one inter-connector starting, there is no reason why we couldn't be exporting wind energy in the next few years if the ESB networks got their s**t together and a small portion of the bank bail outs were put towards something that's actual in our national interest..

easychair

BryanF wrote: »

sounds like a better idea than fracking?

btw do you have any proposals on generating and storing renewable energy yourself?:rolleyes:

Thankfully its not a competition between this scheme and fracking.

This thread is about this particular proposal, which seems more obviously designed to give attention to a hitherto unknown facility, and if we have other proposals the place for them would be in other threads.

BryanF

easychair wrote: »

Thankfully its not a competition between this scheme and fracking.

This thread is about this particular proposal, which seems more obviously designed to give attention to a hitherto unknown facility, and if we have other proposals the place for them would be in other threads.

Perfect, lets take this back to how this should be discussed then.
Easychair can you back-up your distast for unground pumped storage with any peer-reviewed scientific papers or journals. thanks

easychair

BryanF wrote: »

Perfect, lets take this back to how this should be discussed then.
Easychair can you back-up your distast for unground pumped storage with any peer-reviewed scientific papers or journals. thanks

I hesitate to say this, but I think it possible you misunderstand the role of peer-reviews of scientific papers, or even the role of scientific papers.

I am not aware of any "scientific papers" which have made a study of what happens if you pour vast quantities of water into disused mines.

More importantly, it doesn't take a scientific study to know that disused mines are unstable places and are designed to take water away from the mine, rather than store water.

Your statement that I have a distaste for unground (sic) pumped storage is baseless and incorrect. What I have a distaste for is for schemes which have not been thought through in a common sense way, and for other posters who seem to want to invent what I have a distaste for.

djpbarry

Oldtree wrote: »

Renewable power generation and storage are a million miles away from being sustainable in this country and continue to be less financially viable as more oil, coal and gas deposits are both becoming viable to extract and new ones being discovered. Any in depth research shows them to be white elephants.

Well, that’s just not true – onshore wind generation, for example, is one of the cheapest available means of electricity generation.

easychair wrote: »

I am not aware of any "scientific papers" which have made a study of what happens if you pour vast quantities of water into disused mines.

Nor am I, but that’s not what you were asked.

easychair wrote: »

What I have a distaste for is for schemes which have not been thought through in a common sense way...

Kindly point out the “common-sense” flaws in the above scheme.

pljudge321

What I want to know is:

Whats the usable volume of the average mine?

How many mines suitable for such a scheme exist?


Then I'll make a judgement call on whether or not its a viable idea.

easychair

pljudge321 wrote: »

What I want to know is:

Whats the usable volume of the average mine?

How many mines suitable for such a scheme exist?


Then I'll make a judgement call on whether or not its a viable idea.

The first thing to realise is that there is no such thing as a average mine. The second thing to realise is that disused mines are very unstable places. It's not clear why the authors of this particularly dotty scheme have chosen disused mines as the ideal place to propose for such a scheme. Has anyone any idea why they have decided such inhospitable and dangerous places have been chosen?

BryanF

easychair wrote: »

The first thing to realise is that there is no such thing as a average mine. The second thing to realise is that disused mines are very unstable places. It's not clear why the authors of this particularly dotty scheme have chosen disused mines as the ideal place to propose for such a scheme. Has anyone any idea why they have decided such inhospitable and dangerous places have been chosen?

are they putting people down the mine with the water? who exactly cares if its inhospitable?

BryanF

BryanF wrote: »

are they putting people down the mine with the water? who exactly cares if its inhospitable?

As long as it holds water, who cares, but then again even that doesn't really matter if the second storage tank is above ground.

As long as the mine can take the outflow of the turbines during power generation and hold it for a day or two before it gets pumped back up, then it will work.

slowburner

Pardon me for butting in here, but is this proposed scheme not just a variant of the technology used by Siemens at Turlough hill?

Re. porosity of mine shafts - there are 850m deep levels here, full to the brim with water and they've been full since pumping stopped in 1982. The history of the mines in Avoca and many other places, shows that the problem is not keeping water in but keeping it out. When a level is driven in beneath the water table, water storage is not going to be a problem - quite the reverse in fact.

It is, just using "spare" wind generated power to do the pumping.
One of the biggest problems with renewable energy of course is generating power on demand instead of just generating when it's windy or sunny or whatever the tides are doing.

djpbarry

easychair wrote: »

The second thing to realise is that disused mines are very unstable places.

Some mines are unstable, typically at the entrances.

easychair wrote: »

It's not clear why the authors of this particularly dotty scheme have chosen disused mines as the ideal place to propose for such a scheme.

Because using a pre-existing, disused hole in the ground makes a whole lot more sense than excavating a new one?

slowburner

Using an existing shaft where the resource has been exhausted makes perfectly good sense.
Much better than the previous best idea which has usually been landfill or storage of nasty stuff.
There is one place I know where there is a very deep flooded shaft with an (almost) ready made reservoir above it. It's state owned and nobody is quite sure what to do with it - back filling it or making it a mine heritage site are the two options currently being considered.
Wouldn't it be fantastic to see a project like this piloted there? The site has superb wind resources too. The project could even generate sufficient funding for development of the site for mining heritage.

L

Meh. Storage looks great until you actually look at the specifics:

They're extremely capital intensive to develop.

They don't store energy perfectly (what you put in is always much more than what you get back out).

Put together it means you're better off not using storage and instead building flexible conventional plant to compensate for any errors you have in your forecasting.

Red Neck Hughie

I'm a big fan of anything renewable but given that the operators at Ardnacrusha have to be very careful with rates of drainage and fill of the canal (I assume avoiding resonance with the canal banks)- the effects of massive and periodic pressure changes might do a lot of harm underground.

L

L wrote: »

Meh. Storage looks great until you actually look at the specifics:

They're extremely capital intensive to develop.

They don't store energy perfectly (what you put in is always much more than what you get back out).

Put together it means you're better off not using storage and instead building flexible conventional plant to compensate for any errors you have in your forecasting.

The point of using developing & using renewable energy is the simple fact that eventually (could be as soon as 2014) there will be insufficient fossil fuel available at an affordable cost to maintain supplies of electricity at current levels let alone allow growth.

These types of capital intensive projects need to be done soon or there will be insufficient capital available to finance such a project in the future when it will really be needed.

A but like not saving enough seed for next years crop and starving the following year!

djpbarry

L wrote: »

They're extremely capital intensive to develop.

I imagine that using an existing mine mitigates the cost to a significant degree.

L wrote: »

They don't store energy perfectly...

No system is going to be perfect. But round-trip efficiency at Turlough Hill, for example, is about 75% - that’s pretty high.

L wrote: »

Put together it means you're better off not using storage...

Well, that’s a shame, because energy storage is probably something we’re going to be needing a lot more of.

djpbarry

Red Neck Hughie wrote: »

I'm a big fan of anything renewable but given that the operators at Ardnacrusha have to be very careful with rates of drainage and fill of the canal...

Bear in mind that Ardnacrusha was designed almost 90 years ago.

Red Neck Hughie wrote: »

...the effects of massive and periodic pressure changes might do a lot of harm underground.

I think that’s unlikely given that the reservoirs will be contained in tanks.

pljudge321

djpbarry wrote: »

I imagine that using an existing mine mitigates the cost to a significant degree.

I'm not sure how feasible using a mine would be for such a system, you probably need very specific time of bedrock and geological conditions. I cant find any sort of surveys or very many papers on the area so that's just me guessing.

djpbarry wrote: »

No system is going to be perfect. But round-trip efficiency at Turlough Hill, for example, is about 75% - that’s pretty high.

Turlough Hill is used for heavy ramping support and peak shaving i.e. times when you would otherwise have to ramp up some of the CCGT's or turn on the OCGT's. Doing this is highly inefficient and uses a lot more energy than just running providing baseload power. I wouldn't be surprised that the energy saved by Turlough Hill is actually greater than the energy that would have to be used otherwise.

djpbarry wrote: »

Well, that’s a shame, because energy storage is probably something we’re going to be needing a lot more of.

Would be nice, where to actually put it is the issue.

L

Deleted User wrote: »

The point of using developing & using renewable energy is the simple fact that eventually (could be as soon as 2014) there will be insufficient fossil fuel available at an affordable cost to maintain supplies of electricity at current levels let alone allow growth.

That's a straw man argument. You shouldn't conflate renewables with storage. They're not the same thing even remotely (using one doesn't mean the other one is necessary).

Deleted User wrote: »

These types of capital intensive projects need to be done soon or there will be insufficient capital available to finance such a project in the future when it will really be needed.

That capital investment shouldn't be going into storage.

Interconnection, possibly (that's a tricky one to give a good answer on tbh).

Demand response capability, definitely (EVs are a good example here as is CAES).

Pure storage, not really - it doesn't really solve the problems with renewable variability all that well and it costs a packet (I'll get to that later).

Deleted User wrote: »

A but like not saving enough seed for next years crop and starving the following year!

It's less like forgetting to keep seed for next years crops and more like remembering to buy fertilizer rather than just pesticides when you don't have a pest problem. (Still a bad analogy, but hopefully you'll see what I mean).


In a nutshell, the Electricity problem (well, this variability aspect of it anyhow) comes down to matching your generation to your demand. As it's Power generation (time dependent), you basically need to match up your generation with your demand as it happens.

Now, storage helps with this because it allows you to pick up part of your generation and effectively move it to a different time (less time dependent basically as we can store it as energy) - matching the demand whenever it is needed. This comes at a substantial cost because conversion between energy and storage incurs losses.

Alternatively, we can change our demand to better suit the available power generation either by reducing required power (priority systems) or by adding demand that isn't as time dependent when the renewable generation was underestimated by the forecast (Charging your electric car, running assorted compressors, home heating and so on). Doing it this way means we don't end up taking the massive losses that storage creates.

Basically, there's a reason we have built pretty much no storage since the system was in its infancy - it's at its most useful when a system has a lack of generation capacity compared to the possible variability of demand. Not when the generation itself is the more variable part.

pljudge321

L wrote: »

Demand response capability, definitely (EVs are a good example here as is CAES).

I can't really see demand side management with EV's taking off, who's going to pay for the batteries that get worn out after 2 years instead of 10 because they are constantly being cycled. Fridges, washing machines, heating etc seems more feasible.

L

pljudge321 wrote: »

I can't really see demand side management with EV's taking off, who's going to pay for the batteries that get worn out after 2 years instead of 10 because they are constantly being cycled. Fridges, washing machines, heating etc seems more feasible.

Well, I think the idea with them is to use the fact they're reasonably small as individual loads and the high quality of short term wind forecasts to avoid having to cycle individual cars frequently.

Red Neck Hughie

djpbarry wrote: »

Bear in mind that Ardnacrusha was designed almost 90 years ago.
I think that’s unlikely given that the reservoirs will be contained in tanks.

They mentioned running a city for 4 hours, if 2MW generation was enough, and with 200m fall they'd need over 14000m^3. (Not much really but if it had to be excavated...and I'm open to correction as I cant count my fingers without getting confused)
I doubt 2MW would power Dublin's traffic lights, I think they had only 130m drop and I didn't see anything approaching that volume underground in that clip.
Have to call foul on this one I think.

Jim Martin

Quote:
Originally Posted by Oldtree View Post
Renewable power generation and storage are a million miles away from being sustainable in this country and continue to be less financially viable as more oil, coal and gas deposits are both becoming viable to extract and new ones being discovered. Any in depth research shows them to be white elephants.
Well, that’s just not true – onshore wind generation, for example, is one of the cheapest available means of electricity generation.

Not when the wind-turbine companies have to be compensated when there is a surplus of electricity as, I believe, happened in Scotland recently! (they were asked to stop the turbines & were compensated for not generating un-wanted electricity)

Jim Martin

Jim Martin wrote: »

Quote:

Originally Posted by Oldtree View Post
Renewable power generation and storage are a million miles away from being sustainable in this country and continue to be less financially viable as more oil, coal and gas deposits are both becoming viable to extract and new ones being discovered. Any in depth research shows them to be white elephants.
Well, that’s just not true – onshore wind generation, for example, is one of the cheapest available means of electricity generation.

Not when the wind-turbine companies have to be compensated when there is a surplus of electricity as, I believe, happened in Scotland recently! (they were asked to stop the turbines & were compensated for not generating un-wanted electricity)

Which is precisely why systems like this need to be developed and built.

easychair

Jim Martin wrote: »

Well, that’s just not true – onshore wind generation, for example, is one of the cheapest available means of electricity generation.

Really? Does that take into account the hidden subsidies to the producers which we all have to pay in ouir increased electricity bills, just to make wind power viable? Doe it include the cost of connecting those turbines to the national grid?

Wind power is a wonderful thing, but its not problem free.

pljudge321

Jim Martin wrote: »

Not when the wind-turbine companies have to be compensated when there is a surplus of electricity as, I believe, happened in Scotland recently! (they were asked to stop the turbines & were compensated for not generating un-wanted electricity)

That happens all the time here.

Misty Moon

easychair wrote: »

It sounds to me as if these particular "scientists" are more likely to be trying to drum up some publicity for "Clausthal University of Technology", (where that? ed.) rather than putting forward anything new.

It's in the Harz area of Lower Saxony, a state which was in the former east Germany. A university of technology is something sort of inbetween a university and an institute of technology in Ireland. Nothing to sneer at really and yes, they really are scientists. With degrees and everything.

easychair wrote: »

The first thing to realise is that there is no such thing as a average mine. The second thing to realise is that disused mines are very unstable places. It's not clear why the authors of this particularly dotty scheme have chosen disused mines as the ideal place to propose for such a scheme. Has anyone any idea why they have decided such inhospitable and dangerous places have been chosen?

I found this article (in German) in the Süddeutsche Zeitung (a respectable paper, not a tabloid type).

This study was started by the Energy Research Centre of Lower Saxony who brought in the tech uni to the project. They examined a good two dozen regions in Germany and based on that narrowed it down to approximately 100 mines. These seem to have mostly been chosen as the rock is particularly steady and the access shafts are "kilometer deep" (not sure if that means one kilometer deep and am inclined to translate it as kilometers deep - don't have a German handy to check at the mo). However, instead of concrete such as would be used in ground surface case, the researchers want to install a network of pipes on two levels so that the mine remains stable.

There are only so many museums, art galleries and concert venues you can make out of old industrial facilities (factories, mines and so on), so I for one find it good to know that somebody somewhere is trying to also find more practical uses for some of the old works.

On a side note, it's possible that when they said city, they meant town - that's one of thoese things that often gets mixed up.

Lu Tze

djpbarry wrote: »

No system is going to be perfect. But round-trip efficiency at Turlough Hill, for example, is about 75% - that’s pretty high.

They must have magic 100% efficient pumps and frictionless pipelines to achieve that kind of efficiency

easychair

Misty Moon wrote: »

instead of concrete such as would be used in ground surface case, the researchers want to install a network of pipes on two levels so that the mine remains stable.

.

I had understood that the idea was pumped storage, with the storage taking place in a disused mine and above ground.

pljudge321

Lu Tze wrote: »

They must have magic 100% efficient pumps and frictionless pipelines to achieve that kind of efficiency

No thats pretty standard for pumped hydro. The pumps are the turbines themselves run as motors.

Capt'n Midnight

Lu Tze wrote: »

They must have magic 100% efficient pumps and frictionless pipelines to achieve that kind of efficiency

http://debates.oireachtas.ie/dail/2009/06/09/00361.asp

In addition in considering pumped storage constraints [263](A.1.4.14) the authors apply energy efficiency factors for Turlough Hill between 71% when pumping and 50% in the minimum generating state. A recorded averaged actual round trip energy efficiency of the order of 64% is therefore within the range considered by the authors of the study having regard to its concentration on prioritising renewable energy technologies.

Like most systems it's probably more efficient at higher capacity.

djpbarry

pljudge321 wrote: »

Turlough Hill is used for heavy ramping support and peak shaving i.e. times when you would otherwise have to ramp up some of the CCGT's or turn on the OCGT's. Doing this is highly inefficient and uses a lot more energy than just running providing baseload power. I wouldn't be surprised that the energy saved by Turlough Hill is actually greater than the energy that would have to be used otherwise.

I know that the rationale for building Turlough Hill was rather different from what we’re discussing here, but it’s a reasonable comparison none-the-less.

djpbarry

L wrote: »

Basically, there's a reason we have built pretty much no storage since the system was in its infancy - it's at its most useful when a system has a lack of generation capacity compared to the possible variability of demand. Not when the generation itself is the more variable part.

True – storing energy to compensate for lack of baseload is a pretty new concept. Hell, storing energy at all has only really become a pressing concern with the advent of portable electronic devices. We’re not much good at storing energy at present because we’ve never really had a need to do so until recently.

djpbarry

Red Neck Hughie wrote: »

They mentioned running a city for 4 hours, if 2MW generation was enough, and with 200m fall they'd need over 14000m^3. (Not much really but if it had to be excavated...and I'm open to correction as I cant count my fingers without getting confused)
I doubt 2MW would power Dublin's traffic lights, I think they had only 130m drop and I didn't see anything approaching that volume underground in that clip.

14,000 cubic metres isn’t that big:

[latex]25 \times 25 \times 25m > 14,000m^3[/latex].

And I think when they say “city”, they mean “town”.

djpbarry

easychair wrote: »

Really? Does that take into account the hidden subsidies to the producers which we all have to pay in ouir increased electricity bills, just to make wind power viable?

What hidden subsidies? The fact that the construction of wind farms is subsidised is no secret. However, various other forms of power generation are also subsidised by the state, most notably peat-fired generation in Ireland.

Oldtree

I refer you again to this article:

http://www.irishtimes.com/newspaper/ireland/2011/1101/1224306844626.html

This would seem to back up my opinion that we are all subsidising white elephants on a large scale and as the operators don't mind the idea of selling their cheap electricity on to the UK for a profit at our expense, tells us a lot about them.

Renewable power storage and generation are one and the same issue.

Oldtree

Oldtree wrote: »

I refer you again to this article:

http://www.irishtimes.com/newspaper/ireland/2011/1101/1224306844626.html

This would seem to back up my opinion that we are all subsidising white elephants on a large scale and as the operators don't mind the idea of selling their cheap electricity on to the UK for a profit at our expense, tells us a lot about them.

Renewable power storage and generation are one and the same issue.

That article is only referring to selling "spare" electricity to the UK, nothing about local storage.

L

Oldtree wrote: »

Renewable power storage and generation are one and the same issue.

Everytime someone says that, somewhere an electricity researcher loses their wings.

They're not the same issue. They're two separate things that often get mixed in together because they look like a great mix at first glance.

Deleted User wrote: »

That article is only referring to selling "spare" electricity to the UK, nothing about local storage.

Aye, if anything, it's to our benefit because we're using them to soak up wind variability.

djpbarry wrote: »

True – storing energy to compensate for lack of baseload is a pretty new concept. Hell, storing energy at all has only really become a pressing concern with the advent of portable electronic devices. We’re not much good at storing energy at present because we’ve never really had a need to do so until recently.

Fair. Most of the research being done suggests it's a white elephant until we move off a synchronous power system or the storage efficiency increases drastically. I'll be curious to see where it goes the next few years but until then we shouldn't be plowing capital investment into it (especially not as there's other things desperately in need of it).

djpbarry

Oldtree wrote: »

I refer you again to this article:

http://www.irishtimes.com/newspaper/ireland/2011/1101/1224306844626.html

This would seem to back up my opinion that we are all subsidising white elephants on a large scale...

Then I dare say you need to re-read the article. The ESRI report is suggesting that Public Service Obligation Levies (most of which do not subsidise wind generation) need to be re-examined. Nowhere is it suggested that wind projects should be scrapped altogether.

L wrote: »

Most of the research being done suggests it's a white elephant until we move off a synchronous power system or the storage efficiency increases drastically. I'll be curious to see where it goes the next few years but until then we shouldn't be plowing capital investment into it (especially not as there's other things desperately in need of it).

I don’t think anyone is suggesting that we should rush headlong into filling every conceivable space in Europe with water to act as stored energy, because I’d be fairly confident that new and better ways of storing energy will be conceived in the not too distant future. However, this has to be balanced against the fact that the manner in which electricity is currently produced and consumed needs to change pretty quickly, as it’s obviously not sustainable.

djpbarry

easychair wrote: »

The idea of wind or wave power is seductive, but their unreliability makes them of little practical use.

And yet, wind power is making a significant contribution (~10%) to Ireland’s electricity needs.