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Mine shaft storage on news

ChrisJC

Well-known member
SamT said:
n shouting about on the Mars/Space thread, there's apparently loads of cash floating around for research and development. 

I entirely agree, that this is just "Micro" generation.  Just like the many micro hydro system that have sprung up on hillsides all over wales.  But every little helps.

I agree that the opportunities are probably limited and in sure the investors are over egging it. 

The point is that it's pointless, as I will show in a moment. Worthwhile green energy schemes are a great idea, we need lots of them. What we don't need is pointless schemes like this.

Assume a 10ton mass, and a 1 kilometer deep mineshaft. Ignore the energy required to set it all up.
If you lower that mass down the shaft over a period of 1 hour, that will give you 27.8 KiloWatts of power during that period.

That sounds quite useful to me - it would definitely run a few houses, probably a few 10's of houses.

However, a 100Ah car battery will give 1.2KiloWatts for an hour, so you only need 23 car batteries to get the same effect.

And the car batteries are an awful lot less bother.

10 ton weight, 1 kilometer deep mineshaft, or 23 car batteries.  :-\

Chris.
 

Fjell

Well-known member
It is possible to invest more directly in competent renewables, some more high risk than others. This is an example. I am absolutely not promoting this as it is not low risk, it could easily go phut for some reason. And I can tell you the main risk is governments changing the bloody rules on a whim, which has happened to me.

https://www.downingcrowd.co.uk/products/energy

But at least it is trying. Almost the opposite of my pet visceral hate, Bitcoin.
 

SamT

Moderator
ChrisJC said:
The point is that it's pointless, as I will show in a moment. Worthwhile green energy schemes are a great idea, we need lots of them. What we don't need is pointless schemes like this.

Assume a 10ton mass, and a 1 kilometer deep mineshaft. Ignore the energy required to set it all up.
If you lower that mass down the shaft over a period of 1 hour, that will give you 27.8 KiloWatts of power during that period.

That sounds quite useful to me - it would definitely run a few houses, probably a few 10's of houses.

However, a 100Ah car battery will give 1.2KiloWatts for an hour, so you only need 23 car batteries to get the same effect.

And the car batteries are an awful lot less bother.

10 ton weight, 1 kilometer deep mineshaft, or 23 car batteries.  :-\

Chris.

FFS - the armchair physics brigade are out again..

Why is it nobody can get their head round the difference between energy and power..  and why do people always say 'you could run a house' or power 10 houses.. its just nonsense talk.

"a 100Ah car battery will give 1.2KiloWatts for an hour"  :confused:

I'm not suggesting that the amounts of energy are significant but ffs, please just get the maths right if you're going to argue a point.

10 ton = 10000kg,
1 km = 1000m
gravity - 9.8m/s2

Potential Energy (Joules) = mgh  so that 10000 x 1000x 9.8

So 98 million Joules of energy.  Which equates to 27.2 kWh (kWh is the unit of energy most folk can equate to as its one 'unit' on an electricity meter.)

lets say the rig runs at 70% efficiency - so 19 kWh per drop.

My house uses about 12 kWh of energy on an average day.

So your right in saying its a pitiful amount of energy generated, (and we haven't even factored in the energy used to hoist it back up again, but that's a different argument)

But please please, get your units and maths right when arguing these points.



 

SamT

Moderator
FWIW - My solar PV system on the roof (1.5kW max output) will probably only generate about 3kWh worth of energy today (lovely bright but cool sunny day)  About a quarter of what the house uses.  10 years ago you'd have argued that it was worthless, pointless, not cost effective etc etc, but solar PV is now playing a big part in the UKs renewable mix.

I accept that the mine shaft resource is low, but its the instant lambasting of such projects that bugs me.  Perhaps a few little projects will be developed through out the UK. Good luck to them.

Heat Energy from flooded mine workings is a much bigger resource that's not getting the attention/investment it deserves IMHO.
 

ChrisJC

Well-known member
SamT said:
But please please, get your units and maths right when arguing these points.

Has somebody upset you today Sam? because you sound like an angry man.

Anyway, please tell me which units and maths I messed up on, as the numbers look pretty similar to yours.

Chris.
 

Fishes

New member
This doesn't actually generate power but stores it. There are many factors that will determine how both practical and how green it is.

If it creates more carbon to construct and maintain it than you can save by not burning fossil fuels then it is madness. If we take the UK as an example then there are few suitable mine shafts.

Each shaft would need the winding gear, weights, shaft guides, motor/generator, power feed/input to the grid, access road and a whole pile of stuff that I haven't thought. Once we take this into account then we have to consider the lifetime of the equipment and spare parts required over its lifetime. Upkeep of the shaft. How often anyone will have to visit the site and there journey length. How much carbon will this generate?

Alternatively you could just use surplus electricity to generate hydrogen which can replace carbon usage in the production of steel and other industrial processes. Europe's major steel producers are already taking actions to replace blast furnaces with hydrogen direct reduction and  this is a significant carbon source - no need for coking coal, coke ovens or blast furnaces. It is also an effective way to store energy to feed back into the grid and is potentially more practical power source for road vehicles using solid oxide fuel cells.



 

Cantclimbtom

Well-known member
ChrisJC said:
...

10 ton weight, 1 kilometer deep mineshaft, or 23 car batteries.  :-\

Chris.
Really?  That just sounds/feels wrong
I had to go back to check the Joules etc - twice, even though I see the numbers in front of me it still feels difficult to believe, but the numbers are there!

This brings home to me...  Just how good car batteries are at storing energy  and just how much energy people consume at home. And after checking all those figures twice figures, I need to put the kettle on.

Edit: I used to look after some reachlift trucks (and forklifts) and make sure were on charge at shift end and top up the battery with distilled water once a week or twice a week if the evening shift had been doing extra work. maybe a couple of old forklift/reachlift traction batteries can do the same or better job job
 

MarkS

Moderator
Cantclimbtom said:
Really?  That just sounds/feels wrong
I had to go back to check the Joules etc - twice, even though I see the numbers in front of me it still feels difficult to believe, but the numbers are there!

I remember running some quick calculations to see if it would be worth charging batteries on a remote expedition with some sort of slowly descending rock spinning a dynamo. I worked out what theoretical energy would be needed to charge 4 x AAs, and was pretty astounded to find it was the equivalent of lifting a 25 kg mass about 150 m! That wasn't an idea that was pursued.
 

Fjell

Well-known member
MarkS said:
Cantclimbtom said:
Really?  That just sounds/feels wrong
I had to go back to check the Joules etc - twice, even though I see the numbers in front of me it still feels difficult to believe, but the numbers are there!

I remember running some quick calculations to see if it would be worth charging batteries on a remote expedition with some sort of slowly descending rock spinning a dynamo. I worked out what theoretical energy would be needed to charge 4 x AAs, and was pretty astounded to find it was the equivalent of lifting a 25 kg mass about 150 m! That wasn't an idea that was pursued.

There are other solutions to that problem.


 

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Carbide1

New member
SamT said:
ChrisJC said:
The point is that it's pointless, as I will show in a moment. Worthwhile green energy schemes are a great idea, we need lots of them. What we don't need is pointless schemes like this.

Assume a 10ton mass, and a 1 kilometer deep mineshaft. Ignore the energy required to set it all up.
If you lower that mass down the shaft over a period of 1 hour, that will give you 27.8 KiloWatts of power during that period.

That sounds quite useful to me - it would definitely run a few houses, probably a few 10's of houses.

However, a 100Ah car battery will give 1.2KiloWatts for an hour, so you only need 23 car batteries to get the same effect.

And the car batteries are an awful lot less bother.

10 ton weight, 1 kilometer deep mineshaft, or 23 car batteries.  :-\

Chris.

FFS - the armchair physics brigade are out again..

Why is it nobody can get their head round the difference between energy and power..  and why do people always say 'you could run a house' or power 10 houses.. its just nonsense talk.

"a 100Ah car battery will give 1.2KiloWatts for an hour"  :confused:

I'm not suggesting that the amounts of energy are significant but ffs, please just get the maths right if you're going to argue a point.

10 ton = 10000kg,
1 km = 1000m
gravity - 9.8m/s2

Potential Energy (Joules) = mgh  so that 10000 x 1000x 9.8

So 98 million Joules of energy.  Which equates to 27.2 kWh (kWh is the unit of energy most folk can equate to as its one 'unit' on an electricity meter.)

lets say the rig runs at 70% efficiency - so 19 kWh per drop.

My house uses about 12 kWh of energy on an average day.

So your right in saying its a pitiful amount of energy generated, (and we haven't even factored in the energy used to hoist it back up again, but that's a different argument)

But please please, get your units and maths right when arguing these points.

Ffs, 1 ton is 907.185 Kg!
 

pwhole

Well-known member
I remember going to a lecture by Professor Eric Laithwaite at Loughborough Uni in about 1981, and distinctly remember him demonstrating his 'levitation machine', which was a steel flatbed with four opposing-spin heavy gyroscopes mounted on top driven by small motors (I can't remember which way they were spinning, sadly). He got this thing to leap into the air to about half a metre and it must have weighed half a ton. It only stayed up for a second or so before falling back down, and he freely admitted it was the 'best he could do' at the time, but I saw something that I was convinced was impossible happen. I know there's no such thing as free energy, but this made me wonder if 'yet' should be applied to that statement.

He also demonstrated this:

https://www.youtube.com/watch?v=JRPC7a_AcQo
 

Carbide1

New member
https://en.wikipedia.org/wiki/Precession#:~:text=Torque%2Dinduced%20precession%20(gyroscopic%20precession,rotating%20objects%20can%20undergo%20precession.
 

Cantclimbtom

Well-known member
Carbide1 said:
https://en.wikipedia.org/wiki/Precession#:~:text=Torque%2Dinduced%20precession%20(gyroscopic%20precession,rotating%20objects%20can%20undergo%20precession.
Nonsense, that's no fun.

A far simpler explanation is that it's anti gravity, forcefields. Energy flux from the ether is being channeled through dark matter agitated by rotational waves from the spinning energy.... Or something like that.
 

pwhole

Well-known member
As Eric above quoted Freenman Dyson about scientific papers: "Those which are impossible to understand are usually published!"
 

SamT

Moderator
ChrisJC said:
Has somebody upset you today Sam? because you sound like an angry man.

Not particularly, just a pet hate on a favorite topic.

Using power in kW which is a rate of energy use/generation is just nonsensical when talking about energy which is just a quantity.

Its like asking "how much water does that bucket hold" and getting a reply "50 litres a minute mate".   
How far you driven today... "70 miles per hour".

How much energy can this mineshaft generate.. 27.8 kW



 

ChrisJC

Well-known member
SamT said:
ChrisJC said:
Has somebody upset you today Sam? because you sound like an angry man.

Not particularly, just a pet hate on a favorite topic.

Using power in kW which is a rate of energy use/generation is just nonsensical when talking about energy which is just a quantity.

Its like asking "how much water does that bucket hold" and getting a reply "50 litres a minute mate".   
How far you driven today... "70 miles per hour".

How much energy can this mineshaft generate.. 27.8 kW

Sam,
I have checked my original post that upset you so much.

There are no mistakes with regard to the dimensions of the units quoted, in the context in which they were quoted.

I fully understand the mistakes you have deliberately quoted, however I did not make any mistakes of that nature.

I invite you to correct me.

Chris.
 
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