As much pump storage underground as you want thanks to TBMs (tunnel boring machines)?

Post by Dave
As much pump storage underground as you want thanks to TBMs (tunnel
boring machines)?
Can you get as much pump storage as you want thanks to TBMs? They have
improved a lot recently, all you need is the right sort of rock and it's
plain sailing making big caverns. Not sure how much rock you can safely
extract, expect you need to leave 50% minimum, but you can have multiple
levels, and also you don't need tunnels in horizontal lines, but arch
them for strength?
Once you find the place can have phased opening, so part is in operation
when the place is being expanded. Say one cubic kilometre of water,
with a 1000m drop, energy is height x gravity x mass = 1000x 9.8x
1000x1000x1000 = 9.8 TJ = 9.8 x10^12 J. Divide by 3600000 to get kWh =
2.7 million kWh. Enough for a somewhere like Reading for a few hours, or
2.7 GW for an hour.

These figures should be x1000 because a cubic meter of water is a tonne.
So 2.7GW for 1000 hours is plenty to help balance a grid. 9.8x10^15J,
2.7 billion kWh.

For the previous number, 2.7million kWh, need 100mx100mx100m, enough for
a little town using mostly solar.

Gravity doesn't change that much. Expect temperature is 40-50 Celsius
at that depth.

Post by Dave
Tunnelling is easy, but the extracted rock needs to go somewhere. Use
them to construct an upper reservoir in the air, or start building
islands, and making better sea defences?

Dave

2022-08-05 06:48:58 UTC

On 05/08/2022 06, Dave wrote:
Also if you have joined up thinking, you're building reservoirs for the
water supply at the same time, cooking two pies when the oven is on.

Post by Dave
As much pump storage underground as you want thanks to TBMs (tunnel
boring machines)?
Can you get as much pump storage as you want thanks to TBMs? They
have improved a lot recently, all you need is the right sort of rock
and it's plain sailing making big caverns. Not sure how much rock you
can safely extract, expect you need to leave 50% minimum, but you can
have multiple levels, and also you don't need tunnels in horizontal
lines, but arch them for strength?
Once you find the place can have phased opening, so part is in
operation when the place is being expanded. Say one cubic kilometre
of water, with a 1000m drop, energy is height x gravity x mass =
1000x 9.8x 1000x1000x1000 = 9.8 TJ = 9.8 x10^12 J. Divide by 3600000
to get kWh = 2.7 million kWh. Enough for a somewhere like Reading for
a few hours, or 2.7 GW for an hour.

These figures should be x1000 because a cubic meter of water is a tonne.
So 2.7GW for 1000 hours is plenty to help balance a grid. 9.8x10^15J,
2.7 billion kWh.
For the previous number, 2.7million kWh, need 100mx100mx100m, enough for
a little town using mostly solar.
Gravity doesn't change that much. Expect temperature is 40-50 Celsius
at that depth.

Post by Dave
Tunnelling is easy, but the extracted rock needs to go somewhere. Use
them to construct an upper reservoir in the air, or start building
islands, and making better sea defences?

Dave

2022-08-07 14:09:39 UTC

On 05/08/2022 07, Dave wrote:
Was just reading in some investment bumf that one of the big companies I
have funds with is disinvesting from thermal coal.

So the coal miners should be getting a hit on their share price, and
resulting bonuses for executives. All those super big dumper trucks and
skilled workers could be doing something more useful instead, like
making big reservoirs for pump storage, or just water, flood managements
and the usual stuff.

Post by Dave
Also if you have joined up thinking, you're building reservoirs for the
water supply at the same time, cooking two pies when the oven is on.

Post by Dave
As much pump storage underground as you want thanks to TBMs (tunnel
boring machines)?
Can you get as much pump storage as you want thanks to TBMs? They
have improved a lot recently, all you need is the right sort of rock
and it's plain sailing making big caverns. Not sure how much rock you
can safely extract, expect you need to leave 50% minimum, but you can
have multiple levels, and also you don't need tunnels in horizontal
lines, but arch them for strength?
Once you find the place can have phased opening, so part is in
operation when the place is being expanded. Say one cubic kilometre
of water, with a 1000m drop, energy is height x gravity x mass =
1000x 9.8x 1000x1000x1000 = 9.8 TJ = 9.8 x10^12 J. Divide by 3600000
to get kWh = 2.7 million kWh. Enough for a somewhere like Reading for
a few hours, or 2.7 GW for an hour.

These figures should be x1000 because a cubic meter of water is a tonne.
So 2.7GW for 1000 hours is plenty to help balance a grid. 9.8x10^15J,
2.7 billion kWh.
For the previous number, 2.7million kWh, need 100mx100mx100m, enough
for a little town using mostly solar.
Gravity doesn't change that much. Expect temperature is 40-50
Celsius at that depth.

Post by Dave
Tunnelling is easy, but the extracted rock needs to go somewhere. Use
them to construct an upper reservoir in the air, or start building
islands, and making better sea defences?

Jim Pennino

2022-08-07 14:32:53 UTC

Post by Dave
Was just reading in some investment bumf that one of the big companies I
have funds with is disinvesting from thermal coal.

Just about the entire first world has been doing this for years in the
name of climate change.

What rock have you been hiding under?

Post by Dave
So the coal miners should be getting a hit on their share price, and
resulting bonuses for executives. All those super big dumper trucks and
skilled workers could be doing something more useful instead, like
making big reservoirs for pump storage, or just water, flood managements
and the usual stuff.

Yeah, sure...

<snip old crap>

Jim Pennino

2022-08-05 14:56:37 UTC

Tunnelling is expensive and costs from $100 million to $3 billion per
mile for 20 foot twin bore tunnels.

https://tunnelingonline.com/why-tunnels-in-the-us-cost-much-more-than-anywhere-else-in-the-world/

Dave

2022-08-06 14:17:10 UTC

Tunnelling is expensive and costs from $100 million to $3 billion per
mile for 20 foot twin bore tunnels.

Was more thinking that the health and safety for mining would apply,
since it wouldn't be open to the public. Location is key. There are also
open cast mines, like in Australia.

https://www.mining-technology.com/analysis/feature-top-ten-deepest-open-pit-mines-world/

Companies like BHP Billiton and Rio Tinto are top 100 global
corporations, and know exactly what the actual costs are.

In general, there is massive waste of human capital: churning software
and re-doing science, because the management hasn't the vision to move
out of the comfort zone.

Post by Jim Pennino
https://tunnelingonline.com/why-tunnels-in-the-us-cost-much-more-than-anywhere-else-in-the-world/

Jim Pennino

2022-08-06 16:15:20 UTC

Tunnelling is expensive and costs from $100 million to $3 billion per
mile for 20 foot twin bore tunnels.

Was more thinking that the health and safety for mining would apply,
since it wouldn't be open to the public. Location is key. There are also
open cast mines, like in Australia.

The cost and effort to bore tunnels has little to nothing to do with the
cost and effort to dig big holes.

You are avoiding the obvious problem with your initial brain fart.

Post by Dave
https://www.mining-technology.com/analysis/feature-top-ten-deepest-open-pit-mines-world/
Companies like BHP Billiton and Rio Tinto are top 100 global
corporations, and know exactly what the actual costs are.

Which is irrelevant to your brain fart.

Post by Dave
In general, there is massive waste of human capital: churning software
and re-doing science, because the management hasn't the vision to move
out of the comfort zone.

This is arm waving ranting.

Dave

2022-08-07 13:37:07 UTC

Tunnelling is expensive and costs from $100 million to $3 billion per
mile for 20 foot twin bore tunnels.

Was more thinking that the health and safety for mining would apply,
since it wouldn't be open to the public. Location is key. There are also
open cast mines, like in Australia.

The cost and effort to bore tunnels has little to nothing to do with the
cost and effort to dig big holes.
You are avoiding the obvious problem with your initial brain fart.

Which is irrelevant to your brain fart.

Post by Jim Pennino
In general, there is massive waste of human capital: churning software

and re-doing science, because the management hasn't the vision to move
out of the comfort zone.

This is arm waving ranting.

Expecting relevant physics arm waving, like a back of the envelope
showing the energy to make a big hole in the ground reservoir can run a
desalination plant for 145 years, or not.

Note ENERGY not MONEY. They have all the money of mammon, and can sign
off budgets for a good cause.

Here's a tale:
The pharaoh asks the chief accountant, is there the money to build a
pyramid, he says no, and is fed to the crocodiles. The pharaoh asks the
next one, she says no, and is demoted to washerwoman. The pharaoh asks
the next one, he says yes and it will be paid for with papyrus bills
which have your image. The pharaoh is very happy and 20 years later the
pyramid is finished.

Jim Pennino

2022-08-07 14:24:27 UTC

Tunnelling is expensive and costs from $100 million to $3 billion per
mile for 20 foot twin bore tunnels.

Was more thinking that the health and safety for mining would apply,
since it wouldn't be open to the public. Location is key. There are also
open cast mines, like in Australia.

The cost and effort to bore tunnels has little to nothing to do with the
cost and effort to dig big holes.
You are avoiding the obvious problem with your initial brain fart.

Which is irrelevant to your brain fart.