https://www.theregister.com/2024/02/08/europe_deepest_mine_battery/

This will back up a 2 GW power plant for 4 seconds.

On 2/9/24 01:59, john larkin wrote:
> https://www.theregister.com/2024/02/08/europe_deepest_mine_battery/
>
> This will back up a 2 GW power plant for 4 seconds.
>

(Energy storage using a weight suspended in a 530 m deep
mine shaft.)

An object in free fall would take 10 seconds to reach the
bottom of a 530 m shaft, so that is not going to work.

The article is severely dumbed down, but we can glean a bit
of extra info nevertheless: They plan to use a 530 m drop
and claim to store 2 MWh. Neglecting losses, that would
require a weight of 1385 tons. That could be a concrete
cube with sides of 8 m. I'm neglecting the weight of the
cable as well. Maybe I shouldn't...

Anyway, weights, cables and winches are a silly way to
store energy. Too much hardware and not enough energy.
A waste of money.

Jeroen Belleman

On 09/02/2024 10:31, Jeroen Belleman wrote:
> On 2/9/24 01:59, john larkin wrote:
>> https://www.theregister.com/2024/02/08/europe_deepest_mine_battery/
>>
>> This will back up a 2 GW power plant for 4 seconds.

The idea of storage systems is to take the edge of peak loads. This one
is too puny and impractical to go anywhere but the various big pumped
storage reservoirs are quite a useful short term buffer. Likewise some
of the big battery systems that have been deployed (fastest of all).

> (Energy storage using a weight suspended in a 530 m deep
> mine shaft.)
>
> An object in free fall would take 10 seconds to reach the
> bottom of a 530 m shaft, so that is not going to work.
>
> The article is severely dumbed down, but we can glean a bit
> of extra info nevertheless: They plan to use a 530 m drop
> and claim to store 2 MWh. Neglecting losses, that would
> require a weight of 1385 tons. That could be a concrete
> cube with sides of 8 m. I'm neglecting the weight of the
> cable as well. Maybe I shouldn't...

I concur. The idea is quite bonkers. m.g.h still holds good...

Deep mine shafts are interesting places when the cage going down passes
the one coming up there is quite a draft. It is also strange at the
bottom since you are deep enough that the shaft walls are at body
temperature or higher. It takes some getting used to!

I think coiling up the steel "rope" might also prove rather problematic
and the drum that it is on will have to be very big and so have a huge
moment of inertia.

The heftiest strongest steel rope I could find was 80mm with a typical
operating strength of around 320T (3202kN) and breaking at 480T load so
it will need 4 of those to provide support for this massive weight.

https://www.steelwirerope.com/WireRopes/Structural/spiral-strand-ropes.html

I suspect it is much much lighter and can only store 2MW minutes all up!
The idea looks more plausible for 22T weight and 22mm steel rope.

> Anyway, weights, cables and winches are a silly way to
> store energy. Too much hardware and not enough energy.
> A waste of money.

Totally agree. Someone hasn't done their sums!

--
Martin Brown

On Friday, February 9, 2024 at 12:00:00 PM UTC+11, john larkin wrote:
> https://www.theregister.com/2024/02/08/europe_deepest_mine_battery/
>
> This will back up a 2 GW power plant for 4 seconds.

It's not exactly any kind of "breakthrough". These schemes have been around for years.

https://www.adelaide.edu.au/library/about-the-library/sir-marcus-mark-laurence-elwin-oliphant-1901-2000

His homopolar generator - eventually built in Canberra kin 1962 - was a 500MJ energy store, originally intended to power a proton synchrotron, though it ended up powering a rail gun. It took ten minutes to spin up, then delivered a lot of current for a much shorter time - originally through sodium-ptassium liquid metal brushes but later through more conventional (and much less dangerous) carbon brushes.

--
Bill Sloman, Sydney

On Friday, February 9, 2024 at 2:30:18 AM UTC-8, Jeroen Belleman wrote:
> On 2/9/24 01:59, john larkin wrote:
> > https://www.theregister.com/2024/02/08/europe_deepest_mine_battery/
> >
> > This will back up a 2 GW power plant for 4 seconds.

> Anyway, weights, cables and winches are a silly way to
> store energy. Too much hardware and not enough energy.
> A waste of money.

Usually, you go with the river/reservoir/dam if you want low
cost per kWh, because the terrain is free and scales beautifully.
But, you can't carry that in a flashlight, nor is is there always
a reservoir around the corner from you. The cable/weight
fits a small niche requirement, presumably.

If you could plant wind power harvesting in a hurricane path,
the cost of the physical plant is REALLY minimal; there's just
not a good way to store the resulting energy, or get it to shore...
Maybe kite borne generation and hydrogen production in
ocean barges?

On 2/9/24 22:04, whit3rd wrote:
> On Friday, February 9, 2024 at 2:30:18 AM UTC-8, Jeroen Belleman wrote:
>> On 2/9/24 01:59, john larkin wrote:
>>> https://www.theregister.com/2024/02/08/europe_deepest_mine_battery/
>>>
>>> This will back up a 2 GW power plant for 4 seconds.
>
>> Anyway, weights, cables and winches are a silly way to
>> store energy. Too much hardware and not enough energy.
>> A waste of money.
>
> Usually, you go with the river/reservoir/dam if you want low
> cost per kWh, because the terrain is free and scales beautifully.
> But, you can't carry that in a flashlight, nor is is there always
> a reservoir around the corner from you. The cable/weight
> fits a small niche requirement, presumably.

Pumped storage is a useful and fairly widely used technology
to smooth over variations in energy consumption and production.
Its importance will grow with the increase of unreliable solar
and wind generation. It's unlikely to be entirely sufficient
though. There don't seem to be enough places where pumped
storage plants can be economically located. As energy cost
increases, more locations will become economically viable.
>
> If you could plant wind power harvesting in a hurricane path,
> the cost of the physical plant is REALLY minimal; there's just
> not a good way to store the resulting energy, or get it to shore...
> Maybe kite borne generation and hydrogen production in
> ocean barges?

I don't know about your place, but where I live, hurricanes
are rare and violent freak events. Building a system to harvest
the energy of those would have an extremely poor return on
investment.

Jeroen Belleman

On Friday, February 9, 2024 at 1:47:39 PM UTC-8, Jeroen Belleman wrote:
> On 2/9/24 22:04, whit3rd wrote:

> > If you could plant wind power harvesting in a hurricane path,
> > the cost of the physical plant is REALLY minimal; there's just
> > not a good way to store the resulting energy, or get it to shore...
> > Maybe kite borne generation and hydrogen production in
> > ocean barges?

> I don't know about your place, but where I live, hurricanes
> are rare and violent freak events. Building a system to harvest
> the energy of those would have an extremely poor return on
> investment.

The power available, though, is massive.
And, ocean real estate is more plentiful than any other kind...

<https://science.howstuffworks.com/environmental/energy/energy-hurricane-volcano-earthquake1.htm>

Two hurricanes could replace the world's other energy supplies. All of 'em.
Violence tamed is how internal combustion engines work, so that's nothing
new.

On Saturday, February 10, 2024 at 3:48:24 PM UTC+11, whit3rd wrote:
> On Friday, February 9, 2024 at 1:47:39 PM UTC-8, Jeroen Belleman wrote:
> > On 2/9/24 22:04, whit3rd wrote:
>
> > > If you could plant wind power harvesting in a hurricane path,
> > > the cost of the physical plant is REALLY minimal; there's just
> > > not a good way to store the resulting energy, or get it to shore...
> > > Maybe kite borne generation and hydrogen production in
> > > ocean barges?
>
> > I don't know about your place, but where I live, hurricanes
> > are rare and violent freak events. Building a system to harvest
> > the energy of those would have an extremely poor return on
> > investment.
> The power available, though, is massive.
> And, ocean real estate is more plentiful than any other kind...
>
> <https://science.howstuffworks.com/environmental/energy/energy-hurricane-volcano-earthquake1.htm>

But the energy you would be harvesting is the thermal energy of the top fifty metres of the ocean - the condition for a hurricane to build up is as sea surface temperature higher than 26.5C.

There are scheme for harvesting the heat energy of the surface of tropic oceans by using them to evaporate a volatile liquid - such as ammonia - and condense the vapour at the other end of a pipe that descends into the cooler deep ocean.

Willy Ley's "Engineers Dreams" published in 1955, lists it as one of the seven projects he wrote up. It is thermodynamicly practical, but making the pipe-work hurricane-proof seems to be tricky.

> Two hurricanes could replace the world's other energy supplies. All of 'em.
> Violence tamed is how internal combustion engines work, so that's nothing new.

Hurricanes concentrate a lot of violence in one area. The internal combustion engine produces its violence in a controlled way, and doesn't produce a lot of it at once.

--
Bill Sloman, Sydney

On 2/10/24 05:48, whit3rd wrote:
> On Friday, February 9, 2024 at 1:47:39 PM UTC-8, Jeroen Belleman wrote:
>> On 2/9/24 22:04, whit3rd wrote:
>
>>> If you could plant wind power harvesting in a hurricane path,
>>> the cost of the physical plant is REALLY minimal; there's just
>>> not a good way to store the resulting energy, or get it to shore...
>>> Maybe kite borne generation and hydrogen production in
>>> ocean barges?
>
>> I don't know about your place, but where I live, hurricanes
>> are rare and violent freak events. Building a system to harvest
>> the energy of those would have an extremely poor return on
>> investment.
>
> The power available, though, is massive.
> And, ocean real estate is more plentiful than any other kind...
>
> <https://science.howstuffworks.com/environmental/energy/energy-hurricane-volcano-earthquake1.htm>
>
> Two hurricanes could replace the world's other energy supplies. All of 'em.
> Violence tamed is how internal combustion engines work, so that's nothing
> new.

You're just teasing me, right?

Jeroen Belleman