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