energy storage breakthrough

(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

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).

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.

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.

Totally agree. Someone hasn't done their sums!

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.

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

You're just teasing me, right?

Jeroen Belleman