RSA proposed electricity storage using weight by a UK co.

So long as the weight is not a 'piston fit' in the shaft I do not really see why water should be a show stopper, long thin torpedo shaped weights with a hole up the middle or a similar flow bypass feature are possible. Clearly they need to be a lot denser than water, but for example lead is 13 times. I concede that a weight that floated would be a bit trickier ?.

If the figures in the video are to be believed then they are talking of running a town for 2 hours, in shaft of order km depth, and 1m/sec is 3.6km per hour, so we are looking at half a metre per second.

So does it stack up ? To generate at say 10 megawatts, a respectable emergency genset size for perhaps 10,000 houses, at  a weight speed of 1m/sec,

mgh = 10,000,0000 needs a weight of 1 megakilo, or  1000 tonnes. In lead that could be as simple as  a chain of 8 lumps each 1m square and 10m long - Big but not unthinkably so . Rather stronger winding gear would be needed than the traditional headgear of an old mine however so some ground reinforcement may be required. Towards the bottom you have the weight of the cables helping too. Not too silly compared to many ideas in circulation if the holes are almost free.

So long as the weight is not a 'piston fit' in the shaft I do not really see why water should be a show stopper, long thin torpedo shaped weights with a hole up the middle or a similar flow bypass feature are possible. Clearly they need to be a lot denser than water, but for example lead is 13 times. I concede that a weight that floated would be a bit trickier ?.

If the figures in the video are to be believed then they are talking of running a town for 2 hours, in shaft of order km depth, and 1m/sec is 3.6km per hour, so we are looking at half a metre per second.

So does it stack up ? To generate at say 10 megawatts, a respectable emergency genset size for perhaps 10,000 houses, at  a weight speed of 1m/sec,

mgh = 10,000,0000 needs a weight of 1 megakilo, or  1000 tonnes. In lead that could be as simple as  a chain of 8 lumps each 1m square and 10m long - Big but not unthinkably so . Rather stronger winding gear would be needed than the traditional headgear of an old mine however so some ground reinforcement may be required. Towards the bottom you have the weight of the cables helping too. Not too silly compared to many ideas in circulation if the holes are almost free.