My apologies to all, but I can't help myself. It looks like SA...

My apologies to all, but I can't help myself. It looks like SA is soon going to be flooded by pumped Hydro projects!

But, seriously, it does seem to be a strange way to try and make money, buy electricity when it is cheaper and pump water up hill, and then let it make more expensive electricity at certain times by letting it run down hill again. I'm not sure that it is a very sensible long term strategy. Especially when as more people do this, and as more electricity is made, the price differential will decrease as people use cheap electricity (pushing the price up) to store (batteries or up hill water storage) and make more expensive electricity (reducing the scarcity and driving the price down). But, then, I'm not technically competent to comment on this.
But, hopefully I've made you smile for Christmas.