That seems similar to the Dinorwig hydro system.
Yes, same principle. Pump storage schemes work very well in mountainous areas with high precipitation rates. The mineshaft idea is better suited to areas that aren't so hilly but have plenty of disused mines.
Over in Germany they are experimenting with cutting out enormous cylinders of rock from the surrounding ground and then pumping them up with water so the plug rises out of the ground like a giant gasometer - but one that is 100+ metres across and would be pumped 50 metres into the air.
