"A body of 1000 kg is elevated 10 m. The change in potential energy can be calculated as 0.027 kWh"
"That project, called ARES Nevada, will consist in a 5.5-mile track traveling up an 8-degree slope, covering 106 acres of public land near the delightfully named town of Pahrump, Nevada. It will boast 50 MW of power capacity and be capable of producing 12.5 MWh of energy. The company expects to start construction early next year and finish by 2019."
So that is about 1 KM height. The weight must be 4600 tons. Also, trains dont like going uphill.
Pardon the bad math in the video, it is still true.
Sooo, it doesnt scale. Also, compare the mass of some stone to the massive amount of water in a dam.
Also, might as well lift the weight with a cable. Take an abandoned underground oil well, make a continuous cable attach the stones, make automatic stone attachment detachment and done.