Abstract: A power storage system that uses a plurality of weights, which are raised and lowered in an underground hole, by a motor generator assembly, which is energized to raise the weights thus storing potential energy in the position of the weight, and which recovers energy from lowering the weights as the weights are lowered. A connection assembly, connects between the motor generator and at least one weight; where the connection assembly allows disconnecting a weight from a specific connection assembly, and using the motor generator assembly to raise and lower a different weight once the first weight is disconnected. This enables reusing the moving parts such as the motor generator assembly with multiple different weights.