I like this concept. I would think its all going to be about efficiency of the return power. Not a hydro engineer, but I would think that a turbine is not as

I like this concept. I would think its all going to be about efficiency of the return power. Not a hydro engineer, but I would think that a turbine is not as efficient as a wheel tied to an electric motor. X Amount of wheel turns to store and the same X amount to restore the power. It all comes down to the efficiency of the motor vs efficiency of the generator side.