Comment by hunterpayne

Each way you move the energy costs you 50% in efficiency. Which is why pumped hydro has to have a 4x different in the price of energy in vs energy out to make it economically viable. That's why PG&E almost never uses their pumped storage. Only on days where the mid day price of power is very low does it make sense. And keep in mind that California is the ideal place for pumped storage. I seriously doubt that NZ has a 3x duck curve in its energy demand.