Yes I agree it’s expensive but the state has already decided to go down this path. One of the recurring issues I’ve read a lot about though is the “duck curve” that looks at generation from renewables during a normal day (peaking mid to late afternoon) and the demand from business and household use which peaks in demand in the early evening. Since the state is already paying to pump water over mountain ranges, (water movement consumes 14% of the electric power in the state) it seems that expanded storage at or near the highest elevation would allow you to hold that potential energy and draw on it later in the day.

Sean, while technically feasible, hydro storage works much better in the TVA which is heavily depending on uber-cheap hydro power which runs 24/7. We don’t have that option, as the renewable sources we increasingly depend on are VERY expensive and unreliable.