Yes, it does require a change in elevation. The US has many pumped hydro systems. Wikipedia lists ten in the US that are larger than 1,000 MW. https://en.wiki

Yes, it does require a change in elevation. The US has many pumped hydro systems. Wikipedia lists ten in the US that are larger than 1,000 MW. https://en.wikipedia.org/wiki/List_of_pumped-storage_hydroelectric_power_stations https://en.wikipedia.org/wiki/List_of_pumped-storage_hydroel...