There are several large pumped-storage plants in the USA too. They can provide about 2 GW for one day, enough to completely power a city of 1M people, or to smooth out supply fluctuations for a much larger region.

https://en.wikipedia.org/wiki/Raccoon_Mountain_Pumped-Storag...

https://en.wikipedia.org/wiki/Bath_County_Pumped_Storage_Sta...

https://en.wikipedia.org/wiki/Ludington_Pumped_Storage_Power...