During the long winter season, that water is largely in solid form, making it less useful for hydro-battery use.

Hydro plants in cold regions usually have an "ice laying" period where they reduce the output to form a thick layer of ice at their desired level to enable the flow they need and prevent ice-slush from entering the turbines.

Seems like Minnesota is more lakes, but that same concept should apply, and it is not like they freeze to the bottom each winter.

You've also got a sizable river on the eastern border that extends up into northern Minnesota.

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

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

Wtf does six weeks of peak power consumption for a city look like in volume of water? Probably bigger than a city

bit short on hills though