Winter.
Edit: I wonder why you had to copy/paste only part part of the line. They literally address this in the next word:
> ...provided the 1,500- to-1,800 acres of land needed was free and the sun shone steadily
Edit: I wonder why you had to copy/paste only part part of the line. They literally address this in the next word:
> ...provided the 1,500- to-1,800 acres of land needed was free and the sun shone steadily
Even during overcast or rainy days, you'd be surprised how much sun energy still comes through.
Oh, and bonus, wildfire smoke blotting out the sun regularly in the summers now!
Seems sensible to pick a power source that doesn't depend on the sun with that many variables.