More power than anything* the fibre usually comes later.

One going up near me is being built on the site of an old coal fired power plant. Lots of juice and an old dam for water. Theres not exactly 2000 cores of fiber out that way, but I am sure it will come eventually.

Theres some going into old paper mills and logging camps too, same sort of thing, near water, lots of juice, out of the way.

*Sometimes theres a simultaneous fibre buildout, or they are built where theres a lot passing through but its less of a concern afaik.