Have you got a nice big valley with an existing water flow to donate or sell to a new hydro plant?

Hydro is absolutely great (if you ignore local ecosystem ecological damage) but it has very significant land use requirements. These can make it difficult to build practically once you have most of the good spots filled in, so it’s incredibly difficult to price new builds of it. Some areas may be infinite cost because the land topology simply doesn’t exist. Others may have the perfect site and be relatively cheap.