“All that warm water created would be a draw for all sorts of life.”
Good luck getting an environmental permit for that. IIRC, at some facilities where they draw in contaminated river water they not only have to cool the water down before it is released back into the river (which makes sense for rivers) they also have to remove the contaminants from the water they used before they return it to the river!
Perhaps a pipe going deep into the ocean which would pull out cold water then return it warm to the surface far from the shore. With the money Gates has bribes to get the permits would be easy .