I wonder if it would be feasible to put a data center next to a power plant, and use the cooling water to raise the temperature of the water flowing in to the power plant, theoretically it should then take less energy to raise the temperature high enough to generate steam to power the turbines...
I had thought the same thing about using a power plant's steam output to preheat the inbound water. Turns out, that bringing water up to just below boiling is a very small amount of energy, compared to the energy it takes to boil off that same amount of water. As a demonstration, fill a pot with water and put it in the stove. Notice that it will start boiling within about 5 minutes, but it takes maybe a half hour to an hour to boil off the whole pot of water.