It's tough in hot climates. There's plenty of heat to go around. And there are lots of people who live in hot climates who, for latency reasons, need servers near them.

Thus there are kind of two cases to solve for. You can stick a data center in Northern Europe, and that heat might be valuable enough that your approach could be to try to reclaim it. If you stick a data center in Singapore, you'd better focus on generating less heat in the first place or finding better ways to get rid of it.

Even in Singapore the max sea temperature is 32C, which seems cool enough to cool a data-center.

Or perhaps heating a greenhouse in a cold climate where fresh food is expensive or impossible to import.

Arthur C. Clarke wrote a short story about an power generator based on the temperature difference of a long pipe reaching into the cold ocean depths. I think the story was The Deep Range.

Toronto cools some of the larger office buildings downtown by pulling in cold water from the bottom of Lake Ontario.

http://www.acciona.ca/projects/construction/port-and-hydraul...

my local swimming pool is heated by waste-heat of a nearby powerplant

I wonder if the water would be hot enough for a thermal bath/spa?