Microsoft was talking about submarine data centers powered by tidal forces in the early 2000s.
There have been talks of data centers on Sealand-like nation states.
Geothermal ...
Exotic data center builds will always be hyped. Always be within the realm of feasibility when cost is no object, but probably outside of practicality or need.
Next it'll be fusion-powered data centers.
https://cfs.energy/news-and-media/commonwealth-fusion-system...