https://www.bbc.com/news/technology-54146718
"Their first conclusion is that the cylinder packed with servers [855] had a lower failure rate than a conventional data centre."
I sure wish the brits would learn how to spell "center" :-)
presumably it takes a lot less energy, since it has to be easier to keep it cool with sea water than with air conditioning units. People are so clever sometimes (and sometimes not, obviously).
IIRC, they are also able to purge the atmosphere of oxidants and replace it with nitrogen.
yes, that's their explanation for why the failure rate is so low