I've just read the article Microsoft sinks a data center off the Scottish coast (The Verge, 6 June 2018)
I understand that the cooling of a data center is a problem. Data centers produce huge amounts of heat, and they have to run at normal temperatures, otherwise the hardware gets damaged. The cooling is much easier when there is a lot of cool water available, so most data centers are built in countries with a cool climate.
But at the same time, the countries with a cool climate consume a lot of energy to warm up water for their heatings.
Why does Microsoft experiment with a data center under sea, instead of using the data center's warm water to heat surrounding buildings? There are similar solutions in other areas, e.g. combined heat and power facilities with district heating schemes.
I've found some articles about data centers involved in district heating, but I'm wondering why this isn't done more often. Are there any obstacles, hidden costs, or other problems (like, keeping the location of the data center a secret)?