"The energy is often so cheap that in the wintertime some sidewalks in Reykjavík and Akureyri are heated."

Indeed. Is not that the normal situation in northerly cities? Shops in Oslo do not get too many visitors in wintertime if they do not heat their sidewalks.

To make a "green" computer center, it should be situated where the heat it produces can be put to use. Instead of wasteful air conditioning, they should use heat pumps to provide hot water, be it for central heating or comfortable sidewalks.