I recently attended a conference devoted to the theme of energy-efficiency, organized by the Flemish research group Vito.

One presentation, by Dries Vos, a member of the Vito research team, was particularly of interest. Based on a combination of internationally available data and Vito's own research, he came to some staggering conclusions:

• The entire amount of electricity needed to power all datacenters worldwide adds up to 272 TWH/year. that is three times the amount needed to power Belgium as a whole.
• The average PUE (power usage effectiveness) of all datacenters in the United States is 2,15. We have no exact figures available for Belgium or Flanders, but the PUE value would probably be about the same.
• The average PUE of internal datacenters in Flanders is 3. This implies that the average PUE of commercial external datacenters is far below 2.
• Outsourcing your datacenter to a commercial datacenter will lead to significant energy savings.

Conclusion: if all internal datacenters and server rooms were outsourced to efficiently managed external datacenters, this could lead to an energy saving of about 200 GWh/year, enough to power almost 60.000 families, equivalent to a city almost as big as Liege.

You don't have to take it from me, take it from a renowned research organisation.

https://docplayer.nl/17738559-18-12-2012-potentieelbepaling-van-de-technieken-in-vlaanderen-dries-vos.html