Google Data Centres: Following The Moon On The Way To Energy Efficiency  

TreeHugger has a post on a cool new technique from Google to minimise energy used to cool data centres - Google Data Center Uses No Chillers - Will It Soon Follow the Moon?.

A Google data center in Belgium is taking a cool, new approach to keeping from over-heating on hot days. The facility has electricity-sucking chillers to support its cooling systems, relying instead on air from outside. Google anticipates this so-called "free cooling" for about seven days per year, but what's really fascinating is what happens when the weather gets hot.

Quest for Energy Efficiency Back-Story

Chillers used to refrigerate water to cool data centers require, no-duh, a large amount of electricity to operate. This has led to the approach “free cooling:” air from outside the data center is used when the temperature is cool, while falling back on chillers on warmer days. Google's data center near Saint-Ghislain, Belgium completely eliminates chillers altogether. Bonus: an on-site water purification facility allows for the use of water from a nearby industrial canal rather than a municipal water utility.

So what happens on hot weather days?

Google will turn off equipment as needed in Belgium and shift computing load to other data centers.

The end-game of this approach is what cloud technologists refer to as “Follow the Moon” energy management. Were large-scale networks such as Google to implement this concept, workloads would be seamlessly shifted between data centers to take advantage of lower costs for power and cooling during overnight hours. Virtualized workloads would be shifted across data centers in different time zones to capture savings from off-peak utility rates. Cool!