As time goes on, data centers are moving more and more towards green technologies in an effort to become as efficient and carbon neutral as possible. Ultimately however, we are going to reach a critical point where green technology is no longer able to meet the electrical and infrastructure demands of a modern data center and I honestly believe we are already close. Google has already done the almost impossible; an average PUE of just 1.2 across its facilities with its sights firmly set on 1.1 in the near future. How they achieved this is detailed in the article ‘How low can you go?’. In short, this means that for every watt of grid electricity used to power the IT equipment, only 0.2 watts is required to run the facility and the closer we get to 1.0 (or zero watts required to run the facility), the more difficult things become.
Despite the fact that the likes of Google and Facebook are seemingly making monthly breakthroughs in data center efficiency, there is going to come a point where we simply cannot go any lower due to the fact that data centers (in most cases) need some sort of infrastructure in addition to the IT equipment. This can range from building management systems, fans and chillers, down to lighting and running water. All of these represent an overhead. The biggest overhead today remains cooling. Regardless of how you are keeping your servers cool; free-air, sea water or old fashioned air conditioners, you still need power to run the cooling system and for the most part, that power comes straight from the grid. Not necessarily for long though.
University of Arizona physicists have discovered a new way of turning waste heat into electrical power. Using a theoretical model of a ‘molecular thermoelectric device’, it may be possible to re-use probably the biggest emission from most data centers today; hot air. According to Justin Bergfield, a doctoral candidate in the UA College of Optical Sciences and lead author of an article in the scientific journal, ACS Nano, “Thermoelectricity makes it possible to cleanly convert heat directly into electrical energy in a device with no moving parts,”. The technology works in a similar way to how noise-cancelling headphones are able to reduce background noise; a process called ‘quantum interference’ where two opposing but equal waves cancel each other out. In this case, the way in which the device (a sandwich of two electrodes with a molecular ‘forest’ filling) works is by encouraging the buildup of voltage between the two electrodes when quantum interference occurs and a heat source is present.
The technology is currently only in the theoretical stage but has the potential to increase efficiency across a wide-range of applications including manufacturing and automotive. It also represents a real opportunity to dramatically increase the efficiency of data centers where these devices would be used to capture the hot exhaust from the servers and covert it to energy to power the IT load. This could be exploited to a point where a data center could exist ‘off the grid’ or even further where it is able to provide energy back to the grid which would be especially beneficial in particularly power stretched areas such as New York City which are running over capacity.
Clearly at this point, the technology is largely a pipe-dream but it is extremely encouraging to see that research such as this provides us real hope for the future…
Read the complete post at http://www.1e.com/bizblog/post/2010/10/12/The-Data-Center-of-the-Future.aspx