How to cut data centre power demand by 40 percent

Stuart Corner
Wednesday, 11 June 2008 09:29

Opinion and Analysis

The green light has been given for the building of what is claimed will be the greenest data centre in Europe, using only 60 percent of the power of conventional data centres, but this will be achieved only through close synergy between power generation, data centre and the local community.

Lasercharm, a company set up specifically for the project, has been granted planing permission for the 65,000 square metre development the Elean Data Centre Campus on a former World War 2 airfield (and more recently Trident nuclear missile base) near Cambridge in the UK.

Peter Spiteri director of marketing in Australia for data centre supplier Emerson, told iTWire earlier this year that, in a typical data centre for every watt of power used in the core equipment another three watts are needed, and most of this goes in removing the heat generated by this one watt of 'useful' power. However almost all data centres today use 'conventional' refrigeration - not very different to a domestic refrigerator - in which electric motors are used to drive pumps which compress the refrigerant and pump it to the area to be cooled where it expands and in so doing draws heat from its surroundings.

Lasercharm's planned data centre will use a different technique known as absorption cooling in which a second heat source is used to compress the refrigerant by boiling it in a closed vessel such that pressure builds up to the point that it re-condenses. A similar technique is used in gas-powered domestic refrigerators designed for use in locations where there is no mains power.

However to be cost effective and practicable on a large scale a plentiful source of high grade heat is needed: and in the case of the planned data centre this will come from the nearby power station that will supply it. According to Lasercharm this means that the cooling of the data centre will consume "almost no new energy"

It concludes: "Studies have not yet been completed, however at this stage it appears that the data centre's power demand, a theoretical maximum 72MW, could be very significantly reduced through the absorption cooling process. Preliminary estimates suggest that the cooling load may fall by 30MW, a saving of approximately 40 percent."