Jack Pouchet, the director of energy initiatives for Emerson Network Power, is calling for a new metric measuring a data center’s water use as compared to its productivity (measured in Emerson’s own Compute Units per Second).
In a column in Environmental Leader, Pouchet writes that water could be “the next oil,” meaning that the availability of water is often difficult for many in the world, especially clean drinking water in developing nations. Pouchet suggests that the data center industry should be more cognizant of the water it’s using to cool IT equipment, and adding a water use metric to the current Power Usage Effectiveness (PUE) metric — which compares facility energy use to IT energy use — is a good start.
From Pouchet’s column:
It is time for the data center industry to formulate a Water Systems Productivity metric (WSP). Take useful work or even a proxy for useful work, such as the proposed Compute Units Per Second, and divide that by the amount of water used during the period. Water may be measured in units, with 1 unit equal to an acre-foot. However, gallons/liters is also acceptable.
This WSP metric would ideally be reported monthly with your other metrics. Once we start to measure and report water utilization, we will quickly realize that simply flowing more cooling water in order to “economize” may not always be the best answer. Now we will be able to have a meaningful tool to determine the ideal mix between dry-coolers, CW plants and evaporative cooling towers compared to the increased energy used with alternative solutions.