Posts Tagged ‘energy efficiency’

12th June
written by simplelight

One of the major issue with large data centers is power. This is applicable to both large data centers like Microsoft / Google and also to large Enterprise Data Centers which are very energy inefficient.

Definition of Power Effectiveness: Data Center Power Usage Effectiveness (PUE) is defined as the ration of data center power to IT (server) power draw. Thus a PUE of 2.0 means that the data center must draw 2 Watts for every 1 Watt of power consumed by IT (server) equipment. The ideal number would be 1.0, which means there is zero overhead. The overhead power is used by lightning, power delivery, UPS, chillers, fans, air-conditioning etc. Google claims to have achieved a PUE of 1.3 to 1.7. Microsoft runs somewhere close to 1.8. Most of Corporate America runs between 2.0 and 2.5.

A typical large data center these days costs in the range of $150 Million to $300 Million depending upon the size and location. A 15 MW data center facility is approximately $200 million. This is the capital cost so it is depreciated over time.

Most of the facility cost is power related. Anywhere  from 75% to 80% of the cost is power (pdu, chiller, ups, etc).

A typical 15MW datacenter with 50,000 servers costs about  $6.0 million per month for operating expense (excluding people cost) and the share of power infrastructure (pdu, chiller, ups, etc) is between 20% to 24% and actual power for the servers is 18% to 20%. Thus total power cost is between 38% to 44%. These numbers reflect what Microsoft / Google would do. EPA has done a study and they believe these numbers are close to 50% for inefficient data centers.