Large datacentre operators such as Facebook, Google, Microsoft and AWS account for just a fraction of total US electricity consumption and are energy-efficient, but small, medium, corporate and multi-tenant datacentres are still squandering huge amounts of energy, a report has revealed.
The report, by US sustainability consultancy Anthesis and Natural Resources Defense Council, said the largest public-facing companies typically run their datacentres very efficiently, but progress on energy efficiency has slowed in other types of datacentre, where servers are used very inefficiently, consuming power continuously while doing little work most of the time.
The pressure to keep up with technological developments and the rapid pace of operational change have meant that energy efficiency is often a lower priority, the study said.
The revelations come as datacentres' consumption of electricity is projected to increase to about 140 billion kilowatt-hours a year by 2020 in the US alone.
The report said up to 30% of servers in smaller datacentres are “comatose” (or zombie) and no longer needed because projects have ended or business processes have changed, but are still plugged in and consuming electricity.
A similar proportion of servers in large datacentres are idle, obsolete or unused but are still plugged in and operating in “on” mode, consuming energy while doing nothing, it added.
As well as inefficiencies involving “comatose” servers, peak provisioning – whereby datacentre operators install enough equipment to handle peak annual load, but do not power down unused equipment when it is not needed – and low deployment of virtualisation technologies also contribute to datacentre power waste.
Multi-tenant datacentres are shared facilities where customers lease space and power to run their computing equipment, rather than manage their own datacentre. According to Anthesis, this creates a potential split incentive situation, in which the decisions made by customers on the efficiency of their IT equipment have no direct impact on their bills, removing any financial incentive to improve energy efficiency.
Technical solutions such as virtualisation, server power management, and single responsibility for IT and facility costs are well known but are not applied systematically, the study found.
Another reason for slow progress in cutting energy consumption is that projects that could have a dramatic effect on in-house energy efficiency are often not implemented by enterprises because of the perceived risk that they might harm IT performance or result in downtimes.
Many datacentre managers have maintained their reputation by being extremely cautious in an industry where even a minor outage could threaten their employment, according to the report. As a result, once a facility is operational and populated with servers, the incentive to undergo major retrofits or to change operational behaviours is significantly diminished.
Server utilisation is a key factor in IT efficiency because a server’s efficiency drops dramatically as its utilisation decreases. But the research suggested that low server utilisation remains one of the biggest opportunities for datacentre energy savings.
Studies show that average server utilisation remained static at 12-18% between 2006 and 2012.
Improved energy-efficiency practices could cut server room energy waste by at least 40%, saving organisations more than $3bn a year. But a survey of more than 1,000 global datacentre operators by the Uptime Institute revealed that only half said they considered efficiency to be very important.
The Anthesis report recommended system-level policy actions to create the conditions for best-practice energy efficiency across the datacentre market. It also recommended public disclosure of datacentre energy and carbon performance by all operators, not just the tech giants, and the development of templates for green colocation and other multi-tenant datacentre contracts to improve IT’s overall power efficiency.
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