The Stack Archive

Evolving power trends in the data centre

Fri 11 Apr 2014

Direct current, more robust power supplies, standby power systems, air side economisers, running at higher ambient temperatures and replacing copper with aluminium are just some of the methods considered by Guy Ruddock, who is responsible for the development of the data centre and node estate for Colt,  making data centres more efficient.

By 2020, analyst house, IDC predicts that the amount of digital information created and replicated in the world will grow to almost 40 zettabytes (40 trillion GB)—more than 50 times what existed in 2010 and amounting to 5,247 GBs for every person on the planet.

Instant access to this mission critical asset will be an essential requirement for organisations seeking to remain competitive. Undoubtedly, this abundance of data will require highly cost effective solutions for storage, management and processing. At the heart of this is energy efficiency – the Holy Grail when it comes to processing data effectively.

With belts being squeezed, the trend to decrease power usage by making data centres more energy efficient is largely being realised through targeted capital expenditure. PUE (power usage effectiveness) is now routinely being used as a measure of efficiency which is simply the ratio of overall power consumption of the data vs. IT power consumption. The result is a whole host of developments in data centre power.

Today requests for DC (direct current) are increasing throughout data centres. Traditionally used by Telcos at 48V, combining amodular data centre with DC power can limit power wasted during conversion compared with AC (alternating current). As a result, relative demand and AC power is declining gradually.

Businesses are also interested in the resilience of power supplies. For instance, with Tier 3 power supplies, data centre managers are now beginning to look at the possibility of having one side of the power supply active and other side passive (a conditioned mains supply).

Organisations that are satisfied with this approach are also looking at going further by utilising a standby power system. This type of UPS (uninterruptible power supply) provides mains power to the load with very basic filtering and is designed to enable the resilient power supply to take over when it detects the main supply is dropping off – a case of Active Passive vs. Passive.

Air side economisers with adiabatic cooling can significantly reduce the hours requiring mechanical cooling, particularly for warm climates. This reduction in mechanical work has a direct knock-on effect on a reduction of electrical costs making evaporative cooling a big hit in the data centre. Latest designs of adiabatic cooling avoid the problems of the older systems and therefore their adoption is likely to increase.

Another development is the replacement of copper for aluminium within the data centre in order to reduce costs. While aluminium is a more rigid metal (making transformers more difficult to manufacture), the lower cost could mean that aluminium becomes a more routine metal within other components in the data centre.

Standby rated generators can also prove to be a capex nightmare. In Europe and the UK, businesses are rarely subjected to rolling blackouts so familiar in the US, so using this form of generator results in an overestimation of the usage of power which impacts fuel storage and switchgear sizing. With a multi-million pound difference in cost to implement, generators can have a tremendous effect on costs. By utilising a standby-rated set the industry could save millions by simply providing only the power needed rather than the hypothetical figure which would never be achieved in practise.

One key change is the temperature at which the data centre operates. Historically, data centres were maintained at around 21°C, today that figure routinely has a larger range between 18°C – 27°C. This allows for more leeway in utilising cooling systems meaning that cooling systems aren’t required to work as hard to cool equipment. We see this developing further with data centre equipment being able to withstand higher temperatures.

If we are currently seeing equipment run at 27°C the obvious next stage is to run at 35°C, which would remove the need for compression systems altogether. Taken together, these developments in power usage and energy efficiency will have an enormous impact on operating costs for data centres with clear implications for the environment and businesses’ bottom lines.


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