Top-level data centres rely on technology that can provide the highest availability possible: 99.999% uptime. A Tier IV data centre must have Class A continuous cooling technology and multiple, independent and dual-powered systems with sufficient redundant capacity.
This doesn't sound like the greenest data centre. In fact, the Uptime Institute, which sets the criteria for data centres, doesn't specify any environmental requirements for Tier IV accreditation.
However, there is increasing industry pressure to balance the data centre's carbon footprint while still achieving the highest availability possible.
For example, the EU Data Centre Code of Conduct for data centre efficiency encourages (but doesn't order) data centre operators to reduce their carbon emissions.
Fabio Torlini, EMEA director at data centre service provider Rackspace, argues that there does not necessarily have to be a trade-off between data centres being efficient or green.
"It's not as straightforward as that. You can design a data centre that has the best technologies from an uptime perspective, which also offer a carbon reducing side. It just costs more," he said.
Torlini outlined some of the strategies that data centre designers could employ to reduce their facilities' carbon footprint from the outset.
The biggest efficiencies come from the running and maintenance of the data centre, he said. However, the location of the building is of prime importance.
"It costs a lot more to cool a facility in Dubai than in the UK, particularly when it snows. We hardly had to pay for cooling at all with our latest centre in Slough, when the temperature was as cold as it was," said Torlini. He added that when the outside temperature drops below 20°C, little cooling is needed.
Placing the data centre underground can also be beneficial, both from a data security point of view and an environmental one, because it requires less cooling.
Several elements can be incorporated into the centre's design, such as hot and cold aisles for server racks and other equipment. This helps to conserve energy, and lower cooling costs by managing air flow.
Other features that can help boost energy efficiency are separating areas of the data centre that do not need to be cooled or lit. Raising the floor allows the air that is being pushed by air conditioning equipment to pass through. Installing automatic doors in the data centre and intelligent lights can also assist in conserving energy. "These are relatively simple things that help to reduce the carbon footprint from day one," said Torlini.
There is also the operational aspect of lowering a high-performance data centre's carbon footprint.
Torlini said that service providers such as Rackspace can incorporate technologies that allow multiple users to benefit from efficiently run IT infrastructure. Cloud services and virtualisation software allow the data centre to reduce its server count, and use existing servers more efficiently to reduce energy consumption and costs.
Virtualisation allows computing to be brought online as and when it is needed, powering up or down servers and other IT components as required.
Torlini said that as a fully managed service provider, it is in the interests of Rackspace - and its competitors - to be as energy efficient as possible, so they can offer the best deal to their tenant customers.
Secondly, "our enterprise customers ask us what we are doing, what we have we put in place, and which metrics we have. In response we can say we work with the Carbon Neutral Company and have won a number of green awards", he said.
It appears that the pressure to go green with data centres is coming from IT users themselves. We should be prepared to pay the upgrade cost.
Computacenter opens Tier IV data centre in UK
One of the newest Tier IV data centres in Europe belongs to Computacenter. While the managed service provider does not trumpet the facility's green credentials, it has incorporated environmental elements into its design and operation.
The Romford-based data centre opened in January and has a number of elements designed to help reduce its carbon footprint.
Key features include a hot aisle/cold aisle layout for its server racks and other equipment. In addition, power use is monitored at rack level, allowing users to monitor and reduce their energy usage, and gather accurate figures which can be used for 'carbon accounting'.