How Data Centers Are Becoming Greener

Data Centre (Photo credit: Route79)

It’s all too easy when you’re surfing the net to completely forget the impact that doing so may have on environment. We instinctively know that it’s greener to look up some information online than drive down to the library for example, but that is partly because we tend to think of the internet as somehow ethereal with no physical base and therefore no tangible effect on the environment. However, all of the data that we view on the web must be stored somewhere and the vast majority lives on servers in large data centers which unfortunately do have a significant environmental footprint.


Reports in 2007 found that Information and Communication Technologies (ICT) accounted for 2% of the world’s harmful gas emissions with data centers in turn culpable for 14% of that figure. As our use of the internet and the trade in digital information grows - and in particular as the concept of cloud computing continues to take off with our data being stored remotely ‘in the cloud’ (i.e., on providers’ vast server networks) for us to access anytime anywhere - the demand for data centers is continually abounding. Providers are therefore increasingly looking for solutions and innovations to become more efficient to meet the twin objectives of cutting their own costs whilst reducing their unsustainable environmental impacts.


All data centers comprise of two key elements which can each provide a number of opportunities for financial and environmental efficiencies. The first is the actual IT equipment. the stuff that provides the core function and purpose of a center, such as the servers themselves and the network switches serving them. The second is all of the infrastructure that is required to house the IT equipment and keep it running efficiently and securely. The infrastructure can be made up of cooling equipment, security devices, lighting etc.

The ratio of energy that is used in the data center’s infrastructure to the energy used to power the IT equipment is known as Power Usage Effectiveness (PUE) and is the industry standard in measuring their efficiency. A PUE score of 2, for example, would signify that for every unit of power being consumed by the IT equipment a further unit was being consumed by the infrastructure.


Renewable Energy
The first step to becoming a greener data center can be to ensure that the source of the energy or electricity being used is renewable. This can be achieved either partnering up exclusively with a supplier of renewable energy or by sourcing energy directly using sustainable methods. Some providers are going as far as locating solar energy farms on site to obtain the energy they need.


Energy Monitoring
It is also important to have accurate and in depth monitoring of the energy that is consumed at each point within the data center so that further efficiencies can be spotted. Most providers will have monitoring in place to calculate the PUE score but the accuracy of this monitoring and the assignment of energy consumption between the IT equipment and infrastructure can potentially vary slightly from one center to another.


Energy Efficiency
It is unavoidable that the largest proportion of energy used by a data center will be used by its IT Equipment, such as the servers, which is the fundamental purpose of the center. However, savings can still be made here, and throughout the supporting infrastructure, by employing the most energy efficient hardware that can be sourced. A significant amount of energy is, for example, lost in inefficient power suppliers before it even reaches the servers. Although this might mean a high initial outlay the power savings, will over the long term translate to financial as well as environmental savings.


Temperature Management
Often the biggest consumer of power, aside from the IT equipment, is the equipment used for cooling the data center.


There is a slight myth in that conditions inside a data center need to be kept at a low temperature. In reality they can operate efficiently at temperatures up to 80F, so providers can make immediate power savings by simply turning down the thermostat. In addition the main chunk of the cost for keeping the interior of a building cool is usually spent on chiller units. As a result, providers are increasingly looking to other solutions to make both energy and cost savings. Amongst these alternative solutions is the choice of locating the data center in naturally cool environments such as Alaska or Scandinavia and then allowing the cool air from outside to circulate through the building. There are also so-called free cooling mechanisms which (although not strictly free) can use pumps to recycle the cool air within the data center rather than chillers.


As well as circulating cool air, many data centers use cold water to reduce their temperatures. Again this can be a cost effective and sustainable option when for example data centers are located by their own source of water and then use purify the water themselves. Cooling water does need to be purified for this purpose but not to the same extent as mains water so the data center can carry out the process with less wasted energy consumption if they do it themselves using a local source.


Materials
As with any manufacturing process, key savings can be made in the production of all of the equipment used in a data center, from the servers to the cooling systems. By sourcing materials locally, for example, the initial carbon footprint of those materials can be cut. Once they have served their purpose, they may also still have a life beyond that; servers which have been superseded for a particular role or function should still be re-purposed within the center in another role where they are still adequately powerful. Those elements which cannot be reused within the data center may still be of use to others and so reselling them may be a further option.


Finally, units which are completely redundant can still be broken down into their components and then repurposed or resold and, failing that, the core materials in the components should be recycled as appropriate. All repurposing and reselling will reduce the demand for new equipment to be built and acquired and therefore as well as saving the data center money from purchasing new equipment it will also reduce the consumption of the raw materials and the energy used in their construction.


Most large data center providers are constantly exploring new and innovative ways to reduce their PUE scores and therefore their energy consumption, keeping costs down and increasing their green credentials. However, the booming demand for services such as cloud hosting and Colocation means that this challenge will never go away.

© Stuart Mitchell 2011