David Snelling, The Green Grid
This is a guest post for Energy Demand from David Snelling, EMEA Technical Work Group Vice-Chair, The Green Grid
One of the most powerful weapons in the arsenal of IT efficiency is the Power Usage Effectiveness (PUE) metric, developed by The Green Grid. Like many of the best ideas, it is devastatingly simple: a figure representing the ratio between the amount of electricity that a datacentre draws — and the actual power that goes directly to servers.
This matters.
It is estimated that around two per cent of all electricity worldwide is consumed by datacentre facilities. With the continued rise of cloud computing and the exponential growth in the volumes of data that we create and store, this proportion could climb yet higher. In order to cut the impact of computing on the environment – and indeed, to lower the financial cost of IT – it is vital that facilities know how much energy they are wasting and how much they could potentially save.
Elegant energy economics
The PUE metric is an elegant, easy-to-understand tool to show how energy efficient your datacentre is. If your IT equipment is only drawing 1:3 of your total electricity usage, you know that you’re wasting power. Get it down to 1:1.2 and you know that you’re being about as green as it’s currently possible to be.
But PUE is not yet perfect.
The one problem is that there is currently no set of strict rules on how energy consumption is measured. This makes it difficult to compare different facilities with each other, prevents it being used as a point of reference for official legislation, and provides wriggle-room for those few unscrupulous operators who are tempted to “greenwash” their facilities.
Positive sanctions
That is all about to change, however, as the International Standardisation Bodies ISO and IEC are set to make PUE an approved standard in the next couple of months. Standardising the measurement of PUE will give the ultimate sanction to the metric. It will enable governments, regulators and the IT industry itself to give credence to the claims of competing datacentre operators.
The Green Grid has been working closely with the joint group ISO / IEC to agree the details of the new standard, which we expect to be in place by the end of next year.
But even when it comes into force, it will only be one battle won in a long-running war. Energy itself is only one of the costs of IT – there are other battlegrounds on which it is just as important to fight. Not least of these are water consumption and carbon emissions, both of which The Green Grid is addressing with its Carbon and Water Usage Efficiency Metrics.
Together with PUE, these metrics aim to create an understanding of the true costs of IT in an holistic way, and it is equally important that they receive official recognition and standardisation.
For the meantime, though, the ISO/ IEC’s embrace of PUE should be welcomed by all who believe in minimising the damage that today’s IT does to tomorrow’s world.