Let’s Give Some Love To Data Centre Retrofits

Are we ignoring well-understood basic techniques to boost our data centres’ efficiency, because we are mesmerised by the new stuff?

It might just be my bias as a journalist, but all I tend to see is new tech, and new data centres from the giants, always claiming radical ideas to use less energy; or massive changes to infrastructure like the Smart Grid which could cut our overall needs.

Let’s hear it for upgrades

It’s easy to overlook what can be done to existing data centres, in retrofits. But there’s plenty of advice out there. The Electric Power Research Institute (EPRI) recently set out a list of more-or-less quick wins, that can save between five and 20 percent of the energy used in a data centre. And they are all retrofits.

First up, as usual on lists like this, is the power distribution system. Lots of energy is lost in translation, so simplifying is the name of the game.

Using new power supplies is good. 80 Plus rated power supplies deliver at least 80 percent of the power they receive to the racks – and EPRI reckons that can be a 20 percent saving over what data centres currently have installed.

Still in the power network, how about reducing the number of changes and transformations in your power supply systems Stepping voltage up and down, and converting from AC to DC can be wasteful, so EPRI recommends designing any unnecessary changes out of the system.

Replacing an AC system with a DC one can save as much as fifteen percent, the Institute says.

Don’t waste cooling

Airflow is the next on EPRI’s list. This can be more fiddly to get right, and will depend a lot on the actual layout of your data centre. Air is notoriously hard to contain and control, but there are big savings to be had – up to 17 percent, says EPRI – if you stop cooling things that don’t need to be cooled, and there are plenty of firms out there selling plastic curtains and well-designed floor plates to help you do this. .

Newly built data centres will (one hopes) have a very efficient airflow – but I am told you can approach that in your existing plant with a little hard work.
Finally, once you’ve got the air under control, and set up good measurements of what temperature you are actually achieving at your servers, you can save a bit more by letting the temperature go up.

Put it up by five degrees Fahrenheit, and you can save maybe five percent of your energy costs because your chillers will be working less.

All this sounds good but it will never have the glamour of building a new data centre in Sweden (or Finland, as Microsoft is doing) or designing a whole new server.

You will probably never get your existing data centre down to a PUE of 1.2. But if you are starting from a not-unusual PUE of more than 2, these sort of cuts will have done wonders.

This article appeared on Green Data Center News

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