We live in a connected world, one that is becoming more deeply connected every day. So many of our daily interactions take place online – shopping, working, socialising and, of course, reading blogs like this. If you’re using an internet-connected device then a data centre is playing a key role in what you’re doing.

Of course, all this computing capacity uses a lot of power. Data centres are responsible for 14% of electricity consumption in Ireland. This energy is used not just to operate the high-performance servers and other IT equipment in modern data centres that are necessary to keep us all connected, but also to run the cooling systems which ensure these machines do not overheat.

There are several reasons why Ireland is a popular location for data centres; we’re politically stable and business-friendly, we have a well-educated workforce, we’re part of the EU, and we have huge untapped potential for renewable energy.

There’s also the Irish weather. Data centres use an average of 40% of their energy consumption on powering cooling and ventilation systems. In Ireland, that figure is lower because we have a mild climate.

So while the adoption of any solution which improves the Power Usage Efficiency (PUE) of a data centre is welcome – such as investing in renewable power sources, and utilising efficient software and smart hardware design – advances in cooling technology which result in the use of less energy are particularly important.

Ground-breaking work

That’s why the ground-breaking work that Dr Valeria Nico and her colleagues are doing at Stokes Laboratories in the Bernal Institute, University of Limerick, is so important.

There are currently two main types of cooling systems used in data centres. The first is traditional air cooling – basically, a ventilation system which regulates the temperature of servers and other IT equipment by pumping refrigerated air over them.

The second is liquid or immersive cooling – this involves placing the servers in large tanks of dielectric fluid to keep them cool. Liquid cooling can reduce electricity consumption by 50%, however, the set-up costs are more expensive and the servers need to be removed from the tanks of dielectric fluid in order to be maintained.

Dr Nico, a postdoctoral researcher, has taken a different approach to electronic liquid cooling – one where the dielectric fluid is pumped through a closed-loop system directly to the elements which produce heat, such as the CPU.

In this ‘two-phase pumped cooling system’, the fluid doesn’t touch the server, it just flows in a loop to and from where it is needed – similar to how coolant flows around a car’s engine.

This direct liquid cooling system has been developed for the European Space Agency to cool the electronics of small satellites – but it has potentially very exciting applications for data centres.


Bulk and weight are luxuries rarely afforded to anything which needs to be propelled into orbit, so Dr Nico’s system is efficient in both size and energy use. The cooling fluid is propelled by micro pumps measuring as little as 0.9 cm3. These allow a high flow rate while using less than 1W of energy, and they can run off the same power source as the server itself. Maintenance of the server is business as usual because, unlike immersive cooling techniques, the servers are not immersed in fluid.

Dr Nico spoke about the system on an episode of Power & Responsibility – The Data Centre Podcast. She said: “You can either build the cooling system into the server unit or it is easy enough if the server is already built to add the cooling system to it. You don’t need to redesign the whole data centre – you can just add the system.”

Dr Nico also talks about another of her areas of research, which is developing technology to harvest ambient vibration energy and reduce the need for batteries to power the sensors that drive the Internet of Things.

The more connected our world becomes, the greater the need for data centres – and the greater the need for ground-breaking technologies like those developed by Dr Nico and her colleagues to make data centres, and their energy use, more sustainable.

Listen to Dr Nico’s podcast and all other episodes of Power & Responsibility here.

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