Building a better data centre

23 October 2023

Billy Durie, global sector head for data centres, Aggreko

Billy Durie, global sector head for data centres, Aggreko

While the concept of sustainability once boiled down to day-to-day operation alone, it has been increasingly recognised as being circular in nature in recent years, spanning one end of the supply chain to the other. Here, the data centre sector is no exception, with ensuring sustainable construction of these facilities equally as important as minimising their energy usage once online.

Greener operations

To gauge attitudes on this topic, Aggreko recently commissioned a two-part report titled Uptime on the Line, spanning operations and construction respectively, which surveyed 700 data centre professionals across the UK, Ireland, Germany, France, the Netherlands, Norway, and Sweden. One of the key issues explored in part of the report was the use of greener alternatives to power the data centre construction phase, with only a small minority of respondents in each nation stating that greener alternatives are not being adopted.

In the UK, solar and wind were the most popular options, with the later also ranking highly in the Netherlands and Sweden. On the contrary, Germany, France, and Ireland expressed a preference for alternatives fuels such as hydrotreated vegetable oil (HVO) and battery hybrid systems. While there was a clear difference in priorities for each region, all markets were committed to adopting some form of greener technology, which will be key to increasing the sustainability of data centre construction.

Moving into the realm of operations, respondents were also surveyed on their confidence regarding the ability of local and national government to update laws so that renewable energy sources can be used in data centres. Here, most respondents in each region were at least ‘somewhat confident’ in local government. However, it should be noted that a much lower percentage were ‘very confident.’ These splits were reflected in attitudes to national government and may indicate that more regulatory support may be necessary for the sector to fully integrate renewables and achieve sustainable operation.

Location was another key factor covered in the report. Across all those surveyed, four factors came out on top – cost of land, cost of electricity, ambient weather conditions, and access to grid power, with the latter ranking top in most of these markets.

Net zero design

The concept of a truly net zero data centre may have once seemed purely fiction, though new innovations are now rendering this vision closer to reality than ever. One technology leading the way here is immersion cooling, wherein racks are cooled using a liquid coolant as opposed to air. Research has shown that this increases computing efficiency by 96.1%, alongside reducing energy consumption by 50% in just two thirds of the occupied space, allowing for higher rack densities.

Furthermore, other developments are allowing data centres to put more back into their communities than ever. Waste heat recovery systems, for instance, can allow the heat dispersed by the racks to be fed into a district heating system, which can then be used to heat all manner of things, from homes, to greenhouses, to swimming pools. By promoting a circular economy through innovations such as these, a truly net zero data centre may yet be possible.

The primary metric used to measure sustainability of data centres is power usage effectiveness (PUE), as recognised by several leading industry bodies such as the Uptime Institute. For traditional, air-cooled data centres, PUE can range from 1.1-2.9, though research indicates that migrating from air cooling to an immersion system reduces the PUE from 2 to an almost perfect 1.02. With this in mind, looking to a data centre’s PUE is an effective way of gauging energy efficiency, and in turn sustainability.

A sustainable future

The data centres of the future will likely standardise several of the leading sustainability initiatives seen in today’s facilities. To keep the environmental impact of the construction phase down and decrease embodied emissions, the construction phase will likely predominantly be powered by greener sources, spanning wind power, solar power, Stage V generators, battery hybrid technology, and alternative fuels.

From here, immersion cooling will likely become the industry standard, allowing facilities of the future to achieve a PUE closer to 1. Thanks to increased integration of renewables and heat recovery systems, very little energy put into data centres will end up going to waste, allowing these critical facilities to remain sustainable despite their voracious appetites for energy.