Ctg sit23 hub banner.jpg

Green data centres can take the heat

It isn't solar panels and wind turbines that are making data centres greener, but technology enabling servers to run reliably at higher temperatures, says Graeme Burton

The world is being submerged in "greenwash": most notably in the form of solar panels that harvest more in subsidies than they generate in electricity and wind turbines that barely generate enough electricity to boil a kettle. And yet, when a glitzy new data centre is opened, a big show is often made about how environmentally friendly it is, with prominently placed solar panels and wind turbines - which could only ever meet a fraction of the energy such places typically consume.

"Given the power that is required by these buildings, a few solar panels are not going to make a significant difference, especially in winter," says Cyrille Brisson, EMEA business unit manager at power management specialist Eaton Corporation.

If an enterprise genuinely wants to power its data centre using renewable energy, then it should do what Apple has done, says Brisson, and build the wind or solar farm to supply it separately in a more appropriate location. Alternatively, they could source their power exclusively from renewable energy providers.

Power mad

Data centre power consumption is a growing problem. According to chip maker Intel, data centres consume about 1.5 per cent of the world's electricity output, costing $27bn and generating 210 million metric tonnes of carbon dioxide.

Vendors and major data centre users alike, therefore, have increasingly focused not on "green" power generation, but on power consumption: in terms of both the core computing technology, as well as the cooling of the servers.

Social networking giant Facebook, for example, has started custom-building its own servers, publishing a reference design under the Open Compute Project banner. It claims its new data centres are not only 38 per cent more efficient, but also 24 per cent less expensive to build and run than other data centres as a result.

The trouble is, says Steven Campbell-Ferguson, an associate director at architecture and engineering consultancy Arup, that many companies over-specify their power consumption and, therefore, their cooling requirements when it comes to designing new data centres.

"From my point of view on the design side, the two things I need to know from clients are how much power they need for their equipment in kilowatts and how much space they need for their racks," says Campbell-Ferguson.

Components

Tata's UK gigafactory project takes major step forward

Sir Robert McAlpine to build multi-billion-pound factory

Cost of GenAI is a negative for software companies, Gartner
/news/4336424/cost-genai-negative-software-companies-gartner

Artificial Intelligence

Cost of GenAI is a negative for software companies, Gartner

'Revenue gains from the sale of GenAI add-ons ... flow back to their AI model provider partner'

National Grid is turning analogue to digital - Ctrl Alt Lead podcast
/podcasts/4333508/national-grid-analogue-digital-ctrl-alt-lead-podcast

Public Sector

National Grid is turning analogue to digital - Ctrl Alt Lead podcast

'We can't do what we've always done, just more efficiently'

Ctg sit23 hub banner.jpg

Green data centres can take the heat

It isn't solar panels and wind turbines that are making data centres greener, but technology enabling servers to run reliably at higher temperatures, says Graeme Burton

“That’s often where mistakes occur: a lot of IT people think in terms of numbers of racks and the highest possible kilowattage they can get in a rack. They multiply the two numbers together and get a figure that is grossly more than they need.

“As a result, a lot of data centres get over-specified. They read that Dell or IBM has managed to stuff 20 kilowatts (KW) of kit in a rack, for example, and that all racks are therefore 20KW. But the average rack is still one or two kilowatts and loads aren’t increasing as quickly as many might think,” he says.

Hotting up

This over-specification has an impact on the ancillary equipment too – especially the cooling required to maintain the servers in the data centre at optimum temperature.

Even here, while chip and server makers have been pushed hard to improve energy efficiency, heat tolerances have been steadily increasing as well.

In just the past five years, Ashrae – the American Society of Heating, Refrigeration and Air-Conditioning Engineers – has increased the operating temperatures required of data centres in its industry-standard guidance.

A decade ago, the Ashrae guidance would have recommended cooling the air in the average data centre to 21ºC or lower. Today, though, server hardware is being built to be more resilient and can operate reliably at temperatures of 30ºC or more – and the guidance has been updated accordingly. Ashrae pegs the “recommended envelope” to supply air to the front of the rack at between 18ºC and 27ºC. But its “allowable envelope” can take that air supply into the thirties.

“Most manufacturers are making equipment that can work at up to 32ºC degrees, but most data centres are still cooled to about 20ºC or 22ºC,” says Campbell-Ferguson. “So progressive IT managers will be happy to conform to the Ashrae guidance because they are buying hardware that conforms to the new criteria.”

Because at such temperatures, UK-based data centres can use fresh air all year round, that means lower costs in terms of cutting out refrigeration equipment and the space it would require, as well as lower operational costs. It will also take the “magic” power usage effectiveness (PUE) number down to 1.2.

And the message is starting to get through.

“Three or four years ago, no one was doing it apart from companies like Facebook, Amazon and Yahoo because they were looking after their own kit. We’re now seeing co-location suppliers beginning to move – partly because their customer base is getting the message and realising that the design criteria of 20 years ago have changed,” says Campbell-Ferguson.

@GraemeBurton

To register for the Computing Data Centre Summit 2013 on 24 September, go to: www.computingsummit.com/datacentre