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Three years ago, Google’s data centers were using enough electricity to power a city the size of Salt Lake City.Fernando Morales

Making data centres more efficient is one of the biggest challenges in power consumption

When Michel Chartier first started designing data centres − buildings housing computer servers − two decades ago, he didn't think much about energy conservation. The servers would plug into the wall, air conditioners would keep those servers cool and that was it.

Times have changed. As computing needs have grown and an increasing amount of data is being processed on a daily basis, data centres have become massive energy hogs.

"They are huge energy users," says Chartier, president of Kelvin Emtech, a Montreal-based engineering consulting firm. "Now we're trying to make these centres more and more efficient every year."

According to the U.S. Department of Energy, data centres can consume up to 100 times more energy than a standard office building and that number will only grow as more computing power is required.

A typical 5,000-square-foot data centre draws 1,127 kilowatts (KW) of power. About 590 KW of that is used by the servers, while 430 KW goes to cooling the servers, according to Emerson Network Power.

Chartier has spent a lot of time looking for new ways to cool those servers. They generate a lot of heat, and the more servers that are crammed into a room, the hotter the centre. If the temperate exceeds 39 degrees Celsius, the servers can crash. To cool them, a lot of companies simply run air conditioners at full blast, which uses a lot of power, he explains.

The computers will eat up even more power as demand for data increases. Gartner Research estimates that in 2020 there will be 26 billion connected devices, up from 900 million in 2009, all of which will be connecting to data centres and servers for information.

It pays to green the data centre

The push to create greener data centres has been driven by dollars and cents, says Piyush Bhatnagar, Accenture Canada's managing director of technology.  Depending on the industry, between 25 percent and 60 percent of a company's annual IT budget can go towards infrastructure, which includes data centres, and the more these centres grow, the higher the electricity bills.

"Make a 5-per-cent efficiency reduction and you could be talking billions," says Bhatnagar. "And once those changes are made, you reap the benefits year after year."

Chartier is trying to get Power Usage Effectiveness (PUE) − a measure of data-centre efficiency − from the current average of around 2.5 down to 1.5. "If my overall consumption of energy is dropping, it will reduce the PUE he a lot," he says.

Big companies leading the way

The push for better data-centre efficiency is coming from Google, Facebook, Apple and other large companies, says Jonathan Koomey, a research fellow with Stanford University's Steyer-Taylor Centre of Energy Policy and Finance.  They have the most efficient data centres, in part because they're such big brands.

"They're customer-facing companies, and customers care about the environment," he says.

Data Centre Knowledge, an online resource, estimates that Google uses about 500 watts per square foot to run its centres.  In 2011, Google revealed that its centres consumed enough power to run a city the size of Salt Lake City; today, it says its data centres use 50 per cent less energy than the average and that its PUE is 1.12, also much lower than the average.  Other larger companies also have low PUEs; Facebook, for instance, says its measures 1.07.

These companies are more efficient in part because they can afford the upfront costs required to create more efficient centres and any changes they make will save them billions of dollars, says Stanford's Koomey. It's the smaller companies who keep servers on site that have been the slowest to adapt, he says.

Concentrate on cooling

One way to reduce energy usage is to turn off those air conditioners, says Koomey. Before a company can do that, though, it has to revamp its cooling systems. One way is to funnel in colder air from outside. "Bring in outside air and moving it through and quickly remove the heat," he says. "Then you don't have anything other than outside air."

That's called "free cooling," says Chartier of Kelvin Emtech, and it's how Google keeps its centres cool. Facebook does something similar, but it also takes the heat that is generated by the servers and uses it to heat offices in the winter.

Another tactic is to move the centre to a colder climate. Chartier gets a lot of inquiries from U.S. companies who want to build centres in Canada, where the cold climate can keep servers cool for several months of the year.  That's not a foolproof plan, though, says Bhatnagar. Companies don't always want their servers to be thousands of miles away and there are different data privacy rules in Canada than other parts of the world.

Some advances are being made on the server side to allow them to continue operating in extreme heat. However, a more significant technological advancement has to be made or these centres won't be able to continue growing, says Bhatnagar.

"There's a physical limitation we're heading toward," he says. "There has to be a game changer down the road. The incremental approach we've seen is not going to keep pace with our exponential growth in demand."

Virtualize it

Another way to reduce energy usage is server virtualization. This uses software to optimize server space and computing power, allowing companies to get more out of systems without adding more physical servers.

According to Cisco Systems, if eight non-virtualized physical systems are replaced by one virtualized physical server then overall power consumption in a 5,000-square-foot facility can be reduced by 8 per cent.

There's another way to reduce consumption: ditch the servers. In the future, it won't be as efficient for smaller companies to run their own centres, says Koomey. Instead, they'll be using third-party cloud solutions such as Amazon to store their information. If more companies shut their own centres and move to the cloud, overall data-centre energy usage will be reduced.


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