'Negawatt approach' urged for DC power usage

With demand for data centres booming, so is the need for more and more power and cooling, but one electrical distribution specialist is touting the need to be more efficient at the plug end, in order to save energy at the power plant end, a philosophy known as the 'negawatt.'

Speaking to Techworld at BroadGroup's Data Centre Europe 2009 conference in London, Daniel Doimo, President EMEA and Latin America for APC (Schneider Electric), feels that it is now more important than ever to save power at the plug end, because so much power is lost from its generation, through to its delivery.

"It is much better to save power where you use it, as demand (for power) is only going to accelerate," said Doimo. He points out that if we can save power, say 1 kilowatt at the plug end, we would end up saving 3 kilowatts in total, due to the power lost from generation, distribution and consumption.

Doimo is advocating that while the 'generation supply' of power matters, first we have to tackle 'demand behaviour'. He cites the figures that when coal is mined 100 units are produced, but after shipping to power station and transfer down the electricity grid this is down to 35 units. By the time the electricity hits a house or office, it is down to 33 units. Therefore, 1 unit saved at point of use (i.e. the plug) equals 3 units saved at the power plant. The so called, negawatt.

Doimo was clear about the need for the data centre industry to make the most of their energy consumption. Currently power and cooling is 50 percent of electricity usage in a DC. He feels that the world's energy system is currently at a crossroads, with the current global trends in energy supply and consumption being unsustainable.

"Data centres today are a necessity, not like fifteen years ago," said Doimo. He points out that Google, because of its data centres, is the second largest consumer of electricity in California.

He also cites the fact that data centre density is much more intense nowadays. Indeed, in his keynote speech during the conference, Doimo pointed out that five years ago, five servers would have a total power draw of 1KW. In the same space now, you can host no fewer than 40 blade servers totalling 20KW of power consumption. The power density (KW/m2) in IT rooms is "skyrocketing."

"We have developed solutions to reduce power consumption by 30 to 40 percent," he said. He pointed to what he terms the "four Cs" approach to reduce power consumption in the data centre or IT room:

  1. Components - Data centres built today will not be able to host suitable power in the future. Doimo says it is very important to adapt the power you consume today, as it is the only way to be efficient.
  2. Cooling - the best analogy Doimo says is the kitchen, where there are only certain parts that need to be cool, such as the fridge. "You don't need to cool down the whole kitchen," he said. "We take hot air exhaust, on a closed loop, and then chill it. This is an important one, with lots of savings."
  3. Containment - contain the hot air exhausted from the rack, create hot and cold zones.
  4. Control - you can only reduce what you can control. The DC manager needs to control, but also needs predictive information about what will happen if you make a particular change, so called "what if" scenarios. Doimo cited the example of a DC manager in London, who can simulate the addition or change of a rack or server in his data centre in New York. He can then instruct the New York supervisor to carry out the change. "Our control software can notify the London man if the change has not being carried out correctly," he said. "There is no need to fly an engineer out to the site."

Doimo believes that the four Cs, taken together, will save 30 to 40 percent of costs, thanks to reduced power consumption, reduced travel budgets etc.

"We can start to be energy efficient now," Doimo insisted. "Negawatts do not create carbon emissions and we are able to do all this today."

And it seems that power efficiency is big business. APC was acquired by Schneider Electric in 2007 and Schneider formed the Critical Power and Cooling Services business unit, which includes the APC and MGE UPS system brands. This unit has annual revenues of $3.5 billion (£2.37 billion), and employs 12,000 people worldwide.

This story, "'Negawatt approach' urged for DC power usage" was originally published by Techworld.com.


Copyright © 2009 IDG Communications, Inc.

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