HOWTO Green your data-center

Alex sez, "My colleague Jer Faludi has put together a terrific overview of the recent advances in creating greener tech for server farms, which -- since they make up about 1.5 percent of planetary US energy consumption -- are a major target for sustainable computing efforts."
It's not just the computers themselves that use all this power: the combined heat output of all these servers, hard drives and network gear is so large that massive air conditioning is required to keep it all from overheating. "Cooling is about 60 percent of the power costs in a data center because of inefficiency," said Hewlett Packard executive Paul Perez in Data Center News. "The way data centers are cooled today is like cutting butter with a chain saw." Cooling capacity is often the limiting factor of how big these systems can be -- I've talked with more than one engineer whose data center facility sat half empty or more; even though there was plenty of room for more servers, the building's air conditioning was maxed out.
Link (Thanks, Alex!)

Update: John sez, "There's an EPA report which estimates that 'servers and data centres' accounted for 1.5% of US energy consumption in 2006. But that's a long way from 'data centres = 1.5% of the whole world's energy consumption.'"


  1. I’ve been working facilities in a data center for about six months now; the cooling capacity is absolutely our limiting factor, since our buildings are rated for 125 watts per square foot. It’s not uncommon for a blade server rack to handily exceed that number, requiring the customer to get a larger cage to offset the massive amounts of heat being generated by a handful of blade racks.

  2. Nobody even blinked at the insane assertion that data centres alone account for 1.5% of the entire world’s energy?

    Nonsense. The EPA report estimates that ‘servers and data centers’ may account for 1.5% of US energy. US. Not World. And what does ‘servers’ mean in that context?

    To reduce that to ‘data centers take up 1.5% of world energy’ is ridiculous.

  3. Rah for fact-checking!

    See also for some other cites in the attempt to measure energy usage.

    In particular, see the stuff about Mark Miller’s report “the Internet totaled about 8 percent of all U.S. electricity use in 1998 and that it would grow to half of all electricity use in the next decade”, a totally bogus statement that we will be living with for the rest of our lives, along with “ketchup is a vegetable” and “Saddam Hussein has WMDs”.

  4. I’m pleased it got corrected. Now, of course, it looks like Alex and Jez didn’t ever make that claim. I’d have been happier if their claim was left there with a polite comment pointing out that it was incorrect.

  5. Cooling is certainly a big issue but my experience in the last couple years with colocation facilities has been more about power than cooling. Most data centers were built 10+ years ago and were based on the “sell per square foot” model but now that energy costs are so high and servers so dense, I can get as many servers in 1 rack that used to take 5 and want that much power in that 1 rack. Few data centers have that kind of power infrastructure. Obviously the energy to provide the cooling is part of the load but power is usually the issue. Thus, we too end up with giant cages with just a few racks and a lot of free space.

    The upside to this for those of us who spend time in data centers is that now instead of working in tiny little poorly lit and freezing corridors between racks, we have large open spaces which we furnish with big storage cabinets and tables for building servers and such. It has made a nerd’s life somewhat more enjoyable.

  6. Sounds like these places need Sun’s Black Box, basically 250 servers and their cooling systems housed in a 20′ shipping container. Of course, they might then find the limiting factor to be available water.

  7. If you read the article, I cited the source for the 1.5% number. Here it is for those who didn’t: a white paper by Tech Target, called “Green Computing Beyond the Data Center” ( ). The paper has been cited and re-posted by Forbes, BusinessWeek, and many other publications. Sorry if the number is wrong; the EPA’s paper is a more credible source.

  8. What’s the definition of a “white paper”?

    Jer’s link takes me to a page on Forbes which invites me to watch a webcast. There’s no text, as far as I can see, and in order to watch the webcast I have to go through two pages with huge complex intrusive forms — I have to provide them with my phone number? — before I can access it.

    But I did that for the sake of being sure.

    Yes, the webcast, (low-res, badly recorded audio and ugly pixelated slides) after a few minutes, does indeed say that “data centers consume 1.5 per cent of the total electricity on the planet”. Which by now, I hope we all realise is not true.

  9. This is agonising. Another huge, illogical, intrusive form … and the White Paper isn’t available to users outside the US or Canada.

    Having lied and filled out the form about seven times (you can’t get it if you don’t have a fax number) I finally downloaded it and yes, it does contain that error: “1.5% of the planet’s energy”.

    I’d write to the people who produced it but the website is so horrible, and it’s so hard to figure out who to write to, that I just give up.

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