Energy Savings, Strange Attractors, ...

by Jim Stogdill | @jstogdill | comments: 4

... the Intrinsic Cost of State Change, Orbiting Alien Voyeurs, and 200 Square Kilometers of Solar Panels Somewhere in Texas

The Silicon Valley Leadership Group and Berkeley National Labs recently published the results of their first Data Center Demonstration Project (pdf). (Disclosure: My colleague Teresa Tung of Accenture R+D labs was the report's principal author). The study follows up on last year's publication of the EPA's report to Congress (pdf) on data center energy consumption. That report, among other things, estimated the range of savings that data center operators could achieve with varying degrees of technology and practice improvement. This more recent report is based on real world studies and was intended to validate the estimates in the EPA report.

Both reports are good reads if you are interested in reducing the megawatts being consumed in your organization's silicon (though the EPA report has been criticized as being a bit toothless). However, I should warn you that they are fairly long and detailed so the bedside table might not be the best home for them if you want to get through them, at least until the manga versions are released.

The EPA study estimated that "state of the art" technology and processes in the data center might cut energy usage by 55%, the more readily achievable "best practices" come in at 45% savings. State of the art includes a range of approaches including better server utilization through virtualization, better cooling techniques, improved power distribution, sensor networks, etc.

The more recent study, testing those techniques in working data centers, validates the EPA's estimates but also offers the initially surprising conclusion that legacy data centers can be retrofitted to achieve efficiencies close to that of new builds. That conclusion follows from the less surprising finding that the most bang for the buck comes from improvements on the "IT" side of the energy draw (energy efficient servers, virtualization, etc.) rather than from the harder to retrofit "site" side (cooling systems etc.). The dog wags the tail after all and if you can reduce the direct power consumption by the IT equipment, you will simultaneously reduce associated cooling costs whether in an old building with relatively inefficient HVAC or a shiny new one.

The last finding that I'll mention here is that it doesn't look like the time is right yet for widespread adoption of more advanced load management techniques outside of niche applications. The demonstration project had facilities that experimented with them, but the risk aversion that stems from high reliability requirements in production data centers has these experiments mostly restricted to centers that serve R+D rather than production functions.

Maybe one of the most interesting things about the report is what it doesn't (can't) say.

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