5 Myths of Data Center Power Usage Optimization

At a recent CIO / CFO conference, I saw why so many executives tune out when the topic turns to green IT and why they fail to make the "no-brainer" decisions that would immediately benefit their organizations.  At the root of their apathy is the frequency with which they’re bombarded by green claims from vendors that often are misleading and sometimes absolutely meaningless.

As a reader commented on my recent blog Green IT Hype vs. Real Deal:  "too many companies are running around hyping themselves as 'the green solution' while doing nothing more that re-advertising their same old products."

And this, my friends, is a big part of the problem.  Despite valuable green innovations in the data center, the really good ideas are having trouble rising above the clatter of the vendors’ PR and sales machines.

Hopefully, data center executives can hear this: If you can improve your Power Usage Effectiveness (PUE) in ways that produce a fast payback, you will save money and reduce your carbon foot print.  This is like hitting the Daily Double: You conserve natural resources while making money. 

Think of it this way. What if you could instantly increase your car’s fuel efficiency by 35 percent via an upgrade that would pay for itself in the first year based on reduced fuel costs alone? You’d jump at the chance, right? So why is there so little interest in doing the same thing in data centers? Because it’s hard to tell which upgrades are real and which are only "the same old products" in new green wrapping.

I’m not going to dive into specific energy saving technologies; instead, I’m going to provide a framework that will allow you to get beyond the vendor hype and evaluate them on your own. (If you’re curious about what these technologies are, check out my recent CIO.com blogs on built green / built right  and cool ways to save money). 

A quick refresh: A data center’s PUE is the total load required to operate the IT systems plus support systems such as power distribution, humidification, and cooling.  A PUE of 2.0 - which is typical of most data centers today - means that for every dollar spent on IT load you burn up another dollar on support. Some facilities have average annual PUEs over 3.0 (not good) and the best run data centers can sustain PUE levels around 1.3.

So here are five myths regarding PUE engineering that often get in the way of good data center optimization and design and prevent executives from making informed decisions for their data centers:

Myth 1 – PUE is a constant that applies 24/7/365

Not true.  PUE can fluctuate by season, and even by time of day.  For example, if the design leverages the free cooling of outside air, then that benefit will only be available when the outside temperature is optimal.  That’s why it’s important to determine average annual PUE and not best case – which may only apply on cool days and nights.  So when a vendor says that its technology will reduce your PUE to 1.3, take the time to find out if this claim is best case, steady state, or annual average.

Myth 2 - During data center design and construction, you should optimize PUE to full anticipated load.

Not only is this not true, it’s an approach that’s doomed from the start, almost guaranteed to leave you with an underutilized or oversubscribed data center for much of its life cycle. You’d be better served by thinking of your data center as a resource that will morph over time. This will guide you

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