Environmental sustainability in data centers?

Data centers are massive users of power.   A single data center can use as much power as a mid-sized town.  So anything that can be done to reduce power use can have a huge impact on the environment.  Gartner estimates that power consumption by computers accounts for 2 percent of global carbon dioxide (CO2) emissions. That's roughly equal to the carbon output of the entire airline industry.

The words "sustainable" and "data center" usually don't travel in the same circles.  Irrespective of the desire to be more sustainable, data center managers focus on three primary goals:  Meet the computing needs of the organization, keep it reliable, and meet budget parameters. Being greener is a nice side benefit, but often not the primary goal.  Building a more sustainable or "green" IT has more to do with data center management and strategy than with specific "greener" products, although they coexist in the same conversation. Purchasing more energy-efficient equipment is certainly part of the equation.  But managing the power consumption of that equipment can have the greatest impact in sustainability.  Data center sustainability is really the convergence of power use (number of watts or efficiency), performance (amount of compute per watt or effectiveness), and product lifecycle management (how often you buy and discard).  What complicates this picture is that there are a lot of technologies that all contribute to the sustainability picture:  power-efficient servers and cooling, data center design, virtualization, and others.

The easiest thing to do is to focus on using less power, but there are lots of ways to do this.  You can start with the equipment.  As an example, Dell M1000e Energy Smart servers consume 19% less power yet generate 25% more performance per watt than competitors.  They can save 3,200 watts per rack per year, which saves more than $30,000. More importantly they don't generate 18 tons of CO2 emissions, which equal about four acres of pine forest.  You can meet the increasing demands of the organization and still use less power.  Also make sure your power supplies are at 80% efficiency, rather than the 60% – 70% efficiency we commonly see. Processors with greater power efficiency are meaningless if you're losing efficiency before the power gets to them.  Consider changing the way you cool your data center. Cooling gobbles up 40% – 50% of the power in a data center.  An increase of five degrees can lower power use by 5%.  New and different kinds of chillers are significantly more energy efficient because they do a better job of providing reasonable air inlet temperatures to the servers and disposing of hot air.  In the end, it is the temperature of the air going into the servers, not the temperature of the air leaving them that is more important.  Even then, the cold-aisle doesn't have to be a meat locker.  With reasonable inlet temperatures and hot exhaust temperatures, server fans don't run unnecessarily and CRACs don't work as hard – energy is saved in both cases and the servers are still perfectly happy.  Of course, you can't forget desktops and notebook computers, especially Energy Star certified ones.  There are configurations today that consume 70% less power, through a combination of lower power components and aggressive power management tools. According to the EPA, if all businesses were to purchase only Energy Star-certified equipment, they would save $1.2 billion over the life of the computers. Less energy waste means greater sustainability.

Also make sure you don't leave performance on the table.  It is widely known that servers in most data centers run at 5% – 15% utilization.  A server uses 60% of its maximum power sitting idle.   But studies show that increasing utilization to 50% can only increase power use by less than 5%.  The best way to increase utilization of course is though virtualization.   Virtualizing to make one machine work as 15 or 20 does two things for sustainability and accomplishes one major goal:  it more efficiently uses power, it reduces the need to buy more servers, and it helps meet the increasing computing demands of the organization.  Virtualization can also extend the life of your current hardware, because you are keeping up with demand and using what you have in a more effective and efficient way.

Even an efficiently run data center will hit the wall sooner or later.  And that wall could come in the form of a maximum power envelope, a space limitation, or simply the end of the lifecycle of a piece of equipment.  At this point you have the opportunity to design for sustainability rather than simply retrofit pieces of what you already have.  Here is where you can think about the issue more holistically, rather than piecemeal.  One study shows you can get a 97% increase in productivity if you combine energy-efficient servers, virtualization, different kinds of cooling and some basic improvements in data center layout to improve air flow. 

Using less power, buy less, and using things longer means using less resources, in manufacturing, shipping, operation and disposal.  Using less resources means a more sustainable environment – but more importantly, a more sustainable IT.   I'm looking for agreement or disagreement with these ideas.  Better yet, we're looking for your ideas, either below or on IdeaStorm.  Let us know what you think and don't forget to visit http://www.regeneration.com/.

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