I was doing research for an RFP yesterday about carbon footprints as they related to PUE, Data Center Operations, and IT resources in general. What I realized was that IT still looks at itself in silos, not systems. Let me explain...
This morning I got my copy of eWeek and on the cover was a pointer to Green IT Solutions - The Real Deal - on page 16. I'll admit I didnt spend a lot of time on the article because it was just like 100 others I have read the past few months that follow a simple formula:
Virtualization = Green
Um, not exactly...
Let me take you through a systems view of carbon in the data center operations:
The PUE of most data centers is 2.0 or higher. This means that for every dollar spent on powering servers, an additional dollar is spent on common facilities electricity to support systems. In the container model. The PUE is 1.2 which means 80 cents of every dollar captured for common facilities/infrastructure is saved. For a 500 KW deployment with a $0.10 per Kwh charge it means that in a data center with a PUE of 2.0, the cost is $73,000 for electricity. With a PUE of 1.2 the cost is $43,800. Savings per month of $29,200, and all of the electricity is green.
To produce a Kw of electricity from coal, 2.3lbs of carbon are produced (see http://cdiac.ornl.gov/pns/faq.html), so for a 500Kwh environment, multiplied by 2.3 lbs per Kwh is 839,500 pounds or 419 tons per month. Since wind eliminates 98% of carbon emissions, the net carbon footprint per month drops to 8.4 tons per month (see http://www.parliament.uk/documents/upload/postpn268.pdf)
When I look at a virtualization = Green example I see some major gotchas:
1. New equipment will likely need to be purchased. The manufacturing process is not carbon-light.
2. This means more mercury and other nasty stuff in the new equipment plus the old equipment. recycling gets you a couple of brownie points.
3. If a new data center is constructed, or leased, or expanded there is the cost of manufacturing, transporting, and assembling all of the components. If it's still powered by coal - you gained nothing
My point being Virtualization is NOT/KINDA Green and has a measureable but not significant reduction in carbon footprint. My personal stance is that you are far better off getting your utility to get wind energy into your data center and cut carbon by the boatload. Better yet, get wind produced power, use an existing data center someplace cool and open the windows when you can.
The other thing I found very amusing in my research was the data center with a LEED Platinum rating and was powered by multiple 50+ year old coal plants. It's like tinting mercury pink to make it 'safe' isn't it?