Beware: Cloud computing's green claims aren't always true

A recent report from the Carbon Discloser Project shines a green light on cloud computing, but an efficient cloud still could be using dirty power

Cloud computing must be green. After all, those who provide cloud computing technology say so, most cloud advocates say so, and even those who check up on such things say so.

Take the Carbon Discloser Project, for example. It just published a report on cloud computing and carbon emissions, "Cloud Computing: The IT Solution for the 21st Century." The conclusions were exciting: "The results show that by 2020, large U.S. companies that use cloud computing can achieve annual energy savings of $12.3 billion and annual carbon reductions equivalent to 200 million barrels of oil -- enough to power 5.7 million cars for one year."

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However, there are flaws in the report, according to GreenMonk analyst Tom Raftery and as reported in ReadWrite Web. Chief among those flaws is the assumption that energy savings necessarily equate to reduced carbon emissions. "If I have a company whose energy retailer is selling me power generated primarily by nuclear or renewable sources, for example, and I move my applications to a cloud provider whose power comes mostly from coal, then the move to cloud computing will increase, not decrease, my carbon emissions," Raftery says.

It's a valid point: The idea of becoming more cost-efficient typically means you're more carbon-efficient as well -- but not always. If you go green, then you need to hook up fewer and fewer computers to grids that are powered by coal, whether they are cloudlike or not. 

To Raftery's point, sometimes using cloud computing will make it worse, like moving 1,000 local servers from a nuclear- or wind-powered grid to 500 servers in a cloud powered by coal. Although cloud computing typically means resource pooling, thus using fewer computers, it matters more where they run when you consider the greenness of cloud computing -- or any form of computing for that matter.

So, once again, things are not cut and dry. There are many "it depends" moments when we talk about the greenness of cloud computing. But reducing energy usage through the cloud's greater efficiency is still a good development overall.

This article, "Beware: Cloud computing's green claims aren't always true," originally appeared at Read more of David Linthicum's Cloud Computing blog and track the latest developments in cloud computing at For the latest business technology news, follow on Twitter.

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