One of the most enjoyable blog posts I read over the holiday break came from Reuven Cohen, a longtime cloud evangelist and CTO of cloud management software vendor Enomaly.
In a post titled "Is cloud computing actually environmentally friendly," he points to one of the most perplexing aspects of the claim that cloud computing is green:
The problem is there is no uniform way to measure this supposed efficiency. None of the major cloud companies are providing utilization data, so it is not possible to know just how efficient cloud computing actually is--other than it sounds and feels more green.
He addresses the environmental impact of both building data centers and choosing their power sources. He then discusses consumption:
We now have the ability to run our applications on thousands of servers, but previously this wasn't even possible. To say it another way, we can potentially use several years worth of energy in literary a few hours, where previously this wasn't even an option. So in direct contrast, hypothetically we're using more resources, not less. On the flip side, if we bought those thousand servers and had them running (underutilized), the power usage would be significantly higher. But then again, buying those servers would have been out reach for most, so it's not a fair comparison. There we are--back, at where we started. You may use 80 percent less energy per unit, but have 1,000 percent more capacity, which at the end of the day means you're using more, not less energy.
He's right. How can we claim to be creating a greener world through cloud computing with no data to back it up? In fact, there is some significant evidence that the cloud is encouraging more compute consumption, which would erase much or all of the energy savings that the cloud's increased utilization efficiencies would achieve.
Simon Wardley, software services manager at Canonical, discussed this several months ago in his blog:
The shift of common and well defined IT activities from products to standard components provided as online services should lead to a dramatic explosion in innovation.
Standardization always creates this potential.
...Cloud computing is all about providing standard components as services (it's pure volume operations). The problem of course is that we will end up consuming more of these standard components because it's so easy to do so (i.e. in old speak, there is less yak shaving) and it becomes easier to build new and more exciting services on these (standing on the shoulders of giants).
We might end up providing more efficient virtual resources but we will end up consuming vastly more of them.
So, in a sense, the "greenness" of cloud computing is a kind of Schroedinger's box problem today, in which we won't know the actual savings to the environment until someone actually observes--or measures--it.
Krishnan Subramanian, a commentator for CloudAve, is also aware of this paradox, but he points to a story out of Finland that shows some hope that there are additional ways we can help the environment through cloud computing. Apparently, the city of Helsinki is using a data center operation to heat homes--a perfect way to gain value at both ends of the heat exchange process.
I believe one thing to be true: the increased efficiency of the hardware components in most cloud data centers and the increased utilization of these components mean that we are almost certainly doing more work per unit of energy consumed than before. However, I think we'll have to wait awhile before there is evidence of the overall effect of cloud computing on the planet...one way or the other.