How Green is Cloud Computing
In theory, a shared resource like Amazon or Google's public clouds can have higher utilization and thus greater power efficiency. Locate your cloud data center close to a green power source, like a hydro plant, and you can minimize transmission line power losses and be even greener. I could rattle off another dozen reasons why cloud computing should be greener. But is it really?
As Governor points out, one of the challenges with judging cloud greenness is transparency. But there are plenty of others, too. Assuming cloud computing is growing faster than capacity of your typical IT shop, a cloud with stringent service levels would have to over-provision resources to account for peak loads and growth. And since most clouds today provide mostly homogeneous x86 resources, it is difficult today to vector cloud workloads to what might be more power efficient systems, like Sun's CoolThreads servers.
So the debate about cloud efficiency is sure to go on. But IT executives should not worry. Efficiency will not be what enables clouds. Companies need to start to abstract out their systems platform architecture from their applications platform architecture. The days are numbered when someone deploying a new service will go purchase an application, then go purchase systems (including servers, SAN storage, and network switches) to run the application. We are seeing more and more forward looking IT executives start to layer their IT resources, building out a systems platform architecture separate from their applications platform architecture. And once you do that, it becomes easier to deploy some or all of your IT onto a cloud, be it an internal private cloud or a public cloud.
There in a nutshell, you have the logic behind the recent Sun product group reogranization, with three new product groups focused on systems platforms, application platforms, and cloud computing.