Pike Research’s recently published Cloud Computing Energy Efficiency report has been attracting a lot of attention. Most of the commentary has been very positive, and the report clearly aligns with much of the industry’s thinking about the future evolution of the data center.
Not surprisingly, some commentators have pointed out the complexity of assessing the overall impact of cloud computing on energy consumption and greenhouse gas emissions and questioned some of the report’s assumptions. It’s worth looking at some of those complexities in a bit more detail.
Our colleague Katie Fehrenbacher at GigaOM, for example, argued that we need to look more closely at the energy impact of network use. She refers to work done by the University of Melbourne on the use of local and cloud-based computing resources for video rendition. Certainly Rod Tucker and his team at the University of Melbourne have identified cases, such as streaming broadband, where cloud computing is less efficient than local computing.
Common sense tells us that watching a movie stored on the disk drive of a laptop in Australia is more energy-efficient than watching one streamed from a data center in Quincy, Was. But the Melbourne team has also shown many cases where cloud computing is more efficient than local computing and much of their work aims to identify areas where we need to increase the energy efficiency of the network in order to meet new levels of demand. The growth of cloud-based services will mean energy optimization of the network infrastructure will become increasingly important both for the Internet and internal data center networks.
Storage is another area where progress needs to be made if cloud-based computing is to deliver optimal benefits. One consequence of server virtualization is to add to the already fast-growing demand for storage capacity. In our Green Data Centers report earlier this year, we looked at some of the innovative work being done by EMC (s emc), NetApp (s ntap), and other storage vendors on virtualization and other energy-efficient storage technologies.
A more general point that will need to be addressed is how to assess that overall carbon footprint of data center services, cloud-based or otherwise. Our green data centers and cloud computing reports focused primarily on energy use in the data center, as has much of the research in this area. A wider view would look at the overall environmental impact of data centers, and different modes of operations, including the use of clean energy and other resources. The Green Grid, for example, has recently announced new metrics for carbon usage efficiency (CUE) and water usage efficiency (WUE), which take these issues under consideration.
Another issue is the overall potential of IT to reduce greenhouse gas emissions. The influential SMART 2020 report, for example, estimated that while IT is responsible for 2 percent of global emissions, it has the potential to reduce emissions from other sectors by at least 15 percent. Clean transport, smart energy and sustainable buildings all rely on increased use of IT as does the further dematerialization of goods and the use of tools like high-quality video conferencing to reduce business travel. Cloud computing will be vital to the efficient delivery of these new IT services, while also reducing IT’s own environmental footprint.
So we agree with Katie that the issues around cloud computing and energy efficiency are much more complex than can be covered in a short press release. Cloud computing isn’t an absolute, and to deliver the maximum benefits it will have to be done well. There will be a transition in terms of applications and industries and a new problems will be accounted along the way.
But we would argue that the logic of development is clear. Cloud computing models – in all their diversity across public, private and hybrid clouds – will be the dominant business model for the next generation of computing services. We are, however, only at the beginning of the long investigation and debate as to the most energy-efficient and environmentally sensitive ways to provide those services and to use them effectively. We hope our reports on green data centers and cloud computing can make a useful contribution to that debate. Let the discussion continue.
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