Microsoft claims that for large deployments, Microsoft’s cloud solutions can reduce energy use and carbon emissions by more than 30 percent when compared to their corresponding Microsoft business applications installed on-premise.
Microsoft together with Accenture and WSP has conducted a study to the saving of energy and carbon emission by cloud computing. They developed a quantitative model to calculate the energy use and carbon footprint of an organization’s IT applications Microsoft Exchange, Sharepoint and Dynamics CRM) for both cloud and on-premise deployment. This approach aligns with the assessment methodology developed by the Global e-Sustainability Initiative (GeSI),
The study compared the environmental impact of cloud- based versus on-premise IT delivery on a per-user basis and considered three different deployment sizes—small (100 users), medium (1,000 users) and large (10,000 users). The analysis suggests that, on average across the different applications, typical carbon emission reductions by deployment size are:
• More than 90 percent for small deployments of about 100 users
• 60 to 90 percent for medium-sized deployments of about 1,000 users
• 30 to 60 percent for large deployments of about 10,000 users
According to the report the key factors that enable cloud computing to lower energy use and carbon emissions from IT:
- Dynamic Provisioning: Reducing wasted computing resources through better matching of server capacity with actual demand.
- Multi-Tenancy: Flattening relative peak loads by serving large numbers of organizations and users on shared infrastructure.
- Server Utilization: Operating servers at higher utilization rates.
- Data Center Efficiency: Utilizing advanced data center infrastructure designs that reduce power loss through improved cooling, power conditioning, etc.
It is a pity that the report does not go into more depth with the quantitative model that is being used. What is for example the explanation of the big differences between the Microsoft
Cloud delivery and the large on premises delivery for the CRM, Sharepoint and Exchange environment (20%, 81% and 52%)?
The report also isn’t very clear about the influence of the power grid on the conclusions. Although the report is stating that “Apart from efficiency improvements, cloud providers as well as corporate IT departments can reduce carbon emissions by powering data centers from low-carbon electricity sources, such as hydropower or wind energy. This can be accomplished by selecting a site in a utility region with a lower carbon emission factor or by actively purchasing or generating renewable electricity.”
If we also take into account that the energy loss in the power grid, that is from primary energy source to the actual delivery of electrical power at the data center, is almost 70% (around 67% power plant conversion loss and 8-10% transmission grid loss) the power grid must have a big influence on the calculations and thus the conclusions. The question “Cloud computing is green computing?” isn’t answered yet.