Applications hosted on external cloud computing services consume at least 30% less power than internally hosted systems, according to a study commissioned by Microsoft and conducted by Accenture and consultancy WSP Environment & Energy.

The study compared cloud and internal implementations of three Microsoft applications – Exchange, Dynamics CRM and SharePoint. It found that the carbon footprint of cloud implementations was at least 30% less than on-premise equivalents.

The difference was greater for smaller implementations: for 100 users, the carbon footprint was 90% less; for 1,000 between 60% and 90% less. For implementations of over 10,000 users, the carbon footprint was between 30% and 60% less in the cloud.

Microsoft attributes this difference to the economies of scale and efficiencies that cloud providers can apply in their data centres.

It says that certain technological characteristics of cloud computing environments, such as multitenancy and scaling to demand, help cut energy consumption. However, the study did not compare cloud hosting to traditional hosting services in order to substantiate this claim.

It should be noted that Accenture and Microsoft have a joint venture called Avanade, which, among other services, advises companies on how to deploy cloud-based Microsoft systems.