Microsoft Data Centre Green Savings

The Microsoft commissioned report "Cloud Computing and Sustainability: The Environmental Benefits of Moving to the Cloud" (by Accenture and WSP, Noveber 2010) shows savings of 90% for energy use and carbon emissions where a small 100 user data centre is replaced with a cloud-based service. Savings for medium data centres (1,000 users) are less at 60 to 90% and large centres (10,000 users) 30 to 60%.

The analysis was done comparing Microsoft software, but results are likely to be similar for other software. The report did not analyse the cost implications, but as much of the reduction in energy use comes about from more efficient use of equipment there should be savings on hardware (and perhaps also software).

The report lists four factors resulting in savings:

1. Dynamic Provisioning
   
2. Multi-Tenancy
3. Server Utilization
4. Data Center Efficiency

However, these could be simplified down to just one factor: economies of scale. It is more efficient for a large number of users to hare one large system, than many small ones. However, just as the Personal Computer showed that there were advantages (and a demand for) individuals to have control over their own computer use, there is a desire for some level of autonomy. Many of the factors which make large centres more efficient could be applied to smaller installations with the application of new technology and techniques. There are also dis-economies of scale which small data centres could benefit from.

As an example, an organisation could use the same software as used by large data centres for sharing work loads. At peak times low priority applications can be slowed down. Organisations can share processing capacity without using a third party intermediary.

Small data centres can share energy sources with the organisation. For example gas powered tri-generation plants allow electricity, cooling and heating to be provided by one plant. Waste heat from a data centre can be used to warm an office building.

In addition, there are software techniques which can reduce the computing capacity needed and therefore the energy use, without the need for investment in new data centres. An example is to replace inefficient office applications with efficient web based ones. Also replacing inefficient PDF and file formats with efficient HTML equivalents would further reduce processor, networking and storage requirements. A simple approach of offering summary information can further reduce loads. This could produce a 99% reduction in energy use (and equipment requirements).

Table of Contents

Executive Summary 2
Introduction: Is the Cloud a “Greener” Computing Alternative? 3
Research Approach 4
Summary Findings 5
How Does Cloud Computing Reduce Environmental Impacts of IT? 6
Dynamic Provisioning 6
Multi-Tenancy 7
Server Utilization 7
Data Center Efficiency 8
Other Important Factors 8
Case Study – Global Consumer Goods Company 10
Conclusion & Outlook 11
Expanding the Cloud 11
Further Improvements 11
Appendix 12

From: "Cloud Computing and Sustainability: The Environmental Benefits of Moving to the Cloud" by Accenture and WSP, Microsoft, Noveber 2010