by Angela Miller
With the rise of the environmental movement over the last decade, it should come as no surprise that the concept of ‘green computing’ is gathering steam. Now that vendors recognize that from a branding perspective there exists opportunity in being environmentally friendly, many companies are diving into green computing with gusto. But as vendors begin to tout their capabilities, CIOs and IT Managers may find their companies unwilling to invest in these new capabilities simply to meet the objective of being greener.

For most enterprise and small-to-medium businesses, decisions will instead be made on whether the investment presents good return-on-investment (ROI).

To build the right business case, IT decision makers must understand the basics about green computing and how this investment could both improve their corporate social responsibility and their financial bottom line. Armed with the information, implementing changes that positively impact the environment becomes the right ecological and economic decision.

This post focuses on the basic elements that most IT decision makers will find immediately palatable: energy efficiency, reduction in cooling requirements, and consolidation. Future posts will investigate more advanced green computing concepts like alternative energy sourcing, renewable energy credits, carbon offsets, and certification.

Energy Efficiency

According to Dec-2006 IDC study,

“50 cents is spent on energy for every dollar of computer hardware. This is expected to increase by 54 percent to 71 cents over the next four years.”

While many companies do not consider the facility costs as part of the ROI and total cost of ownership (TCO) for IT projects, increasing energy bills may force this issue.

Consider the analysis compiled by Dr. Janathan Koomey at the Lawrence Berkley National Laboratory on just the estimated server energy consumption for the United States:

“Total power used by servers represented about 0.6% of the total U.S. energy consumption in 2005. When cooling and auxiliary infrastructure are considered, that number grows to 1.2%.”

This analysis was quick to point out that it included only the servers and their required infrastructure, not storage and other IT infrastructure components. Clearly it underestimates the overall resource demand for enterprise data centers. Of greatest concern, however, was his point that electricity demand for servers doubled between 2000 and 2005. Obviously this is not a desirable or sustainable trend.

Tremendous savings could be realized by enterprise data centers if they could deploy more energy-efficient infrastructure. The economics for energy efficiency seem obvious.

Reduction in Cooling Demands

One reality of information technology is that it generates tremendous heat that requires cooling in order to ensure stability in the data center. Even the users’ desktops, laptops, and printers, generate significant heat in the typical office building that requires additional cooling. The cost of cooling are some of the most expensive, energy-intensive demands placed on facilities and significantly reducing the heat load will again result in substantial energy savings.


In my experience, taking a walk through a typical corporate data center never looks like the clean and homogenous picture we see in advertising. Instead, data centers I’ve seen contain a mix of server and storage types, most of which are under-utilized in the name of user performance expectations, poor retirement planning, and changing architectural directions. Almost every CIO for which I have worked has attempted the great consolidation project in the hopes of reducing the complexity and maintenance cost of the infrastructure.

Consolidation also makes good environmental sense if the equipment is chosen wisely, is more efficient than the sum of its replaced parts, is operated in a way that optimizes the energy consumption and performance, and is accompanied by a solid retirement plan for the outdated equipment.

Interestingly many consolidation projects seem to result in new equipment being introduced without the departure of the myriad of servers they were intended to replace.

Also of significant concern – the appropriate recycling and disposal of the retired equipment.

Dig deeper on the issues:

I relied on the following sites for analysis in support of this post:

Lawrence Berkley National Laboratory
Wikipedia “Green Computing” definition
David Merrill, Hitachi Data Systems blog
“Green Computing Picks up Momentum” – ComputerWorld