Open Source Cloud Computing - The World's Greenest IT

William Stewart, Ph.D.
CEO Cirrus Computing

This paper shows that open source cloud computing (OSCC), such as offered by Cirrus Computing, is the greenest IT option currently available to small and medium-size organizations. Compared to a baseline of onsite IT, OSCC is estimated to save an average of $1,035 and 0.64 tonnes of CO2 per person on setup, and $742 and 0.46 tonnes of CO2 per person each year.

OSCC is compared first to onsite IT, where four key efficiencies are found with cost and green benefits. The savings are estimated for a cost-conscious small to medium-size organization. Green benefits are identified, and converted from dollars to tonnes of carbon dioxide (CO2) using the average of 0.62 tonnes per US$1K of economic activity (1). OSCC is then compared to an all Web applications approach, and found to be greener primarily due to less use of hosting infrastructure. The question of how much green benefit can be retained from efficiency and productivity gains is discussed briefly in Note (2).

The advantages of OSCC over onsite IT are summarized in the following table.


Cloud Desktops


1 - Local Systems
2 - IT Support
3 - Client Savings
4 - Open Source

5 - Web Applications


Setup Savings


Ongoing Savings


Greatly reduced financial and green costs to setting up an organization or adding members to a team:

  Local Systems: Save the all the costs of acquiring, packing, shipping a lot of no longer needed local back-office IT equipment, such as servers, storage, backup systems, networking, etc.

  Clients: There is no longer any need for all computers to have the same operating system version, or even be the same platform (Lin/Mac/Win), which means more possible reuse of existing client machines instead of having to acquire new ones.

  Licenses: Save all licensing fees for no longer needed software, including server and desktop operating systems, productivity applications, and collaboration software.

  IT Support: Save the setup costs for installation, configuration, and integration of the no longer needed systems into a secure Intranet.

In total, the savings per person for setting up a new organization or department is estimated to be $520 - $1,550 with a mean of $1,035, which in tonnes of CO2 saved is 0.32 - 0.96 with a mean of 0.64.

A configurable spreadsheet
is available here - ODS, XLS.

There are also annual financial and green returns to safeguarding your IT with an OSCC solution:

  Local Systems: Save the annual support costs for no longer needed back-office IT equipment, and the cost and green impact of its conserved energy use. Where servers are powered by green hydro power, gain more benefits no matter where you are.

  Clients: Use existing machines longer, saving some of the costs of acquiring new computers. Acquire lighter clients for modest energy savings year over year.

  Licenses: Save annual fees on your server, system, desktop, productivity, and collaboration software.

  IT Support: Save administration and maintenance of no longer needed back-office systems, and most of it for local clients since they only need to connect to the Internet and run security software.

The total yearly cost savings per person is estimated to be $291 - $1,193 with a mean of $742, which in tonnes of CO2 saved is 0.18 - 0.74 with a mean of 0.46.

(Note: In addition, open source was found to help increase productivity through its ability to provide more integrated capability for the same cost, estimated at $83 - $1,167 per person a year with a mean of $667, which in tonnes of CO2 saved is 0.052 - 0.78 with a mean of 0.41. However, to keep all estimates conservative, this benefit is noted separately and not included in the main totals.)


1 - Local S

The Internet continues to get faster, more ubiquitous, and less expensive at the same time. The switching times at routers continue towards zero. In between, packets travel on copper, fiber, and radio waves at close to the speed of light or 299,792 kilometers a second. Since our world is 40,075 kilometers round at the equator, an Internet packet could some day circle all the way around the earth a little more than 7 times in a single second.

It has always been possible for centralized systems to do the work of local IT more efficiently, at less cost and with less green impact. However, with the Internet becoming so fast, distance really doesn't matter any longer once it is possible to connect users to increasingly powerful centralized computing systems from almost anywhere in the world, without noticeable delay. Centralized computing has long been competitive with the cost of local computing, but now it can be competitive with the user experience as well.

OSCC solutions like those provided by Cirrus Computing leverage this speed to provide the best possible online interface: a virtual desktop. A window that behaves like a local desktop, but securely accessible from almost any computer. This means that all of an organization's systems and information can be fully protected inside a cloud Intranet, without personnel having to give up the usability of a familiar, fully interactive desktop interface.

All of which means that a lot of vulnerable local equipment is no longer required.

1.1 Equipment

Note that all estimates in this paper are intended to be conservative judgements for a cost-conscious SME (1).

Estimate of no longer required local equipment:

  Depending on the performance level of the components, there could be savings in servers, storage, backup, and networking gear of $200 - $500 per person, or 0.12 - 0.31 tonnes CO2.

Estimate of no longer required upkeep of onsite equipment:

  Depending mainly on equipment support agreements and how often the equipment is upgraded and replaced, there could be savings of 10% - 20% of the acquisition cost, which is $20 - $100 per person, or 0.012 - 0.062 tonnes CO2.

What about long term differences in net energy use between the two models? OSCC solutions such as that provided by Cirrus Computing have five advantages that enable them to perform more efficiently, cost effectively, and green than onsite IT:

  Design: Production servers designed to operate with significantly less power than previous generations, a natural response by vendors to the fact that power is now often a hosting data-center's greatest cost.

  Green Power: Some Cirrus Computing servers are powered by green Quebec hydro power, transferring carbon benefits to users no matter where they are.

  Cloud Efficiency: Of course we use cloud systems to optimize use of our servers and minimize processing downtime, so much more efficient and cost-effective than putting in local equipment in every office.

  Architecture: We use a one-organization design that is particularly effective at reducing resource use.

  Fast Software: And of course our systems run fast and generally resource friendly open source software.

Therefore, cycle for cycle, the real and environmental costs of OSCC are lower than onsite IT. An estimate of processing savings:

  A typical office server can use 100 - 250 watts, which over a 40-hour / 50-week / 2,000-hour year is 200 - 500 kilowatt hours (kWh). Electricity costs are variable, so using $0.10 / kWh for comparison purposes, then for each onsite server or set of equivalent sized equipment that is longer needed, you can save $20 - $50 a year for energy use. If you need one such set of equipment for every five people, then the direct cost savings would be $4 - $10 per person per year.

Now, it is a reasonable to conclude that optimization of OSCC resources as described above result in a system that uses less energy per IT task in comparison to onsite IT. Once the inefficiency of having costly local computing actually doing nothing most of the time is factored in, we estimate that the overall energy requirements of an optimized OSCC solution could be 50% - 90% less than an onsite IT solution, which is net 100 - 450 kWh for an overall energy savings of $2 - $9 per person per year, or 0.001 - 0.006 tonnes of CO2.

1.2 Setup

Open source software has three significant advantages over closed source when it comes time to take your systems to the next level, and have it all work together:

  Standards: Open source usually uses accepted standards for interfaces, communications, data structures and the like, since by nature open source is about open communications with other software, not trying to trap customers into one vendor's proprietary software.

  Integration: If there are difficulties integrating open source into a full organization solution, you can do something about it. You can look at the code, design a workaround at one end or put a new one in the middle, and provide users with the full intended power of an integrated solutions. Your CRM knows your email address. Single-sign-on is enabled, so users are properly recognized the first time they open a collaboration application.

  Management: It's possible to make the system management of user desktops a one-click operation, since there are no closed code barriers to any level of automation you wish to build. For example, the super-user in your organization can create a new, fully configured, completely integrated, and working user desktop simply by typing in the new user's user name, clicking the Create button, and waiting 15 minutes for the system to make the desktop available.

With use of an OSCC solution, estimated savings in installation, configuration, and integration of onsite IT:

  There could be savings of 1 - 4 hours of work per person in the organization. Since smaller installations would have less to do and use less expensive assistance, the cost per hour for the work is estimated fairly widely at $20 - $75 per hour, which then amounts to a savings of $20 - $300 per person, or 0.012 - 0.19 tonnes of CO2.


2 - IT Support

Today, most organizations use one of two basic maintenance solutions: Larger organizations might have onsite IT personnel, sometimes augmented by offsite support; Smaller companies may pay for "managed services", companies that provide some remote administration and go onsite when required.

However, with a cloud computing solution, almost all of the usual maintenance requirements are managed - networks, servers, storage, backup, desktops, and applications. Virtual desktops are accessible from almost any computer that can connect to the Internet. Any management still needed by the organization is easier than ever before, with Cirrus Computing's solution enabling the superuser to add a fully configured desktop for a new user at the click of a button. It's possible to establish and manage an organization without any physical offices or IT costs at all besides local Internet access. Which means there are significant savings in the costs of IT support:

Estimate of savings if the support is onsite:

  Consultation with staff of small to medium-size organizations indicates that they could require 2% - 5% of their personnel or equivalent budget be IT related. Assuming average compensation of $75K / year for IT personnel, then across the organization this could amount to $1,500 - $3,750 per person per year. If the Cirrus Computing cloud managed solution can reduce this need by 75%, then it would be a savings of $1,125 - $2,813 per person per year, or 0.70 - 1.7 tonnes of CO2. However, this measure is not included in the totals, which uses the following managed services input instead.

Estimate of savings if the support is through managed services:

  Managed IT service levels depend on several factors, such as how much software is covered in the agreement, and range from $25 - $100 per desktop a month, or $300 - $1,200 per desktop per year. If the Cirrus Computing cloud managed solution can reduce this need by 75%, then it could be a saving of $225 - $900 per desktop per year, or 0.14 - 0.56 tonnes of CO2.


3 - Client Savings

With a cloud solution there is no need to consolidate on one computer platform across the organization, buy new machines, or update computers to stay current with the latest standard. Almost any computer will work.

John can have his Windows laptop, Nancy her Mac Book, Rick his Ubuntu netbook, and all use their organization desktop just fine.

There is also less need over time to buy new client computers because they are getting slow as they become overloaded with local software, which means computers can be kept longer. You can also specify that new computers must be more lightly configured and inexpensive.

Estimated savings in client setup:

  For a smaller organization there could be savings of $500 - $750 for each working client computer with operating system that someone can bring in, instead of having the organization buy a new one. If one-fifth of the team does so, the one-time setup savings would be $100 - $150 for every person on the team, or 0.062 - 0.093 tonnes of CO2.

Estimated savings for client upkeep:

  Most of the client upkeep costs are in replacement, usually at 3 - 5 years. Let's put aside any possible savings for acquisition of a lighter configuration. If we find that use of a computer accessing the client friendly Cirrus Computing solution can be extended from 4 to 6, then with the computer costs of $500 - $750, an extension of two years saves $42 - $63 per person per year, or 0.026 - 0.039 tonnes of CO2.

The main trend on clients is that, as powerful as they continue to get, people will also increasingly want to use complex software systems that need the great power of central processing, such as global search, business software, virtual words, and many others. This could mean that personal devices like smartphones will continue to go multi-purpose and smaller, while computers / netbooks / tablets will continue to go lighter with better screens. If we can reduce the energy use of both the cloud and the clients, then we can address carbon reduction from both sides.

Estimate of client energy savings:

  For some baseline data, a fully configured desktop computer can use 100 - 200 watts, which is 200 - 400 kilowatt hours (kWh) over a standard 40-hour week / 50-week / 2,000 hour year. Electricity costs are variable, however assuming $0.10 / kWh for comparison purposes, then a desktop's energy use would cost $20 - $40 for a year. However, given the number of factors affecting this metric, an estimate of potential savings is not given here. It's noted that scalable savings would likely be best achieved by organizations with more desktops, larger budgets, and formal processes to implement a good conservation program.


4 - Open Source

Using open source software helps reduce acquisition and support costs, makes it possible to provide more capability than before and thereby increase productivity, and supports a globally efficient asset that is continually generating compounding value.

4.1 Licenses

Use of the world's best open source software means never being limited by proprietary licensing costs or restrictions when designing and building the best possible IT solution. For example, when an application is deployed, since there are no user costs it is provided to all members of the organization at once. This also avoids the later administration of users having to request the software, then get it funded, purchased, and eventually provided.

Building with the best open source also means that small and medium-size organizations can for the first time gain the benefits of enterprise-level IT capability - automated scaling and backup, an integrated Intranet, and rich collaboration capability. At the same time, they also save all costs for licensing fees across the entire software stack - networks, servers, databases, desktops, and applications.

The application capability provides a particularly large saving. For example, all users have the professional LibreOffice suite, including word processing, spreadsheet, presentation, drawing, and database applications. All users have single-sign-on to applications like the CRM and document management applications, so that when allowed they can access customer data when required, and create project folders with project team only access.

We don't compare to our full open source solution with many applications available to all users, since it would cost too much as proprietary software, and instead assume a cost-conscious small to medium-size organization that allocates software sparingly (1). Desktop operating systems are included with the clients. Installation costs are included, but without any further software integration or configuration.

Estimate of savings on desktop applications:

  Depending on whether a user gets the basic or full office suite, graphics tools, project management, financial software, and other applications, there could be savings in licensing fees per person of $200 - $400, or 0.12 - 0.25 tonnes of CO2.

Estimate of savings on system and collaboration software:

  In the back-office there are savings for server operating systems, networking software, security systems, databases, and other system elements. There are also savings for collaboration software such as shared calendars, document management, customer relationship management (CRM), human resource (HR) management, secure Wiki, and other multi-user applications. Overall, there could be savings in licensing fees per person of $0 - $200, or 0.0 - 0.12 tonnes of CO2.

Estimate of savings on ongoing support licenses:

  Some organizations don't maintain their software after purchase unless it breaks, while others keep all their software under support licensing all the time. So there could be savings on annual maintenance licensing of 0% - 20% of total setup cost, which per person is $0 - $120, or 0.0 - 0.074 tonnes of CO2.

4.2 Productivity

The greatest benefits of open source are gained not by the programmers that read it, but by the people that use it. With no cost or licensing barriers, powerful software tools can be made available to more users more easily than ever before. Everyone can create, track, find, link, and share information to help them do their job.

Individual users gain the benefits of powerful software to help them do more, faster, easier, and more accurately. Organizations gain the benefits of team-wide information management, automated notifications, project management, and other collaboration tools.

These software capabilities add up to significant productivity gains. Use shared calendars to help book meeting rooms. Use secure instant messaging to help people solve problems quickly. Post project information pages on the secure Wiki to help coordination. Have one single team-wide customer database, with reports and analytics. Document management with automated workflow. An HR Management capability to quickly find skills and manage personnel attributes. And more.

Estimate of productivity benefits:

  • The amount of time saved and productivity increased with team-wide use of good collaboration software could be quite variable depending on the organization. However, as a reference point for comparative purposes, if a staff member is paid $50K a year by their organization, and their contribution generates $75K in value, then if use of the best in modern IT saves them only 1 - 10 minutes a day or 4 - 40 hours a year, it could mean an annual productivity increase per person of $83 - $1,250, without the usual 0.052 - 0.78 tonnes of CO2.

These kinds of productivity increases really add up. However, they are not included in the main totals at the current time, and are broken out separately for information.

4.3 Compounding Value

Use of open source supports another efficiency advantage: it's developed solely to respond to end users, with each software layer building on the previous to produce "compounding value" like a bank account. All the work performed on open source has no purpose other than to improve it. If the work is on a standard open source component, then it is likely to be around for a very long time to come.

Therefore, use of open source software avoids supporting wasteful expenditure of valuable human effort and related carbon, on proprietary software that can be easily dropped, merged, or replaced with something else as industry dynamics change. While in the meantime, the equivalent open source software just gets better and better.

A 2008 analysis reported that Linux, underlying so much of today's cloud, has an intrinsic engineering value greater than $10B. Therefore, it would be reasonable to estimate the value of the rest of the open source space - system software, databases, applications - at some multiple of this figure, say at least $20B. Much of this value can be provided to customers by providers like Cirrus Computing.

If only 3M people work at proprietary software development around the world (BLS), it would represent about $300B - $900B in business each year. If there are 1B users of open source, then on an equal share basis they are avoiding duplicative and wasted expenditures on closed source software in the amount of $300 - $900 per person per year. While this analysis provides grounds to build on, It is not yet expressed in the kind of green savings needed to included in the quantified analysis.


5 - Web Applications

Some organizations consider an all Web applications model, which, since they are delivered across the Internet, can claim at least some carbon benefits for cloud computing efficiencies. However, the Web applications model has three significant architectural differences from both OSCC and onsite IT that first raise the question of whether it is a comparable type of solution, as discussed below.

No Intranet


No Desktop


Limited Apps

Used onsite since the 1990's, a secure Intranet has proven t
o be a very useful foundation for the rest of an organization's IT solution.

For example, an organization Intranet makes it easier to setup a secure shared folder, to provide software to users, to enable transparent and secure authentication, to integrate software to provide enhanced value, and to protect systems from malware and hackers. All these advantages are lost with a Web application architecture, meaning a range of compromises then become necessary.

On the other hand, OSCC solutions like those from Cirrus Computing provide each organization with a real Intranet, better than most onsite installations, just hosted securely in the cloud, where it protects all your applications and data. With a virtual desktop as the access point, even desktop software and files are protected inside the secure cloud Intranet.


nlike both OSCC and onsite IT, Web applications don't provide users with one unified desktop on which to manage their applications and files.

As a half-measure, web applications work ok for some purposes. However, now that the Internet is fast enough for a packet to go around the world several times a second, there is no longer any need to compromise: anyone can have a full virtual desktop available anywhere, a familiar interface improved for decades to maximize human-computer usability.

Web applications provide the mobility and, individually, much of the green benefits of a cloud solution, but at a significant cost.


Once you lose your desktop, whether virtual or stationary, you lose something else that web browsers are not designed to provide: the capability of full featured desktop applications.

Users want blindingly fast apps, with big buttons and powerful features, that work with the rest of their software. Web applications are certainly getting faster, however still cannot match the usability, features, and interoperability of standard desktop applications. Which is why some GoogleDocs users keep copies of MS Office (or better LibreOffice) around to do more complex work.

Other issues long solved in the desktop world also present new and unnecessary challenges for Web applications, like enabling single-sign-on to collaboration applications, which for desktops can be enabled in a very standard and secure manner.

These differences make it reasonable to ask if Web applications are in the same category as onsite IT and OSCC, and if the differences negatively impact an organization's productivity and should be quantified and factored in. While these questions are legitimate, nevertheless it is true that a set of Web applications can now meet most of an organization's basic software needs, and they qualify for many of the green savings discussed in the preceding analysis. Therefore, let's consider the model for comparative differences with OSCC.

For estimation purposes, consider an SME that wishes the convenience and flexibility of a cloud solution, and wishes to build their own from a range of Web applications. They might assemble a suite of all online services by choosing email, calendars, and documents from Google, document management from online Microsoft SharePoint, CRM from, Finances and HR Management and Project Management from online providers, and perhaps a few other components.

From a cost perspective, each individual item of this kind of solution tends to start modestly. As more features and users are needed, total costs can increase quickly. For example, a single user account with some individual online applications can cost more than an entire Cirrus Computing solution. However, due to the wide variability of possible assumptions, cost comparisons are not discussed further here.

From a green perspective, it would appear reasonable that applications from multiple providers, with multiple servers in multiple data-centers, would have duplications of hardware and software infrastructure compared to an integrated OSCC solution from one provider. Similarly, it is reasonable then to conclude that an all Web applications solution has greater cost, energy consumption, and carbon impact than an OSCC solution.

Finally, consider the hybrid approach, using as many applications as possible from large providers to reduce duplications. For example, use everything Google offers, or everything Microsoft offers. However, since these providers lack the breadth and depth of the open source world, even they cannot offer a complete IT solution. Therefore, while consolidation on a few vendors could reduce overall impacts, there will likely always be several Web application providers, and therefore some duplication in infrastructure and related costs compared to integrated OSCC



  1. Estimates. The target customer for the estimates is a cost-conscious, small to medium-size organization of up to 50 people, based in Canada or the U.S.. The estimates for the local equipment and organization and system software should be doubled on a pro-rated basis for organizations of size 51 through 100. The estimates are the author's judgements based on experience, research of the current industry and markets, cost modelling, and consultation with others knowledgable in the industry. The estimates are intended to be conservative, that is, set with an expectation they would be considered to be more likely low than high by most knowledgable IT experts. When range estimates are given, the minimum and maximum are meant to capture 80% of the given case under these conditions. The calculation of an average of 0.62 tonnes of CO2 produced for each US$1,000 of economic activity is here. A configurable spreadsheet containing all estimates is available here - ODS, XLS. The analysis is intended to be an identification of key drivers with a first level estimate of the potential effects, and does not claim any specific degree of overall accuracy.

  2. Retained Benefits. After carbon savings have been achieved by an efficiency of some kind, it would be helpful to know the costs of the alternative activities that take place instead to determine the overall retained benefit. For example, how much of the green benefit of reduced consumption in onsite equipment is actually retained in carbon benefits? If less expensive client computers are acquired, how do we know the savings don't go into larger screens? Of course, these questions are subject to a wide range of factors, and particular to each the case. In general these complexities are not addressed in this paper, where each green advantage is assumed to contribute individually to the whole.

    In the case of efficiency and productivity gains, there is some research that provides some indications. One study showed that in certain circumstances an hour of work saved can translate to about an 80% saving in the associated greenhouse gas impact of that hour (report). This one study does not prove that carbon benefits are always retained, however it does provide an indication that gains in efficiency and productivity can make real savings in carbon impact at the end of the day. (Please send links to additional research in this area to the author.)

  3. Other Savings. While not discussed in the analysis, the primary advantage of the use of open source remains avoidance of lock-in to closed software and the associated uncertainty about long-term availability, features, and cost. Users always retain the ability to build custom features for their open source applications. They avoid forced replacements and upgrades. And they avoid the considerable difficulties of integrating closed software into a useful organizational whole. Each of these advantages deserves further consideration, and the cost savings estimated, however are only noted here at this time, and not discussed further in this analysis.

  4. Bandwidth. The network bandwidth requirements of the NoMachine provider of our virtual desktops is low, about 100 kbps or 0.1 mbps downstream, 15 kbps upstream, for a desktop in typical use. This is in large part because NoMachine uses the efficient open source NX protocols. As one indicator for comparison, if a desktop was actively used for every second of a 160 hour month, it would use about 7 GB downstream bandwidth. Given that most desktops are used only a fraction of the time even when people are sitting in front of them, then we can conclude that the real and environmental costs of these bandwidth friendly connections are relatively low compared to other demands on the Internet. As one number for reference, bandwidth to collocated clients in N.A. data-centers in 2011 was available for less than $0.10 per GB (or $0.70 for 7GB), and these costs will continue to decrease.

  5. Carbon. This analysis uses the term "carbon" as a short-hand term meant to include other greenhouse gases as well.

  6. Standards. Two leading carbon measurement standards are the international standards document ISO 14064 and the even more recent Carbon Trust Standard.

Comments welcome, please send to the author at