Sustainability in IT


Sven Vermeulen Sun 25 September 2022

For one of the projects I'm currently involved in, we want to have a better view on sustainability within IT and see what we (IT) can contribute in light of the sustainability strategy of the company. For IT infrastructure, one would think that selecting more power-efficient infrastructure is the way to go, as well as selecting products whose manufacturing process takes special attention to sustainability.

There are other areas to consider as well, though. Reusability of IT infrastructure and optimal resource consumption are at least two other attention points that deserve plenty of attention. But let's start at the manufacturing process...

Certifications for products and companies

Eco certifications are a good start in the selection process. By selecting products with the right certification, companies can initiate their sustainable IT strategy with a good start. Such certifications look at the product and manufacturing, and see if they use proper materials, create products that can have extended lifetimes in the circular (reuse) economy, ensure the manufacturing processes use renewable energy and do not have harmful emissions, safeguard clean water, etc.

In the preliminary phase I am right now, I do not know yet which certifications make most sense to pursue and request. Sustainability is becoming big business, so plenty of certifications exist as well. From a cursory search, I'd reckon that the following certifications are worth more time:

  • EcoVadis provides business sustainability ratings that not only cover the ecological aspect, but also social and ethical performance.
  • ISO 14001 covers environmental management, looking at organizations' processes and systematic improvements contributing to sustainability.
  • Carbon Neutral focus on transparency in measurements and disclosure of emissions, and how the company is progressing in their strategy to reduce the impact on the environment.
  • TCO Certified attempts to address all stages of a manufacturing process, from material selection over social responsibility and hazardous substances up to electronic waste and circular economy.
  • Energy Star focuses on energy efficiency, and tries to use standardized methods for scoring appliances (including computers and servers).

Power efficiency

A second obvious part is on power efficiency. Especially in data center environments, which is the area that I'm interested in, power efficiency also influences the data center's capability of providing sufficient cooling to the servers and appliances. Roughly speaking, a 500 Watt server generates twice as much heat as a 250 Watt server. Now, that's oversimplifying, but for calculating heat dissipation in a data center, the maximum power of infrastructure is generally used for the calculations.

Now, we could start looking for servers with lower power consumption. But a 250 Watt server is most likely going to be less powerful (computing-wise) than a 500 Watt server. Hence, power efficiency should be considered in line with the purpose of the server, and thus also the workloads that it would have to process.

We can use benchmarks, like SPEC's CPU 2017 or SPEC's Cloud IaaS 2018 benchmarks, to compare the performance of systems. Knowing the server's performance for given workloads and the power consumption, allows architects to optimize the infrastructure.

Heat management (and more) in the data center

A large consumer of power in a data center environment are the environmental controls, with the cooling systems taking a big chunk out of the total power consumption. Optimizing the heat management in the data center has a significant impact on the power consumption. Such optimizations are not solely about reducing the electricity bill, but also about reusing the latent heat for other purposes. For instance, data center heat can be used to heat up nearby buildings.

A working group of the European Commission, the European Energy Efficiency Platform (E3P), publishes an annual set of best practices in the EU Code of Conduct on Data Center Energy Efficiency which covers areas such as airflow design patterns, operating temperature and humidity ranges, power management features in servers and appliances, infrastructure design aspects (like virtualization and appropriate, but no over-engineered redundancy), etc.

This practice goes much beyond the heat management alone (and is worth a complete read), covering the complete data center offering. Combining these practices with other areas of data center design (such as redundancy levels, covered by data center tiering) allows for companies that are looking at new data centers to overhaul their infrastructure and be much better prepared for sustainable IT.

Circular ecosystem

Another part that often comes up in sustainability measures is how reusable the infrastructure components are after their "first life". Infrastructure systems, which frequently renew after 4 to 5 years of activity, can be resold rather than destroyed. The same can be said for individual components.

Companies that deal with sensitive data regularly employ "Do Not Return" clauses in the purchases of storage devices. Disks are not returned if they are faulty, or just swapped for higher density disks. Instead, they are routinely destroyed to make sure no data leakage occurs.

Instead of destroying otherwise perfect disks (or disks that still have reusable components) companies could either opt for degaussing (which still renders the disk unusable, but has better recyclability than destroyed disks) or data wiping (generally through certified methods that guarantee the data cannot be retrieved).

Extended lifecycle

Systems are often working perfectly beyond their 4 to 5 year lifespans. Still, these systems are process-wise automatically renewed to get more efficient and powerful systems in place. But that might not always be necessary - beyond even the circular ecosystem remarks above (where such systems could be resold), these systems can even get extended lifecycle within the company.

If there is no need for a more powerful system, and the efficiency of the system is still high (or the efficiency can be improved through minor updates), companies can seek out ways to prolong the use of the systems. In previous projects, I advised that big data nodes can perfectly remain inside the cluster after their regular lifetime, as the platform software (Hadoop) can easily cope with failures if those would occur.

Systems can also be used to host non-production environments or support lab environments. Or they can be refurbished to ensure maximal efficiency while still being used in production. Microsoft for instance has a program called Microsoft Circular Centers which aims at a zero-waste sustainability within the data center, through reuse, repurpose and recycling.

Right-sizing the infrastructure

Right-sizing is to select and design infrastructure to deal with the workload, but not more. Having a set of systems at full capacity is better than having twice as many systems at half capacity, as this leads to power inefficiencies.

To accomplish right-sizing isn't as easy as selecting the right server for a particular workload. Workload is distributed, and systems are virtualized. Virtualization allows for much better right-sizing as you can distribute workload more optimally.

Companies with large amounts of systems can more efficiently distribute workload across their systems, making it easier to have a good consumption pattern. Smaller companies will notice that they need to design for the burst and maximum usage, whereas the average usage is far, far below that threshold.

Using cloud resources can help to deal with bursts and higher demand, while still having resources on-premise to deal with the regular workload. Such hybrid designs, however, can be complex, so make sure to address this with the right profiles (yes, I'm making a stand for architects here ;-)

Standardizing your infrastructure also makes this easier to accomplish. If the vast majority of servers are of the same architecture, and you standardize on as few operating systems, programming languages and what not, you can more easily distribute workload than when these systems have different architectures and purposes.

Automated workload and power management

Large environments will regularly have servers and infrastructure that is not continuously used at near full capacity. Workloads are frequently following a certain curve, such as higher demand during the day and lower at night. Larger platforms use this curve to schedule appropriate workload (like running heavy batch workload at night while keeping the systems available for operational workload during the day) so that the resources are more optimally used.

By addressing workload management and aligning power management, companies can improve their power usage by reducing active systems when there are less resource needs. This can be done gradually, such as putting CPUs in lower power modes (CPU power takes roughly 30% of a system's total power usage), but can expand to complete hosts being put in idle state.

We can even make designs where servers are shut down when unused. While this is frequently frowned upon, citing possible impact on hardware failures as well as reduced reactivity to sudden workload demand, proper shutdown techniques do offer significant power savings (as per a research article titled Quantifying the Impact of Shutdown Techniques for Energy-Efficient Data Centers).


Sustainability within IT focuses on several improvements and requirements. Certification helps in finding and addressing these, but this is not critical in any company's strategy. Companies can address sustainability easily without certification, but with proper attention and design.

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