Green IT and sustainable networks
In short: IT uses energy to run and cool equipment and creates carbon and waste when hardware is made and thrown away. Engineers can help by right-sizing, using power-saving features, consolidating, extending hardware life and recycling securely. Measures such as PUE and greenhouse gas scopes help track progress.
Why sustainability is an IT topic
Data centres, networks and devices use a lot of electricity, and making hardware uses energy, water and minerals. Many organisations now report their environmental impact, and customers and regulators ask IT teams to show their part. Green IT is about reducing that impact while keeping services reliable and secure. Good news: many green practices also save money.
Key measures
| Measure | What it means | How to use it |
|---|---|---|
| Power usage effectiveness (PUE) | Total facility energy divided by IT equipment energy; standardised in ISO/IEC 30134-2 | Closer to 1.0 means less overhead for cooling and power losses |
| Greenhouse gas scopes | Under the GHG Protocol: Scope 1 direct, Scope 2 purchased energy, Scope 3 supply chain and other indirect | Cloud services and hardware manufacture usually fall in Scope 3 |
| Embodied carbon | Emissions from making and transporting a product | Often a large share for laptops and phones, which favours longer use |
| Energy per unit of work | For example watts per port or per gigabit | Compare equipment generations fairly |
Management systems help too: ISO 14001 covers environmental management and ISO 50001 covers energy management.
Practical actions for network and IT engineers
- Right-size and consolidate. Remove unused servers and virtual machines, merge lightly loaded hosts (see virtualisation) and switch off zombie equipment.
- Use power-saving features. Energy Efficient Ethernet (IEEE 802.3az) lowers power on idle links. Schedule PoE to turn off phones or APs in empty buildings at night where policy allows.
- Choose efficient hardware. Compare power figures and power supply efficiency, not only performance.
- Improve cooling. Use hot and cold aisle containment, blanking panels and sensible temperature set points in line with equipment specifications.
- Use the cloud well. Turn off idle resources, use auto-scaling and choose regions with cleaner energy where latency and data rules allow. This overlaps with FinOps.
- Reduce data. Keep logs and backups as long as needed, not forever. Less storage means less energy.
Lifecycle and security go together
Extending hardware life is one of the most effective green actions, but old equipment must still get security updates. Check vendor end-of-support dates before deciding to keep a device. When hardware leaves the organisation, data must be removed securely. Follow a recognised method such as NIST SP 800-88 for media sanitisation, record what was wiped and use certified recyclers that handle electronic waste properly under local law. Physical destruction is sometimes needed, but wiping and reuse is often greener when it is safe.
Tip: in projects and dissertations, show sustainability with numbers you measured, such as power draw before and after consolidation, rather than general claims.
A common mistake is "greenwashing": claiming benefits without evidence, or shifting emissions to a supplier and calling them gone. Be specific and honest about what has changed.
Practice
A data centre uses 1.5 MWh in total while its IT equipment uses 1.0 MWh. What is its PUE?
Under which greenhouse gas scope do emissions from manufacturing purchased laptops usually fall?
Why must security be considered when extending hardware life?
Key takeaways
- IT affects the environment through energy use, cooling, manufacture and waste.
- PUE, greenhouse gas scopes and embodied carbon are key measures.
- Consolidate, use power-saving features and remove idle resources.
- Extending hardware life helps, as long as security updates continue.
- Sanitise data properly (for example NIST SP 800-88) and recycle responsibly.
Original content written by Mohamed Fayas for FM TecHub. © 2026 FM TecHub. You're welcome to share a link to this page; please don't copy the text elsewhere without permission.