Nov 2, 2024 4 min read Sustainable IT

How to avoid getting fooled by net-zero promises when choosing a data centre location.

November 2024, Issue #12

A few weeks ago, I attended the Socrates Belgium unconference, where I gave a lightning talk about digital sustainability. The key point was to make sustainability a non-functional requirement for all applications we write, if not THE requirement.

Over the following days, we had two follow-up sessions, during which we discussed questions like:

What is Green IT?
How do you know how green an application is?
When is it OK to consume energy in my app?
How green is the electricity for data centres?
...

I will dive deeper into these (and more) questions in this and the coming posts. So, let's start with the last question from the list 😄

Datacentre Emissions

Digital is estimated to account for more than 4% of greenhouse gas emissions (based on 2019 numbers from the Shift project—reference below). Because digital consumption is only going up (AI, BlockChain, etc.), it seems safe to assume we are also on an upward carbon emission trend (not to mention other impacts, e.g. on water, etc.).

Data centres account for roughly 1/3 of these emissions (the other parts are for devices and data traffic). It is estimated that more than 50% (and growing) of the data centre activity is with the big public cloud providers.

Good news: Going Net-Zero!

The good news is that data centres (contrary to, e.g. the majority of vehicles) are already running on electricity, and hence, easier to green.

Moreover, all cloud providers and data centre operators aim to move to net zero.

Net zero refers to a state in which the greenhouse gases going into the atmosphere are balanced by removal from the atmosphere.

Or not?

When data centre operators aim for net zero emissions, they mean market-based carbon emissions. This definition allows them to buy compensation elsewhere. But the emissions still happen, of course... (moreover, the compensations bought do not always truly capture carbon, a big challenge but out of the scope of this post)

A more honest metric is the location-based carbon footprint. It is the carbon that is emitted at the location of the consumption:

Location-based Carbon Footprint = Electricity Consumed x Carbon Intensity of the Electricity Grid at the Consumption Location.

So, if you operate a data centre in a country with 100% green electricity, your consumption may be near zero. On the contrary, a country with many coal-fired power stations in the local grid mix will still yield a significant carbon footprint.

The diagrams below clearly mark the difference:

What can wé do?

If you are running an application with a data centre component, choosing the region where you host significantly impacts your application's location-based carbon footprint. When you are running in the public cloud, it is also a relatively simple change.

For Western Europe, hosting in France or the Nordics is less carbon intensive than hosting in Ireland or Germany, as shown by the Electricity Maps app.

So, the action(s) you can take are pretty straightforward:

Get a bit familiar with the concepts underneath digital sustainability
Ask your data centre operator for the location-based emissions (so that they can no longer get away with a fluffy net-zero policy or ambitions based on market-based emissions)
If you are on a public cloud, move your workloads to green regions
... and spread the word 😄

Sustainability as a (Crucial) Non-functional Requirement

As this article already illustrated, understanding a bit more about how carbon emissions work and using that knowledge to choose the data centre location will help you make better choices in terms of digital sustainability.

So let me repeat my plea: digital sustainability should be(come) a critical non-functional requirement for any IT project.