This is our third post in a series of four articles which dissect how to measure greenhouse gas emissions from operating data centres. Today’s post explores how to actually go about evaluating your organisation’s emissions, including those from on-prem and hybrid infrastructure.
Check out other posts in this series to learn about the primary sources of greenhouse gas emissions in data centres, the role of AWS, Azure, and GCP, and how you can lower your cloud computing footprint. Sign up for our free newsletter to get notified as soon as a new article is released.
To accurately assess greenhouse gas emissions for your organisation, you have to look beyond your immediate environment. Every activity along your entire supply chain needs to be taken into account, and every business activity—including servers that may be hosting your applications and data, whether on-premises or in the cloud in an entirely different country—should be evaluated. This can be a daunting and complex exercise, but at Climatiq, we’re here to support. We’ve got a whole series of articles and resources dedicated to helping you understand how to go about estimating emissions from various business activities. But for now, let’s focus on assessing emissions from computing activities including cloud, on-premise, and hybrid setups.
If you’re hosting your computing activities in the cloud, there’s a high likelihood you’re using one of ‘the big 3’ cloud providers—namely, AWS, Azure, or GCP. Climatiq provides emission factors for each of them, and we’ve written a handy how-to guide for calculating carbon emissions of cloud services. We’ve also built a specific Cloud Computing API endpoint. But let’s sum up the basics here before you get into the nitty-gritty.
To measure your cloud computing footprint you first need to:
The steps that follow are slightly trickier, depending on what you’re looking to measure.
To measure VM (virtual machine) usage, you’ll need to understand CPU count, and the amount of vCPUs the machine has. This information is best pulled from the APIs of your cloud provider. If you’re not sure what the data centre utilisation rate is, 50% is a good fallback. You’ll also have to request info about allocations of disk and memory, and use the CPU, memory, and storage endpoints in tandem to get a full picture. Alternatively, you can define the model of virtual machine in use and then consult a table to find out how many vCPUs, memory, etc. this particular machine has. If the vendor doesn’t provide this data, this is a good reference guide.
If you’re measuring emissions from cloud storage services, you’ll need to take a slightly different approach. There are 3 key things you need to know:
As we mentioned, Climatiq provides emission factors for AWS, Azure, and GCP, but does not currently provide data on other cloud providers. To estimate general cloud carbon emissions from other providers, Cloud Carbon Footprint has a good methodology you can use. For operational emissions, you’ll need to calculate the following:
Your operational emissions will then need to be added to your embodied emissions. Embodied emissions are the estimated metric tons of CO2e generated by the manufacturing of data centre servers for computing usage. These calculations are not included in Climatiq data right now but here is a rundown of how to go about calculating each factor:
— 2.10 Wh per vCPUh [Server]
— 0.89 Wh/TBh for HDD storage [Storage]
— 1.52 Wh/TBh for SSD storage [Storage]
You can find a table of embodied emissions for popular server models here, and also here, with a full list available here on Github. This should allow you to model the carbon intensity of a given cloud data centre, although you may be restricted by how transparent—or opaque!—your provider is.
For on-prem or hybrid set-ups, the general methodology is similar, and CCF has, again, provided a detailed methodology here. The key to assessing your emissions is in understanding:
It’s important to note that these calculations exclude carbon emissions caused by water usage, especially wastewater treatment, which will differ depending on the geographic location. More comprehensive research and data are needed to properly factor this in when estimating the full carbon intensity of computing activities. At time of writing, we are not aware of any good methodologies that fully account for water usage.
We hope this gives you a solid overview of how to accurately calculate emissions from your computing activities, whether that’s fully in the cloud, or use an on-prem or hybrid set-up. We have tons of resources available to help you figure out the sometimes confusing world of greenhouse gas emissions so keep an eye on our blog for upcoming posts. Check back soon for practical tips on how to lower your computing footprint.