Amazon released their 2022 sustainability report which includes an updated list of renewable AWS regions. For 2021 there were 13 AWS regions that were “over 95% renewable”. For 2022, there are 19 regions that are “100% renewable”, notably adding four regions in China and India, and their new regions in Spain and Zurich. This is mostly due to a large increase in dedicated power purchase agreements to over 20GW, and some use of biofuels for backup generators.
Amazon always releases its annual sustainability report in the middle of the following year. They don’t break out AWS separately from the total, but the energy use for Amazon went from 85% renewable to 90% renewable, and the carbon footprint of their electricity use went down 29% year on year. Over-all, despite growing the business by 9% the total carbon footprint of Amazon dropped slightly for the first time.
The methodology used by Amazon is the same as is used by Microsoft Azure, it’s known as the Market Method, and it is based on the energy you pay for, rather than the energy you use. It includes the energy generated by dedicated power purchase agreements, and renewable energy credits bought on the open market. Google use the Location Method, which doesn’t include the energy from their power purchases, and reports more carbon emissions than the Market Method. Ideally everyone would share both.
Amazon does have much more generation capacity than Google and Microsoft, and has many more projects in Asia, which is the area that is taking longest to decarbonize. I think that there isn’t a lot of difference between AWS, Azure and GCP in Europe and America for their renewable energy footprint, but that AWS is significantly ahead in Asia. The scope 3 (manufacturing supply chain etc) carbon footprint of cloud doesn’t vary as much by location, as the machines are the same.
AWS still doesn’t report scope 3 to customers, although they’ve said they are working on it. However they do talk in the report about using low carbon concrete and steel in many of their most recent datacenter construction projects. The Power Usage Efficiency of datacenters (how much energy is used for cooling etc.) is reported regionally by Azure, Google reports somewhat better figures by datacenter campus, and AWS doesn’t report PUE, but is likely to be similar.
The move to renewable electricity does mean that the dominant carbon footprint for cloud usage is scope 3. Users of the AWS Customer Carbon Footprint tool are mostly going to see zero carbon reports until AWS starts to report scope 3.
For a more detailed comparison of the cloud providers based on 2021 numbers see my QCon London talk from last March.
[note that the first posted version of this story incorrectly said 18 regions, and the URL didn’t change when I fixed it].