Data centres: an underrated climate risk

Researchers at the Oeko-Institut and their project partners have developed a methodology for the holistic assessment of the resource efficiency and carbon footprint of data centres. The innovative feature of this methodology is that for the first time, the calculations are based on real figures from data centres during operation. This is important, as these energy-intensive data processing centres are still under no obligation to report on their energy performance.

Using figures collected during monitoring in data centres, the methodology was applied in practice and the following carbon footprints were extrapolated as examples: one hour of video streaming produces 1.45 g of CO₂ eq. in the data centre; online storage releases 100-150 kg CO₂ per year for one terabyte of storage; and a cloud workspace produces 59 kg of greenhouse gas emissions per year.

Standardised energy accounting in the EU

The Green Cloud Computing project was commissioned by the German Environment Agency (UBA) and the findings were presented by German Environment Minister Svenja Schulze on 10 September. Climate protection and digitalisation are two of the priorities identified in the programme for Germany’s Presidency of the Council of the European Union, with standardised energy accounting by European data centres one of the topics to be addressed in this context.

Mandatory energy accounting must be introduced

As a result of digitalisation, the number of data centres and their capacities are surging, with estimated growth amounting to 20-30 per cent annually. “That’s why we need to act now, so that we have an overview of the climate impacts of digital services, but also to avoid supply bottlenecks,” says Senior Researcher Jens Gröger, who conducted the study for the Oeko-Institut. “Digital services are still under the radar at present, whereas other energy-intensive industries are now required to participate in carbon trading, for instance.”

Carbon footprint per unit of service

It is essential that data centres and cloud services be subject to mandatory reporting under an energy certification scheme, so the carbon footprint per unit of service can be calculated on the basis of the reported data. “Energy efficiency labelling is now obligatory for every single light bulb that goes on sale. But how much energy does it take to decode a voice command to the Alexa virtual personal assistant or keep a mailbox operating in the cloud?” Jens Gröger asks. With the Green Cloud Computing calculation method, which is based on defined accounting rules, it should be possible to provide answers to these questions in future for each type of digital service.

Green Cloud Computing: Policy Paper by the Oeko-Institut in conjunction with the German Environment Agency and the Fraunhofer Institute for Reliability and Microintegration (IZM)

Kennzahlen und Indikatoren für die Beurteilung der Ressourceneffizienz von Rechenzentren und Prüfung der praktischen Anwendbarkeit [Metrics and indicators for assessing the resource efficiency of data centres and testing their practical application]: Study by the Oeko-Institut