How Does This Benefit the Environment?

5 GB of unused data deleted = 10 kWh of electricity saved per year?

Unfortunately, it is not that easy to quantify how much our digital clean-up efforts will reduce the university's electricity consumption.

However, we can get a rough idea of the amount of CO₂ emissions caused by the power consumption of our servers. Let’s get technical: according to a study by the German Environment Agency, the operation of data centres generates 105 to 153 kilograms of CO₂-equivalent (CO2e) emissions per terabyte of storage capacity per year.¹

For comparison: In 2023, the global storage capacity of data centres was around 10 zettabytes, which in turn is ten billion terabytes.² The emissions from all the world's data centres would be roughly equivalent to the annual CO₂ emissions of 750 million to 1.1 billion mid-range cars, each driving 15,000 kilometres per year. Hard to imagine.³

Of course, the University of Cologne’s existing storage capacity is not on this scale, but the capacity of the data centres on our campus is also large: 2.6 petabytes (PB) or a good 2,600 terabytes is the capacity of the university’s own Network Attached Storage (NAS). This is the storage system that can be accessed via the university network, and that we often use to store files centrally and share them with colleagues.

The university’s High-Performance Computing (HPC) area also has the same storage capacity (2.6 PB). This includes computers or systems that are extremely powerful and can handle large amounts of data and complex calculations at the university – often used in science and research, for example for simulations or AI applications.

By far the largest storage capacity, however, is provided by the university’s backup and archive systems, which can hold 19.5 petabytes of data.

All of these storage options require constant power, regardless of whether we ever access the stored data again. If we use existing server capacity sparingly, we won't have to put new ones into operation as quickly. And that helps save energy. 

So digital clean-up is a smart investment in the future. A tidy digital infrastructure also has other benefits and makes your day-to-day work easier.

By the way: Did you know that the waste heat from the new RAMSES supercomputer is fed back into the server room to reduce energy consumption? The system also saves additional energy thanks to the new, direct cooling mechanism.

¹ Umweltbundesamt (2020). Hintergrundinformationen Klimawirkung von Videostreaming & Co.
² Bitkom (2024). Rechenzentren in Deutschland: Aktuelle Marktentwicklungen – Stand 2024
³ Statista (2022). Straßenverkehr - So viel CO₂ stoßen Autos aus