Vegetables from Gigabits – Bavaria

When the Bavarian State Minister for Digital Fabian Mehring (Free Voters) talks about the plans for a new data center on the Passau University campus, the anglicisms and superlatives abound. The “Bavarian Green Data Center” is a “best practice”, a “real game changer” and a “lighthouse”. The project is currently in the planning phase and the groundbreaking ceremony is scheduled for next year. By 2026, the ideally climate-positive data center should produce “cucumbers from gigabits”.

What exactly is planned? The green data center should basically consist of two parts: a server area (“data cube”), which is pre-produced in a container design and should be expandable, and an attached greenhouse (“gardening area”), which is heated with the waste heat from the servers.

Those tasked with implementing it don’t find it an easy project: “It’s very complex to plan a climate-neutral data center and a gardening area,” says Harald Kosch. He is Vice President for Academic Infrastructure and IT at the University of Passau. “It has many components: the design component, i.e. how the data cube is designed, and the construction component,” said Kosch. It should not be underestimated that the whole thing should be embedded into the existing infrastructure of the campus; among other things, new cold and hot water distribution systems would have to be integrated.

In addition to Europe, digitalization and sustainability are two of the three focal points of the University of Passau, so the order from the Ministry of Digital was a good fit. Mehring puts it more euphorically: Those responsible at the University of Passau have “an enormous can-do mentality” and the local research priorities fit the project “perfectly”.

The state government is supporting the data center with three million euros for construction and procurement, and funds have also been made available for 1.5 positions for project management and scientific support. Not an insignificant amount, after all the minister’s goals are high. The project should not be a “cloud cuckoo land” but should have “impact” and find imitators.

“It is very, very important for us to use the waste heat from the data center,” says Kosch. The aim is to research the extent to which it is possible to use the heat generated by the servers all year round and adapted to the outside temperatures. This means that the waste heat from the data center should only be introduced into the greenhouse if it is not already heated by the sun.

“The greenhouse is monitored by sensors and controlled automatically to guarantee a suitable climate for the plants,” says Kosch. In summer, the greenhouse should be shaded so that the local cucumbers, tomatoes, salads and culinary herbs do not die.

The waste heat could also heat the shower water in the sports center.

“For transitional temperatures, the plan is to make the waste heat from the university crèche available,” says Kosch. And in summer, the waste heat from the data center is supposed to heat the shower water in the sports center. “There are also ideas to feed the waste heat in the form of hot water into the university’s local heating pipe. This is currently being investigated, but it is very complex,” says Kosch.

The Data Cube will be partially powered by electricity from the university’s photovoltaic systems, for example on the roof of the cube. AI is used to make predictions about the expected server utilization of the data center and the available PV power. The load on the data center and the availability of solar energy should be synchronized as much as possible. Surplus photovoltaic electricity should also be used to operate chillers as heat pumps and use them in the buildings.

And if the sun hides? “If no electricity from the PV systems is available, the Bavarian Green Data Center will obtain electricity from the public grid,” says Kosch. Because electricity from photovoltaic systems is volatile: “A data center cannot be operated with it for economic and response time reasons alone,” he says. So far, the university still receives almost 100 percent green electricity from the public grid. The amount of electricity generated from photovoltaic systems is still “disappearingly” small, but PV systems worth 4.5 million euros are scheduled to go into operation on the campus at the beginning of 2026.

Last but not least, the green data center should also be an acceptance test for the energy transition. By being able to measure consumption and costs, the university also wants to promote being more conscious about energy consumption. For example, when researchers adapt their computationally intensive experiments to the availability of renewable energy. “Users are not yet used to worrying about whether there is enough power available or not,” says Kosch.

First of all, the performance of the Bavarian Green Data Center will not even be sufficient for the entire university operation. The existing data center at the University of Passau, which ensures the operation of the university’s computer infrastructure and administrative operations, will continue to operate and continue to cover the majority of administrative operations. In the future, the new data center will primarily provide performance for increasing AI research, in which processes sometimes run over several days to train models.

A lighthouse alone is not enough for critics.

In any case, the Green Party member of the state parliament Benjamin Adjei is skeptical as to whether the planned data center can change anything across Bavaria. In principle, he sees the development of a climate-neutral data center as positive, he said. “So far, none of the 34 state data centers have been certified as sustainable, only three use the waste heat to any significant extent,” he said. This emerges from the answer to a written question, which he made the topic of in 2022t. A lighthouse project alone has little influence on the Free State’s climate balance, said Adjei.

“So far I don’t have a concept of how findings from the project will ultimately lead to comprehensive measures,” he said. Instead of starting a state flagship project, Adjei calls for existing public data centers to be modernized so that they run with ecologically sustainable standards.

Standards for what sustainable data centers can look like have been around for ten years. The Blue Angel environmental label is awarded to data centers that are operated in a particularly energy-efficient and resource-saving manner.

The University of Passau would also like to receive a Blue Angel for the new data center. According to RAL Umwelt GmbH, which certifies the Blue Angel for the Federal Environment Agency, there is currently only one data center nationwide that meets the criteria. It’s not in Bavaria, but in Cottbus in Brandenburg and is privately operated. But there are no tomatoes or cucumbers there.

The text is based on the research of SZ Dossier, the new political information service of the Süddeutsche Zeitung: sz-dossier.de