According to Martin Feldner, the waste heat from the gigantic new data center on the campus of the Max Planck Institute in Martinsried should not be wasted. The Gräfelfingen Green Party Councilor and Third Mayor is a mechanical engineer by profession and has thought about how the surplus energy could be used. His suggestion is to include the data center in the considerations for a ground pool heat storage in an open gravel pit between Planegg and Gräfelfing.
The new construction of the data center is at the center of the conversion of the Max Planck Institutes, which is scheduled to take more than ten years, and is scheduled to begin as early as next year. In mid-2027, the new center will then deliver around seven megawatts of power in a first expansion stage. When the plans were presented two years ago, the architect and MPI department head Christoph Nagel-Hirschauer spoke of a “own power supply campus”. Negotiations with Stadtwerke München are already underway.
Martin Feldner from Gräfelfing draws comparisons to emphasize the great importance of the new data center: After completion, the center will generate around 20 megawatts of electrical power consumption: “That corresponds to the average output of 17 large wind turbines around 170,000 megawatts per hour as waste heat. That corresponds to the amount of heat from an average deep geothermal well.”
The cooling water, which has a temperature of 50 to 60 degrees, could be further heated with excess electricity
Feldner cannot yet offer a final solution for using this waste heat: “First considerations still have to be deepened,” he says. In any case, it is clear that the cooling water from the data center, which is only 50 to 60 degrees, “cannot be fed directly into the existing district heating network for Martinsried or the planned district heating network for Gräfelfing, since their flow temperatures are significantly higher.”
Feldner suggests storing the warm water temporarily, so to speak, in the planned earth tank heat storage tank: “Whenever there is excess electricity from renewable sources, the water can be brought to a higher temperature level with large heat pumps.” It can then be fed into the district heating network or stored for the winter together with the geothermal summer harvest in a second part of the Graefelfingen earth basin heat storage system.