Contributing to the energy transition by making cooling supply systems more flexible

Press release /

By making cooling supply systems more flexible, CO2 emissions can be reduced by 22 to 39 percent and electricity procurement costs by 35 to 54 percent. Fraunhofer UMSICHT came to this conclusion in the "FlexKaelte" project. At the same time, the researchers found that there are still a number of obstacles and hurdles on the way to flexibilization – from concerns about possible losses in cooling quality and a lack of information regarding the achievable economic potential to the question of how cooperation between the various players can be structured. How these obstacles can be overcome is the focus of the follow-up project "FlexBlue", for which the institute has joined forces with a number of partners.

Kick-off für das Projekt FlexBlue
© Fraunhofer UMSICHT
Kick-off for the FlexBlue project (from left): Tino Leyrer, Klaus Rauch, Annedore Mittreiter, Heiko Maaß, Martin Stöckl, Dana Laband, Keven König, Francesco Ianni, Sebastian Berg and David Wölfle.

The Institute for New Energy Systems at Ingolstadt University of Applied Sciences, the Institute for Automation and Applied Computer Science at the Karlsruhe Institute of Technology (KIT) and the FZI Research Center for Information Technology are involved as scientific consortium partners. They have also gained relevant experience in previous projects ("BlueMilk" and "FlexKälte") on making the cooling sector more flexible and have come to similar conclusions. In addition, RÜTGERS GmbH & Co. KG as a system manufacturer, kraftBoxx GmbH as a specialist in PCM storage and SK Verbundenergie AG as the operator of a virtual storage power plant are working together as consortium partners to contribute their expertise. In addition, seven other organizations from the field are supporting the project as associated partners. "Together, we want to bring together all relevant players in the flexibility value chain in the refrigeration sector in order to develop high-performance and application-oriented solutions," says Dr. Annedore Mittreiter from Fraunhofer UMSICHT. "These solutions should be both technically and economically convincing and serve as a model for the widespread implementation of flexibilized cooling supply systems in the future."

Demonstrators to prove the functionality and usefulness of flexibilization

Specifically, two demonstrators are being set up in real application areas. One is being built at KIT, the other at RÜTGERS GmbH & Co. KG. "For flexible operation, we deliberately rely on additional buffer storage, as the use of capacities that are already available in the environment to be cooled cannot usually be designed efficiently," explains Dr. Heiko Maaß from the Institute of Automation and Applied Computer Science at KIT. "In one demonstrator, we combine photovoltaics, battery storage, a compression chiller and an actively controllable PCM cold storage system, and in the other demonstrator, an active PCM multi-layer heat storage system with a booster heat pump in combination with a combined heat and power plant, an adsorption chiller and a cold storage system."

Making the interfaces of refrigeration supply systems transparent

Another focus of "FlexBlue" is on the operational interfaces between the various players in the flexibilization value chain. These are first identified and characterized together with the various design options and examined with regard to their impact on the realizable flexibility potential. Ultimately, the aim is to be able to make target group-specific recommendations for the planning and operation of flexible cooling supply systems that contribute to decarbonization at the end of the project.

The transfer of knowledge and the activation and networking of stakeholders also play an important role here: they should be motivated and enabled to convert existing cooling supply systems or optimize the planning of new systems accordingly. This is why the project is developing scalable methods and schemes that can be implemented cost-effectively and easily. "Ultimately, we want to ensure that our results are transferable and thus both initiate the implementation of flexible cooling supply systems and make a contribution to the energy transition," says Annedore Mittreiter, summarizing the objectives of "FlexBlue".



The project "FlexBlue – Flexible cooling supply systems against the backdrop of increasing decarbonization" is funded by the Federal Ministry for Economic Affairs and Climate Protection.