Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHTProject completion FlexKaelte
Minimize CO2 emissions and save electricity costs by making refrigeration supply systems more flexible
Feeding and distributing decentralized, time-fluctuating renewable energies into our energy supply system is one of the challenges of the energy transition. In addition to the expansion of energy grids, this also requires the use of energy storage systems for load management. While the focus of research and practice has so far been on the flexibilization of heat supply systems, scientists at Fraunhofer UMSICHT have closed this gap and investigated the potential of cooling supply systems. The result: The economic and ecological benefits of making cooling supply systems more flexible go hand in hand.
Characterization of 73 cold applications
The "FlexKaelte" project began with a meta-study. "The total energy demand determined for the German refrigeration sector is 92.7 TWh – 85 percent of which is electrical and 15 percent thermal," summarizes UMSICHT scientist Christoph Goetschkes. "We have identified a total of 73 different cooling applications and characterized 27 of them in more detail in the form of fact sheets." In addition, fact sheets on refrigeration and cold storage technologies have also been created, in which the functionalities are explained and technological parameters are presented.
Cooling sector has high potential for flexibilization
In a second step, the researchers investigated the flexibility potential of ten exemplary refrigeration application sites: a hospital, a laboratory, a large industrial bakery, an industrial meat processing plant, a cold store, a small data center, a high-performance data center, a supermarket, a hotel and a supplier to the automotive industry. UMSICHT scientist Dr.-Ing. Annedore Mittreiter: "We discovered that refrigeration applications are very heterogeneous and that the demand profile of one and the same refrigeration application can vary significantly for different locations despite similar framework conditions. This means that for practical implementation, individual recommendations must be made for each location as to how the cooling supply systems to be made more flexible should be designed and operated."
Nevertheless, the results for the locations under consideration show overarching similarities, so that the project-based assumption that the refrigeration sector has a high potential for flexibilization could be supported. A mathematical operating optimization model was used to quantify the flexibility potential. It uses the time-resolved year-round cooling demand profile as input and maps both the operation of the cooling generation systems and the cold storage facilities. "Our evaluations show that the economic and ecological benefits of making the cooling supply more flexible go hand in hand," says Annedore Mittreiter. "Compared to reference operation, flexibilization can reduce CO2 emissions by 22 to 39 percent and electricity procurement costs by 35 to 54 percent."
All project results – including the profiles – are available at www.flexkaelte.de. There you will also find an interactive FlexKaelte check, which uses a questionnaire to provide refrigeration users with an initial rough assessment of whether and to what extent there is potential for flexibilization at the site.
Incidentally, a follow-up project is already in the starting blocks: The "FlexKaelte" results will be further developed with numerous practical partners and, among other things, two demonstrators with different system components will be set up.
FUNDING NOTICE
The project "FlexKaelte – Flexibilization of refrigeration supply systems for electrical energy balancing in Germany" was funded by the Federal Ministry of Economics and Climate Protection. Reference number: 01EI1007.