Project
FlexBlue '25 research project
FlexBlue – Contributing to the energy transition by making refrigeration supply systems more flexible
Within the FlexBlue project, the demonstrator is currently being set up at the IAI (Institute for Automation and Applied Computer Science at KIT in Karlsruhe).
At the heart of the system is a 6,000 liter PCM storage tank. Various hydraulic circuits are being tested to
optimize the overall system in order to achieve maximum flexibility.
- 6,000 liter Cold Storage
Incl. cold iso and sheet metal jacket for outdoor installation - 1,900 heatSel Xl ATP 6

Demonstrators at the IAI
The hydraulic and implementation concepts for the demonstrator at the IAI have been drawn up. The necessary measurement and control technology was identified.
The components have been dimensioned, selected and procured and are currently being assembled. Completion is scheduled for Easter 2025.

Demonstrator IAI
Schematic layout of the refrigeration system
An initial amortization analysis for the IAI demonstrator
was carried out with
- real measurement data on load profiles at IAI, the yield from the IAI PV system (64kWp), and exchange prices from 2024,
- characteristic values and the temperature-dependent (non-linear)
EER of the new KKM - and the PCM stratified storage simulation model of the
plant (with idealizing assumptions).
Result
Peak shaving, reacting to flexible exchange prices and maximizing
PV yield utilization can amortize the additional costs for the active storage at the IAI. However, the IAI demonstrator was not dimensioned according to economic efficiency aspects. It is intended to serve as an experimental field for various use cases.

KraftBoxx system storage tank
Delivery by crane from the 6,000 liter Cold Storage tank,
FUNDING NOTICE
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.










KIT research project FlexBlue
Delivery and installation of the refrigeration system with storage tank at the KIT building.