Large, above-ground heat storage plants (with a capacity of 500 to 8,000 m³) have so far mainly been erected in segmented form for cold-water use. The aim of the research project “OBSERW (Segmental Design of Surface Storage Tanks for Heat Supply Systems)” was to make use of this cost-saving design for hot-water storage systems operating at temperatures of up to 98°C as well.

To achieve this, the structure and building technology of the storage systems were, amongst other aspects, completely redesigned. One of the challenges was to find a solution for a temperature-resistant seal of the segments. Together with their industrial partner farmatic tank systems, the researchers of the Chemnitz University of Technology and the University of Stuttgart not only sought to achieve low construction costs combined with high functionality, but also to develop a storage system that can be used universally.

At the start of the project, the sealing and heat insulation material was tested. At the same time, the entire storage construction was completely redesigned and the loading and unloading systems fully optimised. Finally, the developed construction was successfully tested on a small model with a capacity of 100 m³ in a cold and hot test. Nothing now stands in the way of transferring this model to larger-scale storage systems.

The final report of the project (November 2014‒May 2018), funded by the Federal Ministry for Economic Affairs and Energy (BMWi), will be published soon.