In the course of converting the energy supply to renewable energy sources, energy storage systems are also becoming increasingly important in the heat sector. So-called latent heat storage systems (also known as PCM storage systems) offer great potential: filled with special PCMs, they can store heat for longer periods of time than, for example, water storage systems and release it when required. In this case, the thermal energy is stored by changing the aggregate state from solid to liquid and remains constant until the phase transformation of the special material has been completed. Currently, there is only a limited selection of PCMs available in the temperature range of 100 to 220°C. Five partners from industry and research are seeking to meet this research need.

Part of the Prolatent project, funded by the BMWi from September 2015 to the end of February 2019, involved the project partners developing and optimising organic PCMs in the form of sugar alcohols, long-chain paraffins and alcohols, amides and polymers with melting temperatures between 100 and 200°C. The PCMs were developed in the course of the Prolatent project. Compared to other PCMs, these materials have high storage densities. Concurrently, the partners are working on a new heat exchanger concept with flow-through plates to store heat for loading and unloading PCMs. After various tests carried out on smaller-scale models, a demonstration storage tank was set up. The findings gained from this project will serve to significantly expand the range of storage media available in the high-temperature range.