Solar power stored seasonally for the first time in Kaltenbach
Matica AG has installed the second demonstration plant for its SeasOn sorption storage system at Swiss Post in Kaltenbach. Here, surplus solar power is stored in caustic soda for winter utilisation.
At the post office in the village of Kaltenbach, which belongs to the municipality of Wagenhausen, surplus solar power from the summer months can in future be utilised in winter. This will be made possible by a SeasON demonstration system in the new post office delivery centre in Kaltenbach, Matica AG announced in a press release. The thermochemical process developed by the company in collaboration with Lucerne University of Applied Sciences and Arts utilises caustic soda for the loss-free storage of electricity and waste heat.
When the electricity is stored, water is removed from the caustic soda solution and transferred to a separate tank. Concentrated caustic solution and separate water can then be stored at room temperature. If the stored energy is to be utilised, the concentrated caustic solution is diluted again with the separated water. The resulting mixing heat is supplemented by condensation heat. It is generated by vaporising the water in the closed system with the help of low-temperature heat from a heat exchanger.
“For us and the team at Lucerne University of Applied Sciences and Arts, the realisation of the project in Kaltenbach is another important milestone on the way to the market launch of our innovative over-seasonal energy storage system SeasON,” said Matica CEO Marc Lüthi in the press release. “The experience gained from building the system, installing it and analysing the operating phase is essential for the efficient further development of our pioneering solution.”
The Wagenhausen-based company installed its first demonstration plant in Frauenfeld in 2024. A third system is planned for spring 2026 in a housing estate in North Rhine-Westphalia.