GRISU-EX – Dual use of sprinkler tanks as thermal energy storages

Sprinkler tanks are safety-critical installations that provide fire-fighting water for numerous types of buildings, including logistics centres, furniture and retail stores, hotels, office buildings, and production facilities. In Austria, around 10,000 systems exist with a total of approximately 6 million m³ of extinguishing water that ideally is never used. However, if this water volume is thermally activated and, for example, heated by 25 K, it offers – beyond its safety function – a theoretical storage potential of about 175 GWh. This corresponds to the annual space-heating demand of roughly 12,000 average Austrian households and illustrates the energetic potential of this infrastructure.

The project aims, among other objectives, to develop concepts for integrating fire-fighting water tanks as thermal storage units into building heating and cooling systems. Such integration enables load shifting, peak-load reduction, and the storage of surplus energy. This supports more efficient energy use, increases the share of renewable energy, thus lowering CO2 emissions, and reduces long-term operating costs.

The interdisciplinary consortium analyses normative and legal frameworks as well as technical, economic, and safety-related requirements. The results are prepared as application-oriented services for SMEs to enable the safe and economically viable use of sprinkler tanks as energy storage systems.