IEA ES Task 43 – Standardized use of building mass as storage for renewable energies and grid flexibility

The building sector is a major lever for the energy transition, as a substantial share of final energy demand is still supplied by fossil fuels. Renewable energy can replace this supply, but its availability often does not match demand. Without suitable storage solutions, opportunities for decarbonisation and grid stability remain unused. Thermally activated building systems use the thermal mass of building components to condition indoor spaces. Thanks to their thermal inertia, this building mass can also serve as an energy storage medium by being intentionally overheated or undercooled without compromising indoor comfort. This creates flexibility for thermal applications as well as for coupling with electrical systems, for example through power to heat using heat pumps.

However, broad and efficient implementation of this storage function is currently hindered by the need for expert knowledge and by unresolved questions along the entire value chain. Within the IEA Energy Storage TCP initiative, a new IEA Task is therefore being established to advance the standardised use of building mass as storage for renewable energy integration and grid flexibility. The Task addresses key topics ranging from materials and construction to system integration and control, as well as non technical conditions, standardisation and performance indicators. These issues are tackled in four thematic subtasks to develop technical guidance, robust KPIs and practical assessment and implementation approaches.

Austria initiated the Task at the international level. AEE Institute for Sustainable Technologies acts as Task Manager and coordinates the national contribution. BEST Bioenergy and Sustainable Technologies leads the work on system integration and control. Together with Salzburg University of Applied Sciences and e7, the Austrian consortium contributes content to the international Task and transfers results to industry and research through targeted dissemination activities. The project will deliver high quality technical information, best practice examples, system and control concepts and new business models that accelerate market uptake and standardisation while strengthening confidence among investors and end users.