Thermal energy storage technologies play a pivotal role in switching from a fossil fuels-based energy system to a fully renewable energy system. They provide flexibility in the system when supply and demand are not in sync, they enable a larger uptake of variable renewable sources like solar energy, they maximize waste heat re-utilization in industry, they provide peak power thus lowering the required auxiliary power and they provide channels to couple the electricity sector with the heating sector, adding flexibility to the electricity system.

Many thermal energy storage technologies are already on the market and have a good performance and low costs. Especially in applications that require higher temperature, smaller volumes or added functionality of thermal storage technologies, there are still several challenges to be tackled, specifically in the design of components. In compact or higher temperature thermal energy storage, the challenges are limited energy transfer to and out of the system, large part due to the low thermal conductivity of available thermal storage materials and slow reaction rate; abrasion risk; or mixing/two-phase flow difficulties.

The Task has the focus on three key pillars: application-oriented case studies, component design and integration and determination of the state-of-charge. The main objective is to bridge the gap between research on storage materials and practical implementation.

The Kickoff meeting will take place at KTH in Stockholm, Sweden, from 13 to 15 October 2025.
It will be organized as a shared meeting of Task 48 (Thermal energy storage materials) and Task 47.