In their position paper published in August 2015, the scientists of IEA SHC Task 42 (Compact Thermal Energy Storage) summed up the key results of their work between 2009 and 2015. Operating agent Matthias Rommel sees huge potential for latent heat and sorption materials in the long run – in seasonal solar heat storage for small and medium applications, as well as in the building sector. So-called smart grids will also require more heat storage units when devices such as heat pumps and co-generation plants are based on electricity grid requirements. Rommel views the definition of measurement standards for PCM materials as one of the task’s big achievements, which will help in material development. Furthermore, a research group from German research institute ZAE Bayern has performed a first cost estimate of compact heat storage technologies.