Nowadays, the need of thermal storage is paramount to let the renewable energy sources be competitive and reliable in the energy market. Thermochemical heat storage, especially sorption heat storage, has a strong potential to store huge amount of thermal energy with theoretically no losses. Water absorption of salt hydrates guarantees the highest energy density, up to around 3 GJ/m3 for MgSO4∙7H2O, but lacking in good mass and heat transport properties. On the other hand, pure adsorbents such as zeolites 13X assure a better mass and heat transfer due to their better hydrothermal stability, however having lower energy densities (around 0,6 GJ/m3) and high prices.