The latest advancements on thermochemical heat storage systems

Thermal energy storage (TES) is an advanced technology that could address the energy supply-demand balance in building air conditioning systems. TES is also important in view of the increasing utilisation of solar energy. Although sensible heat storage systems and latent heat storage systems have been heavily researched and are widely used domestically and industrially, thermochemical heat storage (THS) systems are currently undergoing a surge in research and development. Recent studies suggest that THS has significant advantages when compared with the other heat storage methods including higher storage density, lower volume requirements, low heat loss (approaching zero), and lower charging temperature. On the other hand the complexity and higher investment costs remain the main obstacles to rolling out these systems commercially. A comprehensive review has been presented here into all aspects of the current, state of the art THS research. It includes comparisons with other storage methods, description of absorption/adsorption cycles, the materials used in these systems and open/closed storage methods, as well as chemical heat pumps. Recent advances in the field are also investigated and discussed.