With the energy challenges to come, development of renewable energy sources is becoming more and more topical. But, because these energies are irregularly supplied, their development is closely related to those of suitable energy storage systems. Among the existing technologies for storing thermal energy, latent heat storage appears to be of huge interest since it can lead to reduced size and cost. This paper reviews various recent patents on phase change materials and on latent heat storage systems over the past six years. Developments concerning the storage medium and also the entire storage system are thus addressed. An overview of existing materials and systems for latent heat thermal energy storage, namely for high temperature applications is also given, in order to identify the main issues in the development of such systems.
The list of patents reviewed here is by no means supposed to be complete or extensive but shows nevertheless evolution trends concerning latent heat storage. An analysis of the repartition of the reviewed patents helps concluding about the expected future developments in this domain.