Thermal storage is a key element in most energy systems and is crucial for achieving a sustainable future with low CO2 emissions. Thermal energy storage means surplus heat or cold is stored, ready for use when a future need arises.

Thermal storage makes it possible to increase the use of variable sustainable sources such as solar and wind energy, to increase self-consumption and self-production of sustainable energy, to increase the efficiency of (sustainable) energy systems and to increase the use of residual heat in both the industry and in the built environment. In domestic applications, thermal storage addresses the imbalance that exists between the demand for heating and the heat supplied by renewable sources (such as solar panels or solar-powered heat pumps)