Phase change hot water energy storage

Are phase change materials suitable for thermal energy storage?

Phase change materials are promising for thermal energy storage yet their practical potential is challenging to assess. Here, using an analogy with batteries, Woods et al. use the thermal rate capability and Ragone plots to evaluate trade-offs in energy storage density and power density in thermal storage devices.

What determines the value of a phase change material?

The value of a phase change material is defined by its energy and power density—the total available storage capacity and the speed at which it can be accessed. These are influenced by material properties but cannot be defined with these properties alone.

How do phase change composites convert solar energy into thermal energy?

Traditional phase change composites for photo-thermal conversion absorb solar energy and transform it into thermal energy at the top layers. The middle and bottom layers are heated by long-distance thermal diffusion.

Does PCM increase the availability of hot water in a storage tank?

They concluded that the addition of PCM in the storage tank increased the solar fraction, improved the energy stored in the hot water tank and thus the availability of hot water to the end-user is increased and improved the reheating of the top layer after a period of discharge.

What is a latent heat storage method?

While the majority of practical applications make use of sensible heat storage methods, latent heat storage such as phase change materials (PCM) provides much higher storage density, with very little temperature variation during the charging and discharging processes and thus proving to be efficient in storing thermal energy.

Do thermal storage materials have a trade-off between energy and power?

Researchers have developed figures of merit 12, 25, 26 to try to quantify the trade-off between the energy and power capabilities for thermal storage materials, and these figures of merit have been used to construct approximations of thermal Ragone plots 27.