Recent advancements in applications of encapsulated phase change materials for solar energy systems: A state of the art review

Abstract

In recent decades, solar energy systems have played an increasingly important role in human societies, including support of the supply of drinking water, hot water, and electricity in arid, semi-arid and remote communities. The most challenging aspects of solar energy systems are storing energy when it is available and using it when there is a high demand for energy without access to solar energy. Encapsulating phase change materials (PCMs) or nano enhanced PCMs can serve as thermal batteries for storing solar energy, whereby it is important to consider the energy characteristics of various encapsulation methods. This includes taking into account encapsulation materials, such as diameter, enthalpy, efficiency, and heat cycling times, in order to integrate them with solar energy systems. In the present paper, production process methods, characteristics and ingredients of encapsulation are reviewed, followed by evaluation of the effect of the composition of encapsulation PCMs on the performance of solar energy applications in in Middle East and North African countries, including photovoltaic/thermal, solar desalination, solar water heater, solar power plant, solar pond, solar thermochemical reactor, and others. Further, the effects of dispersing various nano powders in PCM (encapsulated nano-enhanced PCM) to increase the thermal properties of thermal batteries are reviewed. In addition, a summary of the economic analysis of thermal batteries and evaluating sustainable development goals of solar energy applications as integrated by encapsulated PCMs/nano-enhanced PCMs are conducted and discussed. We conclude by evaluating the trade-off, synergy, future perspectives, and recommendations of encapsulation PCM used in solar energy applications.