Phase change materials in solar energy applications: A review Bhupendra Gupta a,⇑ , Jyoti Bhalavi a , Shlok Sharma a , Anand Bisen b a Jabalpur Engineering College, Jabalpur 482011, India b Department of Mechanical Engineering, KNPC Jabalpur, India article info Article history: Received 24 August 2020 Received in revised form 11 September 2020 Accepted 13 September 2020 Available online xxxx Keywords: Solar energy Phase change materials (PCMs) Organic PCM Inorganic PCM Thermo-physical properties Thermal energy storage abstract Phase change materials (PCMs) are extensively used now a days in energy storage devices and applica- tions worldwide. PCMs play a substantial role in energy storage for solar thermal applications and renew- able energy sources integration. High thermal storage density with a moderate temperature variation can be attained by phase change materials (PCMs). Considerable research has been carried out for energy storage to achieve better efficiency and performance. Phase change Materials (PCMs) available in various temperature range have proved efficient in solar thermal energy storage situations. Incorporating PCMs in solar applications resulted in enhancement in the order of 12 to 87% in thermal efficiencies of the sys- tems. Thermo-physical Properties are the basis of selecting the type of PCM for specific solar application. PCMs like MgCl 2 6H 2 O, Mg (NO 3 ) 2 6H 2 O, CaCl 2 6H 2 O, Paraffin wax, CH3(CH2)16CH3, CH3(CH2)11OH have proved successfully in solar thermal and thermo-electrical applications. This work reviewed and unite the trends of PCMs in energy efficient solar energy storage systems. Ó 2020 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Confer- ence on Innovations in Clean Energy Technologies. 1. Introduction The faster growth of world as different countries competing with each other has led to sudden increase in the demand of energy. The energy already known is in the form of fossil fuels which are being overly used even before the science of harnessing renewable source of energy was developed. According to the Uni- ted States Energy Information Administration, India has the high- est growing energy consumption rate because of its high economic growth. The growth percentage of the consumption is estimated to be about 734 percent which was observed in last 45 years. The maximum percentage of fossil fuel consists of Coal which takes care of India’s energy consumption. The limited amount of fossil fuels which is available is getting used at up at the rate of 4 percent per annum. Combustion of fossil fuels also led to the generation of greenhouse gases. One of the greenhouse gases i.e. Carbon dioxide is increased up to 1.5 times till 2020. This led the world to take steps toward renewable and solar energy sys- tems which can continue the supply hence contributing to the eco- nomic development. The expansion of solar energy awakens the hope of everlasting energy source. It helped to focus on area like solar energy, wind energy and Hydro-power and many more which are in abundance and its true potential is still to be harnessed [1]. Solar energy is which is the heat received from the sun to the earth is about Joules per annum. This amount is ten thousand times greater than the real consumption of energy per annum. This abun- dance of energy made the researchers think about the ways to store the solar energy. The idea of phase change material was help- ful in improving the energy efficiency which was helpful in eco- nomic development and sustainable progress of civilized life. Research in the area of phase change material has seen a rapid growth since the year it was developed. Last 20 years, publications on Phase Change Materials have increased very high as it promotes energy efficient, environment friendly and future towards sustain- able development [2]. 2. Phase change materials Phase change materials are substances which interact with dif- ferent conditions of environment and change their property by showing different phases. The phases refers to the transition of substance from one phase to another (solid to liquid, liquid to gas or vice versa). The change in physical characteristics is accom- panied with absorbing or releasing energy i.e. heat. PCMs can be formed from different constituent particles so different materials https://doi.org/10.1016/j.matpr.2020.09.343 2214-7853/Ó 2020 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Innovations in Clean Energy Technologies. ⇑ Corresponding author. E-mail address: bhupendra243@yahoo.com (B. Gupta). Materials Today: Proceedings xxx (xxxx) xxx Contents lists available at ScienceDirect Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr Please cite this article as: B. Gupta, J. Bhalavi, S. Sharma et al., Phase change materials in solar energy applications: A review, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2020.09.343