Comparative study of wax and nitrate salts for thermal storage for a 500 W fresnel mirror solar concentrator

Abstract

The demand and supply gap of global energy needs is increasing exponentially. This situation is further worsening as the conventional fossil fuel resources are decreasing. Solar thermal is one of the alternatives that can be used to fulfil the power requirements of the world without effecting the environment. Solar is one of the widely available renewable energy resources around the globe. One of the key challenges in harvesting this resource is that it is intermittent, thus its availability is limited. Several techniques are used to overcome this challenge, the method being used now is hybrid technology of conventional and solar; where solar is being used in peak hours. Another technique is to store the excess energy present during day and utilize it during night by using phase change material. This paper presents a comparative study between two phase change materials; nitrate salts and wax for energy storage of a 500 Watt Fresnel Mirror Solar Concentrator. A comparison between their thermal storage capacities, their charge and discharge time is made using CFD tool like COMSOL.