A solar based cold storage unit for the preservation of food products is an excellent way to reduce post-harvest losses at lower energy costs. Energy optimization is essential to improve the reliability of the system. In the case of cooling, a major factor to reduce energy consumption is the uniform distribution of air inside the cooling chamber to maintain the even temperature of stored products. For this, a detailed thermal analysis is required to analyse the cooling process for energy saving and optimum conditions. In the current study, an energy and exergy based thermal analysis of a solar assisted cold storage unit is presented. A parametric investigation and a proper understanding about the influence of thermodynamics on the cooling process were obtained. All the experimentally calculated parameters (energy utilized, energy utilization ratio, energy loss and exergy efficiency) were subjected to a model curve fitting using Sigmaplot-12 and a polynomial cubic model was found best fitted based on the values of coefficient of determination. Thermal analysis showed variations in the rate of energy utilization, energy utilization ratio, exergy losses and exergy efficiency in the range of 3–18 kJ/s, 0.37–0.80, 0.8–2.25 kJ/s and 40–60%, respectively. The average value of COP of the system was found to be 3.95.