Cooking during off-sunshine hours using PCMs as storage media

The possibility of cooking during off-sunshine hours using phase change materials (PCMs) as storage media has been investigated experimentally. For this purpose, two concentric cylindrical vessels were constructed with 2-cm gaps. This gap was filled with stearic acid or magnesium nitrate hexahydrate as the PCMs. The cooker performance is evaluated in terms of charging and discharging times of the PCMs under different conditions. The cooker performance was found to depend strongly on the solar intensity, mass of the cooking medium, and the thermophysical properties of the PCM. The overall efficiency of the cooker during discharging was found to be 3–4 times greater than that for steam and heat-pipe solar cookers, which can be used for indoor cooking.