The possibility of cooking during off-sunshine hours using phase chang
e materials (PCMs) as storage media has been investigated experimental
ly. For this purpose, two concentric cylindrical vessels were construc
ted 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 th
e solar intensity, mass of the cooking medium, and the thermophysical
properties of the PCM. The overall efficiency of the cooker during dis
charging was found to be 3-4 times greater than that for steam and hea
t-pipe solar cookers, which can be used for indoor cooking.