Solar radiation hitting the ground does not have high enough density for cooking. But if radiation is concentrated into a small volume then cooking temperatures can quite easily be reached, see the figure. CAUTION: do not move your eye into the focus because the HIGH ENERGY DENSITY AT THE FOCUS MAY BLIND YOU! A concentrating mirror as small as a few centimeters in diameter can be dangerous if caution is not taken.
Of all solar cooker designs (e.g. box and panel) a parabolic model offers the highest potential performance. Very large parabolic mirrors can even be used to melt metals. Still, a parabolic cooker can be fabricated at extremely low cost by using local materials.
In the following series of figures women and men of Khojpur village in Eastern Nepal show how to make a cooker costing only $3 but able to cook a meal in half an hour with free and abundant fuel. This model is constructed mainly of bamboo and clay-dung mixture. However, there are many other possibilities that you may think of after following how the Nepalese do this one.
Back
Home
Next