A Solar Cooker That Can Cook the Evening Meal: A Panel Cooker with an Oil Thermal Store and a Retained-Heat Basket, Sized for a Family of Five

SIMULATED, NOT MEASURED. Most solar cookers cook at midday, but the main meal in many households is cooked in the evening. This paper specifies a cooker to close that gap: a 1.6 m2 panel cooker heats 22 kg of palm oil to 180 C during the day, the store waits 3.5 hours, and in the evening it cooks rice and a bean and vegetable stew for a family of five in an insulated retained-heat basket. The meal needs 1.62 MJ; the store can deliver 1.93 MJ at the start of evening cooking, a margin of 18.9 percent, serving food at about 92 C. Parts cost 115 US dollars, displacing 330 kg of charcoal per year with a payback of 0.65 years. On a heavily overcast day the store reaches only 84.8 C and delivers none of the meal; the store cannot fry; and the design requires 35 minutes of extra work during the day.