A solar fryer

The design and operation of a large-area frying pan heated by solar radiation is described. A mirror below the pan directs the radiation to the pan bottom, which is coated with a low-emissivity black absorber. The mirror uses flat, hexagonal panels of aluminized-Mylar to provide uniform illumination across most of the pan bottom. The mirror mount allows 8 h/day operation with a single mirror-angle adjustment, plus a seasonal mounting adjustment for full-year use. A 0.46 m (18″) diameter pan and ∼1.2 m (48″) diameter mirror are used in the prototype, which is designed for cooking 0.42 m diameter slices of injera bread in East Africa. The prototype provides ∼640 W of heating power (60% efficiency compared to the full mirror area), and loses ∼100 W while cooking the bread. This allows for cooking ∼4 kg of bread per hour. The pan preheats to the 180 °C cooking temperature in 15-20 min. Materials and design are chosen for low-cost, and the prototype US-retail materials cost is ∼100 US$. The design is scalable to any desired pan size, with cost proportional to pan area. Most of the construction requires only hand tools, encouraging production in the country of use.