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 (1800) diameter pan and 1.2 m (4800) 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 100W 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. 2011 Elsevier Ltd. All rights reserved