Solar cooking success relies on 4 important requirements:
Cooking Time Duration
Remove any one of the 4 basic requirements listed above and solar cooking will fail.
Light Collection and Concentration: Solar cookers use one or more reflectors to concentrate light into the cooking area. Cookers with multiple reflectors provide the best cooking power. Will a single reflector work? Yes. However, cooking will be much slower. Use a multi-reflector cooker to collect and concentrate the light into the cooking area.
Light Absorption: To maximize cooking success, you must consider light absorption and reflection. For best results, use cooking pots that have a dull, dark surface -- a flat black finish is best. Other colors of cookware can work, but the lighter-colored and shinier your cookware, the slower your cooking will be.
Heat Retention: Once light is collected and absorbed, your pot will begin to get hot -- but retaining that heat is crucial to cooking success. Reflective panel cookers like the ASSC can retain heat by using glass bakeware (2 bowls required) or reusable high heat bags to contain your cooking pot.
Cooking Time Duration: We have collected light, turned that light into heat, and have retained that heat. Now we need to have those 3 elements working together for a sufficient duration to complete our task. Most solar cooker designs will provide good temperatures for 4 hours a day - between 10 a.m. and 2 p.m. The best solar cookers will be capable of providing good cooking performance any time the sun is shining 8 to 12 hours each day.
If your solar cooking outing did not produce the results you expected, check the list above.