Solar Dish

The Solar Dish boils water, fries eggs in a skillet in ten minutes, and bakes cornbread in less than half an hour. The outdated, abandoned satellite dishes are a valuable resource. Everybody can easibly turn it into a Solar Cooker. All you need is Sun, satellite dish, roll of aluminum flashing from the local hardware store, some free time and good will... The dish is a prefabricated parabola, a shape that focuses visible and infrared light (or, originally, microwaves) to a single point in space called the focal point. The focal point is located above the center of the dish, where the struts hold the receiver in place. Remove the receiver since it is in the spot where you want to put the food. At the surface of the earth, about 1000 watts of energy fall on every square meter of ground when the sun is overhead. This value is called the solar constant. Multiplying 1000 watts/square meter by the dish area of 3.6 square meters, the dish should be able to collect and focus about 3600 watts of energy. This is a lot more than most cookers, and is about twice the power of a countertop hotplate or griller. The sun is always moving across the sky and the angle of the dish must also change for maximum results.

WARNING: In the focal point it gets so hot that creates nasty burns and/or you could damage your eyes for good! Never place hand in beam and never experiment without protective gear.

Ways to reduce the burn hazard: redesign the shape of the dish so that the focal point is low--well inside the bowl-shape of the dish where it is much less likely that someone will put their hand or face.
Another method is to mount the cooking pot on a rotating arm--then the cook moves the arm to remove the pot from the focal point when the cook needs to open the pot. This way, the cook does not have to reach their hand near the focal point.
Another method is to redesign the shape of the dish so that instead of a narrow point focus, the focus is more spread out.

solar cooking links