Portable solar cooker and water heater

A portable solar water heater was designed, built and tested. This application of solar energy devices is particularly important for the Bedouin community which can gain a great deal from the solar energy that is continuously available in the desert. It can be also used by campers and those who use recreation vehicles. A normal satellite dish of 150 cm diameter was used as a concentrator for solar radiation. The surface of the dish was covered with reflective aluminum foil which was used to concentrate solar energy on a cooking pot in one mode of operation. This mode was operated in two ways: one with bare pot and the other with the pot being covered with glazing by putting it inside a glass box. The device was also used in another mode of operation to heat water for domestic use by placing a specially designed solar collector in the focus. It was found that, when the device was operated in the bare cooker mode, a 7 kg of water at 20 deg. C was brought to a boil in 1 h. Putting the pot inside the glass box reduced the time required for boiling to 40 min and the cooking power was increased by 275%. In the collector mode, the device was able to heat 30 kg of water from 20 deg. C to 50 deg. C in 21/2 h. The highest efficiency obtained for this mode was 77% and the slope of the efficiency curve was -10.63 W/m2 deg. C.