In 2005, I designed a solar oven to help the villagers in Prey Veng, Cambodia to reduce their dependency on fire woods for cooking. The design is base on a parabolic design using highly reflective aluminum foils to concentrate the sunlight to the cooking pot. The concentrated sunlight is able to produce temperature of above 150 degrees Celcius, thus able to boil water (100 degrees Celcius) in the pot and cook food. The cost of the solar oven is about USD60, still very high by Cambodian farmers' standards.
After completing the construction of solar ovens, we taught the village chiefs how to use the oven for cooking. It takes about 1 hour to cook rice. We have tried cooking a mixed vegetable rice using long beans, black fungus, dried prawns, peanuts and rice. The food taste good and simple to cook. The village chiefs were amaze that the solar oven works. They brough the solar oven home to try out cooking using the sun energy.
One year later, in 2006, the Cambodians were able to reduce the cost of the solar oven further to only USD20. They use materials readily available in Cambodia and also simplify the design.
