I'm Gwen Outen with the VOA Special English Development Report.
Millions of people around the world cook their food over a smoky fire every day. It is often difficult to find wood for the fire. People who do not have wood must spend large amounts of money on cooking fuel. However, there is a much easier way to cooking food using energy from the sun. Solar cookers or ovens have been used for centuries. A Swiss scientist made the first solar oven in 1767.
Today people are using solar cookers in many countries around the world. People use solar ovens to cook food and to heat drinking water to kill bacteria and other harmful organisms. There are 3 kinds of solar ovens. The first is a box cooker. It is designed with a special wall that shines or reflects sunlight into the box. Heat gets trapped under a piece of glass or plastic covering the top of the cooker. A box oven is effective for slow cooking of large amounts of food.
The second kind of solar oven is a panel cooker. It includes several flat walls or panels that directly reflect the sun's light onto the food. The food is inside a separate container of plastic or glass that traps heat energy. People can build panel cookers quickly and with very few supplies. They do not cost much. In Kenya, for example, panel cookers are being manufactured for just 2 dollars.
The third kind of solar oven is parabolic cooker. It has rounded walls that aim sunlight directly into the bottom of the oven. Food cooks quickly in parabolic ovens. However, these cookers are hard to made. They must be re-aimed often to follow the sun.
Parabolic cookers can also cause burns and eye injuries if they are not used correctly. You can make solar ovens from boxes or heavy paper. They were not catch fire. Paper burns at 232 degree Celsius. A solar cooker never gets that hot. Solar ovens cook food at low temperatures over long periods of time. This permits people to leave food to cook while they do other things.
To learn more about solar cooking, you can write to Solar Cookers International. The address is 191921 street, Sacramento California, 95814, USA. Or you can visit the group's international website. The address is www.solarcooking.org.
This VOA Special English Development Report was written by Jill Moss. I'm Gwen Outen.
Vocabulary:
cooker: one that cooks, especially a utensil or an appliance for cooking（炊具，厨灶）
parabolic: of or having the form of a parabola（抛物线或抛物面的或有其形状的）
