Usage Tips for Model SK-14

Introduction

This manual is mainly for those who want to use solar energy. It is not meant to be comprehensive, but more as an introduction to one of the ways in which solar energy may be used for cooking

Why use a solar cooker?

About 200 crore people (1 crore=10 Million) , over one-third of the world, are dependent on firewood as the source of their cooking and heating energy. They mainly live in the tropics, in the most favourable areas for the use of solar energy. Every year the cutting of firewood results in the loss of 20,000 - 25,000 km2 of forests (UNEP).

Health aspects

The use of solar cookers also brings health benefits. Diseases spread through contaminated water cause 80% of the illnesses in the world (WHO). Heating water to the pasteurisation temperature of about 70-80 C destroys most organisms. This temperature is easily achieved with solar cookers.

Respiratory deseases are the cause of death for millions of children every year. Many of these occur in the developing countries as a result of polluted indoor air due to cooking over open fires in houses without chimneys or ventilation. This problem could be greatly reduced by using solar cookers which are smokeless. The solar cooker also preserves many micronutrients better than traditional cookers do. Solar cooking is safer than open fire, because there are not any flames, i.e. less burning accidents.

Women's work

In developing countries many people, mostly women, and quite often children have to spend several hours daily collecting firewood. This work is very heavy and causes many injures. Solar cooking can greatly reduce this time. And solar cookers do not need fuel. Women could use the time and money thus saved for other basic needs.

Future

UNICEF has estimated that one third of global fuelwood use (350 million tons per year) could be preserved with solar cookers. Pay-back time is estimated to be less than 1 year.

General instructions

Place your solar cooker in a sunny place. When you use your solar cooker for the first time, pay attention to the cooking times of different meals. With practice you can learn to estimate the time necessary for cooking, and the food will be tasty without your continuous supervision . Because pots get hot in the solar cooker, you should use pot-holders when lifting them.

Orienting the solar cookers

It is best to use solar cookers when the sun is shining from a cloudless sky. The cooker should be placed facing directly towards the sun, so that no shadows fall on the mirrors. In this way the cooker will get the maximum amount of sunshine, and cooks fastest. The cooker's position has to be changed so as to follow the sun's movement.

Maintenance and care of the solar cooker

Take good care of surface materials and the glass, because they are easily damaged or broken. If the glass is dirty, wash it to help the sun's rays pass freely through it. Reflecting surfaces lose their effectiveness if they become broken or are covered by dust or dirt. Wipe dust and dirt off the mirrors and replace broken mirrors. Taking good care of the cooker increases its lifetime and increases its effectiveness.

Cooking with solar cookers

Cooking times.

With some practice you can easily estimate cooking times for different foods. Times vary according to the amount of food, the number of pieces and the outside temperature. The kind of cooking pot you are using and the position of the cooker also affect the cooking time. It is difficult to give exact cooking times. But after a little bit if practice, it easily learnt.

Cooking times can be roughly divided into three categories. Easy-to-cook foods take from twenty minutes to one hour; these include fish, chicken, eggs, vegetables, fruits, rice and pasta. Medium-cooking foods take from One to two hours; these include potatoes, roots, most meats (especially small pieces), seeds, lentils, bread and pastries. Slow-cooking foods take from two to four hours; these include big amounts of food; soup and stew; casserole; and most dried beans. Heating water also takes a long time, especially if you want to heat large amounts.

Practical tips

You should use water as usual when cooking swelling foods such as beans, rice and porridge. Do not use any water for meat, fish, eggs, vegetables and roots, or to heat foods up.
The temperature rises quickly to 120° C , which is high enough for cooking most foods. If you are baking bread, the temperature must be higher (140° - 160° C); similarly, if you want to get a brown baked surface on the food. The temperature should stays high from one to two hours after closing the lid, depending on the outside temperature.
It is easy to sterilise water in the solar cooker, if you have clean pots with tight lids. After water has boiled for ten minutes, it is sterilised for drinking. Boiled water stays usable in a clean, closed pot or in an unopened, tightly-closed cooker.

Suitable pots for solar cookers

The best colour for pots is dull-black, which absorbs light well and converts it to heat. You can easily paint the outside of the pot yourself with a low-cost black heat-resistant paint. Do not paint the inside of the pot!

Materials for pots must resist, conduct and retain heat well. Cast iron, copper, aluminium and enamelled steel are suitable materials. The thicker the material is, the longer it takes to heat. However, thick material also stays warmer longer than thin material.

Keep the pots clean both outside and inside. If you have painted pots, and the surface has worn away, it is easy to repaint them.

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