Heather Little-White, Contributor

Phil Erro cooks vegetables on his solar oven in Fresno, California. - MCT Photos

Solar cooking is an environmentally friendly method compared to traditional forms. Solar cooking is simple, convenient and safe, and does not consume excessive fuel while taking the heat out of your kitchen. Alternative energy generated by the sun has been used for solar cooking with far-reaching social, economic and environ-mental benefits. In countries where people live on meagre incomes with massive wood and coal costs, solar cooking is a blessing.

Sun-generated cooking provides numerous benefits. Primarily, household nutrition is improved as moderate cooking temperatures in simple solar cookers preserve nutrients in foods. Further, very little water is needed for cooking, preventing the loss of water-soluble vitamins and other nutrients. Foods like legumes and wholegrains which require extended cooking times (three to four) can be frequently used in the diet because there is no concern about utilising expensive fuel such as gas or electricity. If beans are pre-soaked, solar cooking time will be reduced.

Speed cooking

The solar energy of the tropics and high altitudes is powerful for speed cooking. Quick solar cooking is influenced by:

Closeness to the Equator

Altitude

Time of year

Time of day

Weather conditions

Type of food

The person who is cooking saves time as there is no wood or coal to source. Certainly, solar cooking will not burn food and stirring is unnecessary because of the moderate temperatures of solar cookers. Water will boil in a matter of minutes in solar ovens. Food can be placed in a solar cooker and be left unattended for hours in the same way you would with an electric slow cooker.

Improved nutrition

In countries where families must trade scarce food for cooking fuel, solar cooking allows them to spend more of their budget on food for the household, subsequently improving the nutrition of family members. Solar cooking improves food safety through more efficient and safe ways of cooking food.

It has been carefully documented that refrigerated food placed in a solar box cooker in the morning several hours before the sun starts to heat up the cooker. When the sun's power hits the oven, the heating of food takes place quickly enough to reduce the danger of food poisoning. When food is cooked in the solar cooker it should not serve as a 'cooling box' as the lower temperatures in the box will create the environment to encourage the growth of bacteria and other microbes.

Smoke-free option

Half of the world's inhabitants burn wood to cook, but with fewer trees and the dwindling sources of wood for fuel, solar cooking should come into its own. Cooking fires are dangerous, especially for children, as they may easily get out of control.

Cooking over fires causes smoke-irritated eyes and may be linked to the growth of cataracts. Lungs become infected by smoke and lead to respiratory infections. Solar cookers are smoke free and pose no pollution threats to the environment. Besides, in rural areas, cookers eliminate the burdensome trips to gather fuel over several miles.

Water pasteurisation

Solar cooking improves food safety through more efficient and safe ways of preparing food.

Where supplies of drinking water are unsafe, solar energy allows for water pasteurisation to prevent water-borne illnesses, especially among children. Worldwide, approximately 1.3 billion people do not have access to safe drinking water. In areas like sub-Saharan Africa, sunshine is the only abundant source of energy that can be used to heat water to temperatures to kill harmful bacteria.

Louis Pasteur's groundbreaking research in the late 1880s demonstrated that heat kills disease-causing microbes. As such, the practice of bringing water to boiling point to kill bacteria has become commonplace. However, what is not well known is that contaminated water can be pasteurised by temperatures below boiling point for safe consumption. For example, bacteria such as E. coli, salmonella, rotavirus and V. cholera are killed rapidly at 140 degrees F or 60 degrees C.

Preserving fruits

Solar cookers have the capability to heat water for household chores, sanitise dishes and utensils, preserve tomatoes and fruits and kill insects in grains and other dry food staples. Health professionals use solar cookers to disinfect dry medical supplies such as medical instruments, bandages, and other cloth materials, as well as heat compresses.

Solar cooker business opportunities

Dyeing fabrics.

Boiling rice straw to make paper.

Extracting wax from honey.

Pasteurising potting soil.

Removing husks from rice grain.

Government benefits

Governments may also benefit by meeting fuel needs of health, nutrition and education sectors in line with the United Nations Millennium Development Goals. There can be enormous budget savings for institutional cooking fuels, disaster relief and refugee camps. Greater use of solar cookers can reduce the cost of biomass and fossil fuels. The use of solar cookers outside the kitchen reduces the circulation of heat in the house and places less load on refrigerators and air conditioners and lowering utility bills.

Solar technology involves a series of processes to trap solar radiation in a cooker where it is reflected off a surface and directed through a transparent cover where some radiation is absorbed, transmitted through and absorbed by the surface which gets hot and transfers heat to the food. The loss of heat to the surrounding atmosphere is minimised by thermal insulation. Box cookers are portable, of any size and they can carry several cooking pots designed for solar cooking. The pots are easy to clean, reducing time spent for washing up and limiting the use of water which may be scarce.

Meals in minutes

Sun-cooked foods retain their natural juices resulting with a superior, moist tasting product. Cooking with the sun appeals to gourmet food lovers, summer bakers, environmentalists and ice fishers. Foods that can be tastily cooked by solar energy under 30 minutes include marinated grilled steak with grilled onions; chicken with sesame sauce; easy pantry pasta; orange beef and broccoli and spicy sausage Jambalaya.

Rainy weather and overcast skies affect the utility of solar cookers. It is not possible to use solar energy to cook at these times or early in the morning as the success of solar cooking lies with an abundance of sun. When there is no sun, other low-emission, fuel-efficient stoves should be used for cooking. Where a main meal must be eaten after dark, it can be kept warm in a 'fireless cooker', which has insulation to keep food warm for several hours.

Early Jews

Historically, solar cooking was historically practised by a sect of Jews who gently heated wafers of ground sprouted grains on rocks heated by the desert sun. The goal was just to heat them to the point where the living enzymes would be preserved to make the food healthy for the body. A Swiss naturalist, Horase de Saussure, who is considered the 'Grandfather of Solar Cooking', built the first solar box that reached temperatures of 190 degrees F.

Cookers started evolving in the 1950s when top engineers were hired to study different aspects of solar cooking. The studies were funded by the United Nations to alleviate the reliance on plant life for fuel with the growth of deserts on arid communities. It was concluded that solar cookers could be constructed easily to cook foods thoroughly and nutritiously.

Solar cooking, an age-old technology, has been poorly understood. Besides, the information on its efficiency has not been widely disseminated. However, there is increasing interest in solar ovens with the rising prices of fuel and the need for alternative ways to cook efficiently. Solar cookers are an important addition to the kitchen and the potential for the development of solar cookers is a wide-open business opportunity.

Heather Little-White, PhD, is a nutrition and lifestyle consultant in the Corporate Area. Send comments to editor@gleanerjm.com or fax 922-6223.