Arizona Solar Center Blog

Overcoming fuel shortages in developing nations

The energy problem is far more extreme in less-developed parts of the world than in the United States. In places like eastern Africa, natives have trouble finding sufficient firewood to cook dinner or heat water to kill bacteria. Women sometimes walk 20 to 30 miles to obtain only a two-day supply of cooking fuel.

The simple solar box cooker is helping people to stay healthy in places such as Zimbabwe, Bolivia, Guatemala, Kenya, Haiti, and Pakistan. In Botswana in 1988, for example, solar box cookers were introduced because of a 50 percent malnutrition rate. This devastating health problem was not caused by food shortages but by a lack of fuel.

Two Arizona women created these cookers, Barbara Kerr, a nurse from Taylor, Arizona, and Sherry Cole, a former freelance writer from Tempe. Their solar box cookers reach temperatures as high as 325 degrees Fahrenheit and easily kill cholera bacteria at 150 degrees. The cookers are constructed with two corrugated boxes, one smaller than the other, 100 feet of aluminum foil, a pint of glue, a lot of newspaper, and a sheet of glass.

Kerr, and Cole’s first box cooker was created in the 1970s, and the first sale went to microbiologist Bob Metcalf of California University in Sacramento. Metcalf formed the organization Solar Box Cookers International in 1987 to promote the cookers for health and environmental benefits worldwide. The group’s expeditions have received support from the Pillsbury Co. Meals for Millions Applied Nutrition Project, Foster Parents Plan and Food Industry Crusade Against Hunger.

Overcoming fuel shortages in developing nations

The energy problem is far more extreme in less-developed parts of the world than in the United States. In places like eastern Africa, natives have trouble finding sufficient firewood to cook dinner or heat water to kill bacteria. Women sometimes walk 20 to 30 miles to obtain only a two-day supply of cooking fuel.

The simple solar box cooker is helping people to stay healthy in places such as Zimbabwe, Bolivia, Guatemala, Kenya, Haiti, and Pakistan. In Botswana in 1988, for example, solar box cookers were introduced because of a 50 percent malnutrition rate. This devastating health problem was not caused by food shortages but by a lack of fuel.

Two Arizona women created these cookers, Barbara Kerr, a nurse from Taylor, Arizona, and Sherry Cole, a former freelance writer from Tempe. Their solar box cookers reach temperatures as high as 325 degrees Fahrenheit and easily kill cholera bacteria at 150 degrees. The cookers are constructed with two corrugated boxes, one smaller than the other, 100 feet of aluminum foil, a pint of glue, a lot of newspaper, and a sheet of glass.

Kerr, and Cole’s first box cooker was created in the 1970s, and the first sale went to microbiologist Bob Metcalf of California University in Sacramento. Metcalf formed the organization Solar Box Cookers International in 1987 to promote the cookers for health and environmental benefits worldwide. The group’s expeditions have received support from the Pillsbury Co. Meals for Millions Applied Nutrition Project, Foster Parents Plan and Food Industry Crusade Against Hunger.

Solar cooking tips

Safety:
· Solar cookers may not look hot, but temperatures of 120 to 425 degrees will certainly burn your fingers. Use potholders.

· Intense reflected light could permanently damage your eyes. Children in particular have a tendency to stand in the brightness of reflected light and should be carefully watched around solar cookers.

· Keep the lid closed so that appetizing fumes, do not escape into the air and attract animals and insects. If a curious animal does approach the cooker, a closed lid prevents unwanted dinner guests. 

Foods:
Solar chefs are limited only by their imagination. Almost any dish becomes a delicious treat when cooked in a solar cooker –beans, bread, cookies, roasts, vegetables and many others. 
Most standard recipes translate favorably to solar cookers but require less water or liquid. Solar chefs also find they need less salt and sugar in solar-cooked foods because of the gentle cooking process.

Temperature and Timing:
Solar cookers should be placed in the sun and preheated for at least one hour before placing food inside. Many, high-quality solar cookers reach temperatures of 350 to 425 degrees or more and cook dinner in the same amount of time as conventional ovens. Other models reach temperatures of only 150 degrees. A barbecue thermometer is a useful tool. 

To reach maximum temperature and fastest cooking time, the cooker should be aimed directly at the sun. It should be turned every 20-30 minutes to maintain a direct angle. Some solar chefs setout cookers in the morning, aiming them toward the sun’s midday position. By late afternoon, dinner is ready to eat without ever refocusing the cooker.  

Cooking between the hours of 10 a.m. to 2 p.m. is best in Arizona’s winter months. In summer, the sky’s the limit!

Solar cooking tips

Safety:
· Solar cookers may not look hot, but temperatures of 120 to 425 degrees will certainly burn your fingers. Use potholders.

· Intense reflected light could permanently damage your eyes. Children in particular have a tendency to stand in the brightness of reflected light and should be carefully watched around solar cookers.

· Keep the lid closed so that appetizing fumes, do not escape into the air and attract animals and insects. If a curious animal does approach the cooker, a closed lid prevents unwanted dinner guests. 

Foods:
Solar chefs are limited only by their imagination. Almost any dish becomes a delicious treat when cooked in a solar cooker –beans, bread, cookies, roasts, vegetables and many others. 
Most standard recipes translate favorably to solar cookers but require less water or liquid. Solar chefs also find they need less salt and sugar in solar-cooked foods because of the gentle cooking process.

Temperature and Timing:
Solar cookers should be placed in the sun and preheated for at least one hour before placing food inside. Many, high-quality solar cookers reach temperatures of 350 to 425 degrees or more and cook dinner in the same amount of time as conventional ovens. Other models reach temperatures of only 150 degrees. A barbecue thermometer is a useful tool. 

To reach maximum temperature and fastest cooking time, the cooker should be aimed directly at the sun. It should be turned every 20-30 minutes to maintain a direct angle. Some solar chefs setout cookers in the morning, aiming them toward the sun’s midday position. By late afternoon, dinner is ready to eat without ever refocusing the cooker.  

Cooking between the hours of 10 a.m. to 2 p.m. is best in Arizona’s winter months. In summer, the sky’s the limit!

Design of Solar Cookers

The Box Cooker

Design of Solar Cookers

The Box Cooker

Costs: Cooking while reducing summer cooling bills

The initial cost of a solar cooker depends upon its size manufacturer and sophistication. Store bought models range in cost from $100 for camping sizes and up to $250 for larger versions.

The cost of homemade cookers depends largely on the builder’s resourcefulness – new materials, for example, cost more than used. Some do-it-your–selfers use only cardboard box, newspaper for insulation, aluminum foil and a piece of glass or plastic. Others include hinged aluminum reflectors, spray in insulation, and tools for cutting metal to make the inside box. Other builders even place their cookers on old rotating television stands for easy adjustment as the sun moves across the sky.

Costs: Cooking while reducing summer cooling bills

The initial cost of a solar cooker depends upon its size manufacturer and sophistication. Store bought models range in cost from $100 for camping sizes and up to $250 for larger versions.

The cost of homemade cookers depends largely on the builder’s resourcefulness – new materials, for example, cost more than used. Some do-it-your–selfers use only cardboard box, newspaper for insulation, aluminum foil and a piece of glass or plastic. Others include hinged aluminum reflectors, spray in insulation, and tools for cutting metal to make the inside box. Other builders even place their cookers on old rotating television stands for easy adjustment as the sun moves across the sky.

How Solar Cookers Work

These solar cookers operated on the same principles as cookers of today. An insulated box is covered with a clear window allowing access to light. The light rays are absorbed by the cooker’s inside surface and are transformed into heat energy. Heat radiates out from the surface and collects inside the cooker. Some of it escapes back through the window or “cracks” in the cooker, but not as quickly as additional light enters.

How Solar Cookers Work

These solar cookers operated on the same principles as cookers of today. An insulated box is covered with a clear window allowing access to light. The light rays are absorbed by the cooker’s inside surface and are transformed into heat energy. Heat radiates out from the surface and collects inside the cooker. Some of it escapes back through the window or “cracks” in the cooker, but not as quickly as additional light enters.

The delicious way to save energy and money

As many as 500 people gather each year for an annual potluck near Tucson. They eat vegetables, bread, pie and lasagna – typical foods at many such gatherings. This potluck, however, is vastly different from most because all the food, even the pizza, is cooked on-location by the sun

The delicious way to save energy and money

As many as 500 people gather each year for an annual potluck near Tucson. They eat vegetables, bread, pie and lasagna – typical foods at many such gatherings. This potluck, however, is vastly different from most because all the food, even the pizza, is cooked on-location by the sun

Glossary

Natural Cooling

Passive cooling techniques can be used to reduce, and in some cases eliminate, mechanical air conditioning requirements in areas where cooling is a dominant problem. The cost and energy effectiveness of these options are both worth considering by homeowner and builders. Contained within this section are rules of thumb and an explanation or the essentials of passive cooling systems.