Saving Biomass Resources Worldwide - Capturing heat: Five earth-friendly cooking technologies and how to build them

Aprovecho has been involved with stove design and cooking systems for more than fifteen years. The Research Center near Cottage Grove, Oregon was created by consultants to the Peace Corps and other Aid Agencies who worked overseas helping to create  The Winiarski Rocket Stove.

Deforestation due in part to fuel needs represents a major threat to ecosystems in many developing countries. Obviously, the answer to threatened forests is to grow trees at a faster rate than forest products are consumed. Wood can then be used at a sustainable rate, where less is taken than produced. Taking a greater amount insures a diminished resource and, if the trend continues, an eventual loss. Many countries in the world will run out of wood, long before they run out of gasoline and oil!

No cooking tool will be universally adaptable in different situations and cultures. One design will not be applicable to all settings, because resources, climates, acceptance, patterns of use, etc., vary from place to place. The designs presented here are single attempts at melding working principles with available resources, which includes the human component. All designs are expected to be modified to fit into a given situation. That's why Aprovecho believes very strongly in teaching people to be designers, not in just teaching designs. No single unchanging design can be considered an "appropriate technology"; local people must help in the design process to create a useful appliance.

The five cooking devices make up an integrated system of cooking that allows the user options and choices. Any design will help in cooking more efficiently, but using devices in combination can result in more dramatic


savings. For example, a fuel efficient stove coupled with an insulated cooker can save tremendous amounts of firewood. A fuel efficient woodstove, by itself, saves no more than 30 to 40 percent of the fuel used in cooking over an open fire. The use of an insulated cooker is essential.

This system involves designs that are easy to learn to make. When it's sunny, it's possible to cook using a very powerful solar oven, with many reflectors. You can boil water using sunshine by building a conical concentrator. When the sun isn't shining, which has been known to happen here in the Pacific Northwest, the staff at Aprovecho can cook using a "Rocket" wood fired stove which is very efficient and almost smoke free. Baking is done in a "Rocket" style bread oven, which is very inexpensive and can bake about 70 pounds of bread at a go. (Both the stove and oven were designed by Dr. Larry Winiarski.) Aprovecho very rarely does any simmering of food. Instead food ready to simmer is placed inside a well insulated box, where it finishes cooking without worries over scorching, boiling over and the like.

It's important for the appropriate technologist to introduce the element most likely to make a positive difference. For example, a Rocket stove can be less helpful than a Rocket bread oven in places where baking consumes a lot of wood. Building a bread oven may be the first priority. Insulated cookers can save more fuel than is gained by replacing an open fire with an efficient wood burning stove.

In a sunny climate, direct solar cooking may be the wisest choice. However, solar cooking is usually slow to be accepted because it is new and slower and a bit limiting. Starting out with a haybox, which is easier to use, might make more sense. In any event, knowing a range of options allows choices when


Conical Solar Cooker.

you're concerned with conserving natural resources, whether it's oil or wood or whatever. The appropriate technologist with a hundred designs in the back pocket seems more likely to produce an acceptable device, with local input, than the technologist with only a few designs back there! A good A.T. designer is a combination of engineer, anthropologist and political scientist.

Following are general descriptions for constructing each of these devices. Each is designed to be inexpensive and simple to build. All are in use at Aprovecho and you are sincerely invited to visit and experience these cookers in operation. Please feel free to adapt these ideas and principles to your unique situation and needs. The extent to which your needs end up being satisfied by your cooker, will determine how successfully we have combined to produce an appropriate technology.