| Boiling Point No. 31 - August 1993 |
Waclaw Micuta of REDI (Renewable Energy Development Institute, Geneva) summarizes his experiences and conclusions of 17 years of work developing and promoting improved cooking stoves for low income people in developing countries.
In Europe, knowledge of building stoves and their proper use has been developing for several centuries. In the 19th and 20th century stoves of stone and brick were progressively equipped with iron components. Masonry stoves for space heating survived longer but have been generally replaced by gas, oil or electricity heated appliances. This development called for specialized enterprises staffed with skilled workers who produce, install, maintain and repair stoves. All over the world stoves for heating and cooking are among the most needed consumer goods.
The author and his friend, Emil Haas, professional stove maker, worked in Africa for many years with the Bellerive Foundation and later with REDI in various countries on improving clay and metal stoves for domestic and institutional use. Their aim was to adapt the efficient stoves developed in Europe to the conditions prevailing in developing countries. Their improved designed clay stoves reached 30-50% fuel efficiency with 50-60 grams of wood per litre of boiling water.
The reasons for their limited success were the poor quality of clay available (good clay was rare and costly), the hard work of preparation, high transport cost, poor durability, lack of maintenance and repair and lack of acceptance by women users because they wanted more attractive, modern looking stoves.
Micuta and Haas then turned their attention to community cookers which were consuming a vast volume of wood and charcoal and presenting a serious environmental and health problem. In 1983, with the assistance of Bellerive Foundation, they developed community stoves of 500 to 200 litre capacity, which were fuel efficient, convenient and were cheaper than those imported from abroad. The first models were built of clay with cast iron fire-boxes, a sheet metal heating plate attached to the body and stainless cooking pots produced in Nairobi to their design.
In 1983 they built eight, 200 litre stoves in Kenya, using brick and sheet steel outer case. From 1986 they changed to all metal stoves which were built to suit local needs in various countries. Emil Haas died in January 1992 but the author continues Emil's work on stoves with the new team of retired, highly qualified technicians striving to obtain high performance with simplicity and low prices. One example of their efforts is a stove for Somalia requested by the International Committee of the Red Cross, ICRC. It consists of a firebox made from pieces of concrete iron rods, a windshield of oil drum steel with the door and 110 litre pot made from half a standard oil drum. The stove has fuel efficiency of 46.7% at boiling point, specific fuel consumption of 51gm of wood per litre boiling water and an average power output of 6.1 kW. Out of three oil drums, two complete stoves are made including pots, lids and doors.
The results achieved by REDI's team attracted attention of international organizations responsible for emergency actions. ICRC asked REDI in 1992 to design heating and cooking stoves for refugees in Bosnia and later to launch local production of 15,000 complete units including 15 litres pots and sheet metal chimneys. Production of a new series of 20,000 units started soon in 1993. Similar action is at present envisaged by the UN High Commissioner for Refugees. The stove heats premises by circulation of air. It produces 100m3/ hour of air at average 73°C. 10 litres of water at 10°C boil in 27 min. Temperature of the heating plate comes to above 300°C and average power output is 7 to 8 kW.
The work on community stoves helped REDI team to find solutions for simple yet efficient family stoves which could replace cooking on three stones or on charcoal braziers. Their conclusion is that all that is needed for a good stove is good combustion of fuel and good recuperation of the heat produced. Use of chimney is optional. This could be done with a well a conceived fire-box with a platform for cooking pots and a windshield which protects the fire, keeps hot gases close to the pot and controls air input with a simple door. Stoves like that should cost no more than the traditional Kenyan "Jiko" and would economize 90% of wood as compared with cooking on charcoal. They would help to protect cooks against serious health problems inevitable with charcoal cooking. The main difficulty in promotion of such stoves would be the need to cut dry wood into small pieces and the need to control air input. To cut out the need for a welded rod firebox, a sheet metal version was developed in 1992 by two REDI associates, Mr Rossier and Mr Schilling at the cost of 6 US dollars per stove (which includes workers wages).
The task of developing local stove industries in developing countries has proved arduous but the author believes there is no other way to achieve a wide spread dissemination of good stoves. People in developing countries should not wait for some miraculous stove which does not exist but should go ahead with designing and building stoves to suit their own needs and capabilities.