| Boiling Point No. 20- December 1989 |
Extracts from a Progress Report by Mark Waltham, (ITDG) on "Low-Wattage Cooker Development" in Nepal, October 1989. (This refers to the article "Electricity Storage Cooking" in Boiling Point No.12, April 1987, which presents part of Ben van Wijhe's proposal for promoting 200W electric cookers in rural Nepali villages.)
"As part of its micro-hydro programme, ITDG is investigating the possibilities of using off-peak electricity rather than wood for cooking. The Low-Wattage Cooker project is the first of these initiatives.
The research and development of the Low-Wattage Cooker has been performed by Development and Consulting Services (DCS) in Butwal (DCS is a joint Nepali venture between HMGN's Directorate of Cottage and Village Industries and the United Mission to Nepal). DCS are experienced micro-hydro engineers, having installed 24 schemes in the last three years alone. Known as the "Bijuli Dekchi", the Low-Wattage cooker consists of two locally available aluminium cooking pans, one fitting inside the other. A low wattage heating element is attached to the bottom of the inner pan. The air gap between the two pans acts as an insulator and reduces heat lasses through the sides and base, resulting in a highly efficient cooker. (A litre of water can be bought to the boil in about half an hour). It has been found that a mere 200W is sufficient to cook rice, dahl, tea etc. The inclusion of a thermoswitch not only protects the pan from boiling dry but turns the Dekchi into an automatic rice cooker. Dekchis have been built in 2, 4, and 8 litre models, these sizes being chosen to enable most household cooking tasks to be performed quickly and efficiently.
Field testing was seen as an integral part of the development process and has been performed continuously, if on a small scale, during the last two years. A large scale field trial will soon be performed in Mustang District. At least 90 Low-Wattage Cookers will be introduced to Jharkot where a 36kW micro-hydro plant is being installed by the Andhi Khola Hydel and Rural Electrification Project.
The Low-Wattage Cooker has been specifically designed for local manufacture. In the early stages of development, the two pans were welded together but it has been found that a rolled joint is cheaper, easier and just as satisfactory. One engineering company in Butwal has already begun to manufacture Low-Wattage Cookers. The first production run of 300 units has been completed."
Ed Note:- Since the element is sealed into the gap, and welding aluminium or reseaming the 2 pans is difficult, replacing the element if it breaks could present a problem. On the other hand, the cookers have lasted well for the two years of teals. In the event of breakages in the future, the material could be recyled in the factories and/or a modification to design a resealable bottom might be considered The cookers are expensive at Rs.1500 (approximately 30 pounds) for a set of three, and about I for each thermoswitch alone.
Ben van Wijhe points out in his paper 'The Bijuli Dekchi - Addressing Nepal's Energy Crisis" (April 1989), that ''no matter how sound a technical solution, its success will mainly lie in its social acceptability". He explains that the difficulties involved in substituting electricity for firewood include the following: the initial investment could be a stumbling block for rural households; the open fire provides not only space heating, light and smoke (which preserves food and keeps insects away), but has a social and religious significance; people have to change their cooking habits (stirring is not possible and cooking must be done in stages); and these electric cookers can not be used for frying, baking, and roasting. They are clearly a second stove rather than a replacement for fire.
Van Wijhe adds, on the other hand, that electric cooking is more convenient, cleaner, and healthier. Also, once the investment has been made, it provides electricity users with the opportunity to make the best use of the supply (when it is charged by power units (W) rather than energy units (kWhs)). For example, a household using electricity for lighting during the evening can connect low-wattage cookers at other times at no extra cost. User acceptability has already been tested on a small scale with positive results. The International Centre for Integrated Mountain Development is undertaking a study to assess the effects of the scheme, with an emphasis on the social acceptance of the Low-Wattage Cookers and the amount of firewood and kerosene that is displaced.
Andy Brown (ITDG) adds that in view of the increased awareness of electric cookers in Nepal, and a national and international concern about the fuelwood crisis, ITDG will also be initiating further research into heat storage technologies for cooking, water and space heating. Heat storage cookers have already been tested in China, Colombia, and Sri Lanka and ITDG is presently putting in proposals to ODA to conduct research into these technologies, which make greater use of the benefits of micro-hydro power. Other sources of power (eg.solar) would not be economically feasible, but there is a potential urban or pert-urban market amongst grid-connected users. Under the increasingly popular split tariff systems the heat storage technology can be connected during cheap rate (off-peak) periods, usually at night, and used during the day.