| Boiling Point No. 30 - April 1993 |
by Hitendra Pillay, University of South Pacific, Suva, Fiji, October 1992
Food in rural and pert-urban areas of Fiji and most South Pacific Island nations (SPI nations) is prepared over traditional 'open fires' with varying degrees of fuel economy. Like all 'open fire' cooking methods, the inconvenience and health risk associated with smoke is also a serious concern. Rural and pert-urban women in SPI countries, in particular Fiji, have expressed a widespread need for cooking methods which are cleaner, easier and more economical (Weir and Richolson, 1980; Joseph, 1984). Due to the sociocultural and economic differences it is impractical to have a single, domestic wood-stove design to suit everyone.
The need for suitable designs for domestic and institutional wood stoves for the SPI nations was realised in the seventies, but from nearly a hundred stove projects only ten made even limited impact on the intended communities. The high failure rate suggests that there maybe something wrong with the nature of these projects. Joseph (1984) and Gerders (1989) cited a number of review papers, addressing factors which might affect the impact and success of stove programmes. For example, the objections to using concrete as a stove construction material and the lack of user education programmes are pointed out in both reviews, yet subsequent designs and projects have done little to address these problems.
Dissemination has been the biggest obstacle facing the stove projects in Fiji and the root cause of the problem is in the product (stove) being seen as an intrusion in the user's lifestyle. Using a foreign design, suited to foreign cooking practice but fabricated in the local area by the local people, will not make the product easily acceptable. Either the product has to address the needs of the potential consumers, or the consumers' expectation of the product has to be changed through education. So far none of the woodstove projects has had an education programme planned within the project.
Although the stove projects in the Pacific showed some sensitivity to socio-cultural aspects associated with introducing new products, they missed some very fundamental considerations in product design and development. For example, do users want wood stoves in the first place or do they prefer kerosene or gas stoves? (The recent competition among gas suppliers in Fiji has made gas easily available and at affordable prices in rural areas of Fiji. Furthermore the cost of the gas stoves is also coming down.) Do they prefer multipot or single pot designs; are the woodstoves really energy efficient and easy to use (user comfort and convenience); is the cost of the improved stoves and woodfuel affordable without subsidy (subsidies cannot be provided indefinitely)? Unplanned subsidised projects cultivate a "handout mentality' end as soon as the 'handout' is stopped users may no longer be interested and as a result the project fails. This is one of the major causes for the large number of failed woodstove projects in Fiji and the Pacific.
It appears that without conducting a detailed design analysis including user needs, environment of use and cost effectiveness, the authorities concerned made decisions on behalf of the people. Obviously the people rejected the product.
Another issue related to user needs is that most previous research and design involved adaptation of stoves developed elsewhere; ea. the Indian CHULHA and the JALEF stove. The concept of adapting designs from elsewhere is useful provided the new user environment and user needs and producer (socio-cultural, economic and technical skills) are considered when modifying the design. The design attempts mentioned earlier mostly concentrated on stoves for cooking in pots and in most cases for more than one pot in contradiction with the traditional food preparation methods and the lifestyle of SPI people. Using multipot stoves to reduce cooking times is not a major concern. Their socio-cultural values cultivate a very relaxed attitude towards life. Commercial objectives such as fuel saving or time saving are often not important; perhaps there is scope for an education programme.
The stove design analysis for most of the stove projects indicated metal as the construction material, but none of the prototypes developed so far has been fabricated from metal. The argument that heat radiation from the surfaces of metal stoves is very uncomfortable for the user may be true for closed kitchens but, in the Pacific, most cooking places are sheds with about 600mm high wall-cover. This allows free air flow which in turn keeps the kitchen environment quite comfortable (again, this indicates a lack of research into the environment of use). The cracking problem associated with concrete should have encouraged experimentation with metal or other alternatives, but this did not happen. The lack of sufficient knowledge regarding the types and associated properties of clay available in the Pacific region prevented the use of clay.
In 1991 the Technology Department at the University of the South Pacific was approached by the Department of Energy (Fiji) to design, build and test a prototype of a domestic woodburning stove. In accordance with design procedures (Archer, 1965), the user needs and the environment of use was researched. With assistance from the Home Economics Department at USP, a survey of SPI food preparation techniques was undertaken. It was established that most Pacific Island food is either boiled or baked in underground pits which act as ovens. As a result of the survey, the need for both direct heat (fast cooking) and low heat (slow cooking) such as an oven was identified. The traditional food preparation technique cooks one food at a time. Cooking-time efficiency is not a major concern as most women in rural areas stay home. Perhaps this is where stove education dealing with time management, which in turn will influence energy conservation, may be useful.
To meet the user requirements the new design has an integrated stove/oven configuration. The SPC had previously carried out some work on drum-type oven design using clay and the DOE had worked on a multipot insert-type stove with a bread oven. The University of South Pacific 'Tech Dept' stove allows the use of two sizes of pots, one at a time. But this does not prevent the use of other size pots which can sit on the top plate. The stove can also be used to cook 'rot)' (similar to chapatis). The design has a firebox, a pot hole, an oven and a chimney as its principle components. The entire stove is made from steel plates of various thicknesses; bent and welded together for the firebox, rolled and welded for the oven. The chimney is rolled out of 20 gauge galvanised sheet. The overall dimensions of the stove are, length 72.5cm, width 30.0cm and height 42.5cm (excluding the chimney - see Fig 1).
The final dimensions of the firebox were obtained after experimenting with the draught to optimise the heat generated. This was effected by varying the opening, ie. the clearance between burning wood and the top plate of the firebox and also adjusting the damper in the flue (not shown). The oven design has two concentric drums, between which hot air from the firebox passes before being released through the flue. Because the hot air comes from one side of the oven the position of the inner drum is important if uniform heating is expected in the oven. With the help of four bolts (not shown), screwed in or out as required, the inner drum was aligned in a suitable position.
The heat from the cooking stove also heats the oven. When the pot seat is not in use a cover closes the opening. The best energy efficiency is obtained when both the stove and the oven are used simultaneously. As cooking simultaneously is contrary to the established cooking practice in the SPI, stove education programmes need to emphasis the related advantages, such as less wood required and time saving.
The prototype was subjected to the VITA Water Boiling Test (WBT) at the stove testing laboratory of the University of South Pacific. The stove was tested for high power phase and low power phase. (In the high power phase a predetermined quantity of water is heated as quickly as possible from the ambient temperature to boiling. The low power phase follows immediately after the high power phase and is the lowest power needed to keep the water simmering for another 30 minutes.)
Some cooking tests were also done. A typical meal for a family of two was prepared which took 36 minutes in the oven using 1.632 kg of wood with 0.16 kg of charcoal remaining and 25 minutes on the stove consuming 0.666kg of wood with 0.070kg of charcoal remaining.
Although the Technology Department stove is still in the prototype stage, it has shown potential. A quick cost estimate suggests that, on a commercial basis, the stove could be produced for about $100 (Fijian) which is still not very cheap when compared to imported two burner gas stoves selling for $75 (Fijian).
Ed Note: We hope to he able to report developments in future editions of Boiling Point.