Improved cookstoves and modern fuels
Since cooking using traditional biomass fuels is both the
dominant energy activity in developing countries and is the source of undue
hardship to people living in poverty, the dissemination of more efficient
cookstoves using traditional or modern fuels is an essential sustainable energy
intervention. Depending on relative fuel and stove prices, substantial
reductions in both operating costs and energy use can be obtained from switching
from traditional stoves using commercially purchased fuelwood to improved
biomass, gas, or kerosene stoves.
Several important lessons have been learned from the hundreds of
cookstove demonstration and dissemination programmes that have taken place in
developing countries, many of which were not initially successful. Cookstove
design has since been geared to maximise combustion of fuel, maximise radiative
heat transfer from the fire to the pot, maximise convection from the fire to the
pot, and maximise conduction to the pot. Most importantly, it aims to maximise
user satisfaction by making the stoves convenient to use (with local fuels,
cooking pots and utensils) and able to easily prepare local dishes well (Kammen,
1995). Primarily, the end-users (mainly women) must find the stoves easy to use
and fuel efficient under a variety of conditions. The stoves must also perform
robustly in the environmental and practical constraints of indoor or outdoor
kitchens.
In rural areas of developing countries, traditional fuels -
wood, crop residues, and dung-remain the primary cooking fuels, while in many
urban areas, charcoal is used also. About 2 billion people depend on these crude
polluting biomass fuels for their cooking and other energy needs. Higher incomes
and reliable access to fuel supplies enable people to switch to more modern
stoves and cleaner fuels such as kerosene, gas, dimethyl ether, electricity,
and, potentially, to modern biomass - a transition that is widely observed
around the world largely irrespective of cultural traditions. These technologies
are preferred for their convenience, comfort, cleanliness, ease of operation,
speed, efficiency, and other attributes. The efficiency, cost, and performance
of stoves generally increase as consumers shift progressively from wood stoves
to charcoal, kerosene, LPG or gas, and electric.
Depending on relative fuel and stove prices, substantial
reductions in both operating costs and energy use can be obtained from switching
from traditional stoves using commercially purchased fuelwood to improved
biomass, gas, or kerosene stoves. There may be opportunities to substitute high
performance biomass stoves for traditional ones or to substitute liquid or gas
(fossil- or biomass-based) stoves for biomass stoves. The key to success in
dissemination is persistence and a sound approach, including careful market
assessment, product design, production testing, market trials and help with
commercialisation. One example of a successful programme has been in Ethiopia,
where a British NGO, Energy for Sustainable Development, has developed and
commercialised two types of improved biomass cookstoves through an iterative
approach of needs assessment, design, product trials, redesign and performance
monitoring. The team works with households, stove producers, installers and
merchants and pays attention to promotion, technical assistance, quality control
and to the provision of business, management and marketing skills to producers.
Over 600,000 stoves of one type, and 54,000 of a second type introduced a few
years later and using about half the fuel of conventional stoves, have been
disseminated, with volumes expected to increase substantially in subsequent
years (EC/UNDP,
1999).