Over ten years ago when the poorest residents of Nairobi started making briquettes out of charcoal dust, they were trying to solve an immediate household problem of unaffordable fuel. Today, their work is helping overcome some of Kenya’s capital city’s most intractable headaches—poverty, unemployment, and poor waste management—and contributing to the country’s sustainable development aspirations, too.
Charcoal briquettes are made by mixing charcoal dust with water and a binding agent such as soil, paper or starch. The resultant ‘dough’ is shaped by hand, or moulded in wooden or metal presses into fist-sized units, which are then air-dried. Women and youth make up the majority of those employed in this informal industry.
By 2010 some of the most successful community groups in Kibera, Kahawa Soweto, and similar low-income neighbourhoods in Nairobi were making up to $2000 monthly from the sale of charcoal briquettes, and women were slashing their cooking-fuel costs to a tenth or less, says a recently published study in the International Journal of Renewable Energy Development. The briquette trade is spreading to rural areas of the country, too.
Milka, a 30-year-old mother of two and a member of the self-help group ‘Kahawa Soweto Youth in Action’, makes her living by selling charcoal briquettes made by her group in Nairobi to residents of a village called ‘Engineer’ about 80 km west of Nairobi, and in Limuru and Kirinyaga. ‘Engineer’ village abuts the Aberdare forest, one of Kenya’s most important water catchment areas and game reserves.
“Instead of spending hours collecting firewood, the women in these villages buy my briquettes because it allows them to spend more time on farming,” says Milka. “It also relieves them of the pain of carrying firewood on their backs for several kilometres daily.
Converting charcoal dust into usable fuel contributes towards Kenya’s national development aspirations in many important ways, says Mary Njenga, a doctoral fellow with the World Agroforestry Centre (ICRAF) and lead author of the new study. “By saving trees that would otherwise be cut down for charcoal or firewood production, briquetting is protecting the country’s forest, savanna and dryland habitats, and contributing towards the country’s reaching its 10% forest cover target by 2030. It is also easing the energy demand from fossil fuels and grid electricity.”
Njenga says briquetting is helping resolve the cooking-energy poverty faced by the poorest households.
Along with co-researchers from the University of Nairobi, University of Tsukuba in Japan; the Swedish University of Agricultural Sciences in Uppsala; and partner NGOs, Njenga found that the poorest urban households often selected foodstuffs they could cook in the shortest time regardless of their nutritional value, in order to save on energy.
“With charcoal briquettes it costs just 3 Kenya Shillings (US$0.04) to cook a traditional meal of maize and beans for a standard household of 5 people. This is nine times cheaper than cooking the same meal with charcoal (KSh 26 or US$0.3) and 15 times cheaper than cooking with kerosene (KSh 45 or US$0.6). As such, households are now able to choose from a wider dietary range,” says Njenga.
As part of the research, Njenga herself made charcoal briquettes using various binding agents, and compared their energy values. Those using ordinary printing paper as a binder produced 25 –27 kilojoules of energy per gram (KJ/g), while those made using soil as a binder produced 25 KJ/g. These values are similar to commercial charcoal’s 25 KJ/g, and between 25–75% higher than briquettes made by community groups in Nairobi. Njenga says this points to a need for capacity building for local communities, to improve the quality of the briquettes they produce.
Some 2.4 million tonnes of charcoal are traded in Kenya annually, over eighty percent of it in urban areas. Breakage during handling and transit leaves in its wake large mounds of charcoal dust at retail and wholesale outlets. This is the raw material for charcoal briquettes, which burn even cleaner than charcoal.
The clean burn of charcoal briquettes dramatically reduces indoor air pollution, one of the leading causes of the 400,000 deaths from respiratory diseases that occur each year in sub-Saharan Africa.
The huge potential for briquetting to contribute to sustainable development, however, needs enabling policy support, which would allow local authorities to provide various types of assistance to bring about efficiencies and reduce risks for briquette producers.
“Space to make and sell the briquettes, reliable and affordable water, and better links with institutions generating waste paper, are just a few examples of support that would really help community groups,” says Njenga.
Dr. Ramni Jamnadass, a co-author of the study and leader of the Tree Diversity, Domestication and Delivery programme at ICRAF, hastens to add that the dependence on charcoal in African cities will be with us for the foreseeable future. As such, purposeful cultivation of trees for charcoal burning must go hand in hand with support for briquetting.
Rather than traditional harvesting of natural vegetation, Jamnadass recommends short-rotation forestry with the right tree species grown in woodlots and agroforestry farms, to supply wood for charcoal production. The right tree species can result in higher charcoal production per unit biomass, and charcoal yield can be more than doubled by shifting from a low-efficiency to high-efficiency kilns, she emphasizes.
“Most of the charcoal in East Africa comes from dryland agroecologies, and the choice of tree species for charcoal production is critically important. The hardy Acacia mearnsii farmed in woodlots, for instance, yields 3.5 times more charcoal than from naturally occurring Acacia drepanolobium,” says Dr. Miyuki Iiyama a scientist at ICRAF and co-author of the new study.
Implications of Charcoal Briquette Produced by Local Communities on Livelihoods and Environment in Nairobi, Kenya. By M Njenga, A Yonemitsu, N Karanja, M Iiyama, J Kithinji, M Dubbeling, C Sundberg and R Jamnadass (2013). International Journal of Renewable Energy Development 2 (1)
Charcoal Production and Strategies to Enhance its Sustainability in Kenya.. By Mary Njenga, Nancy Karanja, Cristel Munster, Miyuki Iiyama, Henry Neufeldt , Jacob Kithinji and Ramni Jamnadass (2013). Development in Practice, 23 (3) 303-314
The Alternative Charcoal Tool (ACT), a screening tool for alternative feedstocks for charcoal production in developing countries.
Planet Forward Interview with Mary Njenga
Miti na mazingira radio broadcast on DW