Researchers have sold over 1 000 solar stoves to rural families in Senegal in a bid to prove that the ovens can improve child and maternal health and reduce household fuel consumption.
Many institutions, including the World Health Organisation (WHO), have backed these claims but to date no scientific evidence has been gathered.
The University of California at Berkeley’s Centre for Evaluation of Global Action (Cega) is undertaking the first study of solar stoves, evaluating the impact of the stoves on the lives of the families who bought them six months ago. The families live in the Thiès region, 70km east of Dakar.
”This is a big innovation,” Theresa Beltramo, one of the lead researchers, said. ”A randomised trial such as this can greatly contribute to the public good by giving scientific evidence of the impact of solar stoves.”
Eva Rehfuess, an expert with WHO’s Department for Protection of the Human Environment, says half the world’s population uses solid fuel – usually wood, charcoal or dung – for household energy, which produces harmful smoke and causes 1,5-million deaths a year, most of those of children.
Pneumonia, linked to indoor air pollution, is the leading killer of children under five worldwide, according to WHO.
Solar benefits
Solar stoves, which reflect energy from the sun’s rays to heat food, do not emit harmful smoke and so are a safe way to cook, says Marie-Ange Binagwaho, director of Solar Household Energy, a US-based non-profit organisation promoting solar energy solutions.
Researchers use ”carbon diffusion tubes” similar to those used by firefighters to measure the amount of carbon monoxide women inhale as they cook.
”We are also measuring the amount of wood consumed daily, how much time [women] spend collecting wood and how often the solar stoves are being used,” Beltramo said.
Researchers are evaluating the families against a control of 500 households who did not buy the solar stoves.
Beltramo hopes the study will prove solar stoves can improve users’ health, reduce fuel usage, and cut the amount of time people spend collecting wood or other fuels.
Villagers upbeat
Cega’s Beltramo says villagers’ response to the stoves has been largely positive.
”Cooking is cleaner with this stove – there is no smoke, my children don’t breathe the smoke,” Ndella Gueye, in the village of Keur Ibra Fall, said.
Fama Mbaye, mother of four, said the stove has saved her time and lowered her kerosene consumption. ”I have a few extra hours while I wait for the stove to cook the food and I use the time to sew clothing to sell.”
She said she preferred the taste of food cooked in a solar oven: ”The taste is better because it heats without smoke and it conserves the taste of the food.”
Limitations
But despite the stoves’ potential, there are financial and practical limitations to their use in Africa, according to Beltramo.
”The cost of importing a stove can reach up to $100,” she said. ”So at the moment, if we sell the stove at $4, they must be subsidised up to 96%. That is not sustainable.”
Solar products have to be imported because essential materials are not available locally. This increases their cost.
Cody Donahue, monitoring and evaluation coordinator of international NGO Tostan, which distributed the stoves, said Tostan had to raise the subsidy because families had so little spare cash due to high food and fuel prices.
Senegalese earn on average less than $2 a day, according to the Organisation for Economic Cooperation and Development.
The stove is also too small to cook for the average Senegalese family, Donahue pointed out.
”Families are big and the solar stove is too small to prepare a thiébou dieune [traditional meal of rice with fish], so they use more than one stove or they use the solar stove only to make side dishes or to cook doughnuts for sale.”
Some villagers, put off by the time solar cooking requires, prefer to stick to traditional wood-fired preparation techniques.
”The stove needs to be bigger. But if the size is right, there is a huge possibility for change in health and also an opportunity for women to pursue other activities besides cooking,” Beltramo said.
Scaling up
WHO’s Rehfuess said to make such schemes work in the long term, the private sector and government must invest in national alternative energy programmes to bring down costs.
”Clearly not enough is being done,” Rehfuess said. ”There are lots of highly motivated organisations working on local initiatives, but if we really want to solve the problem, we need a much greater scale of attention and action.”
For Beltramo, the sustainability of the initiative relies on finding a market-based solution by forging links with the carbon credit market.
Governments and private companies can ”offset” excess carbon emissions by investing in emissions- reduction projects, such as alternative energy schemes, and thereby buying ”carbon credits”.
”Fuel efficient stoves are not officially on the carbon credit market but there is a viable alternative voluntary market used by a lot of companies,” Beltramo said.
One step at a time
The Senegalese Ministry of Biofuels and Renewable Energy is entering into an agreement with Solar Household Energy to produce and sell the stoves locally.
”We hope to make solar stoves available in all 11 regions of Senegal,” said Abdoulaye Touré, solar energy specialist at the ministry.
For Rehfuess there is no time to waste. ”We’ve known about the link between indoor air pollution and respiratory disease for over 100 years but it is taking a long time for everyone to become aware of the scale of the problem.”
Preliminary results of the Thiès solar oven research are due in January 2009. – Irin