Biogas


Turning Vietnam’s waste problem into clean energy


The Vietnamese government is among the sponsors of a project to build several thousand biogas systems in rural Vietnam – which will produce clean energy from pig farming waste. The project has already won an Ashden Award for sustainable energy, as Juliet Heller reports.


M


rs Do Thi Lap works hard farming pigs and planting tea in the Soc Son District of rural Vietnam. Until


recently her family has had to put up with the bad smells of the waste, and the prob- lem of how to get rid of it all. To cook the household’s meals she had to collect fuel wood that could take up to two hours a day. But her life has changed dramatically since buying a biogas plant. Now, she con- verts her pig waste to cooking gas and uses the slurry as a fertiliser for her crops. ‘My son sprays the tea bushes with the slurry and they’re growing a lot better. My cus- tomers say the tea tastes better too.’ Mrs Lap’s income has increased by a fifth since she purchased the system. There are farmers with piggeries right


across Vietnam, producing a vast amount of waste and nasty odour. Eight years ago, the Ministry of Agriculture and Rural Development (MARD) and a Dutch aid agency (SNV) joined forces to develop a nation-wide biogas programme which is turning Vietnam’s waste problem into a source of clean energy.


How biogas works Biogas plants use bacteria to break down wet organic matter like animal dung, human sewage or food waste. This process produces biogas – a mix of methane and carbon dioxide – and a semi-solid residue or slurry as a by-product. This gas is used as a fuel for cooking, lighting or electricity, and the slurry is used as a nutrient-rich fertiliser. Fixed dome plants have a combined slur-


ry container and gas container so that the gas collects under a rigid dome over the slurry. As the slurry breaks down, the bio- gas produced will push some of the slurry into a separate reservoir. To get it started, the biogas plant needs


some methane-producing bacteria (eg cow dung) and, once it starts producing biogas, the bacteria reproduce and keep the process going. MARD’s programme uses Vietnamese-


designed fixed dome plants, ranging from 4m3 to 50m3. The largest ones are used by semi-commercial-scale piggeries and poul- try farms. The smaller plants are used by families using dung from a minimumof six pigs and two cows, and many have the household toilet connected also. The fami- ly sized plant produces enough gas for all


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cooking needs and in some cases for light- ing too.


How the programme works Funding for the biogas programme is from the Dutch Ministry of Development Cooperation, SNV and theVietnamese gov- ernment. The programme aims to support the construction of 170,000 biogas systems by the end of 2012. Already over 100,000 installations have been completed in 43 out of 63 provinces in Vietnam, benefitting more than 500,000 people across the coun- try.


The programme is designed to create a


network of high quality technicians who can work as independent entrepreneurs. To achieve this, it trains local masons in how to build biogas systems and gives them business training in marketing and selling techniques. SNV gives advice and support throughout the programme and intends to hand over the programme to MARD at the end of 2012. The programme is publicised widely


through advertising, brochures, promotion vans and – most importantly – word of mouth. Farmers who want to buy a biogas system are invited to a meeting where the technology is demonstrated and, if they decide to sign up, they are put on a wait- ing list to be approved for a subsidised plant. After a plant has been installed, farmers


are given half a day’s training by the local technician, and given a handbook showing them how to use and maintain the plant. The plants are given a one-year warranty but are expected to last for 20 years or longer if they are properly maintained.


Finances Families pay for the cost of the biogas plant up front. A typical 10m3 household system costs around US$550 (around 70% for materials and 30% for labour) and a gov- ernment subsidy of $67 can be claimed when the plant is certified by aMARDtech- nician as working correctly. Most families use their own savings to


buy the system, typically saving for around 18 months, and some borrow from rela- tives. The bricks and other materials used to


build the biogas plants are local. Each sys- tem is built by a team of five masons, who are all trained by the programme but self- employed. Some of the trained masons are also commissioned privately to produce biogas plants outside of the programme, helping spread the biogas technology even further. Some technicians say they have built as many plants through these direct commissions as through the subsidised pro- gramme, which signals that a real commer- cial market for biogas is developing in Vietnam. This expanding market bodes well for the future of biogas beyond the life of the programme. In 2010, the programme was given an


award by the Ashden Awards for Sustainable Energy, in recognition of its achievements. According to Sarah Butler- Sloss, founder director of the Ashden Awards, ‘we have rewarded and supported many biogas programmes in Africa and Asia over the last 10 years. Butwhat is spe- cial about the MARD/SNV initiative is the effective partnership approach and their impressive efforts to expand the technolo- gy by investing in training and capacity- building.’


Multiple benefits Biogas is not only a free and clean cooking source – replacing LPG, coal, wood and agricultural residues – but it has a remark- able range of benefits. The families who use it value the fact that it gives them a simple way of managing pig manure, help- ing them keep their homes clean and stench-free, with fewer flies. The health benefits of cooking with bio-


Biogas gas holder and pipe, Thuong Do hamlet, Thuong Vu commune, Vietnam


gas include reduced indoor air pollution, which accounts for 1.6mn deaths a year worldwide, and improved hygiene and san- itation. Using slurry as a fertiliser also improves the nutritional content of crops.


Energy World April 2011


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