Tag Archives: biogas

Building a Sustainable Market for Biodigesters in Vietnam – SNV World/EnDev

Since 2003, SNVWorld, with funding from the Netherlands Ministry of Foreign Affairs (DGIS), have been working to develop the biogas and biodigester sector in Vietnam. SNV to date have been providing technical assistance and developing financial capacity in conjunction with the country’s Ministry of Agriculture and Rural Development, with the Department of Livestock Production under the MARD acting as the implementing partner for the project. Vietnam is particularly suitable for the development of biodigester technology, given the high prevalence of livestock farming and the large heads of animals present in the country. In 2016, over 26 million pigs were raised in the country, and utilising the waste products from this livestock farming can provide significant benefits to the economy, as well as sustainability objectives. As of March 2017, the project has installed over 150,000 biodigesters in the country, with a further 80,000 having been installed under spin-off projects implemented by the MARD.

The project has not only focused on installations, but has sought to develop the capacity for a functional, self-sustaining market for biodigester technology in the country. To that end, as of March 2017 the project has created over 2,500 new jobs in rural areas of the country, and trained over 1,700 masons in the construction of biodigesters. The consumer-side has also been targeted by the project, with over 160,000 households receiving both pre-installation training on the use of biodigesters, and post-installation training on the maintenance of the digester chamber and the use of bio-slurry in agricultural applications.

Dome-type biodigester in rural Vietnam. Image: SNVWorld

One of the innovative measures used to assist in developing a sustainable biogas sector in the country was implemented by the NGO EnDev in partnership with SNVWorld and the MARD. The NGO has recently implemented a Results-Based Financing (RBF) scheme in the country to promote the acceleration of biodigester construction, through empowering the supply-side of the biogas market to keep up with demand through subsidy. A financial incentive is provided for the construction and verification of each new biodigester, starting at US$50 for each new digester and falling over time. The intention is that the suppliers who receive this incentive can then reinvest the extra income in attracting more staff and scaling their businesses. The verification system is implemented through a novel online application developed in partnership with SNVWorld and AVKO, combining input data, photos and GPS locations translated to maps that are automatically updated with new information from the field. This system has replaced the traditional hard-copy form submission system for verification of new installations, streamlining the process for both EnDev and installers. The system is currently in use by 146 active installers in 18 provinces in Vietnam, and to date has verified over 35,000 biodigester installations.

In terms of capacity-building, SNV are currently partnering with MARD to continue the training of government installation and verification partners to build capacity in the biodigester sector, in an effort to better support a viable, private-sector supply and distribution market. Government technicians are also being trained in communicating about benefits of biogas technology, supporting enterprises in identifying suitable households and providing them with extension services on the use of bio-slurry.



SNVWorld (2018) Vietnam Biodigester Programme. Available at: http://www.snv.org/project/vietnam-biogas-programme [Accessed 11th March 2018]

Teune (2017) Igniting a Self-Sustaining Biogas Market in Vietnam. Available at: http://www.snv.org/update/igniting-self-sustaining-biogas-market-vietnam [Accessed 11th March 2018]


Taita Taveta County, Kenya – Biogas Partnership for Farming Communities

Taita Taveta county lies approximately 150km northeast of Mombasa and 300km southeast of Nairobi in Kenya. Residents of Wundanyi subcounty were approached in 2013 by a newly-formed NGO, Taita Biogas, to pilot new biogas installations, due to the high prevalence of cattle farming in the region. This gives ready availability for high-quality feedstock for biogas digesters in the form of cattle manure. To date, the NGO has installed over 600 household-scale biodigesters in the country, and has completed two institutional biodigesters for schools in the region, with a third under construction. These institutional-scale installations will use human and food wastes as feedstock rather than cattle wastes.

The business model for the NGO provides an opportunity for consumers who would not be able to afford a biodigester installation outright to install a system. Taita Biogas covers half of the cost of installation, and also arranges contractors to construct and commission the system. The households then pay the remaining amount for installation, usually in the region of KSh145,000 (GBP1,035). In recent years the NGO has expanded operations through partnership with the Micro Enterprise Support Project, another Kenyan NGO supporting farmers venturing into macadamia nut and French bean farming. Whilst this partnership has not been successful to date, due to MESP pulling out in 2017, a new partnership with the organisation is to be formed with additional funding, and a loan finance option provided through the MESP to members for biogas installations.

Household biodigester user Honorata Nyange cleaning utensils at her Lushangonyi home in Taita Taveta County, Kenya. Photo/Malemba Mkongo, star.co.ke

There are a range of benefits available to the farmers who have installed these biogas systems, as well as the institutional-scale digesters installed by regional schools. Households have reported a huge reduction in the amount of money and time invested in collecting firewood and purchasing charcoal, and the institutional users have reported a 50% reduction in the cost of purchasing firewood for cooking since installation of the digesters. In addition, this scheme is innovative in that householders are coordinating with the NGO to apply for regulatory permission from the Energy Commission of Kenya to bottle and sell biogas on the local market, as self-producers. Biogas sells for comparable prices to natural gas on the Kenya market (KSh200/kg (GBP1.43/kg), compared to KSh175-250 (GBP1.25-1.78/kg) for natural gas), and should regulatory permission be granted, these biogas installations have the potential to become an additional revenue stream for the farmers. Finally, household users have reported significant improvements in both cooking quality and ease of use when using biogas compared to firewood or charcoal, with a reduction in combustion residues and ease of lighting when using biogas as a fuel source.

The NGO is currently expanding its operations both on a geographical and technology-focused scale. As well as its operations in Kenya, the NGO is conducting feasibility studies for joint biogas/solar photovoltaic/solar water heater applications in Ethiopia, as well as local training workshops in partnership with an Ethiopian NGO, MCMDO-REESDE, for solar water heating technology, both in terms of installation and local construction.

Star.co.ke (2017) Taita Taveta Dumps Firewood for Biogas. Available at: https://www.the-star.co.ke/news/2018/02/12/taita-taveta-dumps-firewood-for-biogas_c1707691 [Accessed 10th March 2018]
Taita Biogas (2018) What We Do. Available at: http://biogas-taita.de/home.php [Accessed 10th March 2018]

Pay-As-You-Go (PAYG) Models for Cooking Fuels – Innovation for the Poorest Consumers

Daniel Kerr from UCL writes on innovative pay-as-you-go models in use for cooking energy service provision.

In the last 2-3 years, a handful of thermal energy services companies in the developing world, specifically in Sub-Saharan African countries, have begun to take advantage of pay-as-you-go (PAYG) consumer financing models in their energy businesses. These models have significant advantages in comparison to direct purchase, hire-purchase or micro-credit models when dealing with the poorest consumers in societies, for example those living in informal settlements in urban or rural areas. Some companies are taking advantage of these models for selling clean cooking products, such as stoves themselves, whereas others are using this payment structure for cooking fuels.

One company in Kenya taking advantage of these innovations is KOKO Networks. This organisation seeks to offer an integrated neighbourhood-level clean cooking solution with smart technology, via their KOKO points, cloud-connected commerce hubs where consumers and vendors can come to refill the products on sale or make purchases. Currently the company is offering the SmartCook product at these sales points, which is a two-burner clean cookstove with an integrated fuel canister. The fuel used is marketed as Mafuta smart, which is an ethanol fuel derived from molasses manufacture.

What is particularly innovative about this system is that the sales hubs for the company have in the automated purchasing stations for the fuel for the cookstove system. These dispensers refill the provided fuel canister (known as a kibuya smart canister) with the cookstove system, and customers can refill their canister from as little as KHS30 (US$0.29) at a time, offering significant flexibility for the consumer, without the “poor people’s premium” (higher per-unit prices charged for small amounts of consumable products) seen in other commodities. The company operates on a concession business model, with interested parties either setting up their own fuel supply arrangements for the fuel to service their settlement, or purchasing equipment and fuels from KOKO themselves.

KOKO Networks KOKOPoint in store in Nairobi. Customers can purchase a stove or replacement fuel from the kiosk. Image: http://www.globalhearthworks.org/koko/

Other companies in Kenya are taking advantage of PAYG models to enable greater access to their products and services as well. In Nairobi, PayGo Energy is a distribution service for LPG fuels that is using pay-as-you-go services to bring LPG fuel access to a greater number of consumers. The service begins with the installation of an LPG stove, cylinder and smart fuel meter in the home. This smart meter is at the core of the service the company offers, as it automatically communicates to the company when the fuel level is running low, whereupon the company arranges delivery of a replacement, full cylinder to the household. In addition, the system support mobile payments and ordering of fuel replacements, allowing customers to purchase as little as a day’s worth of LPG (around US$0.50) at a time. This logistics system has been adapted to informal settlements, allowing uninterrupted supply to households in informal settlements via motorcycle.

Other organisations are beginning to see the benefits of integrating mobile payment technology with a pay-as-you-go fuel payments model for energy services. KopaGas in Tanzania are another company using smart LPG metering to minimize the challenges posed by last-mile distribution which are typical in providing thermal energy services to communities. This smart gas meter system allows the company to deliver cylinder filling services or replacement full cylinders to communities efficiently, minimising distribution costs. In addition, the company offers a pay-as-you-go service for LPG fuel, as well as offering pay-over-time services for both fuels and cooking equipment. KopaGas has been partnering with EnviroFit, an established LPG equipment and fuel distributor in East and West Africa, in order to scale their service reach.

Through these cases, the market opportunity for offering clean cooking fuels and technologies as an energy service, using innovative fuel and equipment payment models to enable access for the widest range of consumers, can be clearly demonstrated. KOKO Services and KopaGas/PayGo Energy may be using different technology options, but the commonalities in approach exist: offering consumers the ability to purchase small amounts of fuel at a time, via a convenient payment method (either via mobile, at a central filling station, or both), and in the case of the LPG companies, offering consumers the option of household delivery. Through this combination of factors, these companies are breaking the traditional barriers to household thermal energy service delivery, allowing consumers who previously would not have had the financial capacity to afford modern cooking fuels the ability to access these technologies.

– Daniel Kerr, UCL Energy Institute


Global Alliance of Clean Cookstoves (2017) “Pay-as-you-go” technology to boost access to cooking fuel. Available at: http://cleancookstoves.org/about/news/05-30-2017–pay-as-you-go-technology-to-boost-access-to-cooking-fuel.html

KOKO Networks Home: http://kokonetworks.com/

PayGo Energy Home: https://www.paygoenergy.org/

KopaGas Home: https://www.kopagas.com/

The recent evolution of China’s National Biogas Program and lessons learned for application in other regions

This blog aims to describe in brief the history of China’s national biogas program and its transition phases in both the 1980s (moving to prefabricated plastic digesters) and more recently in promoting household scale systems, as well as how this program compares to other government-scale programs in household and centralised biodigesters. [1] [2] [3]

The Chinese National Biogas Program is one of the most cited examples of a successful biogas dissemination program at a government scale. The first biodigesters started appearing in China in the 1920s, and from the 1970s onwards the government began introducing household-scale centralised biodigester systems for rural communities under the predecessor of the current program. The first major transition in the program took place in the 1980s. Previously to this, most biodigesters in the country were constructed on-site from brick or concrete, however this period saw the introduction of what are known in the country as “commercialised digesters”. This covers three constructions of prefabricated biodigesters. Fibreglass-reinforced plastic (FRP) digesters began appearing in the 1980s themselves, whilst so-called plastic soft (PS) and plastic hard (PH) digesters came into the market in the mid-90s. These digesters offered significant commercial and operational advantages, being able to be constructed at a central site and then disseminated, as well as being more reliable, having lower maintenance requirements and a better performance overall.

xia zuzhang china biogas graph

Source: Adapted from Zuzhang (2014) Domestic biogas in a changing China: Can biogas still meet the energy needs of China’s rural households, http://pubs.iied.org/pdfs/16553IIED.pdf

As of 2011, 41.68 million households were using biogas services through the National Biogas Program. As of 2010 production capacity for the three previously-described prefabricated digester types was approximately 2,500,000 per year, and as of 2014, approximately 50 million households had been reached with biogas supply, using over 16 million cubic metres of biogas per year [4]. At least one prefabricated digester manufacturer exists in each Chinese province, over 100 in total. These digesters are also marketed across South-East Asia, and also recently to Sub-Saharan Africa.

However, there exist a number of present challenges to the continued development of the Program. Current funding for biogas digester construction predominantly comes from state, regional and government sources in the form of a subsidy for rural households. Rural households are expected to contribute, but this varies widely from just the labour costs, to 50-70% of the total installation costs. Some funding criteria stipulated by the government also exclude large proportions of the rural population: for a village to qualify for biodigester subsidies for example, at least 70% of the households must own sufficient livestock. This funding regime, as it exists, makes no provision for servicing and maintenance, and whilst biogas service cooperatives are beginning to appear in rural areas, no effort has been made to assess the current proportion of functioning digesters nor repair any identified non-functioning systems at a local government level.

Possibly the largest constraint to the continued operation and growth of the program is internal migration in China. The rural population is falling significantly as urban development continues, with huge number of rural people moving to urban areas for greater employment prospects and wages. This also contributes to biodigester effectiveness; with traditional animal husbandry industries giving way to larger, centralised livestock farming, feedstock regimes are decreasing in suitability in rural China for household-scale digesters, presenting an ongoing constraint to the operation of the program.

– Xavier Lemaire & Daniel Kerr, UCL Energy Institute

[1] Raha, Mahanta & Clarke (2014): http://dx.doi.org/10.1016/j.enpol.2013.12.048

[2] Groenendaal & Gehua (2010): http://dx.doi.org/10.1016/j.energy.2009.05.028

[3] Deng et al. (2014): http://dx.doi.org/10.1016/j.rser.2014.04.031

[4] IRENA (2014) Renewable Energy Prospects: China. Available at http://irena.org/remap/IRENA_REmap_China_report_2014.pdf

Maintenance of biodigesters and issues surrounding maintenance/service arrangements

Even in the presence of mandated service agreements maintenance for biodigesters can still be an issue. For example, time constraints on private contractors [1] from central government to install and maintain digesters, lead to a slipping in maintenance standards. In a village in Assam interviewed in the paper, no follow up visits from the contractors were had for four years, and a 20% digester failure rate was recorded. Communications issues were a key contributor to this: the fact that a provision of a half of the installation subsidy for maintenance of plants over 5 years old was not communicated to households or the contractors.

broken biogas assam india

A broken biodigester in Assam, India, having not been repaired for 6 months. Source: Raha, Mahanta & Clarke (2014) The implementation of decentralised biogas plants in Assam, NE India: The impact and effectiveness of the National Biogas and Manure Management Programme. http://dx.doi.org/ 10.1016/j.enpol.2013.12.048

One of the more overlooked aspects of biogas digester services and operation is the maintenance requirements of digesters. Older digester designs (for example dome-type biodigesters constructed from brick or earth) require a regular maintenance schedule (monthly to quarterly is common) [2] in order to maintain best performance, including maintaining the chemical balance of the digesting chamber and its structural integrity, repairing cracks in the chamber if necessary. More modern household and collective-scale designs are based off a plastic digesting chamber, usually fibreglass-reinforced plastic (FRP), and as such require less intensive maintenance (annual maintenance visits are sufficient), but still have a maintenance burden to address for peak performance (for example, maintaining the chemical balance of the digester through appropriate feedstock insertion).

However, even in the presence of mandated service agreements for biodigesters, for example delivered through a fee-for-service energy service company (ESCO), maintenance can be overlooked. A useful case study illustrating this can be obtained from India’s National Biogas and Manure Management Program (NBMMP) [1]. The NBMMP relied on local governments in India contracting the private construction sector to construct biogas digesters for rural communities. Time constraints on these contractors on installation, stemming from the prevailing climatic conditions limiting the working period of the year due to monsoons, meant that maintenance standards, for which the contractors under the tender from local government were also responsible, and the overall quality of installation of digesters, slipped drastically. Some contractors reported having to fill an annual allocation of 6,000 digester installations in just three months, at a rate of over 60 digesters per day, often for small companies of just 5-10 technicians. Hence, some digesters were not being maintained for four years or more, and there was a 20% overall digester failure rate. Communication between the public bodies and private contractors was also an issue: the NBMMP made provision of half the subsidy granted to households for purchasing digesters as a maintenance grant over a five-year period, which was barely taken advantage of due to a lack of awareness on the part of households and contractors.

This case study makes clear the necessity of accounting for maintenance arrangements in the design of any biodigester business plan or program. Ensuring the maintenance schedule is followed will extend the life of the biodigester and improve its performance, resulting in greater satisfaction with the system from the point-of-view of end-users. This fact makes biodigesters particularly suited to a fee-for-service business model: regular maintenance can easily be combined with regular payment collection visits, reducing the cost burden on the company/organisation and improving service.

The final post in this series will focus on the recent evolution of the Chinese National Biogas Program, and the lessons to be learned for cross-application in other regions globally.

– Xavier Lemaire and Daniel Kerr, UCL Energy Institute

[1] Raha, Mahanta & Clarke (2014): http://dx.doi.org/10.1016/j.enpol.2013.12.048

[2] Surendra et al (2014): http://dx.doi.org/10.1016/j.rser.2013.12.015

Why Isn’t There Greater Adoption of Biogas Technologies in Sub-Saharan Africa?

There are issues surrounding the lack of willingness to finance biodigester projects at all scales in many SSA countries particularly at the household level, lack of financial arrangements for poorer households where technology is most viable, prevailing climatic conditions beneficial but socio-economic conditions (particularly availability of feedstock and financial capacity of rural users) can be problematic.

Household-scale biodigesters can be an effective solution to providing thermal energy services to rural poor communities in the developing world. However, successful examples of biodigester programs in the past at a government or development-agency scale have mostly been confined to China, India and South-East Asia more widely. Notably, there has been a distinct lack of experience of successful biogas projects in Sub-Saharan Africa. The STEPs research project aims to address some of the reasons behind this, and propose potential solutions.

In theory, the prevailing conditions in Sub-Saharan African countries are mostly beneficial for the introduction of biogas digesters. Climatic conditions, on the whole, are suitably warm, with minimal cold periods to impact digester efficiency. In addition, target users are in abundance in rural areas, if considering the local feedstock regime. Small cattle farming is prevalent in a number of SSA countries, and subsistence farmers in rural areas often keep a small head of cattle. Given also the distributed nature of rural populations in a number of SSA countries (particularly, for example, in Eastern South Africa), household-scale biodigesters are an excellent solution for providing thermal energy services to households.

Sovacool Kryman & Smith 2015

Potential uses for biogas and waste products. Sovacool, Kryman & Smith (2015) Scaling and commercializing mobile biogas systems in Kenya: A qualitative pilot study. Renewable Energy, Vol. 75, pp 115-125, http://dx.doi.org/10.1016/j.renene.2014.10.070

However, the lack of successful experience of biogas dissemination programs or businesses can be attributed to a number of factors, first and foremost of which is the cost of biodigesters (ranging from US$30 for a rudimentary drum-type system to over US$700 for a larger household system) [1] [2], and the lack of credit facilities/service regimes to enable access to the technology for the poorest consumers. Biodigester technology still represents a significant upfront cost to a typical rural household, and micro-credit services for clean energy technologies are still in their infancy in SSA countries, with some successful experiences in countries like Kenya or South Africa for solar home lighting or electricity systems in Kenya for example, but little widespread knowledge.

This lack of end-user credit is mirrored in a general lack of energy service companies or institutions offering biodigester services, with the cost issue again a driving factor behind this. Given how critical the maintenance factor is in biodigester installations (an issue which will be explored in the next blog), this lack of service companies, integrating credit or fee-for-service business models with a maintenance and servicing regime, has hampered uptake significantly in the region. The final negative factor is in fact the converse of an advantage: whilst some households will have suitable feedstock availability, compared to average heads of livestock or agricultural waste availability in South-East Asia, SSA has a much lower proportion of households with viable feedstock availabilities. Targeting consumers and areas where feedstock regimes are good is a critical step in ensuring the success of programs or business around biogas digesters in SSA.[2]

The next post in this series will investigate maintenance of biodigesters, and the necessity of maintenance and service arrangements with end-users to ensure efficient and successful operation of biodigesters.

– Xavier Lemaire & Daniel Kerr, UCL Energy Institute

[1] Hojnacki et al, MIT (2011) Biodigester Global Case Studies. Available at: https://colab.mit.edu/sites/default/files/D_Lab_Waste_Biodigester_Case_Studies_Report.pdf

[2] Raha, Mahanta and Clarke (2014) The implementation of decentralised biogas plants in Assam, NE India: The impact and effectiveness of the National Biogas and Manure Management Programme. Energy Policy, Vol. 68, pp. 80-91

The Challenges and Opportunities of Centralised and Decentralised Biodigesters

The STEPs research project explores the relative benefits and dis-benefits of larger centralised biogas systems at a village scale versus smaller family-scale systems. It also investigates the economic and financing factors (centralisation brings economies of scale but can only really be implemented by organisations/governments, family-scale systems may be out of reach of user capital without financing arrangements), environmental factors, and social and behavioural considerations (do users want to collectively cook, issues with economics of pipe gas supply meaning necessity of group facilities etc) inherent in biodigester development.

Biogas digesters can be a valuable solution to providing thermal energy services to rural and urban households in the developing world. The technology is particularly applicable in rural areas, where access to feed stock for the digesting chamber in the form of agricultural wastes and other organic wastes is greater. In general, digesters fall into two broad categories: household-scale biodigesters, and larger, centralised biodigesters.

Laramee & Davis 2013 Dome Biodigester in Tanzania

Dome-type biodigester in Arusha, Tanzania [1]

Household-scale biodigesters are often seen as the most viable option for rural communities and households. These are generally small, with digesting chambers of volumes in the 4 to 13 cubic metres range. These installations will support the cooking needs of a rural household, as well as providing biogas for heating or lighting if required. Tailoring the size of the biogas system to the availability of feedstock for the household is critical for successful functioning of the system: studies have suggested 4-6 heads of cattle is a sustainable target if using agricultural wastes for feedstock, for an average-sized family of five. Individual biodigesters can produce sufficient gas for a single person on as little as 1 kg/day of feedstock.[2]

However, one of the primary limiting factors in the adoption of household biodigesters is financing and end-user capital constraints. Household-scale systems are still relatively expensive for the majority of rural developing-world users, and experience has shown that without the provision of credit facilities in biodigester programs, or government subsidies, adoption rates remain low.

Centralised biodigester systems offer a different set of benefits and challenges. Economies of scale are the major advantage: one centralised system can serve a medium-scale settlement or several small settlements, with a reduced burden for upfront capital costs and maintenance compared to the same service with household-scale systems, in the range of US$100 – 500 per household. The Chinese National Biogas Program [which will be the subject of a later blog in this series], has been the major implementer of centralised systems, however experience also exists in other South-East Asian countries. Examples of this can be found in the centralised digesters built near Beijing to service rural villages. For an upfront cost of ~US$1 million, 1900 households are serviced through each centralised digester, with biogas available at a 20% discount compared to market LPG prices, and the additional benefit of organic effluent being made available for sale to the local farms feeding the digester.[2] The major constraint, however, to wider dissemination of centralised systems is the significantly higher up-front capital costs. This puts the systems out of reach for private users in the majority of cases, government-scale implementation is more common.

Socio-political conditions are another factor that has proved a constraint in biogas implementation projects in developing countries. Centralised biogas digesters can have difficulty with biogas supply to end-users, particularly given the poor economics of installing piped gas supply in small rural communities. Communal cooking facilities have been a solution to this problem in theory, however experience from India suggests that collective cooking is not desired by the rural population, and this has impacted upon the success of centralised digester installations. As with dissemination programs for clean cookstoves, biogas installations need to take into account the end-users needs and desires in design and installation for product use and performance.

The other posts in this series will cover the question of why biogas hasn’t succeeded in Sub-Saharan Africa as it has in South-East Asia, the maintenance question for biogas services, and lessons from the Chinese National Biogas Program.

– Xavier Lemaire & Daniel Kerr, UCL Energy Institute

[1] Laramee & Davis (2013) Economic and environmental impacts of domestic bio-digesters: Evidence from Arusha, Tanzania. http://dx.doi.org/10.1016/j.esd.2013.02.001

[2] Hojnacki et al, MIT (2011) Biodigester Global Case Studies. Available at: https://colab.mit.edu/sites/default/files/D_Lab_Waste_Biodigester_Case_Studies_Report.pdf