DATABASE

Case study

From waste biomass to energy for cooking: MYLITTLECOOKSTOVE.

ongoing



Link
www.ing.unibs.it


Abstract

MYLITTLECOOKSTOVE is an rice-husk fuelled quasi-gasifier stove for household cooking. The stove is a product reliable, efficient, safe, that works with a 'poor' fuel like rice husk, adaptable to local cooking practices and socio cultural aspects, made with materials and tools available locally, affordable by end users.


Project Description

Improper management of agricultural wastes may lead to many negative sanitary and environmental impacts in rural contexts of the developing world. Some particular residues like rice husk are often burned in open-air by the farmers just to dispose them. This is a common practice which generates uncontrolled dangerous emissions, while wasting a potential energy source. At the same time, in many developing countries the use of traditional solid fuels in rudimental devices (such as open fires or three stone fire) is common. This results in a very low-efficiency usage of the fuel and huge health impacts for women and children that are exposed to harmful smokes and burn risks, besides increasing the stress on a delicate environment threatened by uncontrolled tree cutting. Rice husk is a waste biomass locally available in several contexts in developing countries (not also South-East Asia but also in Sub-Saharan Africa) and may represent a good alternative to wood for household energy supply. CeTAmb LAB designed and tested an effective-improved-cookstove to allow the use of such a biomass. The stove's structure is made of mud-bricks and is equipped with a chimney and an internal metal-net basket to allow air-flows through the biomass stacked in the closed combustion chamber. In the present configuration both direct combustion and gasification occur, generating heat which is appropriate for cooking tasks. Such a lay-out is due to constraints arising from the local context. Effectiveness of the technology has been the main driver of the stove's development and many helpful solutions, as electric air-blowers, have been discarded. Also economic and social issues have been addressed, each one adding more constraints. Building materials have been chosen in order to guarantee a low cost and easiness of use and maintenance, favoring locally available items as much as possible. Besides this, a simple construction method for the stove is feasible and, hence, local enterprises could be promoted by dissemination projects, enabling the genesis of a new market, necessary for the technology to be self-sustainable. The first prototypes were thought for the Logone Valley, between Chad and Cameroun. Field testing and local-constraint-driven design allowed to propose a technology appropriate for the intervention area, according to local needs and peculiarities. The same stove model was then proposed for the Mwea region, Kenya. Here, after a further co-development and testing of the stove in collaboration with local technicians and users, a sample of households were provided with the stove in order to assess the acceptance of the proposed technology to the real daily life of final beneficiaries. This approach allowed to adapt the technology to the local habits and practices, increasing the chances of appreciation by the final users.


BENEFICIARIES

The stove design was addressed to a particular local context, the Logone valley at the border between Chad and Cameroon, where an international development cooperation project was implemented to improve the poor energy access of local population. The good availability of rice husk, a local agricultural by-product currently without any use neither value on the local market, suggested recovering this biomass for cooking purposes. According to local socio-technical constraints a prototype of rice husk stove was designed and tested, in order to assess the best technical performances and to identify the most proper materials. The introduction of MYLITTLECOOKSTOVE in the cooking energy pool of households in the local context studied results economically sustainable according to the outputs of an economic model proposed. All the scenarios elaborated show how the rice husk stove adoption would reduce significantly the household fuel expenditure (up to 50%), within the local availability of such a biomass. Adoption and acceptability of the stove was assessed through a number of semi-structured interviews to a sample of the early-adopters of the proposed improved stove. This survey allowed understanding some local cooking patterns before and after the adoption of the improved stove and some social characteristics of the interviewed householders. The same stove model was then proposed for the Mwea region, Kenya. Here, after a further co-development and testing of the stove in collaboration with local technicians and users, a sample of households was provided with the stove in order to assess the acceptance of the proposed technology to the real daily life of final beneficiaries. This approach allowed to adapt the technology to the local habits and practices, increasing the chances of appreciation by the final users. In this paper the authors discuss, starting from the weakness and critical points of the technology highlighted in the experience in Chad/Cameroon, the adaptation process implemented on the field in Kenya and the feedbacks of users, highlighting the lessons learnt during the process of development and the pilot deploying of the stove. The support of local technicians in this phase in unavoidable, being the access key to the knowledge of the local cooking practices and habits and the related needs. After the co-development phase the modified stove was proposed to a group of 15 local households in order to test in the field the real adaptability of the stove to the local cooking practices. A number of Controlled Cooking Tests (CCTs) (11) and Kitchen Performance Tests (KPTs) (6) were performed both with the proposed stove and with the traditional three stone fire.


Results

The introduction of a new technology in a certain context is a slow and delicate process, especially when the innovation proposed touches a traditional practice, such as the daily cooking. By one side an innovation needs to guarantee a better technical level in terms of performance and operation in comparison to the baseline. By the other side, it needs to be adapted to the local context and tailored to the local habits and preferences in order to be really adoptable and appreciable by the beneficiaries. The stove presented in this paper, after a R&D phase performed in the laboratory of Brescia (Italy) with inputs from a field case study (the Logone Valley in Chad/Cameroon) was proposed in a similar context, the Mwea region in Kenya. Here a first phase of co-development in collaboration with local technicians allowed to overcome the weaknesses identified in the stove prototypes. Some changes in the final lay-out were done before testing the technology in a pilot study with 15 households. The new stove configuration has a reliable operation and allows the firepower and temperature regulation. The results of the pilot study revealed the good performance of the stove, highlighted by the outcomes of the tests performed. In particular a significant impact was observed on the daily fuel expenditure (-70%) and in the indoor air quality in the households that adopted the stove, in comparison to the ones that used the traditional 3stone fire. The advantages from the use of the stove were welcomed with a positive feedback from the population. New practices in the daily fuel/stove use and further modifications to the stove were also observed in the pilot study. That was taken as an indicator of an on-going ownership process of the technology. The results obtained in families where the stove was introduced are several. The use of rice husk, free in large quantities, allowes to use money not to purchase wood but to purchase food (diversification of the family diet). The use of rice husk avoids natural resources loss (consumption of wood), reducing the deforestation and desertification phenomenona. The thermal inertia of the improved stove allows to cook food and to heat the water up to pasteurisation, reducing viral pathologies. The efficiency of combustion allows the reduction of CO2 and particulate emission into the atmosphere. Indoor air quality improves, with benefit for woman and child health (indoor air pollution is among the leading causes of mortality in developing countries). The structure of the stove allows to cook in an upright position with relief of the spine. The use of the stove reduces food cooking time, so mothers have more time to devote to the children.


Business Model

The dissemination of low-technology but high-efficiency models was implemented according to the socio-economic conditions of the local people (minimal investment capacity due to the very low level of income) and of the skills and the tools available for small local artisans (in particular the lack of electricity impacting in basic manufacturing capabilities). Some demonstrational days were organized to show to potential stove beneficiaries the benefits of the adoption of the stove, gathering the interest of the local population for the new cooking technology. A future project will deal with the scaling up of the stove, not through a plain distribution but addressing potential adopters through an incentive model tailored in order to guarantee the effective adoption of the stove in the daily life.


Lessons Learnt

The introduction of a new technology in a certain context is a slow and delicate process, especially when the innovation proposed touches a traditional practice, such as the daily cooking. By one side an innovation needs to guarantee a better technical level in terms of performance and operation in comparison to the baseline. By the other side, it needs to be adapted to the local context and tailored to the local habits and preferences in order to be really adoptable and appreciable by the beneficiaries. MYLITTLECOOKSTOVE, after a R&D phase performed in the laboratory of Brescia (Italy) with inputs from a field case study (the Logone Valley in Chad/Cameroon) was proposed in a similar context, the Mwea region in Kenya. Here a first phase of co-development in collaboration with local technicians allowed to overcome the weaknesses identified in the stove prototypes. Some changes in the final lay-out were done before testing the technology in a pilot study with 15 households. The new stove configuration has a reliable operation and allows the firepower and temperature regulation. The results of the pilot study revealed the good performance of the stove, highlighted by the outcomes of the tests performed. In particular a significant impact was observed on the daily fuel expenditure (-70%) and in the indoor air quality in the households that adopted the stove, in comparison to the ones that used the traditional 3stone fire. The advantages from the use of the stove were welcomed with a positive feedback from the population. New practices in the daily fuel/stove use and further modifications to the stove were also observed in the pilot study. That was taken as an indicator of an on-going ownership process of the technology.


Key Feature

The stove uses rice husk, a widely available biomass that is often seen as a waste. Thus, the recovery of such a resource as fuel can be welcomed positively. The fuel supply does not compete with resources necessary for food production being a waste by-product of rice production and often does not have another use. Heat generation from rice husk cannot be achieved efficiently with a simple 'direct' combustion. Proper gasification would be the best technical way, but this work has focused on an intermediate solution, where rice husk in part burns 'directly' and in part is gasified. Natural draft, fundamental for gasification, is provided by the pressure gradient given by the height of the chimney if the pot is sealed in its proper position. The rice husk is put in a metal-net basket that is placed in the center of the combustion chamber. This geometry forces air to flow through the rice husk, allowing the production of combustible gases that can burn just below the pot, where secondary air enters the combustion chamber through the central duct in metal-net. A small starting fire (using a little amount of wood or charcoal) is placed in the central duct and this allows the process to start. After the ignition, the starting fire runs out and the central duct is free for the secondary air flow. Crude earth is a traditional material that has been used for ages in many developing countries. A basic requirement for this stove design is the local availability of most of the materials, as well as the access to most of the necessary construction techniques. In this manner the users can be enabled to easily maintain their new technology and, if the wears due to the daily use are repairable by the end-users, also durability issues and simplicitly are targeted. Therefore, mud-bricks have been chosen to build the stove structure.


Other significant information

Dissemination followed different ways because different cultures and languages were involved. At academic level, several scientific contributions and papers were published, presenting the details of the experiences of CeTAmb LAB researchers. At technical level, the website fuocoperfetto.altervista.org open shares the documentation produced for MLC. COL'OR NGO published on its website a video presenting the project in Kenya. At local level, the process is more informal and relies mainly on the distribution of the leaflet that explain how DIY the stove. Local media have publicized the experience.


Main Donor

University of Brescia
(Scientific community)

Implementing Actor

CeTAmb LAB - Research Laboratory on Appropriate Technologies for Environmental Management in resource-limited Countries (Scientific community)