1.2 Detalhes do contato das pessoas capacitadas e instituições envolvidas na avaliação e documentação da tecnologia

Nome do projeto que facilitou a documentação/avaliação da Tecnologia (se relevante)

DESIRE (EU-DES!RE)

Nome da(s) instituição(ões) que facilitou(ram) a documentação/ avaliação da Tecnologia (se relevante)

University of Botswana (University of Botswana) - Botsuana

1.3 Condições em relação ao uso da informação documentada através de WOCAT

Quando os dados foram compilados (no campo)?

19/02/2009

O/a compilador/a e a(s) pessoa(s) capacitada(s) aceitam as condições relativas ao uso de dados documentados através da WOCAT:

Sim

2.1 Descrição curta da tecnologia

Definição da tecnologia:

Production of methane gas from cow-dung for use in house-hold cooking, heating and lighting in order to reduce fire wood demand

2.2 Descrição detalhada da tecnologia

Descrição:

Biogas plant: The biogas plant can be constructed in several ways as long as it can provide a medium for the biological material be digested. Biogas is the name given to the gas that is produced during the decomposition of some organic waste specifically to produce methane gas. The gas is then captured in a storage tank (on site) to be used for household energy needs. In many parts of the world where this technology is used (including Botswana) the most common form of input material is cow dung making it more appropriate for rural environments.

Purpose of the Technology: Advantages: the technology offers two major advantages; first, at every level of use i.e. individual or institutional, savings in terms of energy is realized. The only costs that are borne are at installation, otherwise input of cow dung has a minimal cost of collection (if any at all). The second advantage is that there is reduced usage of fuel wood which translates into less cutting down of trees leading to reduced deforestation and degradation of land. A disadvantage is the initial investment which is significant for poor farmers.

Establishment / maintenance activities and inputs: Construction of the biogas plant: construction of the plant consists of three main chambers: namely, the Digester pit where all the microbiological reactions or decomposition of the material takes place. The digester has to be built to be air-tight with the released gas only escaping into the gas holder. The gas holder is connected to the digester by way of a pipe. Its main purpose is to collect all the gas that has been fermented. The mixing pit is the input chamber where the dung is mixed with water and fed into the digester. The amount and quality of water required for this is no constraint, even in this water stressed area. Construction the biogas plant has to be done according to specifications. A technical drawing of the plant is shown on page 3. The purpose of the technology is to use it for house-hold energy (for cooking, lighting and running appliances).

Natural / human environment: In Botswana the technology was introduced by the Rural Industries Innovation Center which is a government funded research institution. Despite the existence of this company for many years, the uptake has been very low due to poor marketing and extension services and lack of financial assistance to poor farmers.
Biogas is suitable either for a farm, cattle post or rural setting where the inputs (cow dung) are easily available. But there are possibilities of experimenting with other bio-degradable materials in major centres where cow dung is not readily available.

2.3 Fotos da tecnologia

2.5 País/região/locais onde a tecnologia foi aplicada e que estão cobertos nesta avaliação

2.6 Data da implementação

Caso o ano exato seja desconhecido, indique a data aproximada:

• 10-50 anos atrás

2.7 Introdução da tecnologia

Especifique como a tecnologia foi introduzida:

• através de projetos/intervenções externas

Comentários (tipos de projeto, etc.):

The technology is promoted by a government funded NGO, but has its origins outside the country

3.1 Principal/principais finalidade(s) da tecnologia

• Reduz, previne, recupera a degradação do solo
• Preserva ecossistema
• Criar impacto econômico benéfico

3.2 Tipo(s) atualizado(s) de uso da terra onde a tecnologia foi aplicada

Comentários:

Major land use problems (compiler’s opinion): Overgrazing of the commons, droughts, saline water and over-harvesting of fuelwood for cooking, heating leading to deforestation and land degradation

Major land use problems (land users’ perception): Overgrazing of the commons, droughts, saline water and over-harvesting of fuelwood for cooking, heating leading to deforestation and land degradation.

Grazingland comments: Biogass technology is not applied in the Boteti area at the moment, only at DESIRE test site.

Selective felling of (semi-) natural forests: specific tree species are felled for fuelwood even though people are supposed to take only fallen-dead wood

Type of cropping system and major crops comments: Mixed cropping is the traditional practice but government extension advice promotes monocropping which the majority find expensive and risky.

Type of grazing system comments: Biogass technology is not applied in the Boteti area at the moment, only at DESIRE test site.

Constraints of settlement / urban

3.3 Mais informações sobre o uso da terra

Abastecimento de água para a terra na qual a tecnologia é aplicada:

• Precipitação natural

Comentários:

Water supply: Also post-flooding

Número de estações de cultivo por ano:

• 1

Especifique:

Longest growing period in days: 179 Longest growing period from month to month: Oct - Mar

Densidade animal (se relevante):

1-10 LU /km2

3.4 Grupo de GST ao qual pertence a tecnologia

• Tecnologias de eficiência energética

3.5 Difusão da tecnologia

Comentários:

Total area covered by the SLM Technology is 0 m2.

This technology is basically on a point location, even though it is to benefit a wider area in terms of conservation

3.6 Medidas de GST contendo a tecnologia

Comentários:

Main measures: management measures

3.7 Principais tipos de degradação da terra abordados pela tecnologia

Comentários:

Main type of degradation addressed: Bc: reduction of vegetation cover, Bs: quality and species composition /diversity decline

Main causes of degradation: deforestation / removal of natural vegetation (incl. forest fires) (harvesting of fuelwood for cooking, sometimes live trees are harvested.), land tenure (Area is communal grazing land)

Secondary causes of degradation: over-exploitation of vegetation for domestic use (Trees are cut for bush fences), droughts (The study area is prone to droughts), poverty / wealth ((lack of alternative livelihood sources))

3.8 Redução, prevenção ou recuperação da degradação do solo

Especifique o objetivo da tecnologia em relação a degradação da terra:

• Recuperar/reabilitar solo severamente degradado

Comentários:

Secondary goals: prevention of land degradation, mitigation / reduction of land degradation

4.1 Desenho técnico da tecnologia

4.2 Especificações técnicas/ explicações do desenho técnico

The diagram shows the technical layout of a biogas plant; showing the position of the main components: Digester, Gas holder, Mixing pit, and outlet. Cow dung & or kitchen waste (except bones) is mixed with water to form a sludge. This sludge is fed into the digester pit where decomposition and fermentation takes place. As the sludge ferments, methane gas is produced. Methane is a combustible gas and can therefore be used for cooking and lighting. Specially designed gas stoves and lanterns may be required as the gas would not be purified and hence ‚thicker‘ than commercially produced gasses. However, the design can include a water filled pipe bend (u shaped) between the gas holder and outlet pipe. The water in this pipe would help to purify the gas before it is fed to the household appliances. The gas holder tank floats in water, through which the gas bubbles escape and methane gas collects into the floating tank. An outlet through which decomposed material leaves the plant is necessary. Old sludge would float and be removed through this opening (Diagram drawn by G. Koorutwe, Department of Environmental Science, University of Botswana).

Location: Mopipi. Boteti Sub-District

Date: 05/10/11 (revised)

Technical knowledge required for field staff / advisors: high (Skilled technician is needed for installation)

Technical knowledge required for land users: moderate

Main technical functions: reduction of wood exploitation

Secondary technical functions: promotion of vegetation species and varieties (quality, eg palatable fodder), enhancement of tree growth

Structural measure: Digestion pit
Depth of ditches/pits/dams (m): 3.38
Width of ditches/pits/dams (m): 2.06

Structural measure: Gas holder
Depth of ditches/pits/dams (m): 2
Width of ditches/pits/dams (m): 1.6

Construction material (other): bricks, pipes, cement, iron sheets

Change of land use practices / intensity level: Use of biogass for cooking would lead to reduced cutting of wood for cooking

4.3 Informação geral em relação ao cálculo de entradas e custos

Outro/moeda nacional (especifique):

Pula

Indique a taxa cambial do dólar norte americano para a moeda local (se relevante): 1 USD =:

6,5

4.4 Atividades de implantação

	Atividade	Tipo de medida	Periodicidade
1.	Construction	Gestão	N/A

4.5 Custos e entradas necessárias para a implantação

	Especifique a entrada	Unidade	Quantidade	Custos por unidade	Custos totais por entrada	% dos custos arcados pelos usuários da terra
Mão-de-obra	Labour	Tank	1,0	198,0	198,0	100,0
Equipamento	Tank	Tank	1,0	615,0	615,0	100,0
Equipamento	Bricks	Tank	1,0	77,0	77,0	100,0
Equipamento	Cement	Tank	1,0	123,0	123,0	100,0
Equipamento	Plumbing material	Tank	1,0	154,0	154,0	100,0
Material de construção	Earth	Tank	1,0	31,0	31,0	100,0
Custos totais para a implantação da tecnologia					1198,0

Comentários:

Duration of establishment phase: 0.5 month(s)

4.6 Atividades recorrentes/manutenção

	Atividade	Tipo de medida	Periodicidade/frequência
1.	Filling up with cow dung and water	Gestão	1 Day

4.7 Custos e entradas necessárias pata a manutenção/atividades recorrentes (por ano)

	Especifique a entrada	Unidade	Quantidade	Custos por unidade	Custos totais por entrada	% dos custos arcados pelos usuários da terra
Equipamento	Cow dung	Tank	1,0	33,0	33,0	100,0
Custos totais para a manutenção da tecnologia					33,0

Comentários:

Costs were calculated for labour and material based on the real cost of construction at the Mopipi Site.

4.8 Fatores mais importantes que afetam os custos

Descreva os fatores mais determinantes que afetam os custos:

Material, labour and equipment used in construction are the most determining factors affecting the costs (installation cost is US$ 1198).

5.1 Clima

5.2 Topografia

Comentários e outras especificações sobre a topografia:

Altitudinal zone: 501-1000 m a.s.l. (Part of the Makgadikgadi basin)
Slopes on average: Flat (ranked 1, mainly low lying land of lucrustrine (pans) formation) and gentle (ranked 2, gently sloping (plains))

5.3 Solos

Caso disponível anexe a descrição completa do solo ou especifique as informações disponíveis, p. ex. tipo de solo, PH/acidez do solo, nitrogênio, capacidade de troca catiônica, salinidade, etc.

Soil depth on average: Shallow (ranked 1, generally soils are 40cm deep, underneath is a calcrete layer at about 40cm deep) and deep (ranked 2, some sandy area away from pans e.g. the Gidikwe Ridge )
Soil texture: Coarse/light (ranked 1, away from pans/river/flood plain = main soil type) and fine/heavy (ranked 2, sticky when wet in the depression)
Soil fertility: Low (ranked 1, sandy areas (Arenosols)) and medium (ranked 2, in flood plains of the Boteti river)
Topsoil organic matter: Low (ranked 1, low on sandy areas/soils) and topsoil organic matter (ranked 2, on the flood plains for molapo farming)
Soil drainage/infiltration: Good (ranked 1, very good on sandy soils) and medium (ranked 2, flood plains are medium)
Soil water storage capacity: Very low (ranked 1, on sandy soils) and medium (ranked 2, on flood plains)

5.4 Disponibilidade e qualidade de água

Comentários e outras especificações sobre a qualidade e a quantidade da água:

Ground water table: >50m (ranked 1, for Boreholes) and 5-50 m (ranked 2, wells in the Boteti River bed)
Availability of surface water: poor/none (dry season-unreliable river flow/rainfall)
Water quality (untreated): Poor drinking water (treatement required, salty water in most areas, ranked 1) and unusable (sometimes too salty even for livestock consumption, ranked 2)

5.5 Biodiversidade

Comentários e outras especificações sobre biodiversidade:

Biodiversity: High (several game reserves (protected areas) nearby, ranked 1) and low (grazing areas with arable agriculture, ranked 2)

5.6 Características dos usuários da terra que utilizam a tecnologia

Indique outras características relevantes dos usuários da terra:

Land users applying the Technology are mainly Leaders / privileged
Difference in the involvement of women and men: There is no difference, as this is mainly a family thing or institutioanal like in schools and community halls
Population density: < 10 persons/km2
Annual population growth: 2% - 3%
10% of the land users are very rich and own 50% of the land (Cattle farmers).
60% of the land users are average wealthy and own 30% of the land (Most inhabitants).
30% of the land users are poor and own 20% of the land (Subsistance farm).
Off-farm income specification: Saves money for buying commercial gas and electric power. Helps conserve the forests. Limited off-farm income opportunities for everyone including non-adopters of the technology.
Level of mechanization: Animal traction (mostly donkeys for draught power)
Market orientation of annual cropping production system: Mixed (subsistence/commercial) Could be used/produced for domestic and commercial purposes.
Market orientation of grazing land production system: Subsistence and commercial/market
Market orientation of forest production system: Mixed (subsistence/commercial) in both cases use of biogas is approppriate

5.7 Média da área de terra própria ou arrendada por usuários da terra que utilizam a tecnologia

5.8 Propriedade de terra, direitos de uso da terra e de uso da água

Propriedade da terra:

• Comunitário/rural
• Indivíduo, não intitulado

Direitos do uso da terra:

• Acesso livre (não organizado)
• Indivíduo

Direitos do uso da água:

• Comunitário (organizado)
• Indivíduo

Comentários:

The SLM can be used by anybody - not specified to any group. Dual grazing rights is a problem (private ranchers can also use the commons).

5.9 Acesso a serviços e infraestrutura

6.1 Impactos no local mostrados pela tecnologia

Impactos socioeconômicos

Produção

Renda e custos

Impactos socioculturais

Impactos ecológicos

Ciclo hídrico/escoamento

Solo

Biodiversidade: vegetação, animais

Clima e redução de riscos de desastre

Outros impactos ecológicos

6.2 Impactos externos mostrados pela tecnologia

6.3 Exposição e sensibilidade da tecnologia às mudanças climáticas graduais e extremos/desastres relacionados ao clima (conforme o ponto de vista dos usuários da terra)

Mudança climática gradual

Mudança climática gradual

	Estação do ano	Tipo de mudança climática/extremo	Como a tecnologia lida com isso?
Temperatura anual		aumento	bem

Extremos (desastres) relacionados ao clima

Desastres meteorológicos

	Como a tecnologia lida com isso?
Temporal local	bem
Tempestade de vento local	bem

Desastres climatológicos

	Como a tecnologia lida com isso?
Seca	bem

Desastres hidrológicos

	Como a tecnologia lida com isso?
Inundação geral (rio)	bem

Outras consequências relacionadas ao clima

Outras consequências relacionadas ao clima

	Como a tecnologia lida com isso?
Período de crescimento reduzido	bem
temperature decrease	não bem

Comentários:

Biogas technology may be limited under extreme cold conditions whereby fermentation may be limited by cold temperatures.

6.4 Análise do custo-benefício

Como os benefícios se comparam aos custos de implantação (do ponto de vista dos usuários da terra)?

Como os benefícios se comparam aos custos recorrentes/de manutenção(do ponto de vista dos usuários da terra)?

Comentários:

Very costly to set up, if no government aid. It is however very good for long term water provision.

6.5 Adoção da tecnologia

Se disponível, determine a quantidade (número de unidades familiares e/ou área abordada):

10

Comentários:

1% of land user families have adopted the Technology with external material support

10 land user families have adopted the Technology with external material support

Comments on acceptance with external material support: A very insignificant number of individual farmers have used this technology

Comments on spontaneous adoption: The technology has mostly been used where the Research institution has installed in farmers' properties. Only in very few instances around the country have individuals installed it for themselves.

There is a little trend towards spontaneous adoption of the Technology

Comments on adoption trend: There seems to be very little marketing of biogas in the country

6.7 Pontos fortes/vantagens/oportunidades da tecnologia

Pontos fortes/vantagens/oportunidades na visão do usuário da terra
Problems of diminishing firewood species are reduced. How can they be sustained / enhanced? Because it is not every or all species that is used for firewood, the targeted species are quickly diminished
Cost of getting firewood is reduced How can they be sustained / enhanced? Distance to wood collection places are ever increasing hence users have to buy from truck or donkey cart owners
More time is freed How can they be sustained / enhanced? This especially applies to children (of school going age) in that they would have more time for their home works.

Pontos fortes/vantagens/oportunidades na visão do/a compilador/a ou de outra pessoa capacitada
Low maintenance and inputs are required for this technology How can they be sustained / enhanced? There is need for promotion of the technology
The structures to be put in place are very basic How can they be sustained / enhanced? There is need for the government to subsidize farmers in installing biogas plants, especially in the rual areas.
Good for rural households where firewood is used extensively. How can they be sustained / enhanced? Improve income of rural families so that they could afford the technology

6.8 Pontos fracos, desvantagens/riscos da tecnologia e formas de superá-los

Pontos fracos/desvantagens/riscos na visão do usuário da terra	Como eles podem ser superados?
Too expensive for poor farmers to adopt without assistance	Donor/government subsidies

7.2 Referências às publicações disponíveis

Título, autor, ano, ISBN:

Brown, V. J., 2006. BIOGAS: A Bright Idea for Africa. Environ Health Perspectives. 114(5), pp. A300–A303.

Disponível de onde? Custos?

internet

Título, autor, ano, ISBN:

Dayal, M., Vimal, O.P., Singh, K.K., 1989. Biomass gasification in India — DNES activities. Biomass, Volume 18, issues 3-4,pp. 197-204

Disponível de onde? Custos?

http://www.ganesha.co.uk/Articles/Biogas%20Technology%20in%20India.htm