The potential for the production of bioenergy for lighting and cooking using Jatropha (Jatropha curcas L. Euphorbiaceae) by small scale farmers on the Kenyan coast

  • Möglichkeiten der Nutzung von Jatropha (Jatropha curcas L. Euphorbiaceae) als Koch- und Beleuchtungsenergie durch Kleinbauern an der kenianischen Küste

Boerstler, Fritjof; Schoop, Wolfgang (Thesis advisor)

1. Aufl.. - Aachen : Grin (2010)
Dissertation / PhD Thesis

Zugl.: Aachen, Techn. Hochsch., Diss., 2010


The overall objective of this study is to examine the potential of introducing renewable biomass for a decentralized household energy provision in rural areas at the Kenyan South Coast. The main question posed in this research is whether the renewable products of an oil tree and related energy end-use appliances could potentially be a cheap, widely available and socially accepted substitute for kerosene and traditional biomass. The research data and results are based on a UNDP GEF SGP funded pilot project. The project was conceptualized by the author and implemented with local communities with support from the German Development Service (DED), the World Wide Fund (WWF) and various government institutions in Kwale District between 2006 and 2010. The first theoretical part of this study describes the negative socio-economic, environmental and health related impacts of the current household energy provision and energy use in Developing Countries (DCs). It becomes obvious that the households’ strong dependency on kerosene and traditional biomass severely hampers the achievement of national and international development goals. The potentials and barriers when introducing renewable energy technologies (RETs) in DCs are presented by using selected project examples. The discussion emphasizes that not only economical, institutional and infrastructural factors contribute to the low dissemination rates of RETs in DCs but also the social acceptance by potential users. Finally the results from this investigation are used to discuss the current and future household energy provision in Kenya. The second part of the study elaborates on the possibility of sustainably introducing the oil tree Jatropha curcas L. as a bioenergy source to rural households. For that purpose the feasibility of introducing the Jatropha value chain on a community level was tested and analyzed by taking three crucial aspects into consideration; the tree’s environmentally sound production (cultivation), the economic transformation (processing) of the seed material into usable fuel and socially accepted end-usage of the Jatropha products. In this context the UN-funded project served as a baseline for the data collection. After conducting a socio-economic survey among 137 households participating in the project, the introduction of a Jatropha value chain was analyzed in three chronological steps: (i) Firstly, the most viable region for the tree’s cultivation was determined by monitoring seed production rates from three different agro-ecological zones. (ii) A manually operated hydraulic press was designed and tested to produce Jatropha oil and briquettes. (iii) The acceptance of a specially designed Jatropha oil lamp (Akiba lamp) was determined. Furthermore, the heat efficiency of Jatropha briquettes was tested and compared to firewood (kitchen test). Results from the socio-economic household survey indicated that traditional biomass and kerosene were the most vital energy sources for households in the research area. Seventy-three per cent of the interviewed households exclusively used firewood for cooking, resulting in an average consumption of 4.2 kg per household per day. Over 60% of the households collected their firewood from adjacent forests while the remaining 40% gathered the wood from their farms. average, each household spent 4.8 hours per week in search of firewood. In respect of lighting, kerosene was used by 99% interviewee with an average consumption rate of 2.8 litres per household per week. The analysis of the Jatropha value chain showcased that it was possible to implement all parts of the chain in high potential growing zones of the research area: (i) The trial areas located in agro-ecological zones with relatively high rainfall in the coastal lowland had the highest seed production after two years of growth. In contrast, the trial area located in the coastal upland with prevalently lower rainfall only produced small amounts of seed within the same period. (ii) The hydraulic press was able to simultaneously produce Jatropha oil and briquettes with an extraction rate of 11% oil and 89% briquettes. (iii) The Akiba lamp consumed half as much oil as the commonly used kerosene lamp. The results of this work reveal that the Jatropha value chain could be successfully implemented in selected rural areas of Kenya and other DCs with similar agro-ecological and socio-economic conditions. It therefore has the potential to provide a renewable, alternative energy source to kerosene and traditional biomass as well as other more complex energy technologies that are difficult to introduce to DCs.