Identifying optimal locations for large scale Jatropha cultivation for biodiesel production in Tanzania's semi arid regions.
Rapidly increasing concerns about energy security coupled with detrimental environmental impacts posed by the dependence on fossil fuels, and an urgent need for rural development in Africa are key drivers for the search for fuel alternatives. The international effort into the development of criteria and indicators for sustainable bioenergy production clearly recognizes that bioenergy production must not be at the expense of biodiversity and food security. Owing to its multi-purpose capabilities i.e. its ability to rehabilitate eroded lands, drought resistance as well as its biophysical and maintenance requirements, Jatropha was selected as a potential candidate for the production of biodiesel. Jatropha is not new to the people of Tanzania, the study area of the project. Research has shown that, its associated social, environmental and economic benefits are crucial to economic development of the country. At present, all of Tanzania’s petroleum based products are imported; about 90% of the energy consumed is derived from biomass; road, rail and electricity networks are underdeveloped. Environmental degradation is also a concern in the country. The aim of the study was to identify three optimal locations for large scale Jatropha cultivation for biodiesel production in Tanzania’s semi arid regions. Geographical Information Systems was used to overlay several remotely sensed data from previous research namely semi arid regions delineations, agro-ecological sub-zones that had Jatropha potential as well as the administrative zones of Tanzania. The unavailable and/unsuitable areas were verified against literature and this enabled the areas that were under cultivation, were housing biodiversity or were generally constrained to be filtered out from the study area. The three largest, available and potentially suitable areas that the study identified for large scale Jatropha cultivation occupied about 7.6 million hectares. Assuming an optimal seed yield and an oil content of 35%, these areas are capable of producing about 14.4 million litres of Jatropha oil per annum. Targeting a SADC fuel import substitution of 10%, these 14.4 million litres of Jatropha oil that the three areas will meet about 83% of the country’s energy needs. Owing to the state of electricity generation in Tanzania, these three areas are able to generate about six percent of electricity and this can contribute to some extend to the country energy needs. From the analysis it was clear to note that the production of biodiesel for blending or for electricity generation is going to be economically viable from the three selected regions. The available and suitable areas that were not consolidated within the three selected regions can be used for small scale Jatropha cultivation and their produce can be fed to large scale commercial oil production or they can use the biodiesel to produce their own electricity. Jatropha will have to be irrigated to enhance a viable economic yield; infrastructure will need to be constructed to areas that are not served by roads and railway lines. All of this bodes well for enhancing rural development. The government has already had the foresight to establish the National Biofuels Task Force which will need to monitor investors to ensure no enforced human displacement and/or exploitation in areas where the large scale farms are to be established.