This is an assessment of key economic, environmental and social issues pertaining to jatropha biofuels, based on almost 150 studies covering 26 countries. The assessment aims to furnish a state-of-the-art overview and identify knowledge gaps. So far, total jatropha production has remained small. Numbers and value of jatropha projects have even declined since 2008.
The economic analyses indicate minimal financial feasibility for projects. Yield increase and value addition (e.g., through utilising by-products) are necessary. Plantations seem to fare the worst, mainly due to the higher financial inputs used in a plantation setting and the still limited yield levels. Smallholders can only achieve financial feasibility in low-input settings and when opportunity costs are low. Unfortunately, hardly any Cost Benefit Analyses (CBA) are based on real data; partly due to a lack of long-running jatropha projects.
The environmental impact varies greatly across locations. Most studies indicate significant Greenhouse Gas (GHG) benefits over fossil fuels; however, this is only achieved with limited inputs and no loss of high C-stock biodiversity. The determinants in Life Cycle Analyses (LCA) are yield, input level, by-products utilisation, transesterification, transport distances, and land cover. More LCA research is required with more accurate data, and focusing on nitrous oxide emissions and the relation between production intensity and biodiversity impacts.
Minimal negative social impacts have been revealed so far, but discontinuation of projects affects communities through income losses and fostering more negative attitudes towards new projects. Moreover, hardly any studies quantify social impact comprehensively. Detailed data collection is necessary, involving baseline studies to start with.
If its financial feasibility is improved, jatropha can still become an option for sustainable energy production, GHG mitigation and rural development, especially through smallholder models. Successful implementation requires careful advance assessment of local circumstances, such as the political climate, gender aspects and land ownership structures.