Jatropha curcas L. has been tested as an energy source in a number of development projects and research programmes since the early nineties, and it has shown very positive results.

Jatropha c. (sci.: Euphorbiaceae, ger.: Purgiernuss, engl: Physic nut, fr.: Pourghère) is related to the Castor family. It is a scrub plant widely spread in South America, Asia, and Africa , which grows under comparatively dry conditions (250-1200 mm precipitation p.a.) and in poor soil.

Its nuts are toxic which makes it valuable in rural areas as a hedge-plant to protect fields against animals. And, for the same reason, it is not cultivated as food crops. This qualifies it as an energy source in developing countries because there is no competition with local food markets.

Jatropha c. produces seeds with oil content of 37-58%. The oil can be combusted as fuel without being refined and it burns with a clear, smoke-free flame. In a development project conducted by the German Agency for Technical Cooperation (GTZ) in Mali, it has been successfully tested as fuel for simple diesel-engines with a precombustion-chamber used in agricultural production for mills and water pumps. The esterification with methanol or ethanol then produces biodiesel (methyl- or ethyl-ester) which can be used for diesel engines in ordinary vehicles.