Energy analysis of Jatropha plantation systems for biodiesel production in Thailand

Jatropha curcas L. has been considered as a potential feedstock for biodiesel production in several tropical countries. Two Jatropha plantation models currently being considered in Thailand, a perennial plantation for 20 years and annual harvesting, are compared vis-à-vis the energy benefits. The advantage of the perennial plantation is that fruit yield is low in the first 2 years but stabilizes after the second year; thus, the biodiesel production is maximized. On the other hand, the biodiesel yield for annual harvesting is low but substantial energy is gained from the wood which can be used for power production. The overall energy output from the annual system is about twice that of the perennial system whereas the biodiesel production is less than half. The energy values of both the systems are high and the net energy ratios as high as 6–7 indicating a substantial energy benefit.