Energy Requirement of Extra Virgin Olive Oil Production

The scope of this chapter is to calculate the net energy of the production chain for virgin olive oil. Therefore, the determination was carried out for the direct and indirect energy inputs and the energy present as feedstock in the outputs (products and by-products). To perform this analysis, all of the production processes for olives and for oil extraction were studied. For the agricultural phase, three systems of cultivation were taken into consideration: the centenary olive grove (COO), the “intensive” olive grove (HDO) and, the more recently introduced, “super-intensive” olive grove (HSDO). The last two models are distinguished by the high number of trees per hectare and by an intense mechanization of agricultural practices. Regarding the oil extraction phase, four different technologies were compared: the pressure system (PS), the two-phase system (2PS), the three-phase (3PS), and the system, called “de-pitted”, which provides for the separation of the pits before the oil is extracted (DPS). The analysis showed that the production of olives needs more than 90% of energy requirements, much of which is met by non-renewable sources of energy. The production of fertilizers, and also irrigation, are the production factors that require a considerable amount of energy. Among the three agricultural systems analyzed, the COO system of cultivation is the one that requires less energy as compared to the other systems. The scenario that enables the most energy return, however, is the SHDO system of cultivation, due to the greater amount of pruning residues that can be obtained.