The profitability of photovoltaic (PV) systems for irrigating Mediterranean greenhouse crops is analyzed. A standalone direct pumping PV system is proposed. A simulation model of the system was developed in order to obtain the economically optimal design of this system and evaluate its feasibility. The model is composed of several submodels: the photovoltaic power generation capacity submodel, the direct pumping management submodel and the submodel that evaluates the irrigation water requirements for a representative greenhouse and the overall economic performance of the system.The effect of the total number of irrigation sectors per hectare on the performance of the system has been analyzed. Two management strategies have been considered: to irrigate with only one irrigation sector simultaneously or to irrigate with a variable number of irrigation sectors as a function of the incoming power provided by the PV array. The optimal operation strategy provided by the model was the first one as the second was penalized by the higher cost of the pumps. The system becomes profitable for at least 4 sectors per hectare. The profitability and energy use efficiency of this type of systems are relatively low, although these values could be improved if the excess of energy were used for other purposes, such as ventilating or cooling the greenhouse