This paper shows the optimization of a PVWind system to supply the demand of water pumping in a small town in Bolivia. This work has been done with the HOGA program (Hybrid Optimization by Genetic Algorithms). The objective function to minimize in the design process is the total Net Present Cost (NPC) of the system. The system is defined as a combination of components (PV panels and wind turbines). In this case HOGA has used as an enumerative method of design, evaluating all the possible solutions to the design problem. In the example shown, the optimal system found is a Wind-Only system, not a hybrid system, due to the prices of the components and the metheorological conditions for this case.