The increasing utilization of wind and solar energy for power supply in remote locations involves serious consideration of the reliability of these unconventional energy sources. Most utilities use deterministic criteria in the planning and design of these systems. The main disadvantage of deterministic criteria is that they do not recognize and reflect the inherent random nature of the site resources, the system behavior, and the customer demands etc. Probabilistic techniques can be used to overcome this drawback and incorporate the inherent uncertainty in these factors. Power system planners and designers sometimes experience difficulties in interpreting and using probabilistic reliability indices. This difficulty can be alleviated by incorporating deterministic considerations into a probabilistic evaluation using the well-being concept. A simulation technique is presented in this paper which extends the conventional well-being approach to generating systems using energy storage. The proposed technique is illustrated and applied in this paper to several small stand-alone power systems. The effects on the system well-being of some of the major system parameters and the deterministic criteria are illustrated.