Generally, hourly measured source and load data are used to size stand-alone hybrid energy system. However, the power generated by wind turbines and PV panels change rapidly because of the continuous fluctuation of wind speed and solar radiation. Therefore, these fluctuations must be considered in sizing stand-alone hybrid energy system. On the other and, energy demand changes during the day. Within the context of the study, the effects of demand and sources data resolution on the stand-alone hybrid system sizing were analyzed considiring minutely and hourly sources and load data.