Abstract: Intermittent nature of solar and wind resources have been the main problem associated to power generation from both the sources. Integrating solar with wind generation system through proper sizing analysis will be able to produce a sustainable and reliable output from the system. Sizing analysis needs to be performed for the components in the system design such as PV panels, wind turbines, charge controllers, batteries and inverters. This study explains the development of a sizing analysis software for a PV and wind integrated hybrid generation system. Sizing analysis for the hybrid generation system in this study incorporates a novel design of a sun tracking system. Experiments performed to validate the performance of different types of sun trackers proved that a two-axis sun tracker performs better than a fixed solar panel and a one-axis sun tracker. However it was also found that two-axis sun trackers are not suitable for large scale electricity generating system in Malaysia due to the location which is at the equator. The sizing analysis was verified by developing and testing a 12 V hybrid PV and wind generating system for an AC load of 85 Wh and DC load of 45 Wh with a storage capacity of 100 Ah at 50% Battery Depth of Discharge (DOD) for 3 days of storage. The sizing analysis explained in this study takes into account the available resource on weekly average at the location and load demand need to be performed to make the hybrid generation system more sustainable.