This paper proposes multiple optimal combinations of hybrid renewable energy systems for a resort island based on actual generation-side energy auditing, assessment of seasonal renewable energy resources availability versus load profiles, and techno-economic analyses. The resort island selected is Tioman, as it represents the typical energy requirements of many resort islands in the South China Sea. The island relies mainly on diesel fuel for electricity generation. However, diesel is subjected to high and volatile market prices, high operation and maintenance costs, and poses environmental risks. Therefore, to mitigate diesel fuel dependency, an optimal combination of hybrid renewable energy systems is proposed. The project starts with an actual generation-side auditing including the distribution of loads, seasonal load profiles, and types of loads as well as an analysis of local development planning. Subsequently, surveys of available renewable resource potentials such as solar, wind, and hydro were conducted that involved collection and analysis of meteorological data. Furthermore, reconnaissance study for hydro potentials has been based on topographic maps and hydrological studies. Finally, HOMER (Hybrid Optimization Model for Electric Renewable) software was used to perform techno-economic analyses for the hybrid system. Results of the analyses include the optimal system configurations, cost of hybrid system, fuel saving, and CO2 emission reduction. (C) 2015 Elsevier Ltd. All rights reserved.