Adequate recognition of the wind energy potential of coastal states may have far-reaching effects on the development of the energy systems of these countries. This study evaluates wind energy resources in Taiwan with the aid of a geographic information system (GIS), which allows local potentials and restrictions such as climate conditions, land uses, and ecological environments to be considered. The findings unveiled in this study suggest a significant role for offshore wind energy resources, which may constitute between 94% and 98% of overall wind resources in Taiwan. Total power yield from wind energy could reach between 150 and 165 TWh, which would have, respectively, accounted for between 62% and 68% of Taiwan's total power generation of 243 TWh in 2007. Based on the Taiwan's current emission factor of electricity, wind energy has the potential to reduce CO2 emissions by between 94 and 102 million ton per year in Taiwan, which is, respectively, equivalent to 28% and 31% of the national net equivalent CO2 emissions released in 2002. However, the challenge of managing the variability of wind power has to be addressed before the considerable contribution of wind energy to domestic energy supply and CO2 reduction can be realized. (C) 2009 Elsevier Ltd. All rights reserved.