The energy policy of Taiwan government plans to increase renewable energy to 20% of total power supply by 2025. This study investigates the offshore wind power development for Taiwan and risk management of offshore wind farms. In our study, index insurance is designed for the selected offshore wind farm site No. 26. By analyzing NASA data from 1980 to 2017, ARIMA (0,0,0)x(0,1,1)_(12) is used to forecast the offshore wind power production and which are applied in pricing the index insurance.