A detailed analysis of the recoded failure data of the wind turbines in Zafarana wind farm namely Site-3 has been introduced. The failure cost consequences of one of the main components of the wind turbine have been introduced for cost analysis and maintenance planning.The effect of variation of the capacity factor and the down time on failure cost consequences is introduced. The down time has a significant effect on the failure cost consequences of wind turbine components. The failure recoded data have been illustrated for one year for the same site for different wind turbine components while the capacity factor has only effect on gearbox and blade failure cost.For failure rate and reliability analysis, the Weibull distribution has been introduced, the modified maximum likelihood method has been used to evaluate the Weibull distribution parameters. The failure rate and reliability have been studied for different wind turbine components. The initial failure rate after one month (720 h) was 0.0026 while the failure rate was 0.0084 at the end of the year (8760h) for the generator critical components.