Wind Turbine Reliability, How Does It Compare with Other Embedded Generation Sources

Wind turbines are being introduced into the distribution and transmission networks of Europe in increasing numbers. Their reliability has become a factor in network reliability. This has been exemplified by a report from Germany about the reserve necessary to maintain a secure supply with high levels of wind-powered generation in the system. Some difficulty arises because of the variable nature of the wind resource but some is attributable to the unreliability of wind turbines as power sources. This paper surveys the reliability of wind turbines in Denmark and Germany using data collected from Windstats over the past 7 years. The survey shows that turbines in Germany appear less reliable than turbines in Denmark. The reason for the difference is the greater number of newer, larger turbines being introduced in Germany, which increase Failure Rates because of Early Failures. The authors intend to use the data extracted from this survey to predict the reliability of large wind turbines placed in more inclement positions in the network, for example offshore.