How reliable are wind turbines?
Modern wind turbines can be extremely reliable, with the percentage of time that many systems are available to produce power (often called "availability") often being 99% and more. This article, contributed by a test engineer, puts the reliability expected of a wind turbine into perspective by comparing it with that of an automobile. Another perspective is provided by comparisons with helicopters, the rotor blades of which must often be replaced after several hundred hours, while wind turbine blades commonly last 10 to 20 years and more.
