Patent ID: 8319361

Claim:
A method of monitoring a wind energy installation which comprises: a tower; a gondola provided on the tower and being rotatable around a longitudinal axis of the tower; a rotor attached to the gondola, said rotor being provided with at least one rotor blade, and wherein the rotor is rotatable about a horizontal axis of the gondola; a distance sensor positioned on the gondola, wherein the distance sensor is oriented toward a point at which a distal end of the rotor blade passes through a vertical axis; and wherein the method of monitoring is with respect to a possible collision of the rotor blade with the tower, wherein during operation, a deflection of the rotor blade is measured by means of a contactless distance measurement taken by the distance sensor and, if the deflection exceeds a predetermined critical measurement, a collision warning is emitted, wherein the position of the sensor on the gondola is chosen such that the deflection of the rotor blade is determinable at every possible rotational position of the gondola during rotation of the gondola around the longitudinal axis of the tower.