The present invention relates to method for estimating energy production (107) from a wind turbine (101) with plurality of blades (102). The method comprises obtaining one or more infrared images (103) of each blade (102) of the wind turbine (101). Further, identifying one or more cross-sectional regions (302) of each of the blade (102) using the one or more infrared images (103) based on a boundary region (301), wherein the boundary region (301) is indicating a transition from a laminar air flow to a turbulent air flow. Furthermore, determining plurality of polar values indicative of an aerodynamic profile for each of the one or more cross-sectional regions (302) based on one or more panel method based techniques and the boundary region (301). Finally, estimating the energy production (107) for the wind turbine (101) based on one or more blade (102)-element momentum (BEM) based techniques using the plurality of polar values.

A system and method are configured to monitor changes associated with an air gap in a brake assembly of a wind turbine yaw drive by: (1) receiving one or more sensor signals from one or more sensors that are indicative of changes associated with the air gap; and (2) comparing the changes associated with the air gap to certain thresholds to determine if the air gap is in need of attention. The system includes at least one proximity sensor arranged adjacent to the air gap, to monitor the air gap, and a controller. The controller is configured to receive the sensor signal(s) indicative of the changes associated with the air gap. The controller also is configured to compare the changes associated with the air gap to one or more air gap thresholds, and to implement a control action based on this comparison.

The invention describes a method of controlling a wind turbine (2), which method comprises steps of measuring one or more climate parameters (.sub.t, T.sub.air, T.sub.surface) in an interior (2.sub.int) of the wind turbine (2); estimating, on the basis of the climate parameters (.sub.t, T.sub.air, T.sub.surface), the electrical resistance (RW.sub.t) of an insulating material (210M) deployed in an electrical component (21) of the wind turbine (2); and evaluating the need for a dry-out procedure on the basis of the estimated resistance (RW.sub.t). The invention further describes a wind turbine (2) with a monitoring arrangement (1) configured to perform the inventive method.

A method of operating a wind turbine is provided. The method includes steps of monitoring the temperature of a component of the wind turbine to obtain a temperature progression for that component; determining the gradient of the temperature progression; and curtailing the power output of the wind turbine on the basis of the temperature progression gradient. The disclosed further describes a wind turbine including a curtailment module configured to curtail the power output of the wind turbine on the basis of a temperature progression gradient.

A method is provided for monitoring the temperature of an electric generator of a wind turbine, wherein the generator has a stator, a rotor and a temperature monitoring unit. The temperature monitoring unit has a passive control element on the rotor and a receiving unit on the stator. A change in temperature on the rotor leads to a mechanical or optical change in the passive control element. The mechanical or optical change in the passive control element is acquired by the receiving unit on the stator.

A method of operating a wind turbine is provided. The method includes steps of monitoring the temperature of a component of the wind turbine to obtain a temperature progression for that component; determining the gradient of the temperature progression; and curtailing the power output of the wind turbine on the basis of the temperature progression gradient. The disclosed further describes a wind turbine including a curtailment module configured to curtail the power output of the wind turbine on the basis of a temperature progression gradient.