Nacelle direction not calibrated to true north

Understanding the "Nacelle direction not calibrated to true north" check

What is the purpose of the failed anemometer turbine issue?

• There is an offset from a turbine’s reported nacelle direction and true north. In many cases this is not harmful to operation, but can be if wind sector management is enabled. Additionally, a drifting nacelle calibration can make wind direction-dependent analytics difficult.

Can you see this in 10-min data? 

• This issue can be identified in 10-minute data by comparing the wind direction to other metrics on the wind site

What does this look like / How do you identify this issue?

• In this case, turbine 48 was showing a higher amount of sector curtailment in comparison to other turbines surrounding it.
• Below we can see a high number of curtailment in the power and the associated wind direction over time.

How can you tell the issue is corrected?

• It was identified that this turbine’s nacelle calibration was off by 10-15° resulting in excess shutdowns and a loss of 6-8% AEP for the turbine
• Correction of this issue correlates to a $12,192-16,256 improvement per turbine