Significant energy loss due to farm curtailment

Understanding the approach of the significant energy loss due to farm curtailment check

What is the purpose of the failed anemometer turbine issue?

  • A given turbine is losing energy due to farm curtailment. 
  • This check also allows us to assess whether the farm curtailment strategy is effective.  For example, in this plot the farm controller behavior is highlighted.  Each colored line represents the power generated by a single turbine, but the average turbine output (shown in black), is constant throughout.  WindESCo’s analytics recognizes this collective farm behavior and identifies when a turbine is appropriately curtailed by the farm controller.

Can you see this in 10-min data? 

  • This issue somewhat can be seen in 10-minute data, however identifying the source of the problem can be difficult without high frequency data.  
  • In this case for the example below we see the farm total power versus median nacelle wind speed for all turbines, corrected for density, with detected curtailment highlighted in red. Using data between 2022-08-21 and 2022-11-19.

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

  • Ideal farm total power (in green, estimated using contract power curve of each turbine) vs. actual total power (in blue), with curtailment marked with red dots. The red shaded area indicates the period marked by the issue.  In this case, daily energy loss due to farm curtailment exceeded 5.0% for 5 days during the period between 2022-11-01 and 2022-11-09.

How can you tell the issue is corrected?

  • Sometimes it is not possible to correct this issue because curtailment is part of expected operations.  WindESCo can, however, confirm if the appropriate farm curtailment strategy is in place and if there is any additional curtailment beyond what is expected.
  • When the issue is fully corrected the curtailment is removed and no longer visible in the farm total power curve.