• I see underperformance alarm active but it doesn't look like it is under performing currently?
  • Where can I understand why the underperformance alarm was triggered?
  • How do I understand the underperformance thresholds and how to tune them?


Underperformance alarms are setup through the power curve application and use user configurable thresholds to determine when an asset is underperformaning. It is then populated in the alarm log, visible in asset operations, and rolled into the availability application for statistics. To read up on how to setup underperformance alarms please reference 

Example Case Study

One of the best ways to understand the underperformance alarm is to pull the relevant tags into Trend. Additioanlly you will want to understand the thresholds configured and the source tag logic used.

For the answer we will be going through an example with the following configuration:

  • Time detection period (hours): 6
  • Change in performance (%): 15
  • Minimum detection power (kW): 500
  • Alarm desciption: Underperformance vs historical

This means:

  • Underperformance will be Flagged (min 6 hours)
    1. If 
    2. Estimated Turbine Production > 500 kWh for previous 6 hour period
    3. &&
    4. Performance Index Avg < 75% for previous 6 hour period

  • Performance Index: (For this example. confirm your installations performance index by checking the calculation in tag manager or contacting support).
    • PI is calculated on a 10 minute interval
    • PI is only calculated when wind speed > 5.5 m/s
    • PI is calculated based off 10m SQL Active Power vs 10m Bazefield Calculated Theoretical Power
      • Theoretical Power derived from 10m SQL Wind Speed
      • Contractual Power Curve in the Asset Model

Example view in alarm log:

Example view in availability (you can click on the Allocation for a quick link)

Example of opening in Trend: (After adding Performance Index tag and Performance Alarm tag)

Another example of trend and how the 6 hour detection periods operate:


Product Version

Bazefield Portal 8.6.1