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Greenbyte Documentation

Performance Index Time Window (Availability Corrected)

The Performance Index Time Window (availability corrected) is a metric of an inverter's actual performance but limited to a selected time window each day.

It compares actual power to potential power for timestamps when the inverter is running. It calculates when the inverter is actually producing – when there are no active stop events. The Performance Index (availability corrected) can be used to find inverters that under-perform during normal operation.

Technology

Solar

Remarks

A Time window consists of two Metadata fields Time Window Start and Time Window End on the Inverter level. They are entered as the hour of the day in Local time and define the time interval in which the signal shall be calculated.

Required metadata fields:

  • Performance Irradiance Cut-In (W/m2) (Inverter metadata 13)

  • Performance Time Window Start (hh) (Inverter metadata 11)

  • Performance Time Window End (hh) (Inverter metadata 12)

Equation
Performance_Index_Time_Window__Availability_Corrected__-_Equation.png

Where:

PITWAC

is the Performance Index Time Window Availability Corrected Inverter

PCP,perf

is Cascading Potential Power - Solar

I

is Solar Irradiance Reference

Cut-inIP

is the Performance Irradiance Cut-in (W/m2) (Inverter metadata 13)

t

is the Timestep

tTWstart

is Performance Time Window Start (hh), a defined starting hour, t >= tTWstart. (Inverter metadata 11)

tTWend

is Performance Time Window End (hh), a defined ending hour, t < tTWend. (Inverter metadata 12)

ATS

is Time-Based System Availability (Inverter)

T

is the device resolution in hours

E

is the Energy or Power with Fallback

Inputs
Performance_Index_Time_Window__Availability_Corrected__-_Inputs.png
Usage Example

In this example, you can see how the Performance Index (availability corrected) is calculated for the full day, but the Performance Index Time Window (availability corrected) (green line) is only calculated for the part of the day defined by the time window.

Performance_Index_Time_Window__Availability_Corrected__-_Usage_Example.png