Calculate performance ratio (PR) by comparing actual measured yield against the reference yield from irradiance data.
Input Parameters
Results
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Reference Yield
kWh/kWp
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Performance Ratio
%
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Expected PR at Age
%
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PR Deviation
%
Note: Performance ratio is the industry standard metric for PV system quality. Typical PR ranges: 75-85%. PR accounts for all system losses including thermal, wiring, inverter, and soiling.
Reference
Reference Yield = POA Irradiance (kWh/m²)
Specific Yield = Actual Energy / Capacity
PR = Specific Yield / Reference Yield × 100
Expected PR ≈ 82% − 0.5%/yr × (age − 1)
First year PR ≈ 80% (includes LID)