Performance Ratio Calculation

Performance Ratio (PR) shows the percentage of total potential energy for the array that is converted to AC energy. 

Mathematically, the PR is defined in the following formula:

Annual AC Energy to Grid (kWh)
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Annual POA Irradiance (kWh/m2) * DC Solar System Size (kWp)

· Annual AC Energy to Grid: 158917 kWh

· DC Size: 100 kW

· Annual POA Irradiance: 1868.23 kWh/m2

We can calculate the performance ratio as 158917 / (1868.23 * 100) = 85.06% 

Note: PR is different from unit generation (kWh/kWp). PR is also different from System Loss.