captest.prtest.perf_ratio

captest.prtest.perf_ratio(ac_energy, dc_nameplate, poa, unit_adj=1, degradation=0, year=1, availability=1)

Calculate performance ratio.

Parameters:
  • ac_energy (Series) – Measured energy production (Wh) from system meter.

  • dc_nameplate (numeric) – Summation of nameplate ratings (W) for all installed modules of system under test.

  • poa (Series) – POA irradiance (W/m^2) for each time interval of the test.

  • unit_adj (numeric, default 1) – Scale factor to adjust units of ac_energy. For exmaple pass 1000 to convert measured energy from kWh to Wh within PR calculation.

  • degradation (numeric, default None) – Apply a derate (percent, Ex: 0.5%) for degradation to the expected power (denominator). Must also pass specify a value for the year argument. NOTE: Percent is divided by 100 to convert to decimal within function.

  • year (numeric) – Year of operation to use in degradation calculation.

  • availability (numeric or Series, default 1) – Apply an adjustment for plant availability to the expected power (denominator).

Returns:

Instance of class PrResults.

Return type:

PrResults