captest.prtest.perf_ratio_temp_corr_nrel

captest.prtest.perf_ratio_temp_corr_nrel(ac_energy, dc_nameplate, poa, power_temp_coeff=None, temp_bom=None, temp_amb=None, single_irr_weighted_temp=False, wind_speed=None, base_temp=25, module_type='glass_cell_poly', racking='open_rack', unit_adj=1, degradation=None, year=None, availability=1)

Calculate performance ratio.

Parameters:

  • ac_energy (Series) – Measured energy production (kWh) 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.

  • power_temp_coeff (numeric, default None) – Module power temperature coefficient as percent per degree celsius. Ex. -0.36

  • temp_bom (Series) – Measured back of module temperature. The temp_amb and wind_speed arguments are not used if this argument is not None; skips calculating BOM temps from ambient temperature, wind speed, and POA irradiance.

  • single_irr_weighted_temp (bool, default False) – Set to True to calculate a single irradiance weighted temperature to use when temperature correcting the power. Some contract language calls for this but it does not follow the calculation defined in the NREL paper.

  • temp_amb (Series) – Ambient temperature (degrees C) measurements.

  • wind_speed (Series) – Measured wind speed (m/sec) corrected to measurement height of 10 meters.

  • base_temp (numeric, default 25) – Base temperature (in Celsius) to correct power to. Default is the STC of 25 degrees Celsius. The NREL Weather-Corrected Performance Ratio technical report uses the term ‘Tcell_typ_avg’ for this value.

  • module_type (str, default 'glass_cell_poly') – Any of glass_cell_poly, glass_cell_glass, or ‘poly_tf_steel’.

  • racking (str, default 'open_rack') – Any of ‘open_rack’, ‘close_roof_mount’, or ‘insulated_back’

  • 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) – NOT IMPLEMENTED Apply a derate for degradation to the expected power (denominator). Must also pass specify a value for the year argument.

  • year (numeric) – NOT IMPLEMENTED Year of operation to use in degradation calculation.

  • availability (numeric or Series, default 1) – NOT IMPLEMENTED Apply an adjustment for plant availability to the expected power (denominator).