pvlib.spectrum.get_reference_spectra#

pvlib.spectrum.get_reference_spectra(wavelengths=None, standard='ASTM G173-03')[source]#

Read a standard spectrum specified by standard, optionally interpolated to the specified wavelength(s).

Defaults to ASTM G173-03 AM1.5 standard [1], which returns extraterrestrial, global and direct spectrum on a 37-degree tilted surface, optionally interpolated to the specified wavelength(s).

Parameters:
  • wavelengths (numeric, optional) – Wavelengths at which the spectrum is interpolated. [nm]. If not provided, the original wavelengths from the specified standard are used. Values outside that range are filled with zeros.

  • standard (str, default "ASTM G173-03") – The reference standard to be read. Only the reference "ASTM G173-03" is available at the moment.

Returns:

standard_spectra (pandas.DataFrame) – The standard spectrum by wavelength [nm]. [W/(m²nm)]. Column names are extraterrestrial, direct and global.

Notes

If wavelength is specified, linear interpolation is used.

If the values in wavelength are too widely spaced, the integral of each spectrum may deviate from its standard value. For global spectra, it is about 1000.37 W/m².

The values of the ASTM G173-03 provided with pvlib-python are copied from an Excel file distributed by NREL, which is found here [2]: https://www.nrel.gov/grid/solar-resource/assets/data/astmg173.xls

Examples

>>> from pvlib import spectrum
>>> am15 = spectrum.get_reference_spectra()
>>> am15_extraterrestrial, am15_global, am15_direct = \
>>>     am15['extraterrestrial'], am15['global'], am15['direct']
>>> print(am15.head())
            extraterrestrial        global        direct
wavelength
280.0                  0.082  4.730900e-23  2.536100e-26
280.5                  0.099  1.230700e-21  1.091700e-24
281.0                  0.150  5.689500e-21  6.125300e-24
281.5                  0.212  1.566200e-19  2.747900e-22
282.0                  0.267  1.194600e-18  2.834600e-21
>>> am15 = spectrum.get_reference_spectra([300, 500, 800, 1100])
>>> print(am15)
            extraterrestrial   global    direct
wavelength
300                  0.45794  0.00102  0.000456
500                  1.91600  1.54510  1.339100
800                  1.12480  1.07250  0.988590
1100                 0.60000  0.48577  0.461130

References

Examples using pvlib.spectrum.get_reference_spectra#

ASTM G173-03 Standard Spectrum

ASTM G173-03 Standard Spectrum