pvlib.clearsky.ineichen

pvlib.clearsky.ineichen(time, latitude, longitude, altitude=0, linke_turbidity=None, solarposition_method='nrel_numpy', zenith_data=None, airmass_model='young1994', airmass_data=None, interp_turbidity=True)[source]

Determine clear sky GHI, DNI, and DHI from Ineichen/Perez model

Implements the Ineichen and Perez clear sky model for global horizontal irradiance (GHI), direct normal irradiance (DNI), and calculates the clear-sky diffuse horizontal (DHI) component as the difference between GHI and DNI*cos(zenith) as presented in [1, 2]. A report on clear sky models found the Ineichen/Perez model to have excellent performance with a minimal input data set [3].

Default values for montly Linke turbidity provided by SoDa [4, 5].

Parameters:

time : pandas.DatetimeIndex

latitude : float

longitude : float

altitude : float

linke_turbidity : None or float

If None, uses LinkeTurbidities.mat lookup table.

solarposition_method : string

Sets the solar position algorithm. See solarposition.get_solarposition()

zenith_data : None or Series

If None, ephemeris data will be calculated using solarposition_method.

airmass_model : string

See pvlib.airmass.relativeairmass().

airmass_data : None or Series

If None, absolute air mass data will be calculated using airmass_model and location.alitude.

interp_turbidity : bool

If True, interpolates the monthly Linke turbidity values found in LinkeTurbidities.mat to daily values.

Returns:

DataFrame with the following columns: ghi, dni, dhi.

Notes

If you are using this function in a loop, it may be faster to load LinkeTurbidities.mat outside of the loop and feed it in as a keyword argument, rather than having the function open and process the file each time it is called.

References

[1] P. Ineichen and R. Perez, “A New airmass independent formulation for
the Linke turbidity coefficient”, Solar Energy, vol 73, pp. 151-157, 2002.
[2] R. Perez et. al., “A New Operational Model for Satellite-Derived
Irradiances: Description and Validation”, Solar Energy, vol 73, pp. 307-317, 2002.
[3] M. Reno, C. Hansen, and J. Stein, “Global Horizontal Irradiance Clear
Sky Models: Implementation and Analysis”, Sandia National Laboratories, SAND2012-2389, 2012.
[4] http://www.soda-is.com/eng/services/climat_free_eng.php#c5 (obtained
July 17, 2012).
[5] J. Remund, et. al., “Worldwide Linke Turbidity Information”, Proc.
ISES Solar World Congress, June 2003. Goteborg, Sweden.