pvlib.irradiance.extraradiation¶
-
pvlib.irradiance.
extraradiation
(datetime_or_doy, solar_constant=1366.1, method='spencer', epoch_year=2014, **kwargs)[source]¶ Determine extraterrestrial radiation from day of year.
Parameters: - datetime_or_doy : numeric, array, date, datetime, Timestamp, DatetimeIndex
Day of year, array of days of year, or datetime-like object
- solar_constant : float, default 1366.1
The solar constant.
- method : string, default ‘spencer’
The method by which the ET radiation should be calculated. Options include
'pyephem', 'spencer', 'asce', 'nrel'
.- epoch_year : int, default 2014
The year in which a day of year input will be calculated. Only applies to day of year input used with the pyephem or nrel methods.
- kwargs :
Passed to solarposition.nrel_earthsun_distance
Returns: - dni_extra : float, array, or Series
The extraterrestrial radiation present in watts per square meter on a surface which is normal to the sun. Pandas Timestamp and DatetimeIndex inputs will yield a Pandas TimeSeries. All other inputs will yield a float or an array of floats.
References
[1] M. Reno, C. Hansen, and J. Stein, “Global Horizontal Irradiance Clear Sky Models: Implementation and Analysis”, Sandia National Laboratories, SAND2012-2389, 2012.
[2] <http://solardat.uoregon.edu/SolarRadiationBasics.html>, Eqs. SR1 and SR2
[3] Partridge, G. W. and Platt, C. M. R. 1976. Radiative Processes in Meteorology and Climatology.
[4] Duffie, J. A. and Beckman, W. A. 1991. Solar Engineering of Thermal Processes, 2nd edn. J. Wiley and Sons, New York.