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SolarUtils is set of Python wrappers around the publicly available NREL <http://www.nrel.gov/>_ SOLPOS <http://rredc.nrel.gov/solar/codesandalgorithms/solpos/>_ and SPECTRL2 <http://rredc.nrel.gov/solar/models/spectral/>_ C-language computer programs that calculate solar position and spectral decomposition. Please read the NREL disclaimer and license <http://www.nrel.gov/disclaimer.html>_. Usage of this software implies acceptance of the terms.

Installation

Use pip to install SolarUtils from the PyPI <https://pypi.python.org/pypi/SolarUtils>_::

pip install SolarUtils

You can also download a source distribution from PyPI or clone the repository and use Python distutils::

python setup.py install

Requirements

SolarUtils has no requirements for usage however for installation, testing and to build the documentaiton you will need the following pacakges:

• NumPy
• PyTest
• Sphinx

Usage

See SOLPOS Documentation <http://rredc.nrel.gov/solar/codesandalgorithms/solpos/aboutsolpos.html>_ and SPECTRL2 Documentation <http://rredc.nrel.gov/solar/models/spectral/spectrl2/documentation.html>_ for more detail.

Examples

>>> from solar_utils import *
>>> import pandas as pd
>>> location = [35.56836, -119.2022, -8.0]
>>> datetime = [2013, 6, 5, 12, 31, 0]
>>> weather = [1015.62055, 40.0]
>>> (angles, airmass) = solposAM(location, datetime, weather)
>>> zenith, azimuth = angles
>>> zenith
15.074043273925781
>>> azimuth
213.29042053222656]
>>> am, amp = airmass
>>> am
1.0352272987365723
>>> amp
1.0379053354263306]

>>> units = 1
>>> location = [33.65, -84.43, -5.0]
>>> datetime = [1999, 7, 22, 9, 45, 37]
>>> weather = [1006.0, 27.0]
>>> orientation = [33.65, 135.0]
>>> atmospheric_conditions = [1.14, 0.65, -1.0, 0.2, 1.36]
>>> albedo = [0.3, 0.7, 0.8, 1.3, 2.5, 4.0] + ([0.2] * 6)
>>> specdif, specdir, specetr, specglo, specx = spectrl2(
...     units, location, datetime, weather, orientation,
...     atmospheric_conditions, albedo
... )
>>> spec = pd.DataFrame(
...     {'DIF': specdif, 'DIR': specdir, 'ETR': specetr, 'GLO': specglo},
...     index=specx
... )
>>> f = spec.plot()
>>> f.set_title('Solar Spectrum Example')
>>> f.set_xlabel('Wavelength, $\lambda [\mu m]$')
>>> f.set_ylabel('Spectral Irradiance, $I_{\lambda} [W/m^2/\mu m]$')
>>> f.grid(True)
>>> f.figure.show()