def test_calculate_back_horizon_shading():
arguments = {
'surface_azimuth': 0.0,
'surface_tilt': 30.0,
'gcr': 0.5,
'n_pvrows': 2,
'pvrow_height': 1.5,
'pvrow_width': 1.,
'rho_ground': 0.2,
'rho_pvrow_back': 0.03,
'rho_pvrow_front': 0.01,
'solar_azimuth': 90.0,
'solar_zenith': 30.0,
'circumsolar_angle': 50.,
'horizon_band_angle': 6.5,
'calculate_front_circ_horizon_shading': False,
'circumsolar_model': 'gaussian'
}
# Create shapely PV array
array = Array(**arguments)
# Test the horizon band shading part
solar_zenith = 45.
solar_azimuth = 90.
surface_tilt = 30.
surface_azimuth = 0.
dni = 0.
luminance_isotropic = 0.
luminance_circumsolar = 0.
poa_horizon = 1.
poa_circumsolar = 0.
array.update_irradiance_terms_perez(solar_zenith, solar_azimuth,
surface_tilt, surface_azimuth, dni,
luminance_isotropic,
luminance_circumsolar, poa_horizon,
poa_circumsolar)
expected_horizon_shading = np.array([90.25751984, 0.0974248])
calculated_horizon_shading = array.surface_registry.query(
'pvrow_index==0 and surface_side=="back"')[[
'horizon_band_shading_pct', 'horizon_term'
]].values[0]
calculated_no_horizon_shading = array.surface_registry.query(
'pvrow_index==1 and surface_side=="back"')[[
'horizon_band_shading_pct', 'horizon_term'
]].values[0]
TOL = 1e-7
np.testing.assert_allclose(expected_horizon_shading,
calculated_horizon_shading,
atol=0,
rtol=TOL)
np.testing.assert_allclose(np.array([0., 1.]),
calculated_no_horizon_shading,
atol=0,
rtol=TOL)
def test_irradiance_terms_perez_but_isotropic():
"""
Check that the irradiance terms calculated for this configuration and
using the isotropic diffuse sky dome is working as expected
There is some direct shading on the back surface in this configuration
"""
# Simple sky and array configuration
dni = 1e3
dhi = 1e2
solar_zenith = 80.
solar_azimuth = 0.
surface_tilt = 70.
surface_azimuth = 180.
arguments = {
'n_pvrows': 3,
'pvrow_height': 1.5,
'pvrow_width': 1.,
'gcr': 0.4,
}
# Create vf array
array = Array(**arguments)
# Calculate irradiance terms
array.update_view_factors(solar_zenith, solar_azimuth, surface_tilt,
surface_azimuth)
array.update_irradiance_terms_perez(solar_zenith, solar_azimuth,
surface_tilt, surface_azimuth, dni,
dhi, 0., 0., 0.)
# Check that the values are as expected
expected_irradiance_terms = np.array([
0., 0., 0., 0., 173.64817767, 173.64817767, 173.64817767, 173.64817767,
173.64817767, 0., 0., 866.02540378, 866.02540378, 866.02540378, 100.
])
tol = 1e-8
np.testing.assert_allclose(array.irradiance_terms,
expected_irradiance_terms,
atol=tol,
rtol=0)