1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
|
"""
irradiance.py from pvlib
========================
Extremely stripped down, reimplementation/vendorized version from:
https://github.com/pvlib/pvlib-python/
The rational for not including this library as a strict dependency is to avoid
including a dependency on pandas, keeping load time low, and PyPy compatibility
Most of the functions will import pvlib and use it for calculations, except
for one case which allows this to be used without `pvlib`
For a full list of contributors to this file, see the `pvlib` repository.
The copyright notice (BSD-3 clause) is as follows:
BSD 3-Clause License
Copyright (c) 2013-2018, Sandia National Laboratories and pvlib python Development Team
All rights reserved.
Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:
Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright notice, this
list of conditions and the following disclaimer in the documentation and/or
other materials provided with the distribution.
Neither the name of the {organization} nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
"""
from math import acos, cos, degrees, exp, isnan, radians, sin
nan = float("nan")
def aoi_projection(surface_tilt, surface_azimuth, solar_zenith, solar_azimuth):
projection = (
cos(radians(surface_tilt)) * cos(radians(solar_zenith)) +
sin(radians(surface_tilt)) * sin(radians(solar_zenith)) *
cos(radians(solar_azimuth - surface_azimuth)))
return projection
def aoi(surface_tilt, surface_azimuth, solar_zenith, solar_azimuth):
projection = aoi_projection(surface_tilt, surface_azimuth,
solar_zenith, solar_azimuth)
aoi_value = degrees(acos(projection))
return aoi_value
def poa_components(aoi, dni, poa_sky_diffuse, poa_ground_diffuse):
poa_direct = max(dni * cos(radians(aoi)), 0.0)
if poa_sky_diffuse is not None:
poa_diffuse = poa_sky_diffuse + poa_ground_diffuse
else:
poa_diffuse = poa_ground_diffuse
poa_global = poa_direct + poa_diffuse
irrads = {}
irrads['poa_global'] = poa_global
irrads['poa_direct'] = poa_direct
irrads['poa_diffuse'] = poa_diffuse
irrads['poa_sky_diffuse'] = poa_sky_diffuse
irrads['poa_ground_diffuse'] = poa_ground_diffuse
return irrads
def get_ground_diffuse(surface_tilt, ghi, albedo=.25, surface_type=None):
diffuse_irrad = ghi*albedo*(1.0 - cos(radians(surface_tilt)))*0.5
return diffuse_irrad
def get_sky_diffuse(surface_tilt, surface_azimuth,
solar_zenith, solar_azimuth,
dni, ghi, dhi, dni_extra=None, airmass=None,
model='isotropic',
model_perez='allsitescomposite1990'):
if model == 'isotropic':
return isotropic(surface_tilt, dhi)
else:
from pvlib import get_sky_diffuse
return get_sky_diffuse(surface_tilt, surface_azimuth,
solar_zenith, solar_azimuth,
dni, ghi, dhi, dni_extra=dni_extra, airmass=airmass,
model=model,
model_perez=model_perez)
def get_absolute_airmass(airmass_relative, pressure=101325.):
airmass_absolute = airmass_relative*pressure/101325.
return airmass_absolute
def get_relative_airmass(zenith, model='kastenyoung1989'):
z = zenith
zenith_rad = radians(z)
if 'kastenyoung1989' == model:
try:
am = (1.0 / (cos(zenith_rad) +
0.50572*((6.07995 + (90.0 - z))**-1.6364)))
except:
am = nan
if isinstance(am, complex):
am = nan
else:
raise ValueError('%s is not a valid model for relativeairmass', model)
return am
def get_total_irradiance(surface_tilt, surface_azimuth,
solar_zenith, solar_azimuth,
dni, ghi, dhi, dni_extra=None, airmass=None,
albedo=.25, surface_type=None,
model='isotropic',
model_perez='allsitescomposite1990', **kwargs):
poa_sky_diffuse = get_sky_diffuse(
surface_tilt, surface_azimuth, solar_zenith, solar_azimuth,
dni, ghi, dhi, dni_extra=dni_extra, airmass=airmass, model=model,
model_perez=model_perez)
poa_ground_diffuse = get_ground_diffuse(surface_tilt, ghi, albedo,
surface_type)
aoi_ = aoi(surface_tilt, surface_azimuth, solar_zenith, solar_azimuth)
irrads = poa_components(aoi_, dni, poa_sky_diffuse, poa_ground_diffuse)
return irrads
def isotropic(surface_tilt, dhi):
sky_diffuse = dhi * (1 + cos(radians(surface_tilt))) * 0.5
return sky_diffuse
def ineichen(apparent_zenith, airmass_absolute, linke_turbidity,
altitude=0, dni_extra=1364., perez_enhancement=False):
if isnan(airmass_absolute) or isnan(apparent_zenith):
return {'ghi': 0.0, 'dni': 0.0, 'dhi': 0.0}
# use max so that nighttime values will result in 0s instead of
# negatives. propagates nans.
cos_zenith = cos(radians(apparent_zenith))
if cos_zenith < 0.0:
cos_zenith = 0.0
tl = linke_turbidity
fh1 = exp(-altitude/8000.)
fh2 = exp(-altitude/1250.)
cg1 = 5.09e-5*altitude + 0.868
cg2 = 3.92e-5*altitude + 0.0387
ghi = exp(-cg2*airmass_absolute*(fh1 + fh2*(tl - 1.0)))
# https://github.com/pvlib/pvlib-python/issues/435
if perez_enhancement:
ghi *= exp(0.01*airmass_absolute**1.8)
# use fmax to map airmass nans to 0s. multiply and divide by tl to
# reinsert tl nans
if ghi > 0.0:
ghi = cg1 * dni_extra * cos_zenith * tl / tl * ghi
else:
ghi = 0.0
# BncI = "normal beam clear sky radiation"
b = 0.664 + 0.163/fh1
bnci = b * exp(-0.09 * airmass_absolute * (tl - 1))
if bnci > 0.0:
bnci = dni_extra * bnci
else:
bnci = 0.0
# "empirical correction" SE 73, 157 & SE 73, 312.
try:
bnci_2 = ((1.0 - (0.1 - 0.2*exp(-tl))/(0.1 + 0.882/fh1)) /
cos_zenith)
except:
bnci_2 = 1e20
multiplier = (bnci_2 if bnci_2 > 0.0 else bnci_2)
multiplier = min(multiplier, 1e+20)
bnci_2 = ghi*multiplier
dni = min(bnci_2, bnci)
dhi = ghi - dni*cos_zenith
return {'ghi': ghi, 'dni': dni, 'dhi': dhi}
|
