Environmental Engineering Reference
In-Depth Information
Figure 2.26
Relative Shading Losses
s
as a Function of the Shading Angle
α
and Surface Tilt Angle
γ
t
in Berlin (52.5°N)
The gain factor
g
considers the irradiation gains due to the surface tilt
angle (see also section on irradiance gain due to surface tilt or tracking, p64).
The factor
g
is the ratio of the annual global irradiation
H
G,tilt
on the tilted
surface and the global irradiation
H
G,hor
on a horizontal surface:
(2.47)
The overall correction factor
c
considers the tilt gains and the shading losses.
It is the ratio of the irradiation at point
P
0
to that on a horizontal surface:
(2.48)
Table 2.13
Shading losses
s
, Gain Factor
g
and Overall Correction Factor
c
for Point
P
0
at Different Ground Utilizations and Tilt Angles Calculated for
Berlin (52.5°N)
γ
t
= 30°
γ
t
= 10°
α
α
u
s
g
c
s
g
c
1:1.5
38.8°
0.246
1.193
0.900
18.6°
0.048
1.088
1.036
1:2.0
23.8°
0.116
1.193
1.055
9.7°
0.015
1.088
1.072
1:2.5
17.0°
0.074
1.193
1.105
6.5°
0.009
1.088
1.078
1:3.0
13.2°
0.048
1.193
1.136
4.9°
0.006
1.088
1.081
1:3.5
10.7°
0.035
1.193
1.151
3.9°
0.004
1.088
1.084
1:4.0
9.1°
0.029
1.193
1.158
3.3°
0.004
1.088
1.084
