1
2
1
2
energize
the earth
buy the sun
www.inventux.com
Recent studies
*
show:
Micromorph thin-film modules are better than
crystalline modules under real environmental conditions
When purchasing solar modules, many clients orientate themselves
around theoretically determined efficiency levels in order to calculate
future energy output. The declared efficiency is based on simulated
“Standard Test Conditions“ (STC), which are built solely on circum-
stances in the laboratory. Therefore, these parameters reflect real
Laboratory parameters as compared with real environmental conditions
environmental conditions only to a limited extent. The average values
in reality, that is to say “Most Frequent Conditions“ (MFC), lead to a
significant change in energy output of the various module types. It is in
this way that micromorph thin-film modules from Inventux are substan-
tially more powerful under real conditions than crystalline modules.
Inventux modules maintain the majority of their excellent
performance even with increasing module temperature
The performance of most other modules drops significantly
Inventux Plus: Increasing energy yield and returns with
higher temperature when compared to crystalline modules
Temperature coefficients Inventux modules
**
Standard Test Conditions
(STC)
Simulated values
Most Frequent Conditions
(MFC)
Real values
Solar irradiation
1,000 W/m
2
, direct irradiation solely on laboratory
parameters (without clouds, smog, etc.)
400 - 800 W/m
2
*, diffuse and direct irradiation incl.
environmental influences (with clouds, smog, etc.)
Module temperature
25
°C
approx. 40
-
75
°C
**
Inventux modules offer high returns with diffuse light
Crystalline modules deliver reduced performance
Inventux Plus: Optimal energy output even with irradiation
under 800 Watts (European conditions during 80 % of the year)
Only approx. 40 % direct solar irradiation per year
Diffuse light predominates in Central Europe with about 60 %
!
Problem: The STC-simulation is solely based on direct
solar irradiation at 1,000 W/m
2
Solar irradiation in Central Europe
*
All module types show module temperatures that are
significantly higher than the ambient temperature
!
Problem: In order to reach the STC-simulation module
temperature of 25 °C at 1,000 W/m
2
irradiation, the
ambient temperature needs to be at -13 °C
Module temperature in Central Europe
*
Low light characteristics Inventux modules
**
Irradiation
[W/m
2
]
No
rm
al
ize
d
ef
fic
ie
nc
y
fa
ct
or
[η
/η
10
00 W
]
200
1.2
0.4
0
0.8
400
600
800
1000
0
58% of the average
irradiation in Europe
J
F
M
A
M
J
J
A
S
O
N
D
160
120
80
40
0
Direct irradiation
Diffuse irradiation
Month
120
50
Module
temperature
[°C]
Pe
rfo
rm
an
ce [
%
]
100
80
60
Range of average module
temperature in Europe
Irr
ad
ia
tio
n
[k
W
h/
m
2
x m
on
th
]
*
Sour
ce: e.g. Solar Energy
Materials & Solar Cells 93
(2009), 1062-1065
*
Sour
ce: Calculation per
for
med using ISFH Hameln/Emmer
thal model
**
Sour
ce: T
est-measur
ements at the Photovoltaik-Institute Berlin
STC
MFC
STC
Inventux
modules
Crystalline
modules
Gained surplus
with Inventux
Inventux
modules
Crystalline
modules
Gained surplus
with Inventux
*
Sour
ce: Planning and Installing Photovoltaic Systems, DGS 2008
**
Sour
ce: Solar Engineering GmbH, OC Oerlikon and
self test-measur
ments
80
15
25
35
45
55
65
20
30
40
50
60
70 75
MFC
M
od
ul
e t
em
pe
ra
tu
re [
°C
]
Irradiation
[Watt]
40 °C ambient temp.
20 °C ambient temp.
10 °C ambient temp.
-13 °C ambient temp.
0
200
400
600
800
1000
1200
-10
0
10
20
30
40
50
60
80
STC
70
30 °C ambient temp.
M
FC
Range of average module temperature in Europe
*
So
ur
ce
: F
ra
un
ho
fe
r-I
ns
tit
ut
e
fo
r P
hy
si
ca
l
Measur
ement T
echniques IPM
**
So
ur
ce
: S
el
f t
es
t-m
ea
su
re
m
en
ts
a
t t
he
Photovoltaik-Institute Berlin
