A Short Experimental Study on Photovoltaic Cells
Authors: Ashwini Kumari A S1, Pooja NG2
1
2
Systems Lab, Centre for Nano Science & Engg. (CeNSE), IISc, Bangalore
Electronics & Instrumentation, Siddaganga institute of Technology, Tumkur
ABSTRACT:
In the experimental study conducted on three commercial photovoltaic cells with resistive load, it was
observed that any change in irradiance leads to higher percent change in output current than output voltage,
at peak power load condition. It was also observed that the load required to draw a peak power, decreases
with irradiance.
Introduction
Photovoltaics:
Photovoltaic’s (PV) is a method of generating electrical power by converting solar radiation into direct current
electricity using semiconductors that exhibit the photovoltaic effect. Photovoltaic power generation employs
solar panels composed of a number of solar cells containing a photovoltaic material. Materials presently used
for photovoltaic’s include mono crystalline silicon, polycrystalline silicon, amorphous silicon, cadmium
telluride, and copper indium gallium selenide/sulfide. Due to the growing demand for renewable energy
sources, the manufacturing of solar cells and photovoltaic arrays has advanced considerably in recent years.
The amount of power available from a PV device is determined by;



The type and area of the material;
The intensity of the incident light and
The wavelength of the incident light
Applications of Photovoltaic’s:Photovoltaic’s can be used in a variety of applications including:






consumer products such as watches, toys and calculators
emergency power systems
vaccine and blood storage refrigerators for remote areas
aeration systems for ponds
power supplies for satellites and space vehicles
portable power supplies for camping and fishing
For further details please refer the following link
http://www.esdalcollege.nl/eos/vakken/na/zonnecel.htm
http://cd1.edb.hkedcity.net/cd/science/physics/NSS/Energy01_Dec08/PhotoVoltaicsCells.pdf
http://www.ni.com/white-paper/7229/en
Experimental Setup:
For conducting experiment, three different types of commercial solar panels were chosen as shown in the Pic 1
and
the
specifications
of
the
solar
panels
are
as
follows
Pic1: Solar panels: Solar panel 2, 3 and 1 (from left to right)
Solar panel 1: It was integrated with a Solar Mobile Charger device. Hence the specifications are not known.
Solar Panel 2:
Serial No:
Solar Panel 3:
Serial No:
BE03S12
Pmax-03Wp
Vpm-16.0V
Max System Operating voltage 750VDC
J-12040826
Max Power Pmax 5Wp,
Voltage at Max power Vmp 17.0V,
Current at Max power Imp 0.295A,
Open circuit voltage Voc 21.4, Isc (short circuit current) 0.33A
The solar panel was tested on under indoor and outdoor bases conditions with resistive load.
Test procedure:
Indoor Test:
For indoor testing two different lamps were used first one is the black lamp (incandescent) and the second one
is the white lamp (florescent) using these lamps the following test case were formed.
Case 1: When both the lamps are ON.
Case 2: When black lamp is ON, white lamp is OFF.
Case 3: When black lamp is OFF, white lamp is ON.
Case 4: When both the lamps are OFF.
Step 1: Connect Solar panel 1 as per the circuit diagram below.
Step 2: Turn both the lamps on. (Case 1)
Step 3: Vary the load by varying the potentiometer from minimum to maximum values and note down voltage
and current readings for various load values.
Step 4: Repeat Step 3 with Case 2, Case 3 and Case 4.
Step 5: Repeat Steps 1 to 4 with Solar panel 2 and Solar panel 3.
Fig: 1 Shows the circuit diagram of solar panel indoor test arrangement
Pic. 2: Solar panel set up with case 1
Pic. 3: Solar panel set up with case 2
Pic. 4: Solar panel set up with case 3
Outdoor Test:
Circuit and the underlying procedure remain same for the outdoor testing. It should be kept in mind that the
output power would be much higher and hence would require load (or potentiometer or resistors) of higher
power ratings.
We used potentiometer of 0.5 W rating for the output power less than 0.5 W and used fixed resistors
(100Ω/1W, 100Ω/5W, 10Ω/1W 3.3Ω/10W, 2.2 Ω /10W etc) for higher power output.
Fig: 2 shows the circuit diagram of solar panel outdoor test arrangement
Pic5. Solar panel outdoor setup
Results:
All the indoor and outdoor experimental results are presented in this section.
Note: (1) All the outdoor experiments were conducted on 22.09.2012, from 11.55 AM to 12.40PM on the
terrace of CeNSE, IISc, and Bangalore. (2) Normalized values of current (I) and output power (P) are plotted in
case of outdoor graphs. Current and power are normalized to the maximum reading obtained. Multiplication
factor is mentioned in each graph.
Graph 1a: Graph of solar panel-1under Indoor test
current (mA)
1.2
power (mW)
1.0
0.8
Normalised (P) x 159 in (mW),
Normalised (I) x 60 in mA
0.6
0.4
0.2
0.0
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5 2.75 3 3.25 3.5 3.75 4 4.25 4.5 4.75 5 5.25 5.5 5.75 6
Voltage (V)
Graph 1b: Graph of solar panel-1under outdoor test
This data was taken on 22.09.2012 at 12.40 PM at Cense café area
Graph 2a: Graph of solar panel-2 under Indoor test
Normalised I ( x 398), Normalised p ( x 5.63)
1
Current (mA)
1
power (W)
1
1
0
0
0
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19
voltage (V)
Graph 2b: Graph of solar panel-1under outdoor test
This data was taken on 22.09.2012 at 11.55 PM at Cense café area
Graph 3a: Graph of solar panel-3 under indoor test
1
1
Current (mA)
1
power (w)
Normalised I ( x 272) in (mA) ,
Normalised P ( x 2.93) (mW)
1
0
0
0
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19
voltage (V)
Graph 3b: Graph of solar panel-3 under outdoor test
This data was taken on 22.09.2012 at 12.32 PM at Cense café area
Summary
Solar panel 1
Outdoor
Indoor case-1
Indoor case-2
Indoor case-3
Indoor case-4
Voc (V)
Isc (mA)
V @Pmax
(V)
5.073
4.93
4.85
3.26
1.81
I @Pmax
(mA)
55
6.58
6.55
0.43
0.13
Pmax
(mW)
279
32
32
1.40
0.24
R @Pmax
(Ω)
92
749
740
7581
13923
5.073
5.44
5.42
4.04
2.86
60
8.5
8.2
0.8
0.2
Voc (V)
Isc (mA)
V @Pmax
(V)
I @Pmax
(mA)
Pmax
(mW)
R @Pmax
(Ω)
19.76
16.89
16.56
13.3
10.21
398
8.6
6.35
2.62
0.87
19.38
12.93
377
6.15
7306
2102
50
80
13.36
4.64
62
2879
9.77
6.26
1.69
0.64
17
4
5781
9781
Solar panel 2
Outdoor
Indoor case-1
Indoor case-2
Indoor case-3
Indoor case-4
Solar panel 3
Outdoor
Indoor case-1
Indoor case-2
Indoor case-3
Indoor case-4
Voc (V)
Isc (mA)
V @Pmax
(V)
I @Pmax
(mA)
Pmax
(mW)
R @Pmax
(Ω)
19.22
17.10
16.82
13.45
9.94
20
9.80
7.97
3.24
1.07
17.5
14.26
169.5
6.74
2966
97
100
2115
13.97
5.80
81
2409
10.30
6.85
2.19
0.69
23
5
4703
9927
Conclusion:
1) At Pmax, the percent change in output current (I) is more than the percent change in output voltage (V)
with change in incident irradiance.
2) With increase in irradiance, load (R) required to draw maximum power (R @Pmax), decreases.