Download solar cell - WordPress.com

Experiment No…..
Objective- To study the
1. Voltage and current of a solar cell.
2. Voltage and current in series and parallel combinations.
3. Draw power curve to find Maximum Power Point (MPP).
4. To obtain the efficiency of a solar cell.
With the help of solar cell trainer.
Apparatus RequiredSolar Panel, Solar cell trainer kit, Digital Multimeter, Table lamp, Patch cord (Connecting wires).
Figure- Solar panel & solar energy trainer
TheorySolar cells in series boost voltage but the current remains same whereas when it is in parallel
it boosts current rating but the voltage remains the same.
Total voltage of the series combination is equal to the sum of the voltage of all solar cells.
VTotal = V1+ V2+V3 + V4 + V5 + V6
Total current of the series combination is equal to the individual current of each solar cell.
ITotal = I1 = I2 = I3 = I4 = I5 = I6
Total voltage of the parallel combination is equal to the individual voltage of each solar cell.
VTotal = V1= V2 = V3 = V4 = V5 = V6
Total current of the parallel combination is equal to the sum of the current of all solar cells.
ITotal = I1 + I2 + I3 + I4 + I5 + I6

The maximum power point (MPP) is the maximum value of power where the product of
voltage and current is greatest.
The resistance, RMPP, at which the output power is maximum, can be calculated by the
following formula:
𝑅𝑀𝑃𝑃 =
𝑉𝑀𝑃𝑃
𝐼𝑀𝑃𝑃
The efficiency of the solar cell is the ratio of produced electrical power (Pout) and the incident
radiant power (Pin) and mathematically it may be represented as:
𝜂=
𝑃𝑜𝑢𝑡
𝑃𝑖𝑛
Where Pout (Output Electrical Power) = Maximum Power Point (MPP)
Pin (Incident radiant power) = Approximated Irradiance x Area of solar cell
= (F x Ip) x A
Here A = Area of a solar cell (Length x Breadth) m2
Approx. Value of A is [{(1.3 ⤫ 6) ⤫ 4} ⤫ 4] × 10-4 m2.
Ip = Practical value of current (maximum photoelectric current measured) indicated on the
ammeter
F is a constant and is given by
𝑀𝑎𝑥𝑖𝑚𝑢𝑚 𝑠𝑜𝑙𝑎𝑟 𝑖𝑟𝑟𝑎𝑑𝑖𝑎𝑛𝑐𝑒
F=
(Specified by Manufacturer)
𝑀𝑎𝑥𝑖𝑚𝑢𝑚 𝑣𝑎𝑙𝑢𝑒 𝑜𝑓 𝑐𝑢𝑟𝑟𝑒𝑛𝑡
The maximum irradiance in summer is approx. 1000 W/m2. The maximum value of the current
specified by the manufacturer is achieved at this value i.e. 150 mA in the given solar cells. (The
parameter of the solar cell/panel is related to the standard test conditions of 1000 W/m2 and cell
temperature of 25° C.)
𝟏𝟎𝟎𝟎𝑾⁄ 𝟐
𝒎
F=
𝟏𝟓𝟎𝒎𝑨
Procedure:
(a) Voltage and current of a solar cell.
1. Take the Solar Energy Trainer NV6005 along with Solar Panel.
2. Place the solar panel in the stand and adjust the panel at an angle of about 45° with the
ground. Direct the sunlight straight at the solar panel (angle of 90°).
Note: If sunlight is not properly available then any source of light like lamp can be used.
3. With the DB15 connector connect the Solar Energy Trainer NV6005 with the Solar Panel.
Then wait for 1 minute to avoid errors due to temperature fluctuations.
4. Measure the voltage (V1) of S1 solar cell by connecting its output across voltmeter with the
help of patch cords. Similarly, you can measure the voltages of other solar cells. Record the
voltage of all cells (VI, V2, V3, V4, V5, V6) respectively in the Observation Table.
5. Measure the current (I1) of S1 solar cell by connecting its output across ammeter with the
help of patch cords. Similarly, you can measure the currents of other solar cells. Record the
current of all cells (II, I2, I3, I4, I5, I6) respectively in the Observation Table.
(b) Voltage and current in series and parallel combinations.
1. Connect all six cell in series combination through patch chords (as shown in figure) and
measure the voltage and current by voltmeter and ammeter.
Figure-1(Series combination)
2. Similarly Connect all six cell in parallel combination through patch chords (as shown in
figure) and measure the voltage and current by voltmeter and ammeter.
Figure-2(Parallel combination)
(c) Draw power curve to find Maximum Power Point (MPP).
Note: In order to find maximum current in our case, we will use only four cells in
Parallel combinations.
Figure-3(Circuit diagram for maximum power point)
1. Set the potentiometer to maximum resistance i.e. at fully clockwise position and measure and
record its resistance into the Observation table.
2. Connect the combination of solar cell as shown in the fig.-3 circuit diagram. Record the values of
corresponding voltage and current into the Observation table.
3. Now gradually move the potentiometer in anticlockwise direction so that the resistance of the
potentiometer decreases. Now measure the resistances at successively smaller values and record
the corresponding values of voltages and current into the Observation table.
Note: Always to measure the resistance of potentiometer at any position, first remove the patch
cords from P1 and P2 and measure resistance by multimeter. Reconnect these connections again
for further measurements.
4. Plot the IV characteristics from the measurements recorded in Table, to show how the
photoelectric current depends on the photoelectric voltage and to find maximum power point.
Expected IV curve is shown in fig.-4.
5. From IV characteristics you can easily find the maximum power point (MPP).Maximum
power point (MPP) occurs where the product of voltage and current is greatest.
Figure -4
6. Now calculate the efficiency of solar cell by this formula
𝜂=
𝑃𝑜𝑢𝑡
𝑃𝑖𝑛
ObservationsSolar
cell
Table-1
Voltage Current Voltage of
Current of
series
series
combination
combination
S1
S2
S3
S4
S5
S6
Sr.No.
Resistance,
R
()
……….
……..
Table-2
Voltage,
V
(Volts)
Current,
I
(mA)
Voltage of
parallel
combination
………
Current of
parallel
combination
………
Power Calculated
P=V.I (Watts)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
CalculationsResults and Conclusions1. Solar cells in series boost voltage but the current remains the same.
2. Solar cells in parallel boost current rating but the voltage remains same.
3. Voltage of all the six cells in series combination is not equal to that of the sum of individual
of each solar cell. This deviation is due to the presence of internal resistance which is practically
present in the real cell. Similar type of explanation can be given for the current in parallel
combinations.
4. Maximum power point (MPP) of solar cell from the graph is found to be ………
5. Efficiency of the solar cell is found to be …………………
Precautions1. Connection has to be made properly as per given in the concerned circuit diagram.
2. Least count of voltmeter has to be taken before taking any readings through it.
3. Least count of ammeter has to be taken before taking any readings through it.