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ABSTRACT

At short circuit, the solar module produces electric current but no voltage. At open

circuit, the solar module produces voltage but no current. Electric power is defined as the

product of the current and the voltage. Hence, for both short circuit and open circuit, the solarmodule produces no power. Somewhere in between these two operating points is the Maximum

Power point of the solar module where the maximum power possible is being generated. In this

experiment the student is to find the values of voltage and respective current generated by the

modules, find the power, and plot graphs. For the first experiment, no light is allowed to reach

the solar module. DC power supply was used to supply energy to the system. The voltage is

increase by a step of 0.25 and 0.5 until 2.75V and the respective current readings was recorded.

The maximum voltage must not exceed 3.0V to avoid damaging the solar module. For second

experiment where light is directed toward the solar module, the resistance was changed, and

respective voltage and current readings is taken. The characteristic curve is interpreted and to

find the open circuit voltage, short circuit current and maximum power point is determined from

graph power against voltage. For the third setup, the effect of light intensity and concentration is

studied by changing the angle of incidence and distance of the source of light onto the solar

module. From result, photocurrent is highest when the light strike solar module perpendicularly

and at the shortest distance between solar module and the light source.

OBJECTIVES

The objectives of the experiment are as given:

- To study the dark characteristic curve of solar module- To study light characteristic curve of solar module by changing the resistance- To study effect of distance and angle of incidence of the light source to the unit

photocurrent.

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PROCEDURE:

Figure 2 Schematic diagram for dark side

Part 1 Dark IV Curve

1. The apparatus is set up as shown in figure 2 by connecting the solar module to the DCpower supply in "forward direction".( i.e. the positive terminal of the DC power supply to

the positive terminal of the solar module and the negative terminal of the DC power

supply to the negative terminal of the solar module)

2. The solar cell is covered completely with a piece of paper to ensure absence of light.3. The voltage of the DC power supply is adjusted to different voltages (in 0.5 volt steps

between 0 and 1.5 volts, and in 0.25 volt steps between 1.5 and 2.75 volts).

4. The dark voltage and current value is recorded.5. The data is placed in Microsoft Excel and current vs voltage curve is plotted.

DC

Power

Supply

A

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Figure 3 schematic diagram for light side

Part 2 Light IV Curve

I. Controlling the resistance from variable resistor1. The apparatus is set up as shown in Figure 3.2. The solar cell is set facing towards a source of artificial light, such as a spot-

3. The Short Circuit Current ( by having maximum resistance) and Open Circuit Voltage(by disconnecting the variable resistor) are measured.

4. The resistance of the variable resistor is increased, until the maximum resistance inthe variable resistor

5. The current and voltage is recorded.6. The data is placed in Microsoft Excel7. Current vs voltage curve and Power vs voltage is plotted.

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II. Changing the incident angle of the artificial light

Figure 4 Circuit schematic diagram and experiment setup

1. The apparatus is set up as shown in Figure 4.2. The solar panel is positioned using a protractor at position 0 from left (perpendicular

to the light source).

3. The solar panel is adjusted to 0 angle from left with the reference of protractor.4. The angle of artificial light facing the solar panel is increased by 10 until reach 90.5. The value of current is recorded.6. Step 3 till step 5 is repeated from 90 from the right until decrease to 0.7. The mean current is calculated from the left and right current..8. The data is placed in Microsoft Excel.9. The current vs angle and current vs cosine angle curve is plotted.

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III. Changing the distance of the artificial light towards the solar panel

1. The circuit is set as in the diagram above ( Ammeter is in series, Voltmeter parallel).2. The solar panel is set facing towards a source of artificial light.3. The distance of the artificial light towards the solar panel is set to 0.50m by using a

ruler.

4. The distance is increased by 0.10m until reached 1.50m.5. The value of current is recorded for each distance.6. The data is placed in Microsoft Excel7. The current vs distance is plotted.

Figure 5 circuit diagram and experiment setup

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DATA COLLECTION:

Part 1 Dark IV Curve

Voltage (V) Current

(Amp)

0.50 0.00

1.00 0.00

1.50 0.00

1.75 0.01

2.00 0.06

2.25 0.35

2.50 1.37

2.75 3.00

Part 2 Light IV Curve

I. Controlling the resistance from variable resistor

Resistance

()Voltage (V) Current (A)

0.00 0.09 0.7

0.30 0.37 0.7

0.50 0.46 0.7

1.00 0.84 0.7

2.00 1.67 0.7

3.00 2.04 0.58

5.00 2.1 0.43

10.00 2.16 0.21

20.00 2.18 0.11

50.00 2.19 0.04

100.00 2.19 0.02

2.19 0

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II. Changing the incident angle of the artificial light

Angle, () Left current

(mA)

Right current

(mA)

Mean current

(mA)

0.00 0.40 0.40 0.40

10.00 0.37 0.40 0.39

20.00 0.36 0.38 0.37

30.00 0.32 0.36 0.34

40.00 0.29 0.31 0.30

50.00 0.25 0.24 0.25

60.00 0.22 0.20 0.21

70.00 0.16 0.15 0.16

80.00 0.10 0.09 0.10

90.00 0.04 0.05 0.05

III. Changing the distance of the artificial light towards the solar panel

Distance (m) Current (mA)

0.50 0.36

0.60 0.27

0.70 0.20

0.80 0.15

0.90 0.12

1.00 0.10

1.10 0.08

1.20 0.07

1.30 0.06

1.40 0.05

1.50 0.04

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RESULTS AND DISCUSSIONS

Part 1 Dark IV Curve

From the graph, we can see that, there is no current flow from voltage reading of 0.5 to

1.75 V. The current then increases exponentially when the voltage further increase to 2.75 V

The use of Dark IV curves in solar cell analysis relies on the principle of superposition.

That is, in the abscence of resistive effects, that the light IV curves is the dark IV curve shifted

by the light generated current.

A second problem is that in dark IV measurements the current is flowing in the opposite

direction and the current paths are different. The change in the current path causes a lower series

resistance in the dark measurements to the light measurements.

-0.50

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

0.00 0.50 1.00 1.50 2.00 2.50 3.00

Current(I)

Voltage (V)

Current versus Voltage

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Part 2 Light IV Curve

I. Controlling the resistance from variable resistor

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 0.5 1 1.5 2 2.5

current

voltage

Current vs Voltage

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

0 0.5 1 1.5 2 2.5

Power

Voltage

Power vs Voltage

MPP

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For current vs. voltagegraph, we can see the current constant at 0.7A although the

voltage increases from 0 V to 1.67 V. After that, the current started to decrease to 0.58A when

the voltage further increase until 0A is recorded when the voltage is at 2.19V.

When there is no current drain, the solar module has an open-circuit voltage of approx.

2.19 volts (R = ). An individual silicon solar cell typically has an open-circuit voltage of 0.5 -

0.6 volts.

If we short-circuit the solar module (R = 0 ), the maximum current (short -circuit

current) flows. In result of the characteristic curve, the short circuit current amounts to about

0.7A.

The maximum power point "MPP" refers to the point at which the solar module can output

its maximum power at a specific level of irradiation. MPP obtained from this experiment is1.22

Watt.

II. Changing the incident angle of the artificial light

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.00 20.00 40.00 60.00 80.00 100.00

Current(I)

Angle ()

Current vs Angle

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The current vs. angle graph shows from angle of 0o to 90o, the current shows uniform

decrement which is from 0.4A to 0.04A. This shows that, current produced by the solar cell is

inversely proportional to the angle of incidence. The greater the angle of incidence, the lower the

current produced. This is because the greater the angle of incidence, the lower the light intensity.

Since, the light intensity decreases, the current produced by the photovoltaic cell also decreases.

For current vs. cosine angle of incidence graph, it shows irregular pattern of the relationship

between the two variables. The deviations may occurred due to the ideal cosine law are caused

by fluctuations in the cone of light

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.00 0.20 0.40 0.60 0.80 1.00 1.20

Current(I)

Cosine angle ()

Current vs Cosine angle

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III. Changing the distance of the artificial light towards the solar panel

The shape of the Current vs. Distance graph is a result of how light intensity from a point

source diminishes over distance. From the graph, we can see that as the distance of the light

source increases, the current decreases. The current should increase as a 1/d2

relation, because

the intensity of the light striking the surface decreases as a 1/ d2

relation.

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60

Current(I)

Distance (m)

Current vs Distance

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50

Current(I)

Inverse Squared Distance (m-2)

Current vs Inverse Squared Distance

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You may not see this exact relation here because we are not dealing with a perfect point

light source. The current is inversely proportional with the intensity or brightness of the light,

assuming that the voltage is held constant.

The sensitivity of the output current and power with light distance makes it essential to

maintain the same light intensity for all future lab measurements. Keeping the distance between

the bulb and PV module constant when comparing measurements, or keeping the angle of the PV

module and sunlight constant through all measurements will meet these criteria.

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CONCLUSIONS

The result of the experiment shows that we managed to achieve our objective in this

experiment. We managed to obtain the characteristic curved of the dark solar module, which is

increasing exponentially. We also managed to obtain the characteristic curve of the light solar

module by changing the resistance. Besides, we have study the effect of the distance and angle of

the light source to the photocurrent unit. The relationship can be seen clearly on the result and

the graph generated. As a conclusion, we managed to complete our experiment successfully.