Lab Report #9
To: Dr. Atherton, Instructor
From: Haylee Brewer
Date: November 26th, 2024
Re: Characteristics of Photovoltaics – Power to the Load
Summary:
This experiment explores the relationship between the voltage and maximum power
output of a solar cell. It demonstrates that the electrical load on the solar cell is influenced by
more than just the size of the cell itself. Using a potentiometer, the activity investigates the
concept of maximum power transfer, where the power delivered to the load is optimized when
the load impedance matches the impedance of the sola cell.
Collected Data:
P = V^2 / R
2.01 V^2 / 98.3 ohms = 0.0411 mW
2.38 V^2 / 117.8 ohms = 0.0481 mW
3.00 V^2 / 149.9 ohms = 0.06004 mW
4.29 V^2 / 215.3 ohms = 0.0855 mW
6.40 V^2 / 327.2 ohms = 0.1252 mW
5.28 V^2 /265.2 ohms = 0.1051 mW
7.34 V^2 / 464.21 ohms = 0.1161 mW
7.72 V^2 / 1054 ohms = 0.0565 mW
7.76 V^2 / 1478.5 ohms =0.0407 mW
7.81 V^2 / 2161.9 ohms = 0.0282 mW
7.82 V^2 / 3255.4 ohms = 0.0188 mW
POWER mW
140
125,1834
116,0587
105,1222
120
Power mW
100
80
60
85,4812
60,04
48,0849
41,0997
56,545
40,72885
28,2141
18,37849
40
20
0
Resistance ohms
Conclusion:
The data collected shows a gradual increase in voltage, but power initially rises and then
reaches a peak before declining. This behavior is due to the efficiency of power transfer from the
solar cell. The maximum power transfer occurred with a 327.2-ohm resistor, yielding a power
output of 125.18 mW. This is because the resistance of the load matched the internal resistance of
the solar cell. Resistors greater than 300 ohms resulted in lower power output, despite higher
voltage. In conclusion, selecting the appropriate resistor that matches the internal resistance of
the solar cell ensures maximum power transfer.