Vernier Software and Technology
Vernier Software & Technology

Fill Factor and IV Curve of a Solar Panel

Figure from experiment 18B from Renewable Energy with Vernier


When considering a solar panel installation, engineers take into account a metric called the fill factor, or FF. This is one way of gauging the efficiency of a solar panel without measuring the irradiance from the sun at the location of the solar panel.

In this experiment, you will vary the load in the solar panel circuit to determine the fill factor. You will create a current-potential curve, also known as an IV curve. The letter I is the standard symbol used to represent current in equations.

IV curves show the maximum current, maximum voltage, and maximum power a solar cell can generate. The rectangle formed by the graph axes and a vertical line from the open circuit voltage (VOC) and a horizontal line extending from the short circuit current (ISC) extends over a large area of the graph. A smaller rectangle is defined by the graph axes and the current and voltage at maximum power output (IMP and VMP). The fill factor is the area of the smaller rectangle divided by the area of the large rectangle:

Cannot create image: \text{FF} = \frac{I_{MP}V_{MP}}{I_{SC}V_{OC}}

The open circuit voltage VOC is the voltage when the resistance is infinite (i.e., when there is no load connected to the system) and the circuit is open, therefore no current can flow. The short circuit current ISC is the current when the resistance is approximately 0 Ω and the voltage is 0 V. This case is measured by closing the circuit with a plain wire instead of a load.


  • Use an Energy Sensor to determine current, potential (voltage), and power.
  • Create an IV curve for a solar panel.

Sensors and Equipment

This experiment features the following Vernier sensors and equipment.

Option 1

Option 2

Additional Requirements

You may also need an interface and software for data collection. What do I need for data collection?

Renewable Energy with Vernier

See other experiments from the lab book.

1Renewable Energy: Why is it So Important?
2What is Energy?
3Project: Energy Audit
4Voltage and Circuits
5Current and Resistors
6Mechanical Power
8Exploring Wind Turbines
9Effect of Load on Wind Turbine Output
10Blade Variables and Power Output
12Turbine Efficiency
13Power Curves
14Power and Energy
15Project: Maximum Energy Output
16Project: Build a Wind Farm
17Exploring Solar Panels
18AEffect of Load on Solar Panel Output
18BFill Factor and IV Curve of a Solar Panel
19Variables Affecting Solar Panel Output
20Effect of Temperature on Solar Panel Output
21Project: Build a Solar Charger
22Exploring Passive Solar Heating
23Variables Affecting Passive Solar Heating
24Exploring Solar Collectors
25Variables Affecting Solar Collectors
26Project: Solar Cooker

Experiment 18B from Renewable Energy with Vernier Lab Book

<i>Renewable Energy with Vernier</i> book cover

Included in the Lab Book

Vernier lab books include word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.

Buy the Book

Dev Reference: VST0852

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