 Vernier Software & Technology

# Fill Factor and IV Curve of a Solar Panel

## Introduction

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: $\text{FF} = \frac{I_{MP}V_{MP}}{I_{SC}V_{OC}}$

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.

## Objectives

• 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 2

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.

 1 Renewable Energy: Why is it So Important? 2 What is Energy? 3 Project: Energy Audit 4 Voltage and Circuits 5 Current and Resistors 6 Mechanical Power 7 Generators 8 Exploring Wind Turbines 9 Effect of Load on Wind Turbine Output 10 Blade Variables and Power Output 11 Solidity 12 Turbine Efficiency 13 Power Curves 14 Power and Energy 15 Project: Maximum Energy Output 16 Project: Build a Wind Farm 17 Exploring Solar Panels 18A Effect of Load on Solar Panel Output 18B Fill Factor and IV Curve of a Solar Panel 19 Variables Affecting Solar Panel Output 20 Effect of Temperature on Solar Panel Output 21 Project: Build a Solar Charger 22 Exploring Passive Solar Heating 23 Variables Affecting Passive Solar Heating 24 Exploring Solar Collectors 25 Variables Affecting Solar Collectors 26 Project: Solar Cooker

### Experiment 18B from Renewable Energy with Vernier Lab Book #### 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.