Vernier Software & Technology

# Photovoltaic Cells

## Introduction

Energy produced by the sun is called solar energy. It is produced during nuclear reactions that take place throughout the volume of the sun. The energy travels to Earth in the form of light. Photovoltaic (PV) cells, or solar cells, change the light energy to electrical energy that can be used to power calculators, cars or even satellites. A photovoltaic cell is usually made of a semiconducting material such as silicon. When light strikes the cell, it provides enough energy to move electrons through the cell producing an electric current. A single photovoltaic cell is approximately the size of a fingernail and puts out a very small current when struck by the light. Objects requiring higher currents to operate can be powered by wiring large numbers of photovoltaic cells together.

Items powered by solar energy are said to be using solar power. Streetlights that must operate in the dark store the energy in a battery while the sun is shining and then use the energy at night. Scientists working in remote places rely on solar power to operate their computers and equipment. What things can you think of that are powered by solar energy?

## Objectives

In the Preliminary Activity, you will measure the current and voltage produced by a photovoltaic cell when exposed to sunlight. You will calculate the power output of the cell using the relationship

${\text{P = V I}}$ ${\text{Power}} = {\text{voltage }} \times {\text{ current}}$

Where power has units of watts (W), voltage has units of volts (V), and current has units of amperes (A).

After completing the Preliminary Activity, you will first use reference sources to find out more about photovoltaic cells before you then choose and investigate a researchable question.

## Sensors and Equipment

This investigation features the following Vernier sensors and equipment.

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

## Investigating Environmental Science through Inquiry

See other experiments from the lab book.

 1 Seasons and Angle of Insolation 2 A Local Weather Study 3 Investigating Dissolved Oxygen 4 Water Quality 5 Long Term Water Monitoring 6 Water Treatment 7 Investigating Salinity 8 Soil Temperature 9 Soil Salinity 10 Soil pH 11 Soil Moisture 12 Soil and Acid Rain 13 Managing Garden Soil Moisture 14 Cell Respiration (CO2) 15 Biodiversity in Ecosystems 16 Biochemical Oxygen Demand 17 Water Cycle Column Investigations 18 Decomposition Column Investigations 19 Ecocolumn Investigations 20 Global Warming 21 UV Investigations 22 Comparing Sunscreens 23 Primary Productivity 24 Modeling Population Growth 25 Insulation Study 26 Fossil Fuels 27 Energy Conversion 28 Wind Power 29 Photovoltaic Cells 30 Investigation of Passive Solar Heating 31 The Effect of Acid Deposition on Aquatic Ecosystems 32 Measuring Particulates 33 Investigating Indoor Carbon Dioxide Concentrations 34 A Pollution Study

### Investigation 29 from Investigating Environmental Science through Inquiry 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.