Learner Lesson 5: How Do Solar Cells Turn Light into Power?
Lesson Overview
In Lesson 4, you built circuits, measured voltage and current, and calculated power and energy for a battery-powered load. In this lesson, the power source changes: instead of a battery, you use a solar cell, a device that turns light into electrical energy.
You will build a simple solar-cell circuit, measure its voltage and current under different light conditions, and calculate the power it produces. The measurement habits are the same ones you already know, but now the output depends on something new: how much light reaches the cell, and at what angle.
At the end, you will use your own data as evidence to explain how light level, angle, and shading change a solar cell’s power. Then you will connect that to a real engineering problem: how to size and place solar panels so a mini-grid can reliably power homes, schools, and clinics.
Questions You Will Be Able to Answer by the End of This Lesson
- How does a solar cell turn light into electrical energy?
- How do light levels and angles change a solar cell’s voltage, current, and power?
- How do engineers decide whether a solar panel can supply enough power for a device or mini-grid?
Key Vocabulary and Concepts
|
Term |
Definition |
|---|---|
|
Solar cell |
A device, usually made of silicon, that converts light energy into direct-current (DC) electrical energy. |
|
Photovoltaic effect |
The process by which light striking a solar cell frees electrons and creates an electric current. |
|
Semiconductor |
A material (such as silicon) that conducts electricity under the right conditions; solar cells are made from it. |
|
Direct current (DC) |
Charge flows in one direction; batteries and solar panels provide DC electricity, and classroom battery circuits are examples of DC circuits. |
|
Voltage (V) |
The electrical push the cell produces. Measured in volts (V). |
|
Current (I) |
The flow of electric charge the cell drives. Measured in amperes (A) or milliamps (mA). |
|
Power (P) |
How quickly electrical energy is used. Measured in watts (W). P = V × I. |
|
Solar array |
A group of solar panels electrically connected together to generate DC electricity for a solar power system. |
|
Mini-grid |
A small, local electricity system that generates, stores, and distributes power to connected loads in a defined area, such as a village, school, clinic, or group of nearby buildings. |
|
Shading |
When part of a solar cell is blocked from light, lowering its output. |