Grade Levels: 5th - 12th
Estimated Time Blocks: 1-2 hour sessions
Objective:
In this activity, students will build a working solar-powered fan using basic components. This project will introduce them to the concepts of solar energy, circuits, polarity (anode and cathode), and the fundamentals of how electricity flows through a circuit.
Electronics:
- 9V battery
- 0.5W Mini solar panel module (1 for $6.99): https://www.amazon.com/dp/B008J9BZIA
- Small fan (4-pack for $11): https://www.amazon.com/gp/product/B07LBDL3W3/
- Alligator clips or copper tape (optional): https://www.amazon.com/WGGE-WG-026-Pieces-Colors-Alligator/dp/B06XX25HFX
- Wire stripper or small scissors (for removing wire casing): https://www.amazon.com/WGGE-Professional-crimping-Multi-Tool-Multi-Function/dp/B073YG65N2
- Paper or cardboard (for fan base structure)
- Zip ties or tape (for attaching components)
- Glue (for stability)
Important Note: To connect the fan to the battery, you will need to remove the white casing covering the wires. This exposes the metal ends, allowing you to connect the wires to the battery using alligator clips or copper tape.
Goal: Understand the fundamentals of how solar panels generate electricity, the concept of polarity (anode and cathode), and how electricity flows in a circuit.
1. What is Solar Power?
Solar panels generate electricity by converting sunlight into electrical energy. This process is called the photovoltaic effect, where the cells inside the solar panel absorb sunlight and release electrons, creating an electric current. This type of current is direct current (DC), which flows in one direction.
2. Understanding Circuits:
A circuit is a closed loop that allows electricity to flow from a power source (like a solar panel or battery) to a device (such as a fan) and back. For electricity to flow, the circuit must be complete—meaning there must be no gaps in the pathway.
3. Polarity: Anode (+) and Cathode (-)
In any circuit, it's important to understand polarity, which refers to the direction in which current flows.
- Anode (+): This is the positive terminal of the battery or solar panel. Current flows out from the anode.
- Cathode (-): This is the negative terminal, where the current returns.
Activity – Identifying Anode and Cathode:
- On your 9V battery, you’ll notice a larger terminal marked with a (+) sign (the anode) and a smaller terminal marked with a (-) sign (the cathode).
- Similarly, the solar panel will have two wires: one usually marked with a red color (anode) for positive and another (black or blue) for negative (cathode).
Goal: Prepare the fan and solar panel by stripping the wires, understanding their connections, and creating a basic circuit.
1. Wire Stripping:
- Carefully use a wire stripper or small scissors to remove about ½ inch of the plastic casing from the end of the wires on both the fan and the solar panel. You can see in the image above what it looks like before and after you remove the casing from the fan.
- Why? Exposing the metal inside the wires allows electricity to flow when connected to the power source (solar panel or battery).
2. Understanding Connections:
- Solar Panel Wires: The red wire is the anode (+), and the black wire is the cathode (-).
- Fan Wires: The same color scheme applies: the red wire is positive (+), and the black wire is negative (-).
3. Connecting the Solar Panel to the Fan:
- To complete the circuit, you need to connect the solar panel to the fan. Connect the red wire (anode +) of the solar panel to the red wire (anode +) of the fan. Similarly, connect the black wire (cathode -) of the solar panel to the black wire (cathode -) of the fan.
- Tip: You can use alligator clips or copper tape to secure these connections.
4. Testing the Circuit:
- Take your solar panel into sunlight to test the circuit. If connected properly, the fan should start spinning when exposed to enough sunlight.
- If the fan doesn’t spin, double-check your connections—ensure that the red and black wires are connected to the corresponding positive and negative terminals on both the fan and the solar panel.
Goal: Learn how to add a 9V battery to the circuit as a backup power source.
1. Why Use a Battery?
- Sometimes the solar panel might not receive enough sunlight (e.g., on a cloudy day). In these cases, a 9V battery can be used as a backup power source to keep the fan running.
2. Connecting the 9V Battery:
- Locate the two terminals on the 9V battery: the larger terminal is positive (+) and the smaller terminal is negative (-).
- Using alligator clips or copper tape, connect the red wire (positive) from the fan to the larger (+) terminal on the battery, and connect the black wire (negative) to the smaller (-) terminal.
- Tip: Make sure that the polarity is correct when connecting the fan to the battery—reversing the connections could prevent the fan from spinning.
3. Testing the Fan with the Battery:
- Once connected, the fan should start spinning immediately. If it doesn’t, double-check the connections and ensure the battery is functional.
Goal: Build a stable base to hold the fan and solar panel, making the setup functional and visually appealing.
1. Designing the Base:
- Use cardboard or thick paper to design a simple stand for the fan. The base should hold the fan upright and allow for the solar panel to be placed at an angle where it can absorb maximum sunlight.
2. Attaching the Fan and Solar Panel:
- Attach the fan securely to the base using zip ties, glue, or tape. Make sure the fan is stable and won’t tip over.
- The solar panel should be placed at an adjustable angle so students can experiment with positioning for maximum sunlight absorption.
3. Understanding Solar Panel Placement:
- Why the Angle Matters: Solar panels work best when they are positioned directly facing the sun. Adjusting the angle of the solar panel allows students to test how different angles affect the performance of the fan.
Goal: Conduct the final assembly of the solar-powered fan, test it under different conditions, and refine the setup as needed.
1. Final Assembly:
- Ensure that the wires connecting the fan and solar panel (or battery) are secure.
- Test the fan both indoors (with the 9V battery) and outdoors (in sunlight) to observe the differences in how the fan spins.
2. Testing the Solar-Powered Fan:
- Take the fan outside on a sunny day and observe how the fan performs. Adjust the angle of the solar panel to get the best performance.
- Test the fan in the shade or indoors to see how the lack of sunlight affects its performance. This will show students how important light exposure is for solar-powered devices.
3. Discussion:
- How did the angle of the solar panel affect the performance?
- What happened when the fan was connected to the battery instead of the solar panel?
- What other devices could be powered by solar energy in the same way?
- Why is it important to correctly match the anode (+) and cathode (-) when connecting components in a circuit?
- How does the amount of sunlight impact the energy generated by the solar panel?
- What challenges did you face during the project, and how did you solve them?
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