Week Three
Subject: Basic Technology
Week of Third Term: 3rd Term
Class: Primary Five
Topic: Basic Electricity
Subtopic: Electricity Generation by Solar Energy, Electricity Generation by Chemical Energy to Light
Objectives
At the end of the lesson, pupils should be able to:
- Explain how electricity is generated from solar energy.
- Describe the process of generating electricity using chemical energy to light a bulb.
- Demonstrate how solar panels convert sunlight into electricity.
Entry Behaviour
Before starting this lesson, pupils should already know:
- The basic concept of electricity as a form of energy.
- The role of conductors and non-conductors in electricity flow.
Instructional Materials
- Solar panel (model or image).
- A small solar-powered device or calculator.
- Battery, copper wire, and a small light bulb (to demonstrate chemical energy to light).
Reference Materials
- Ijiyemi, C. (2016). Foundations of Science & Technology for Primary School Book 5. Metropolitan Publishers: Lagos.
- Oyinlola, M., Rahaman, B., & Ezeume, I. (2015). Basic Science and Technology for Primary School Book 5 (Bec Edition). Spectrum Book Limited: Lagos.
Content
Electricity Generation by Solar Energy
What is Solar Energy?
Solar energy comes from the sun. The sunlight carries energy that can be used to make electricity. It can be used in the school, home, office and also on streetlights
Why Use Solar Energy?
- Renewable: The sun provides energy every day, so it won’t run out.
- Clean: It does not create pollution.
- Cost-Effective: Once installed, solar panels can reduce electricity bills.
How Electricity Is Generated from Solar Energy
Steps of Electricity Generation from Solar Energy
- Sunlight Hits Solar Panels
- Solar panels are made of many small parts called solar cells.
- These cells are designed to collect sunlight.
- Conversion of Light into Electricity
- When sunlight hits the solar cells, it moves tiny particles called electrons inside the cells.
- This movement creates an electric current, which is the flow of electricity.
- Electricity is Sent to a System
- The electricity generated by the solar panels is sent to a device called an inverter.
- The inverter changes the electricity into a form that can be used in homes, schools, or offices.
- Powering Devices
- The electricity is then used to power lights, fans, and other appliances.
Electricity Generation by Chemical Energy to Light
What is Chemical Energy?
Chemical energy is stored inside materials like batteries. It can be changed into electricity and used to make light.
Examples of Devices That Use Chemical Energy:
- Flashlights
- Remote controls
- Toys that run on batteries
How Electricity is Generated Using Chemical Energy to Light a Bulb
Steps to Generate Electricity Using Chemical Energy
- The Battery Stores Chemical Energy
- A battery contains chemicals inside it that store chemical energy.
- The energy is stored in two parts of the battery: the positive terminal (+) and the negative terminal (-).
- Connecting the Battery to a Bulb
- When you connect a battery to a bulb using wires, a circuit is formed.
- This circuit allows the chemical energy to flow as electric current.
- Chemical Energy Turns Into Electrical Energy
- Inside the battery, a chemical reaction happens, releasing stored energy.
- This energy flows through the wires as electricity.
- The Bulb Lights Up
- The electricity reaches the bulb and flows through a tiny wire inside the bulb called a filament.
- The filament gets very hot and starts to glow, producing light.
Why is This Process Useful?
- It powers devices like flashlights and toys when there’s no electricity supply.
- Batteries are portable, so they can be used anywhere.
Lesson Presentation (Step-by-Step Procedure)
Step 1: Introduction
Begin by asking pupils if they have ever seen a solar panel or a solar-powered device, such as a calculator or light. Discuss the importance of alternative energy sources like solar energy and how they are used to generate electricity.
Step 2: Explanation
- Solar Energy: Explain that solar energy comes from the sun and can be converted into electricity using solar panels. Solar cells in the panel absorb sunlight and convert it into electricity. This process is eco-friendly because it does not cause pollution.
- Chemical Energy to Light: Discuss how chemical energy, such as that stored in a battery, can be converted into electrical energy. When the battery is connected to a device like a light bulb, it releases energy that travels through the wire to light the bulb.
Step 3: Demonstration
- Solar Energy: Show a small solar panel and demonstrate how it powers a small device (like a solar calculator). Explain how the energy from the sun is converted to electricity and used to power the device.
- Chemical Energy: Set up a simple circuit with a battery, copper wire, and a light bulb. When the battery is connected, show how the chemical energy in the battery is converted to electrical energy, which then lights the bulb.
Step 4: Guided Practice
Ask pupils to work in pairs to connect a solar-powered device (or solar calculator) to observe how it works. Then, guide them through setting up a simple circuit with a battery, wire, and light bulb to demonstrate the conversion of chemical energy to electrical energy.
Step 5: Independent Practice
Provide pupils with a worksheet that asks them to:
- Draw and label a solar panel.
- Describe how solar panels generate electricity.
- Identify other examples of chemical energy conversion to electrical energy.
Step 6: Feedback
Walk around and observe pupils as they set up their circuits and complete their worksheets. Provide feedback, answer questions, and ensure that pupils understand the concept of converting solar and chemical energy into electricity.
Evaluation
Formative Assessment:
As pupils work through the guided and independent activities, assess their understanding by asking questions like:
- How do solar panels generate electricity?
- How does a battery produce electricity to light a bulb?
Summative Assessment:
At the end of the lesson, assess pupils’ understanding with a short quiz:
- How does solar energy generate electricity?
- What is chemical energy, and how is it used to light a bulb?
Summary/Conclusion
Summarize the lesson by revisiting the key points:
- Solar energy is a renewable source of electricity that is generated using solar panels.
- Chemical energy can be converted into electricity to power devices like light bulbs through the use of batteries.
Reinforce that both methods of generating electricity are clean and efficient forms of energy.
Assignment
For homework, ask pupils to:
- Write two advantages of using solar energy to generate electricity.
- Draw a simple diagram of how a battery and light bulb work together to produce light.