Solar PV Components Inverters, Batteries and Charge Controllers for SS 1

Class: SS 1
Term: First Term
Week: 9
Age: 15 years
Duration: 60 minutes
Subject: Solar PV Installation and Maintenance
Curriculum Theme: Principles of solar photovoltaic (PV)
Focal competence: Demonstrate the knowledge of Solar PV System as a viable source of renewable energy for environmental sustainability
Key competencies/values: Communication; Collaboration
Skills:

• identify components in solar PV systems

Previous Lesson: First Term Solar PV Installation and Maintenance revision
Topic: Solar Pv System: Components In Solar Pv Systems And Their Functions (I)
Subject Matter: Components in solar PV systems and their functions

Specific Objectives

By the end of the lesson, pupils/students should be able to:

Cognitive Domain

• identify components in solar PV systems.

Affective Domain

• appreciate the importance of each component in a solar PV system.
• value safe handling practices for solar PV components.

Psychomotor Domain

• point out the different labels on an inverter.
• demonstrate basic safe handling procedures for solar PV components.

Social Domain

• collaborate effectively in group discussions about solar PV components.

Reference Materials

The following resources were used in planning this lesson:

• 2025 New Revised Senior Secondary Education Curriculum (SSEC)
• Relevant State Unified Scheme of Work
• The HeadTeacher Scheme of work For The New Revised Senior Secondary Education Curriculum (SSEC)
• Basic Solar PV Installation and Maintenance Textbook for Senior Secondary Schools

Instructional Materials

The teacher will teach this lesson with the aid of:

• Charts showing diagrams of solar PV systems and their components
• Pictures of inverters, solar batteries, and charge controllers
• Actual inverter (if available)
• Actual solar battery (if available)
• Actual charge controller (if available)
• Whiteboard/Blackboard and markers/chalk

Rationale for the Lesson

This lesson is essential for students to understand the fundamental building blocks of a solar PV system. Knowing the function and safe handling of inverters, batteries, and charge controllers is crucial for anyone involved in solar PV installation and maintenance. This knowledge forms the basis for designing, troubleshooting, and safely working with solar energy systems.

Prerequisite/Previous Knowledge

Students should have a basic understanding of electricity, including direct current (DC) and alternating current (AC), and a general awareness of renewable energy sources.

Lesson Content/Board Summary

Solar PV System: Components In Solar PV Systems And Their Functions (I)

Introduction to Solar PV System Components

A solar photovoltaic (PV) system converts sunlight into electricity. It comprises several key components that work together to generate, store, and deliver power to electrical loads. Understanding each component’s function is vital for effective system operation and maintenance.

Inverters

An inverter is an electronic device that converts direct current (DC) electricity, typically produced by solar panels or stored in batteries, into alternating current (AC) electricity. AC power is what most household appliances and the national grid use.

1. Place in a Solar PV System: Inverters are usually placed between the DC power source (solar panels or battery bank) and the AC loads (appliances) or the utility grid. They are essential for making solar electricity usable in most residential and commercial settings.
2. Basic Input/Output Relationships:
   1. Input: DC voltage and current from solar panels or batteries.
   2. Output: AC voltage and current suitable for electrical loads (e.g., 230V AC, 50Hz in Nigeria).
3. Labels on an Inverter: Common labels found on an inverter include:
   1. DC Input Terminals (+ and -)
   2. AC Output Terminals
   3. Ground Terminal
   4. Power Rating (e.g., 1000W, 3kVA)
   5. Input Voltage Range (e.g., 12V, 24V, 48V DC)
   6. Output Voltage and Frequency (e.g., 230V AC, 50Hz)
   7. LED Indicators (for power, fault, battery status)
   8. Cooling Fan/Vents
   9. On/Off Switch
4. Safe Handling of Inverters:
   1. Always ensure the inverter is disconnected from both DC input and AC output before handling or maintenance.
   2. Avoid touching terminals when the inverter is operational.
   3. Install in a well-ventilated area to prevent overheating.
   4. Do not expose to moisture or direct sunlight.
   5. Follow manufacturer’s instructions for installation and operation.

Batteries (Solar Batteries)

Solar batteries are designed to store electrical energy generated by solar panels for later use. This is crucial for providing power during periods of low sunlight (e.g., cloudy days, night-time) or when solar generation is insufficient to meet demand.

1. Function:
   1. Energy Storage: Store excess DC electricity from solar panels.
   2. Power Supply: Provide power to loads when solar panels are not generating enough electricity.
   3. System Stability: Help stabilize the system by providing a consistent voltage.
2. Safe Handling of Solar Batteries:
   1. Wear appropriate Personal Protective Equipment (PPE) such as gloves and eye protection when handling batteries.
   2. Avoid short-circuiting battery terminals, as this can cause sparks, fires, or explosions.
   3. Install batteries in a well-ventilated area to dissipate gases (e.g., hydrogen) that can be produced during charging.
   4. Do not overcharge or over-discharge batteries, as this can damage them and pose safety risks.
   5. Keep batteries upright and secure to prevent spills of corrosive electrolytes.
   6. Dispose of old batteries responsibly according to environmental regulations.

Charge Controllers

A charge controller (also known as a charge regulator) is an electronic device that manages the power flow from the solar panels to the battery bank and from the battery bank to the load. It protects the battery from overcharging and over-discharging.

1. Function:
   1. Overcharge Protection: Prevents batteries from being charged beyond their capacity, which can damage them.
   2. Over-discharge Protection: Disconnects the load when battery voltage drops too low, preventing deep discharge that can permanently damage the battery.
   3. Optimized Charging: Ensures batteries are charged efficiently, extending their lifespan.
   4. Load Control: Some charge controllers can manage DC loads, switching them on or off based on battery voltage or time.
2. Safe Handling of Charge Controllers:
   1. Ensure the charge controller is correctly wired according to the manufacturer’s instructions, connecting the battery first, then the solar panels, and finally the load.
   2. Install in a dry, cool, and well-ventilated location.
   3. Avoid exposing the controller to moisture or extreme temperatures.
   4. Do not exceed the maximum current or voltage ratings specified by the manufacturer.

Teaching Methods/Instructional Techniques

Discussion, Demonstration, Guided Practice, Question and Answer, Explanation, Group Work, Practical Activity

Instructional Procedures

Step 1: Introduction

Time: 5 minutes

Teaching Skill: Questioning/Engagement

Teacher’s Activity: The teacher greets the students and asks them to recall what they know about solar energy and its components from previous lessons or general knowledge. The teacher then introduces the topic: “Solar PV System: Components In Solar PV Systems And Their Functions (I)”.

Pupils’ Activity: Pupils respond to questions and listen attentively to the introduction.

Learning Point: Prior knowledge activation

Step 2: Introduction to Inverters

Time: 10 minutes

Teaching Skill: Explanation/Demonstration

Teacher’s Activity: The teacher explains what an inverter is, its function in converting DC to AC, and its place in a solar PV system. Using charts or an actual inverter, the teacher points out its basic input/output relationships and common labels. The teacher also highlights safe handling practices for inverters.

Pupils’ Activity: Pupils observe the charts/inverter, listen to explanations, and ask questions for clarification.

Learning Point: Inverter function and labels

Step 3: Group Discussion on Inverters

Time: 10 minutes

Teaching Skill: Group Work/Facilitation

Teacher’s Activity: The teacher divides students into small groups and guides them to discuss the function of inverters, their input/output, and the importance of safe handling. The teacher moves around to facilitate discussions and answer questions.

Pupils’ Activity: Students discuss in groups, identifying inverter characteristics and safe practices.

Learning Point: Inverter understanding reinforcement

Step 4: Introduction to Batteries

Time: 8 minutes

Teaching Skill: Explanation/Illustration

Teacher’s Activity: The teacher introduces solar batteries, explaining their primary function of storing energy in a solar PV system. The teacher uses pictures or an actual battery to illustrate and discusses important safe handling procedures for batteries.

Pupils’ Activity: Pupils listen, observe pictures/battery, and note key functions and safety points.

Learning Point: Battery function and safety

Step 5: Introduction to Charge Controllers

Time: 8 minutes

Teaching Skill: Explanation/Illustration

Teacher’s Activity: The teacher introduces charge controllers, explaining their role in protecting batteries from overcharging and over-discharging. The teacher uses pictures or an actual charge controller to show its appearance and discusses its safe handling.

Pupils’ Activity: Pupils listen, observe pictures/controller, and understand its protective role.

Learning Point: Charge controller function

Step 6: Comprehensive Group Discussion

Time: 7 minutes

Teaching Skill: Collaboration/Application

Teacher’s Activity: The teacher brings the class together and guides a brief discussion, asking students to summarize the functions of inverters, batteries, and charge controllers and how they work together in a solar PV system. The teacher emphasizes the importance of safe handling for all components.

Pupils’ Activity: Students contribute to the discussion, summarizing functions and safety.

Learning Point: Component interrelationship and safety

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

1. What is the primary function of an inverter in a solar PV system?
2. Mention two labels you would expect to find on an inverter.
3. Why are batteries important in an off-grid solar PV system?
4. State one safety precaution when handling solar batteries.
5. What is the main role of a charge controller?

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Component identification and functions

Step 8: Note-Taking

Time: 10 minutes

Teaching Skill: Guided Writing

Teacher’s Activity: The teacher guides pupils/students to copy the essential Board Summary notes on inverters, batteries, and charge controllers into their notebooks.

Pupils’ Activity: Pupils/students copy the notes carefully into their notebooks.

Learning Point: Board summary recording

Step 9: Conclusion

Time: 2 minutes

Teaching Skill: Consolidation

Teacher’s Activity: The teacher briefly summarizes the lesson by reiterating the importance of inverters, batteries, and charge controllers as essential components of a functional and safe solar PV system. The teacher encourages students to continue exploring solar energy.

Pupils’ Activity: Pupils listen and reflect on the lesson’s main points.

Learning Point: Lesson summary and reinforcement

Continuous Assessment/Further Study

Type: Homework

Instruction: Answer the following questions in your notebook:

1. Describe the conversion process that occurs in an inverter.
2. List three safety precautions that should be observed when installing or maintaining solar batteries.
3. Explain how a charge controller protects a solar battery.
4. Draw a simple diagram showing the connection of a solar panel, charge controller, battery, and inverter to a load.

Lesson Keywords

• Inverter – An electronic device that converts direct current (DC) to alternating current (AC).
• Battery – A device that stores electrical energy for later use.
• Charge Controller – A device that regulates the voltage and current from solar panels to the battery to prevent overcharging or over-discharging.
• DC (Direct Current) – Electric current that flows in only one direction.
• AC (Alternating Current) – Electric current that periodically reverses direction.
• Solar PV System – A system that converts sunlight into electricity using photovoltaic cells.

Differentiation

Support: For students who struggle, the teacher will provide simplified diagrams and allow them to work in pairs with more capable students. Visual aids will be used extensively to reinforce understanding. The teacher will also provide a glossary of terms.

Extension: Advanced students can research different types of inverters (e.g., pure sine wave vs. modified sine wave) or battery technologies (e.g., lead-acid vs. lithium-ion) and present their findings to the class. They can also explore the sizing considerations for each component in a small solar PV system.

Suggested Lesson Videos

For further understanding, students can search on YouTube for:

• “solar pv components inverter battery charge controller functions SS1”
• “how solar inverter works for beginners”