Types of Solar PV Systems Grid-tied and Hybrid for SS 1

Class: SS 1
Term: First Term
Week: 8
Age: Approximately 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:

• discuss the types of solar PV systems

Previous Lesson: Solar PV Components Inverters, Batteries and Charge Controllers
Topic: Solar Pv System: Types Of Solar Pv Systems: Grid-Tied Hybrid
Subject Matter: Types of solar PV systems

Specific Objectives

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

Cognitive Domain

• Define a solar photovoltaic (PV) system.
• Identify the main components of a basic solar PV system.
• Discuss the characteristics of Grid-tied solar PV systems.
• Explain the features of Hybrid solar PV systems.
• Describe Off-grid solar PV systems.

Affective Domain

• Appreciate the importance of different solar PV system types for various energy needs.
• Value solar energy as a sustainable power source.

Psychomotor Domain

• Differentiate between Grid-tied, Hybrid, and Off-grid solar PV systems using visual aids.
• Sketch a basic diagram illustrating the components of a solar PV system.

Social Domain

• Collaborate effectively in group discussions about solar PV system types.

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)
• Senior Secondary Solar PV Installation and Maintenance Textbook for SS 1

Instructional Materials

The teacher will teach this lesson with the aid of:

• Charts showing different solar PV system types
• Pictures of solar panels, inverters, batteries, and charge controllers
• Actual inverters
• Solar batteries
• Charge controllers
• Whiteboard/Blackboard and markers/chalk

Rationale for the Lesson

Understanding the different types of solar PV systems is fundamental for students pursuing solar PV installation and maintenance. This lesson provides essential knowledge about how solar energy is harnessed and integrated into various settings, from homes connected to the national grid to remote locations. It equips students with the foundational concepts necessary for practical applications and problem-solving in the field of renewable energy.

Prerequisite/Previous Knowledge

Students should have a basic understanding of electricity, energy sources, and the concept of renewable energy.

Lesson Content/Board Summary

Solar PV System: Types Of Solar PV Systems: Grid-Tied And Hybrid

What is a Solar Photovoltaic (PV) System?

A solar photovoltaic (PV) system is an electrical power system designed to supply usable solar power by converting sunlight into direct current (DC) electricity using semiconductors. It comprises several interconnected components that work together to capture, convert, store, and distribute solar energy.

Basic Components of a Solar PV System

The fundamental components of a solar PV system include:

1. Solar Modules (PV Panels): These convert sunlight into DC electricity.
2. Inverter: Converts the DC electricity from the solar panels into alternating current (AC) electricity, which is used by most household appliances and the national grid.
3. Charge Controller: (Used in off-grid and hybrid systems) Regulates the voltage and current coming from the solar panels to the battery bank, preventing overcharging and prolonging battery life.
4. Battery Bank: (Used in off-grid and hybrid systems) Stores excess solar energy for use when the sun is not shining (e.g., at night or on cloudy days).
5. Mounting Structure: Physically supports the solar panels, typically on a roof or ground.
6. Wiring and Electrical Protections: Connects all components and ensures safety.
7. Load Supply: The electrical appliances and devices that consume the generated power.
8. Grid Connection: (For grid-tied and hybrid systems) The connection to the national electricity supply network.

Types of Solar PV Systems

Solar PV systems are primarily classified into three main types based on their connection to the electricity grid and their energy storage capabilities:

1. Grid-tied (On-grid) Systems
2. Off-grid (Stand-alone) Systems
3. Hybrid Systems

Grid-tied (On-grid) Solar PV Systems

Grid-tied solar PV systems are connected to the public electricity grid. They do not have battery storage and rely on the grid to supply power when solar production is insufficient. Excess electricity generated by the solar panels can be fed back into the grid, often earning the system owner credits or payments (net metering).

How it works:

1. Solar panels convert sunlight into DC electricity.
2. An inverter converts DC electricity to AC electricity.
3. This AC electricity powers the home’s loads.
4. Any excess AC electricity is exported to the national grid.
5. When solar production is low or absent, the home draws electricity from the grid.

Advantages:

1. No need for expensive batteries, reducing initial cost and maintenance.
2. Ability to sell excess electricity back to the grid (net metering).
3. Reliable power supply as the grid acts as a backup.
4. Lower carbon footprint by reducing reliance on fossil fuels.

Disadvantages:

1. Does not provide power during grid outages (unless equipped with a specific grid-tied inverter with backup feature).
2. Dependent on grid availability and policies for net metering.

Off-grid (Stand-alone) Solar PV Systems

Off-grid solar PV systems are completely independent of the public electricity grid. They are designed to be self-sufficient and typically include a battery bank to store energy for use during periods of low sunlight or at night. These systems are ideal for remote locations where grid connection is unavailable or too expensive.

How it works:

1. Solar panels convert sunlight into DC electricity.
2. A charge controller regulates the DC electricity flow to the battery bank.
3. Batteries store excess energy.
4. An inverter converts DC electricity from the batteries to AC electricity for household loads.
5. All power consumed comes directly from the solar panels or the battery bank.

Advantages:

1. Complete energy independence from the grid.
2. Provides power to remote areas without grid access.
3. No electricity bills from the utility company.

Disadvantages:

Hybrid Solar PV Systems

Hybrid solar PV systems combine the features of both grid-tied and off-grid systems. They are connected to the public electricity grid but also include a battery bank for energy storage. This allows them to draw power from the grid, export excess power to the grid, and also provide backup power during grid outages using the stored battery energy.

How it works:

1. Solar panels convert sunlight into DC electricity.
2. A hybrid inverter manages power flow, converting DC to AC.
3. Electricity powers the home’s loads, charges the batteries, or is exported to the grid.
4. When solar production is low, power can be drawn from batteries or the grid.
5. During grid outages, the system can automatically switch to battery power to supply critical loads.

Advantages:

1. Provides backup power during grid outages (unlike standard grid-tied systems).
2. Allows for energy independence while still having the reliability of grid connection.
3. Ability to store excess solar energy for later use, reducing reliance on the grid during peak demand.
4. Can sell excess electricity to the grid.

Disadvantages:

1. Higher initial cost compared to grid-tied systems due to batteries and more complex inverters.
2. Batteries require maintenance and eventual replacement.
3. More complex installation and system management.

Teaching Methods/Instructional Techniques

Discussion, Demonstration, Guided Practice, Question and Answer, Explanation, Group Work, Visual Aids.

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. The teacher then introduces the topic: “Types of Solar PV Systems: Grid-tied, Hybrid, and Off-grid,” explaining that understanding these types is crucial for solar PV installation.

Pupils’ Activity: Pupils respond to questions about solar energy and listen attentively to the topic introduction.

Learning Point: Prior solar knowledge activation

Step 2: Defining Solar PV System and Components

Time: 10 minutes

Teaching Skill: Explanation/Demonstration

Teacher’s Activity: The teacher explains what a solar photovoltaic (PV) system is, emphasizing its role in converting sunlight to electricity. Using charts and pictures, the teacher identifies and briefly explains the function of basic components like solar modules, inverters, charge controllers, and batteries. The teacher guides students to participate in a class discussion on the meaning and principles of solar PV systems.

Pupils’ Activity: Pupils listen, observe the charts and pictures, and participate in the discussion, asking questions for clarification.

Learning Point: Solar PV system definition

Step 3: Introduction to Grid-tied Systems

Time: 10 minutes

Teaching Skill: Explanation/Discussion

Teacher’s Activity: The teacher introduces Grid-tied solar PV systems. Using charts and pictures, the teacher explains how these systems connect to the national grid, highlighting the absence of batteries and the concept of net metering. The teacher discusses the advantages and disadvantages of grid-tied systems.

Pupils’ Activity: Pupils observe the visuals, listen to the explanation, and contribute to the discussion on grid-tied systems.

Learning Point: Grid-tied system characteristics

Step 4: Introduction to Off-grid Systems

Time: 10 minutes

Teaching Skill: Explanation/Comparison

Teacher’s Activity: The teacher explains Off-grid solar PV systems, emphasizing their independence from the national grid and the necessity of battery storage. The teacher uses charts and pictures to illustrate how these systems work and discusses their advantages and disadvantages, comparing them briefly with grid-tied systems.

Pupils’ Activity: Pupils observe, listen, and participate in comparing off-grid systems with grid-tied systems.

Learning Point: Off-grid system features

Step 5: Introduction to Hybrid Systems

Time: 8 minutes

Teaching Skill: Explanation/Synthesis

Teacher’s Activity: The teacher introduces Hybrid solar PV systems as a combination of grid-tied and off-grid systems. The teacher explains how they offer both grid connection and battery backup, using visuals to show their operational flow. The advantages and disadvantages of hybrid systems are discussed.

Pupils’ Activity: Pupils observe, listen, and engage in understanding the integrated nature of hybrid systems.

Learning Point: Hybrid system benefits

Step 6: Group Discussion and Differentiation

Time: 7 minutes

Teaching Skill: Group Work/Facilitation

Teacher’s Activity: The teacher divides students into groups and guides them to use charts and pictures to discuss the differences and similarities between Grid-tied, Off-grid, and Hybrid solar PV systems. The teacher moves around, providing support and clarifying misconceptions.

Pupils’ Activity: Pupils discuss in their groups, identifying key distinctions and commonalities among the system types.

Learning Point: System type differentiation

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 a solar photovoltaic (PV) system?
2. Mention two basic components of a solar PV system.
3. Differentiate between a Grid-tied and an Off-grid solar PV system.
4. State one advantage of a Hybrid solar PV system.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Types of PV systems assessed

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 the types of solar PV systems into their notebooks.

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

Learning Point: Solar PV system notes

Step 9: Conclusion

Time: 5 minutes

Teaching Skill: Summarization

Teacher’s Activity: The teacher briefly recaps the main points of the lesson, reiterating the importance of understanding the different solar PV system types for various applications. The teacher encourages students to continue exploring renewable energy solutions.

Pupils’ Activity: Pupils listen to the summary and prepare for the next lesson.

Learning Point: Lesson concepts consolidated

Continuous Assessment/Further Study

Type: Homework

Instruction: Answer the following questions in your notebook.

1. List and briefly explain the three main types of solar PV systems.
2. Imagine you live in a remote village with no access to the national grid. Which type of solar PV system would be most suitable for your home, and why?
3. Research and write down two manufacturers of inverters commonly used in solar PV systems in Nigeria.

Lesson Keywords

• Solar PV System – A system that converts sunlight into electricity.
• Grid-tied System – A solar PV system connected to the public electricity grid without battery storage.
• Off-grid System – A stand-alone solar PV system completely independent of the grid, typically with battery storage.
• Hybrid System – A solar PV system connected to the grid and also equipped with battery storage.
• Inverter – A device that converts DC electricity to AC electricity.
• Charge Controller – A device that regulates battery charging from solar panels.
• Net Metering – A billing mechanism that credits solar energy system owners for the electricity they add to the grid.

Differentiation

For struggling learners, the teacher will provide simplified diagrams and focus on identifying the main components and a single defining characteristic for each system type. Advanced learners will be challenged to research specific real-world examples of each system type in Nigeria and discuss their economic implications.

Suggested Lesson Videos

For further understanding, search on YouTube for: types of solar pv systems grid tied hybrid off grid nigeria SS1