Meaning, Types and Electricity Generation with Solar PV Systems for JSS 1

Solar Photovoltaics (PV) System

Performance Objectives

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

1. define Solar Photovoltaics,
2. identify types of Solar Photovoltaic Modules;
3. explain how a Solar Photovoltaic system generates electricity.

Meaning of Solar Photovoltaics (PV)

Solar Photovoltaics, often shortened to Solar PV, refers to a technology that converts sunlight directly into electricity.

The word “solar” means relating to the sun. “Photovoltaics” comes from “photo,” meaning light, and “voltaic,” meaning electricity. So, photovoltaics means generating electricity from light.

Solar PV systems use special devices called solar panels or solar modules to capture sunlight. These panels contain materials that produce an electric current when exposed to light.

Types of Solar Photovoltaic (PV) Modules

Solar PV modules, also known as solar panels, are made from different materials and processes. The two main types of solar PV modules are monocrystalline and polycrystalline.

Monocrystalline Solar PV Modules

Monocrystalline solar modules are made from a single, pure crystal of silicon. This gives them a uniform, dark black appearance.

These modules are known for their high efficiency, meaning they can convert a larger amount of sunlight into electricity compared to other types. They also tend to have a longer lifespan.

Polycrystalline Solar PV Modules

Polycrystalline solar modules are made from multiple silicon crystals melted together. This gives them a speckled, bluish appearance.

These modules are generally less efficient than monocrystalline modules but are often more affordable to produce. They are a common choice for many solar installations.

Solar PV and Electricity Generation

A Solar PV system generates electricity by converting sunlight into electrical energy. This process involves several key components working together.

How a Solar PV System Generates Electricity

The process of generating electricity with a Solar PV system involves the following steps:

1. Sunlight Absorption: Solar panels, which contain many solar cells, are installed in a place where they can receive direct sunlight. When sunlight hits the solar cells, the energy from the light excites electrons within the cell material.
2. Electricity Production: The excited electrons start to move, creating an electric current. This current is a direct current (DC) electricity.
3. Current Conversion: Most household appliances and the national grid use alternating current (AC) electricity. An inverter is used to convert the DC electricity produced by the solar panels into AC electricity.
4. Electricity Use and Storage: The AC electricity can then be used to power household appliances directly. If more electricity is produced than is needed, it can be stored in energy storage devices, such as battery banks, for later use.
5. Distribution: In some systems, excess electricity can be sent to the national grid through network meters and energy distributors. A charge controller manages the flow of electricity to and from the battery bank, protecting it from overcharging or deep discharging.

Solar cables and other accessories connect all these components, ensuring the safe and efficient flow of electricity throughout the system.