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How solar panel works? A comprehensive guide

How solar panel works? A comprehensive guide

May 28, 2024          By Ali     6 minutes read

How solar panel works

Table of Contents

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1. Introduction

Solar energy is power we get from the sun. It is very important because it helps us use less fossil fuels like coal and oil, which can harm the environment.

Solar energy is clean and renewable, meaning we will never run out of it as long as the sun shines. Over the years, more people and businesses have started using solar energy because it’s better for our planet and can save money in the long run.

This guide will help you understand. We’ll simply explain how solar panel works.

Even though solar panels might seem complicated, this guide will make it easy to understand. Whether you are just curious or want to become a solar energy expert someday, this guide is for you.

Solar energy is the power we get from the sun. The sun sends out energy in the form of light and heat. Solar panels capture this energy and turn it into electricity that we can use to power our homes, schools, and gadgets.

2. Historical Background

The photovoltaic effect is how solar panels turn sunlight into electricity. It was discovered in 1839 by a French scientist named Edmond Becquerel. Later, in the 1950s, scientists developed the first practical solar cells using silicon. These solar cells could turn sunlight into electricity efficiently, and this is how modern solar panels started.

3. Types of Solar Radiation

Solar radiation is the energy that comes from the sun. There are different types of solar radiation.

  1. Visible Light: This is the light we can see. It’s what makes our world bright during the day.
  2. Infrared Radiation: We can’t see this type, but we can feel it as heat.
  3. Ultraviolet (UV) Radiation: We also can’t see UV rays, but they can cause sunburns.

Types of solar radiation

4. Importance of Solar Energy

Solar energy is very important for two big reasons:

4.1. Environmental Benefits

Solar energy is clean. It doesn’t produce pollution or harmful gases, so it helps keep our air and water clean. By using solar energy, we can reduce the impact of climate change and protect our planet.

4.2. Economic Benefits

Solar energy can save money. Once you have solar panels, you can use the sun’s energy for free. This can lower electricity bills and reduce costs for businesses and homeowners. Solar energy can also create jobs in the solar industry, helping the economy grow.

5. How the Photovoltaic Effect Works

The photovoltaic effect is the process by which solar cells turn sunlight into electricity. Here’s a deeper look at how it works, step-by-step:

1. Sunlight Absorption:

  • Sunlight contains tiny energy particles called photons.
  • When sunlight hits the solar cell, these photons are absorbed by the cell’s material (usually silicon).

2. Energy Transfer:

  • The absorbed photons transfer their energy to electrons in the silicon atoms.
  • This energy transfer gives the electrons enough energy to break free from their atoms.

3. Electron Movement:

  • When the electrons gain enough energy, they start moving around.
  • Solar cells have a built-in electric field that pushes these free electrons in a specific direction.

4. Creation of Electric Current:

  • The movement of electrons creates an electric current, a flow of electric charge.
  • This current flows through the solar cell and can be captured by metal contacts on the top and bottom of the cell.
5. Electricity Generation:
  • The electric current is then directed out of the solar cell through wires.
  • This current can be used to power electrical devices, charge batteries, or be fed into the electrical grid.

6. Types of Solar Panels

Types of solar panel ( engineers guidebook )

6.1. Monocrystalline Solar Panels

  • Monocrystalline solar panels are made from silicon wafers cut from a single silicon crystal.
  • They have a uniform dark color and are usually square or rectangular in shape.
  • The silicon wafers are arranged in a grid pattern and covered with a protective layer of glass.
  • Monocrystalline panels are known for their high efficiency.
  • They have a long lifespan, typically lasting 25 years or more with minimal maintenance.
  •  
Advantages
  • High efficiency: They can produce more electricity in less space.
  • Long lifespan: They last a long time and provide consistent performance.
  • Good performance: They work well even on cloudy days
Disadvantage’s
  • Higher cost: Monocrystalline panels are usually more expensive compared to other types.
  • Manufacturing process: The process of making monocrystalline silicon is energy-intensive and can have environmental impacts.

6.2. Polycrystalline Solar Panels

  • Polycrystalline solar panels are made from silicon crystals that are melted together.
  • They have a speckled blue color and a rectangular shape with a grid-like pattern.
  • The silicon crystals are not as pure as those in monocrystalline panels, resulting in a less uniform appearance.
  • Polycrystalline panels are slightly less efficient than monocrystalline panels.
  • They still have a good lifespan, typically lasting 15-20 years with proper care.
Advantages
  • Lower cost: Polycrystalline panels are usually more affordable compared to monocrystalline panels.
  • Less energy-intensive manufacturing: The process of making polycrystalline silicon is less energy-intensive, making it more environmentally friendly.
  • Good performance in high temperatures: They perform well even in hot climates.
Disadvantage’s
  • Lower efficiency: They may produce slightly less electricity compared to monocrystalline panels.
  • Less efficient in low light conditions: They may not work as well on cloudy days compared to monocrystalline panels.

6.3. Thin-Film Solar Panels

  • Amorphous Silicon: These panels are made by depositing silicon atoms onto a substrate, creating a thin film. They are flexible and can be used in various applications.
  • Cadmium Telluride (CdTe): These panels use a thin film of cadmium telluride as the semiconductor material. They are known for their high efficiency and low cost.
  • CIGS (Copper-Indium-Gallium-Selenide): These panels use a thin film of CIGS as the semiconductor material. They are lightweight and have good performance in low light conditions.
  • Thin-film solar panels are generally less efficient than crystalline silicon panels, meaning they convert less sunlight into electricity.
  • They have a shorter lifespan compared to crystalline silicon panels, typically lasting around 10-15 years.
Advantages
  • Lightweight and flexible: Thin-film panels can be used in various applications and can be installed on curved or irregular surfaces.
  • Cost-effective: They are often cheaper to produce compared to crystalline silicon panels.
  • Good performance in low light conditions: Some types of thin-film panels, like CIGS, perform well even in cloudy weather.
Disadvantage’s
  • Lower efficiency: They produce less electricity compared to crystalline silicon panels.
  • Shorter lifespan: Thin-film panels may need to be replaced sooner than crystalline silicon panels.

6.4. Bifacial Solar Panels

  • Bifacial solar panels have a layer on both sides that can absorb sunlight, unlike traditional panels that only absorb from one side.
  • This double-sided feature allows them to capture sunlight from both the front and back, increasing their efficiency.
  • Bifacial panels are more efficient than traditional panels because they can collect sunlight from two directions.
  • They have a similar lifespan to traditional panels, usually lasting 25 years or more with proper care.
Advantages
  • Higher efficiency: Bifacial panels can produce more electricity because they can use sunlight from both sides.
  • Versatile installation: They can be installed in different ways, like on the ground or on a rooftop.
  • Better performance in certain conditions: They work well in areas with reflective surfaces, like snow or sand.
Disadvantage’s
  • Cost: Bifacial panels may be more expensive than traditional panels, though prices are decreasing.
  • Mounting complexity: Installing bifacial panels requires careful planning and may need special mounting systems.

7. Solar Panel Components

Components of solar panel (engineers guidebook )

1. Solar Cells

  • Solar cells come in different types, like monocrystalline, polycrystalline, and thin-film.
  • They are arranged in a grid-like pattern on the solar panel.
  • The efficiency of solar cells depends on factors like the type of material used and the manufacturing process. 

2. Encapsulation

  • Encapsulation is like a protective layer that covers the solar cells.
  • It keeps the solar cells safe from things like moisture and dirt.
  • Common materials used for encapsulation include ethylene-vinyl acetate (EVA) and glass.

3. Glass Cover

  • The glass cover is like a shield that protects the solar cells from weather and other damage.
  • It can be tempered glass or special anti-reflective glass.

4. Frame

  • The frame is like the skeleton that holds the solar panel together.
  • It can be made from materials like aluminum or stainless steel.

5. Junction Box

  • The junction box is like the brain of the solar panel.
  • It collects the electricity generated by the solar cells and sends it out as usable power.

6. Bypass Diodes

  • Bypass diodes are like traffic signals for electricity in the solar panel.
  • If part of the panel is shaded or broken, it helps the electricity flow around the problem area.
  • They help manage the flow of electricity and prevent damage to solar cells.
 

Parts of solar panel (engineers guidebook )

 

8. How Solar Panels Generate Electricity

How solar panel works ( engineers guidebook )

1. Sunlight Hits the Solar Panel:

  • When sunlight shines on the solar panel, it contains tiny energy particles called photons.

2. Photovoltaic Effect:

  • Solar panels have special materials called solar cells.
  • These solar cells have layers of silicon, which is a type of semiconductor.
  • When sunlight hits the solar cells, the photons transfer their energy to the electrons in the silicon atoms.

3. Electron Movement:

  • The energy from the photons makes the electrons in the silicon atoms move around.
  • This movement creates an electric current, which is a flow of electric charge.

4. Electricity Generation:

  • The electric current flows out of the solar panel through wires.
  • This electricity can be used to power things like lights, appliances, and gadgets.

5. Inverter Conversion:

  • The electricity produced by the solar panel is in the form of direct current (DC) electricity.
  • Most homes and buildings use alternating current (AC) electricity, so the DC electricity from the solar panel needs to be converted.
  • A device called an inverter changes the DC electricity into AC electricity, which is what we use in our homes.

6. Usable Electricity:

  • The AC electricity produced by the inverter can now be used to power the electrical devices in our homes, schools, and other places.
  • Any excess electricity can be sent back to the electrical grid for others to use, earning credits or money for the solar panel owner.

9. Degradation and Lifespan

1. Factors Influencing Degradation:

  • Weather: Extreme weather like hail or heavy snow can damage panels.
  • Quality of Materials: Better quality materials last longer.
  • Maintenance: Regular cleaning and inspection help panels last longer.

2. Expected Lifespan 

  • Lifespan: Solar panels usually last 25 to 30 years. Over time, they produce a little less electricity each year.
  • Performance: Most solar panels come with a guarantee that they will still produce a certain amount of electricity after a number of years, usually 80-90% of their original output after 25 years.

10. Common Issues and Solutions

1. Dirt and Debris

  • Issue: Dirt and debris can block sunlight.
  • Solution: Clean the panels with water and a soft brush.

2. Shading

  • Issue: Trees or new buildings might cast shadows on the panels.
  • Solution: Trim trees or move panels if possible.

3. Loose Connections

  • Issue: Wires or parts might come loose over time.
  • Solution: Tighten any loose connections and call a professional if needed.

11. Case Studies

1. Residential Solar Installations

  • Examples: Imagine a family in a sunny neighborhood putting solar panels on their roof. They use the sun’s energy to power their home.
  • Benefits: They save money on electricity bills and help the environment by using clean energy. They can even sell extra electricity back to the power company!

2. Commercial Solar Projects

  • Examples: A big store or a school might put solar panels on their large roofs. For example, a supermarket chain installs solar panels in all their stores.
  • Benefits: They save a lot of money on electricity, which helps them keep prices lower. Plus, they show customers and students that they care about the environment.

3. Innovative Projects

  • Examples: Some unique projects include solar-powered cars, solar panels on boats, or floating solar farms on lakes.
  • Impacts: These projects show how versatile solar energy can be. They help reduce fuel costs, lower pollution, and demonstrate new ways to use solar power daily.

FAQ'S

How do solar panels work step by step?

  • Photon Absorption: Sunlight hits the solar panels, and the photovoltaic cells within the panels absorb photons from the sunlight.

  • Electron Excitement: The energy from the photons excites electrons in the photovoltaic cells, causing them to become loose and move.

  • Electric Field Creation: The movement of electrons creates an electric field within the cells, which generates a flow of electrical current.

  • Direct Current (DC) Generation: The electrical current generated is in the form of direct current (DC).

  • Inverter Conversion: An inverter converts the DC into alternating current (AC), which is the type of electricity used in homes and businesses.

  • Power Usage or Storage: The AC electricity can either be used immediately to power appliances and devices or stored in batteries for later use.

Solar panels generate electricity through the following process:

  1. Photon Absorption: Solar panels, composed of photovoltaic cells, absorb sunlight.

  2. Electron Excitement: The absorbed sunlight energizes electrons in the cells, causing them to move.

  3. Electric Field Creation: This movement creates an electric field within the cell, producing a flow of electrical current.

  4. Current Generation: The flow of electrons generates direct current (DC) electricity.

  5. Conversion to AC: An inverter converts the DC electricity to alternating current (AC), which is used to power homes and businesses.

Solar panels typically last 25 to 30 years, with performance warranties usually covering 20 to 25 years. Proper maintenance can extend their lifespan.

 

The amount of kW a solar panel can produce in a day depends on its size, efficiency, and the amount of sunlight it receives. On average, a standard 300-watt solar panel can produce about 1.5 to 2.5 kWh per day, assuming 5 to 8 hours of optimal sunlight.

Solar panels produce direct current (DC) electricity. This DC is then converted to alternating current (AC) by an inverter, making it suitable for use in homes and businesses.

Two disadvantages of solar cells are:

  1. High Initial Cost: The upfront cost of purchasing and installing solar panels can be significant.
  2. Weather Dependent: Solar panel efficiency decreases on cloudy days and they do not produce electricity at night.
Two advantages of solar cells are:
  1. Renewable Energy Source: Solar cells provide a sustainable and inexhaustible source of energy from the sun.
  2. Low Operating Costs: Once installed, solar panels have minimal maintenance costs and can significantly reduce electricity bills.

Solar panels are primarily made of photovoltaic cells, which are usually composed of silicon. These cells are encased in a protective layer of glass and mounted on a metal frame, with wiring and other components to facilitate electricity generation and connectivity.

A PV (photovoltaic) cell in a solar panel is a semiconductor device that converts sunlight directly into electricity. Made primarily of silicon, PV cells generate an electric current when exposed to sunlight, forming the basic building block of solar panels.

Yes, solar panels do require some maintenance to ensure optimal performance and longevity. Here are a few maintenance tasks typically recommended:

  1. Regular Cleaning: Keep the surface of the solar panels clean from dirt, dust, leaves, and debris that can reduce sunlight absorption.

  2. Inspect for Damage: Periodically inspect panels for cracks, breaks, or other physical damage that could affect their efficiency.

  3. Check Connections: Ensure all electrical connections are secure and free from corrosion.

  4. Trim Nearby Vegetation: Trim back any trees or foliage that may shade the panels during peak sunlight hours.

  5. Monitor Performance: Keep track of the panel’s performance through monitoring systems to detect any drop in efficiency or output.

The principle of solar panels revolves around the phenomenon of photovoltaic effect. Here’s a breakdown of the principle:

  1. Photon Absorption: Solar panels are made of photovoltaic cells, usually composed of silicon. When sunlight (photons) strikes these cells, they absorb the photons.

  2. Electron Excitation: The absorbed photons transfer their energy to electrons in the semiconductor material (like silicon), causing some electrons to become free from their atoms.

  3. Electric Field Generation: This creates an electric field across the layers of the cell.

  4. Electric Current Generation: The separated electrons are forced by the electric field to flow in a specific direction, creating an electric current.

  5. Direct Current (DC) Output: The current produced by the solar panel is direct current (DC) electricity.

  6. Conversion to Alternating Current (AC): For use in homes and businesses, an inverter converts the DC electricity into alternating current (AC), which is the standard type of electricity used in most buildings.

Calculating solar power involves several steps to determine the amount of electricity a solar panel system can generate. Here’s a simplified outline:

  1. Determine Solar Irradiance: Find the average solar irradiance in your location. This is typically measured in kilowatt-hours per square meter per day (kWh/m²/day) and can be obtained from solar resource maps or databases.

  2. Consider Panel Efficiency: Solar panels have an efficiency rating, usually between 15% to 20%, which indicates how well they convert sunlight into electricity.

  3. Calculate Panel Output: Multiply the solar irradiance by the area of your solar panels (in square meters) and by the panel efficiency. This gives you the daily energy output in kilowatt-hours (kWh) per day.

  4. Account for System Losses: Factor in losses due to factors like inverter efficiency, shading, dirt on panels, and wiring losses. These losses typically reduce the actual output compared to the theoretical maximum.

  5. Calculate Annual Output: Multiply the daily output by 365 days to estimate the annual energy production of your solar panel system.

This calculation provides an estimate of how much electricity your solar panel system can generate under ideal conditions.

The theory of solar panels revolves around the photovoltaic effect, which is the process through which sunlight is converted into electricity. Here’s a concise explanation:

  1. Photovoltaic Effect: Solar panels are made up of photovoltaic cells, typically composed of silicon or other semiconductor materials. When photons (light particles) from sunlight strike these cells, they transfer their energy to electrons in the semiconductor material.

  2. Generation of Electric Current: This energy excites electrons, causing them to move, which generates an electric current. The movement of electrons creates a flow of electricity.

  3. Direct Current (DC) Output: The electricity produced by the solar panels is in the form of direct current (DC).

  4. Conversion to Alternating Current (AC): To be used in homes and businesses, the DC electricity is converted into alternating current (AC) by an inverter.

Author

Muhammad ali

Muhammad Ali

Muhammad Ali holds a PhD in Mechanical Engineering from MIT and is currently conducting groundbreaking research on sustainable energy systems. His innovative work in renewable energy integration has earned him numerous accolades in the engineering community.

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