How Do Solar Panels Work?

Solar panels are renewable energy sources made of photovoltaic cells that efficiently transform sunlight into electricity by the photovoltaic effect. The alternative Name for solar panels is photovoltaic panels.

Solar panels work by generating electricity when sunlight hits the photovoltaic cell’s surface, exciting the electrons making them pass through the material, and thus creating an electric current. This electron flow is absorbed by the electrical circuit connected to the solar panel and produces usable electricity.

Photovoltaic cells are the technologically advanced components of solar panels, which are made of semiconductor materials, such as crystalline silicon, that help convert sunlight into electricity.

Silicon is used in photovoltaic cells because of the way it conducts electricity after it is exposed to sunlight. However, it is a bad conductor in its purest form. Therefore, doping the solar cells by the process of placing impure substances into the silicon crystal structure to improve its electrical conductivity properties.

The most common doping materials used in solar cells are Phosphorus to create excess electrons (n-type doping) and Boron to create electron imbalance or holes (p-type doping).

The Importance of solar panels in modern energy solutions plays a significant role owing to renewable nature and environmental benefits. They help reduce our dependence on fossil fuels, cut greenhouse gas emissions, and encourage low-carbon energy production.

In order to understand how solar panels produce electricity for your home, you will have to know the science of solar panels, the Photovoltaic Effect, as well as technologies like thin film, organic, quantum dot, and perovskites that are emerging alternatives to Silicon solar cells.

Let us explore the answers to many common questions whether solar panels work at night, different types of solar panels and factors affecting solar panel efficiency.

The Science of Solar Panels: The Photovoltaic Effect

Usually, solar panels generate electricity using the photovoltaic effect, discovered by Alexandre-Edmond Becquerel in 1839, where materials, like silicon produce an electric current after they are exposed to sunlight.

The photovoltaic effect refers to the process by which light energy, usually from the sun, is converted into electrical energy. This effect is fundamental to solar cells, the building blocks of solar panels.

Here are simple steps to understand how the photovoltaic effect works:

Step 1: Light Hits a Solar Cell

Sunlight, made up of tiny energy particles called photons, shines on the surface of a solar cell. These photons carry energy from the sun.

Step 2: Photons Transfer Energy to Electrons

The most important components of solar panels consist of photovoltaic cells, generally known as solar cells, which are attached and arranged within a frame. These cells are placed between protective glass layers coated with materials like ethylene-vinyl acetate (EVA).

Inside the solar cell is a material called a semiconductor, often silicon. The photons strike the semiconductor and transfer their energy to electrons in the material. This energy “excites” the electrons, giving them enough energy to break free from their atomic bonds.

Step 3: Formation of Electron-Hole Pairs

When an electron is freed, it leaves behind a “hole” where it used to be. This pair of a free electron and a hole is called an electron-hole pair.

Step 4: Electric Field Guides Electrons

The solar cell has an electric field built into it (thanks to a special internal design called a p-n junction). This electric field pushes the freed electrons in a specific direction, creating a flow of electric current.

Step 5: Electrons Flow Through an External Circuit

The flow of electrons through an external circuit generates electricity. This electricity can then be used to power devices, stored in batteries, or sent to the electrical grid.

Step 6: Continuous Process

As long as sunlight keeps hitting the solar cell, photons will keep exciting electrons, and the process will continue to generate electricity.

What are the alternatives to Silicon solar cells?

Here are a few Alternatives to Silicon Solar Cells:

1. Thin Film Solar

Thin film solar cells comprise a few semiconductor materials placed in thin layers over a base material like glass, plastic, or metal. Besides this, there are so many things to know about thin-film solar panels.

Benefits of Thin Film Solar:

• Flexible
• Lightweight
• Low-cost Manufacturing

Types of Thin Film Solar:

• Amorphous Silicon (a-Si)
• Cadmium Telluride (CdTe)
• Copper Indium Gallium Selenide (CIGS).

2. Organic Solar Cells

Organic solar cells make use of organic (carbon-based) materials as the active layer in the photovoltaic device. All of these materials are usually polymers or very tiny organic molecules.

Benefits of Organic Solar Cells:

• Flexibility
• Low-cost manufacturing
• Large-scale production

Types of Organic Solar Cells:

• Polymer solar cells
• Compact or Small-molecule solar cells
• Hetero junction thin-film solar cells
• Tandem solar cells

3. Quantum Dot Solar Cells

Quantum dot solar cells are composed of quantum dots, and nanoscale semiconductor particles, which are made of materials like cadmium selenide or lead sulphide, into the solar cell structure.

Benefits of Quantum Dot Solar Cells:

• Tunable band gap
• The potential for high efficiency
• Compatibility with solution-based processing

Types of Quantum Dot Solar Cells:

• Colloidal quantum dot (CQD) solar cells
• Pbs quantum dot heterojunction solar cells
• Perovskite quantum dots
• Schottky solar cells
• Meg solar cells

4. Perovskite Solar Cells

Perovskite solar cells (PSCs) are a specific form of thin-film photovoltaic (PV) technology. They are created using synthetic crystals that closely resemble the crystal structure of a naturally found mineral. PSCs are structures made up of multilayered materials that are formed by printing, coating, or vacuuming laid down on an internal base layer. You can also learn more about Perovskite solar cells.

Benefits of Perovskite Solar Cells:

• Charge-carrier mobilities
• Create lightweight solar panels
• Hybrid-tandem partners
• Excellent Light absorption
• Optoelectronic applications
• Low production costs

Types of Perovskite Solar Cells:

• Regular n-i-p structures
• Inverted p-i-n structures
• ETL free configurations
• HTL free configurations
• Perovskite-silicon tandem architectures

How do solar panels produce electricity for your home?

You can entirely rely on Solar panels to provide electricity for your home through the following step-by-step process:

1. Absorption of Sunlight, using Solar panels installed on the roof or in an open area, absorbs sunlight during the day.

2. Photovoltaic Conversion, through which solar panel cells convert the captured sunlight into direct current (DC) electricity through the photovoltaic effect.

3. Inverter Conversion, by which the DC electricity generated by the solar panels is then fed into an inverter, further converted into alternating current (AC), mostly used in homes.

4. Electricity Consumption of home appliances is obtained from the AC electricity produced by the solar panels.

5. Surplus Electricity can be sent back to the grid if the solar panels supply more electricity than what your home requires, and this process is achieved through net metering.

6. Net metering is a billing system that makes it possible for homeowners with solar panels to claim power credits for the surplus electricity they send back into the grid. Hence, these credits can compensate for the electricity they use from the grid when their solar panels are not able to generate enough electricity (such as at night).

7. Off-grid electricity is a type of system where residential buildings are not connected to the utility grid. However, solar panels can continue to provide electricity by using a battery system. Any excess electricity generated at the end of the day is stored in batteries to use when solar production is insufficient (at night or on cloudy days). Hence, it makes it possible for homes to depend completely on solar energy for their electricity needs, even while disconnected from the grid.

Do Solar Panels work at night?

Solar panels do not produce electricity at night because they are dependent on sunlight to produce electrical energy using the photovoltaic effect. In the same way, their power to perform is greatly decreased on cloudy days.

However, the solar panel’s efficiency rate fluctuates based on factors like — weather temperatures, panel placement, sun exposure, and the different kinds of solar cells used.

What are the different types of solar panels?

Here are the 5 different types of solar panels, namely:

• Monocrystalline Silicon
• Polycrystalline Silicon
• Thin-Film Solar
• Bifacial Solar Panels
• Concentrated Photovoltaic (CPV)

The most common type of solar panels are the Monocrystalline and polycrystalline silicon panels. Further, thin-film solar panels follow it. Also, Bifacial panels and CPV systems are very less common, but it is gradually gaining popularity in a few applications.

Here is a detailed table describing the benefits of solar panels:

TYPE OF SOLAR PANEL	BENEFITS
Monocrystalline and polycrystalline panels	High efficiency Durability Long lifespan
Thin-film solar panels	Lightweight Flexible Unconventional installation areas
Bifacial panels	High energy production  Captures sunlight in both sides
CPV systems	Reflecting sunlight efficiently Efficient photovoltaic cells

What is the efficiency of solar panels?

The maximum efficiency of solar panels varies depending on the technology used. Nowadays, the highest efficiency for commercial solar panels is around 21-24% for monocrystalline silicon panels. At the same time, it is 15-20% for polycrystalline silicon panels. Recently developed technologies like — perovskite and multi-junction solar cells have already established the possibilities for higher efficiencies under the test settings in the laboratory. You can also learn about monocrystalline vs polycrystalline in detail to decide which panel would be best for you.

Factors that affect Solar Panel Efficiency are:

• Solar panel types and technologies
• Material Quality and manufacturing process
• Temperature and sunlight level
• Panel position and the tilt angle
• Shading and obstructed view
• Dust, dirt, and pollutant
• Electrical loss in wiring and inverter systems

Therefore, the solar panel efficiency rates are completely based on these above factors. However, timely maintenance and efficient system design are essential for improving the performance of solar panels.