Solar panels use the sun’s energy to power a home or building. But how does the energy get absorbed? And how does it know where to go once it’s absorbed?
This article will provide a rundown of how solar panels work so you understand how your home is getting the clean energy it requires.
What is The Photovoltaic Effect?
Solar panels provide energy through a photovoltaic effect. Each panel is made up of silicon cells. Silicon is a semiconductor that generates electricity.
Solar inverters convert the direct current (DC) produced by solar cells into usable alternating current (AC). Wires and plates capture the current and turn it into usable energy that powers your home and appliances.
Other types of solar technology do not use photovoltaics. We’ll get to them later in the article.
The Origins of Solar Energy
Before delving deeper into solar panel mechanisms, let’s talk about the sun. How does the sun produce energy?
The sun is filled with protons, or hydrogen atoms, that constantly fuse and collide. The hot temperature and pressure contribute to the collisions to create helium.
The collisions produce an astounding 500 million tons of hydrogen atoms every second. The sun emits this energy as electromagnetic radiation, which reaches the Earth in the form of photons that can be absorbed by solar panels.
When photons encounter solar panels, the panels separate the electrons from the atoms and set them in motion. The electrons produce electricity which is captured by the panels and converted into electric current. The process is known as the photovoltaic effect, a technology that plays a huge role in solar energy generation.
A Closer Look at the Photovoltaic Effect
The photovoltaic effect was first discovered by French physicist Edmond Becquerel in 1839. It is a characteristic specific to semiconductors. It allows them to generate electric current when exposed to sunlight.
The technology process can be broken down into three steps as follows:
1. Sunlight reaches the solar cells. It energizes electrons and sets them in motion.
2. The electrons flow out from between cell layers and create an electric current.
3. Metal plates and wires capture the electrons to generate usable electricity.
Solar cells are typically made of silicon, a nonmetal semiconductor that absorbs sunlight and converts it to electricity. The material is found in almost every computer. It is the most common solar cell material.
However, some solar cells are made of cadmium-telluride or copper indium gallium. These materials are commonly found in thin-film solar panels which are made by depositing thin layers of photovoltaic material onto a substrate.
Panels that use silicon will contain two layers of the material. Each layer is treated with phosphorus and boron. These positive and negative doping agents create the positive and negative sides of the cell. They form an electric field between the silicon layers.
The junction between the layers allows lose
electrons to flow through the cells and out of the electric field to generate an electric current.
Each solar cell has a metal plate on either side that collects the electrons that flow out of the electric field. They transfer them to connecting wires. They flow through the wiring to a solar inverter which converts them to usable energy and disperses them throughout your home.
Silicon Alternatives
Silicon is the most popular solar panel semiconductor, but other semiconductors may be used. They are commonly found in thin-film solar panels which are made from lightweight, flexible materials. They are so-called because they are made of light-absorbing layers that are 350 times smaller than silicon cells.
The main four types of semiconductors used on thin film solar panels are:
Cadmium telluride
Amorphous silicon
Copper indium gallium selenide
Gallium arsenide
Thin film panels feature organic solar cells that work with carbon-based semiconductor materials. Manufacturers produce them by dissolving organic compounds in ink and printing them onto thin plastics. They also go by the names “polymer solar cells” and “plastic solar cells.”
A thin film solar panel may also feature perovskite solar cells. Perovskite is a man-made material with a crystal-like structure that efficiently converts photons into usable electricity. They are built using a technique similar to printing newspapers.
Other Solar Panel Components
Solar cells are a primary contributor to electricity generation. However, other components are essential to a solar panel's functionality. They include:
Glass Casing: The glass casing protects silicon cells and increases panel durability
Insulation and Back Sheet: Both the insulation and back sheet reduce heat dissipation and protect against humidity inside the panel. The insulation also makes the panel more efficient.
Different Types of Cells
The silicon cells inside panels can be in one of two cell formations as follows:
Monocrystalline: Monocrystalline cells are made of a single silicon crystal
Polycrystalline: Polycrystalline cells are made up of silicon fragments
Monocrystalline cells provide more room for electrons to move around. They offer more efficient energy production than their polycrystalline counterpart. They are also more expensive.
How Do Solar Panels Generate Electricity in the Home?
1. Solar cells use the photovoltaic effect to produce an electric current.
2. The inverters convert DC electricity to AC electricity. The inverters may feature transformers that regulate DC and AC voltage.
3. The AC energy flows to your home’s electricity panel. The electricity is dispersed throughout your home into your outlets to power your lights, devices, and appliances.
4. Locations with net metering allow electricity to flow to and from the power grid. Excess energy reaches the grid. Utility companies provide credits for the power you send from your home reducing the cost of your electric bills.
Other Solar Technologies
Solar power produced by panels is the most common type of solar energy generation. But there are other resources available. Let’s briefly examine other systems to determine how they produce energy.
Solar Hot Water
Solar hot water systems use solar energy to heat the water in your home. The system’s components include a storage tank, heat exchanger, backup heater, controller system, and collectors.
Unlike solar panels, solar hot water systems do not rely on electrons. Rather, they use collectors which are typically installed on a rooftop. Sunlight passes through the collectors’ glass covering and reaches an absorber plate. The plate’s coating captures the solar energy and converts it to heat.
The heat is infused into a transfer fluid of either antifreeze or potable water which lives in the plate’s small pipes. The pipes transport the liquid throughout the home.
Concentrated Solar Power
Concentrated solar power is often used to generate energy on a larger scale. Utility companies use the technology to power the electricity grid as a sustainable alternative to fossil fuels.
Like solar hot water, CSP transforms sunlight into heat. It uses mirrors that reflect the sun and directs it to an absorber or receiver that collects and stores heat.
Can a Solar Panel Power Your Entire Home?
A solar panel can power an entire home. However, likely, it will not cover all your energy usage.
The amount of energy produced will depend on your home’s location. If you live in a sunny climate and your roof absorbs optimal sunlight, your panels will produce enough energy to be a worthwhile investment. If you live in a cloudy area, or if your rooftops are shaded by trees or structures, your panels will not produce a lot of electricity.
A storage device or battery backup will store energy, so you don’t have to rely on the grid when the sun isn’t out. However, the stored energy can eventually run out.
If You Have Solar Panels, Do You Still Get an Electric Bill?
Yes, you still get an electric bill, even if you have solar panels. However, if your solar panels generate enough energy to power your home throughout the month, your solar bill may be zero.
In some instances, solar panels may even produce excess energy. If this is the case, you can save even more money through net metering.
Net metering allows you to sell the energy you don’t use back to the utility company. They will pay you in the form of credits that make energy use even more affordable.
Do Solar Panels Work at Night?
There are energy sources that can power your solar panels at night. However, the generated energy will be very low. If you have a battery backup, it will store the energy collected during the day, transform it into electrical energy, and use it to power your home at night. It will work as an alternative to your solar panels.
Will My Solar Panels Save Me Money?
Solar panels can be a money-saving solution. The amount you save will vary depending on your location, the cost of your system and installation, and other factors.
Solar America ensures optimal profitability by directing you to the most affordable local installers. We work with the top installation companies in the country. We offer free quotes and no obligation to buy.
Contact us at 1-855-999-6970 or sign up for our convenient service. We will help you get the most from your solar power installation.
