Artem Sokol

02/24/2021

Writing for Engineering

Technical Description

Solar Panels

A solar panel is a mechanism that is used to create electricity. The function of a solar panel is to capture the solar energy produced by the sun and its beams and convert that solar energy into a usable form of energy known as electricity. A solar panel looks like a large almost glass like sheet that is divided into grids. Solar panels come in a variety of shapes, colors, and sizes, the three most popular types of solar panels are Monocrystalline, Polycrystalline, and Thin-Film. Each solar panel variation has a particular advantage/disadvantage, but the function and process of how they complete that function is the same for all variations. The principal parts of any solar panel are photovoltaic cells which are made up of silicon a conductor, metal frame/casing, sheet of tempered glass, an encapsulant usually made of Ethylene Vinyl Acetate (EVA), a conductive wire, and an inverter. Some solar panels may also contain batteries to store excess energy. The solar panel works by capturing and storing light from the sun, this light is comprised of particles that are used to knock electrons free from their molecules. Once the electrons are free the metal casing is used to direct the electrons towards a conductive wire. Once the electrons flow through the wire and into the inverter, a usable form of electricity is created. A solar panel is a conglomerate of photovoltaic cells, which are too weak to create a desirable quantity of energy on their own. Solar arrays are then created by placing multiple solar panels in one system.

Photovoltaic cells and their components:

Tempered glass-

In a photovoltaic cell a sheet of tempered glass is used as a top covering. The tempered glass has one main task and that is to protect the more fragile and expensive components underneath it. Tempered glass is four times stronger than regular glass and much safer. Furthermore, tempered glass is transparent, and it captures almost all the sunlight that passes through it.

Metal casing-

A photovoltaic cell is covered from the top by a sheet of glass and covered on the sides and from the bottom by a metal casing. The metal casing can not cover the top of the cell because it is not transparent, and no sunlight would be captured. The casing is meant to protect the cell, but its main task is to act as a conductor and direct the escaped electrons to a conductive wire.

Silicon conductor-

Arguably the most important component of a photovoltaic cell is the silicon layer. The silicon layer creates an electrical field, in which the positively charged particles the protons and the negatively charged particles the electrons are constantly attracting and repelling one another creating particle movement and thus an electrical field. Not all photovoltaic cells use solely silicon layers, some may incorporate other elements such as gallium and arsenic in hopes of creating a more potent electrical field and thus generate more electricity. Silicon is however more affordable and attainable and is the most commonly used element in photovoltaic cells.

Encapsulant-

An encapsulant sandwiches the silicon layer from the top and bottom. The encapsulant has multiple functions in a photovoltaic cell. The encapsulant serves as an adhesive to connect the top layer and lower layer of the cell. An encapsulant is also used to prevent moisture from developing inside the silicon layer which can damage or ruin the entire cell. The encapsulant’s most important function is providing transmissivity and ensuring that no light escapes from the cell. The silicon layer of the cell is reflective and as a result a large percentage of the light captured would simply reflect and escape the cell. The encapsulant is specifically designed to have almost no reflectivity and therefore ensure a minimal amount of light is lost. The encapsulant is designed to have a high electrical transmissivity, this allows for electrons to freely flow through the medium. If the encapsulant did not have a high transmissivity the freed electrons would not be able to escape the silicon layer and no electricity would be generated.

Conductive wire-

The only function of the conductive wire is to provide a path for electrons to leave the photovoltaic cell and direct them to the inverter which is connected to the cell. The wire is conductive to allow a free and easy flow of electrons.

Inverter-

When the electrons are freed from the silicon layer, they create electricity in the form of a direct current. A direct current is useless for everyday electrical appliances, which only operate with an alternating current. The function of the invertor is to change the direct current into an alternating current which can be used for all electrical necessities.

Conclusion:

When all the components of the photovoltaic cell are put together the magic happens. Solar energy from the sun in the form of visible light passes through the transparent tempered glass covering on the surface of the cell. The light then passes through the encapsulant and into the silicon layer. The silicon layer is made up of an electrical field which is caused by the movement of positively charged protons and negatively charged electrons. The light from the sun is comprised of particles including positively charged photons. Through the law of attraction, the positively charged photons are attracted to the negatively charged electrons. When the photons collide with the electrons, they dislodge them from the silicon atom and the electrical field. The “freed” electrons then pass through the transmissive encapsulate and are attracted to the conductive metal casing that surrounds the cell. The metal casing allows for electrons to flow through it freely and directs it to the conductive wire which is attached to the cell. Once the electrons are out of the cell, they flow through the wire which is connected on the other end to an inverter. The inverter then transforms the electron’s direct current into an alternating current, which is the type of electricity that is used in most electrical appliances. Finally, once the electricity has been changed to an alternating current the inverter delivers the electricity to the user/consumer.

Solar panels provide three massive benefits for the consumers who choose to invest in solar energy. The first benefit and the most overlooked is the financial aspect of purchasing solar panels. Although the upfront costs of purchasing and installing solar panels may seem unflattering, in the long-term solar panels save their consumers a lot of money. Rather then consuming the energy provided by the government and their third-party energy suppliers, owners of solar panels have an independent source of energy. Owners of solar panels save hundreds on their monthly utility bills compared to consumers who still depend on energy provided by their local municipalities. Furthermore, owners of solar energy often sell their excess energy and can receive immediate compensation, further reductions on their utility bills, and in certain situations even tax breaks from their state government.

The second benefit of solar panels is the most obvious, they provide a form of clean energy. Fossil fuels create dangerous and toxic gases that deteriorate our atmosphere and create hazardous environmental effects such as air/water pollution, land degradation, and climate change. Many people choose to overlook these negative attributes of non-renewable energy because they believe fossil fuels are cheaper, more effective, and easier to monetize. Unfortunately, if we do not begin to acknowledge the negative effects of non-renewable energy, we will run out of clean land, water, and air, long before we run out of fossil fuels. Solar energy provides a clean and safe alternative. Solar panels are solely reliant on the light produced by the sun and leave no negative side effects on our environment.

The third and final benefit of solar panels is arguably the most important. By investing in solar energy, you are investing in the future. Whether people want to admit it or not we are burning through fossil fuels at unparalleled rates. With technology at the forefront of society our energy requirements have skyrocketed, and we burn fossil fuels almost religiously. Fossil fuels are in limited supply and require millions if not hundreds of millions of years for new ones to be created. It is simple logic that if our energy requirements continue to rise and our main source of energy continues to be depleted, we must find an alternative form of energy to both satisfy our needs and take the burden off our limited and non-renewable sources of energy. Solar energy is the long-term solution to our problem. Solar energy is easily renewable and as long as the sun is shining our supply is vast and almost unlimited. Investing in solar energy now, will save consumers significant amounts of time, worry, and money in the future. Transitioning to solar energy may seem difficult and tedious now, but in the future solar power has the potential to prevent a global energy crisis. Solar panels provide a cost efficient, clean, and renewable source of energy. Solar energy is the future of energy.

Diagram:

The above diagram displays how a completed solar panel looks. In this diagram the silicon layer component is referred to as the “Crystalline Cells”, as the silicon used in solar panels is often in a crystal form. The metal casing component is referred to as the “Frame” in this diagram. The “Junction box” displayed in the image is where the conductive wire component travels through and ultimately reaches the inverter which is not displayed in this diagram. The inverter is not included in the diagram because the inverter is usually positioned outside of the solar panel system and is connected to the system through the conductive wire and junction box. The encapsulant and tempered glass components are also both shown in the diagram.

Citations:

Richardson, Luke. “How Are Solar Panels Made? Parts of a Solar Panel: EnergySage.” Solar News, EnergySage, 16 Feb. 2021, news.energysage.com/what-are-solar-panels-made-of-list-of-solar-pv-materials/.

“Why Solar Panel Glass Is Very Important When Choosing Solar Panel Type?” Power From Sunlight, 27 Sept. 2017, www.powerfromsunlight.com/why-solar-panel-glass-is-very-important-when-choosing-solar-panel-type/.

“Module Materials.” PVEducation, www.pveducation.org/pvcdrom/modules-and-arrays/module-materials.

Montgomery, James. “New PV Module Encapsulation Materials Led By New Cell Types.” Renewable Energy World, 9 Sept. 2019, www.renewableenergyworld.com/solar/new-pv-module-encapsulation-materials-led-by-new-cell-types/.

Anand, Amod. “What Are Solar Panels? All You Want to Know About Solar Power System.” LOOM SOLAR, LOOM SOLAR, 7 Feb. 2018, www.loomsolar.com/blogs/news/what-are-solar-panels-all-you-want-to-know-about-solar-power-system.

“The Hidden Costs of Fossil Fuels.” Union of Concerned Scientists, 15 July 2008, www.ucsusa.org/resources/hidden-costs-fossil-fuels.

“Don’t Believe the Naysayers – Solar Benefits Do Outweigh the Costs.” NuEnergen, www.nuenergen.com/dont-believe-the-naysayers-solar-benefits-do-outweigh-the-costs/.