Materials that Make the Perfect Solar Panel

olar panels are becoming a common sight, and they're doing an impressive job of turning our sunny days into a powerhouse of renewable energy. But, ever wondered what goes into the production of these shiny marvels?

In this article, we're going to crack open the mystery of solar panel manufacturing. We'll delve into the key materials that give these panels their power, and we'll also peek into the exciting new materials that are just on the horizon.

Embracing Solar Energy as a Vital Solution

Solar power is enjoying increasing global popularity for several compelling reasons. Here are some key factors driving the growing adoption of solar energy:

• Safe Energy: The increasing global demand for solar stems from the need for environmentally friendly and safe power sources. Solar energy produces minimal air pollutants, as photovoltaic (PV) panels generate electricity without emitting greenhouse gases or harmful substances, making it a clean and safe energy option.
• Cost-Effective Investment: The use of solar energy has emerged as the most cost-effective choice for new electricity generation in many regions worldwide. The declining costs of solar panels have made residential systems more affordable, with average prices ranging from $17,430 to $23,870 in the U.S. Moreover, it is anticipated that PV electricity generation costs will decrease by an additional 60% by 2040, establishing solar as the most affordable method for electricity production across many regions.
• Renewable and Abundant Energy Source: Solar power is derived from sunlight, a renewable energy source that can be replenished. With enough sunlight reaching the Earth's surface every hour and a half to meet global energy needs for an entire year, solar panels offer a sustainable solution.
• Versatility and Scalability: Solar energy can be harnessed for various applications, from powering individual homes and businesses to providing electricity in remote locations. Its scalability enables it to be used for both small devices and large-scale power plants.
• Environmental Benefits: The utilization of solar energy is beneficial for improving air quality and for reducing water usage in comparison with other forms of energy production. By generating electricity without producing air and water pollution, solar power indirectly contributes to a healthier environment by reducing reliance on more environmentally harmful energy sources.
• Job Creation: The solar industry has turned out to be a significant contributor to job creation. The US Department of Energy reported that the growth rate for energy jobs surpassed that of general U.S. employment in both 2021 and 2022. Job growth in the solar sector is also observed globally, with countries like China, India, and various European nations experiencing employment opportunities.
• Technological Advancements: Ongoing innovations in solar technology are driving progress in the industry. Enhancements in efficiency, energy storage, printable solar technology, and solar design are making photovoltaics more accessible and efficient, meeting the growing need for sustainable power generation.

The What, How, and Why: Materials Used to Make PV Panels

Have you ever been curious about what lies behind the scenes when you see solar panels shining in the sunlight? Do you ever wonder about the materials and technology used to enable these devices to function? Let's take a closer look at the solar panel material list.

Silicon: The Solar Superstar

Silicon is, without a doubt, the star of the solar panel show. Approximately 95% of all solar panels in production today are made from silicon-based PV cells. So why is silicon so special?

The secret lies in its atomic structure. Silicon belongs to group 14 of the periodic table, meaning it has four valence electrons. When a photon from the sun hits a silicon atom, it can impart enough energy to knock one of these electrons loose. The freed electron can then move freely, generating an electric current. This property is the fundamental mechanism through which solar panels convert sunlight into electricity.

Solar panels commonly use two primary types of silicon: monocrystalline and polycrystalline. Monocrystalline silicon is made of a single-crystal structure, providing the electrons more room to move, resulting in a higher efficiency. On the other hand, polycrystalline silicon has a multi-crystalline structure, which gives it a lower efficiency but at a reduced cost.

Metal Components: Holding Everything Together

Behind the scenes of the high-tech silicon solar cells, there are the less glamorous but equally important metal components that hold everything together. Metal frames, usually made of anodized aluminum, provide structural support to the solar panels, making them durable and resistant to various weather conditions.

Copper is another material commonly used metal in solar panels, primarily found in the wiring and bus bars, responsible for conducting the electricity generated by silicon cells. Copper's superior conductivity and resistance to corrosion make it an ideal choice for this purpose.

Silver is often utilized in the form of a paste that's applied to the front of the solar cell, where it helps to collect the electrons and transport them out of the cell. Despite its cost, silver's excellent conductivity and stability have made it a necessary material in high-efficiency solar panels.

Glass and Plastic: Enhanced Protection and Efficiency

Typically, solar panels use tempered glass as the top layer, offering a durable and transparent surface that allows sunlight to reach the silicon cells while providing protection against environmental factors like hail, rain, or wind.

Typically, a layer of plastic (commonly EVA - ethylene-vinyl acetate) is used beneath the glass and silicon cells, serving various functions. Firstly, it provides insulation, helping to protect the PV cells and metal components from environmental damage and electrical shorts. Secondly, it encapsulates the cells, aiding in their longevity by preventing moisture and dirt from infiltrating the system. Lastly, its light-transmissive properties enable maximum light exposure to solar cells, enhancing their efficiency.

To wrap up, a backsheet (usually a polymer or plastic material) is added to the bottom of the panel, providing further protection against humidity and ensuring electrical safety.

Behind the Scenes: How Solar Modules Are Made

From Sand to Silicon: The Preparation Process

The journey of creating solar panels begins with the use of a very common material - sand. More precisely, it's the quartz in the sand, as it's rich in silicon dioxide. It undergoes a process of high-temperature heating in an electric arc furnace alongside carbon, which reduces it to metallurgical-grade silicon. This is further refined to remove impurities, resulting in very pure silicon - a critical component of solar panels.

Next, the purified silicon is melted and carefully cooled to form silicon ingots, using a process called the Czochralski process. The ingots are then sawed into thin, wafer-like pieces. These wafers are doped with impurities like boron or phosphorus to create an electric field within the silicon, an essential characteristic that allows a solar cell to work.

Panel Production: The Assembly Line

After preparing the silicon wafers, they are coated with an anti-reflective layer to help absorb more sunlight, typically silicon nitride. Once coated, metal conductors are printed onto the silicon wafer in a grid-like pattern. These conductors will collect the electrons that are knocked loose from the silicon by photons in sunlight.

These wafers turned into cells are then assembled into a solar panel. The cells are connected together in series, creating a circuit. They are then encapsulated in protective materials, typically EVA (ethylene vinyl acetate), and a sheet of tempered glass is added on top to protect the delicate cells. Finally, the entire assembly is framed for easy installation.

Peering Ahead to the Future of Solar Tech

While silicon-based panels have been the mainstream choice for decades, the future of solar technology is constantly evolving, promising more efficient and cost-effective solutions. For instance, perovskite solar cells have shown the potential to outperform traditional silicon cells in terms of efficiency and cost. Thin-film technology is another area with growing interest due to its light weight and flexibility, allowing for integration into various surfaces and structures.

Furthermore, scientists from Colorado State University are putting forth a proposal to create solar cells using molybdenum disulfide, a natural material that is abundantly found. This substance holds the potential to increase the efficiency of solar panels twofold, providing a multitude of opportunities to explore in the industry.

Wrapping It Up: The Exciting Future Awaits for Solar

Unraveling the complexity behind solar panels, we’ve seen how each component, from silicon cells to metal frames and protective layers, play a critical role in harnessing solar energy. But as we gaze ahead, it’s clear that the future of solar technology will not merely be a continuation of what we know today. Emerging technologies like perovskite solar cells and thin-film technology promise to break new grounds in efficiency and versatility.

Additionally, the possibility of creating solar cells using abundant materials such as molybdenum disulfide to develop PV cells holds the potential to bring about a revolutionary transformation in the solar industry, potentially doubling the efficiency of our current models. As we wrap up, let's remember that we are at the dawn of an exciting era for solar tech, where the innovations of tomorrow could redefine our understanding of solar energy and its potential.

Sources:

https://www.energysage.com/

https://innovationorigins.com/en/

https://www.energy.gov/

https://phys.org/news/