For many of us, the image of a solar panel represents sustainability, progress, innovation, and a brighter, cleaner future. With the rise of solar technology in recent years, solar panels and photovoltaic (PV) cells have become synonymous with eco-friendly technology and the environmental movement. But, are solar panels truly “clean”?
Some naysayers suggest that solar panels are not, in fact, as clean as they are purported to be. This is because solar panels are, allegedly, built with components and metallic elements that are rare, unsustainable, or indirectly aligned with the fossil fuel industry.
When we first caught wind of this argument, we knew that we had to put it to the test. That is why our experts spent days researching every component of modern solar panels—to provide you, our readers, with an in-depth report on every aspect of solar panel construction and the various materials required throughout their supply chain, from end to end.
But First, What AreSolar Panels, Exactly?
Before we ask the question, what are solar panels made of, we should first ask what solar panels are. Although the answer may sound self-evident at first, the reality is much more complex than most assume.
In short, solar panels are the most basic component of solar energy. Well, except perhaps for the sun. Solar panels, also known as photovoltaic (PV) panels, absorb sunlight and convert the photon energy particles found within it into electricity. Until the electricity is ready to be used in a device, it is stored in a simple lithium-ion battery.
Today, solar panels are most commonly used to supply power to off-grid locations, such as wilderness cabins, camping sites, and remote research centers. However, it is becoming more common for solar panels to be found on residential properties in urban and suburban areas. Every year, an increasing number of homes are switching to solar energy for their energy needs—thanks, almost exclusively, to advancements made in solar panel technology.
A (Brief) History of the Solar Panel
The question what are solar panels made of is a multifaceted one. This is because solar panels have been made of different substances throughout their history. Although many people assume that solar cell technology is a recent invention of the 21st century, solar panels have existed for over a century.
The young French physicist Edmond Becquerel first discovered the photovoltaic effect in 1839, which is the physical process by which sunlight converts to electric energy. Later that century, this scientific discovery would lay the foundation for Charles Fritts’ first-ever solar cell, which was made of selenium sheets and gold.
It was not until the 1940s in the United States when the first modern silicon-based solar panel was made by Russel Ohl. In the following decade, solar panels made of silicon started to become mass-produced and, by the 1970s, were incorporated in regular consumer devices such as calculators. Thus, the modern solar panel was born.
Wait, How Do Solar Panels Work?
Without knowing how solar panels operate, there is little good in knowing what are solar panels made of. Although we are due to admit that the physical processes associated with the photovoltaic effect are beyond the scope of this article, we will provide a simplified overview of the basic solar and PV-related operations.
Solar panels are composed of rows of solar cells. These solar cells are made of silicon, phosphorus, and boron. These materials are picked for important reasons. First, the phosphorus provides a negative electric charge and, second, the boron provides a positive charge. Together, they provide a neutral charge to the panel.
The cells on solar panels take in sunlight and isolate the photons found within it. From there, the panel can generate an electric current. Now, here is where it gets complicated. When the photons hit the solar panel, the electrons attached to the photons are ejected from their atomic orbits and are released into the electric field.
When a solar panel is connected to a power grid, such as those available in well-developed towns and cities, excess energy is stored in the main grid. Power metering devices allow for solar panels to provide energy during the nighttime hours when sunlight is unavailable.
In solar systems that are not attached to municipal power grids, excess energy is stored in battery banks. These battery banks are relatively new technologies that are under constant reconfiguration, so it can be difficult to provide a clear description of this aspect of solar panels.
Regardless of the configuration used, solar cells will send a solar array composed to direct current (DC) electricity to a battery bank at the opposite end. With the help of an inverter device, solar arrays are scaled down or up to the size required to meet the energy demands of the user. All excess energy is stored in the batteries within the battery bank for later use.
How Much Do They Cost?
The cost of a solar panel will depend on one’s geographical location and the size of the panel they want. Plus, it can be difficult to accurately predict solar panel prices because, in recent years, the cost of solar technology has dropped considerably. Better yet, federal, state, and municipal tax credits and financial incentives are now available which lower the cost even more.
As a rough estimate, however, it can be safely assumed that an installed solar panel costs between six and nine US dollars per watt. In other words, a 10-kW system might cost anywhere from 60 to 90 thousand dollars. However, this figure is arrived at without considering tax credits or rebates. We recommend checking in with your local authorities to see if there are any incentives for solar panel acquisitions and installations in your area.
What Are Solar Panels Made Of
Now that we understand the essentials of solar technology, we can finally answer the question what are solar panels made of. If you have been following along closely until now, you might have already realized the three main components of modern solar panels. The three main components of a solar cell are:
However, these three elements merely provide the chemical-physical basis to allow the photovoltaic effect to take place. In other words, you need the positive and negative charges provided by the boron and phosphorus, respectively, to convert sunlight into an electric current that is usable in consumer devices.
But, solar panels are made of more than just these things alone. Rather, there are several key aspects of solar panels that do not often get included in discussions of solar technology. We have provided a list of them below:
- Aluminum frame
- Sheet glass casing
- 12V electrical wire
- Bus wire
- Ethylene-vinyl acetate (EVA)
Without the components listed above, it would be impossible to manufacture a complete, fully-functional panel. Although the solar cells themselves are made of silicon predominantly and charged with the chemical elements of boron and phosphorus, basic materials such as glass and aluminum are also required to make the finished product.
Silicon: The Key Ingredient
There is no material used in the making of a solar panel that is more important than silicon. Many of us are familiar with silicon because of its ubiquitous usage in Silicon Valley, also known as the technology capital of the world. This is because silicon is used in the manufacturing of computer chips and processors. But, this same material is also used to make solar cells.
There are several kinds of silicon that are used to make different types of consumer products. However, the type used in the production of solar panels is called crystalline silicon (c-Si). In total, there are three distinct types of silicon materials, which are:
- Crystalline silicon (c-Si)
- Multicrystalline silicon (multi-Si)
- Monocrystalline silicon (mono-Si)
In the production of silicon wafers used in the production of solar technology, the first, c-Si, is by far the most commonly used. As a material, silicon is structurally unique because it is a semiconducting material. In other words, it has an electrical conductivity value that falls between that of a conducting material, like gold or copper and an insulator like glass.
Why is a semiconductor like silicon important for energy-related technology? Because as their temperature increases with the absorption of sunlight, their resistance decreases. In this way, silicon makes for a highly efficient and safe material for energy to pass through and switch between.
The beauty of silicon-based manufacturing is that, like aluminum, silicon is one of the most highly abundant materials on the planet. Luckily for us, the key ingredient in the formation of solar panels is a sustainable and affordable substance that will likely not run out any time soon. That’s why you can rest assured knowing that solar materials are equally as sustainable as the technology they support.