Across the past two decades, going solar is no longer a fringe idea, and has become the world’s favorite source of power. In fact, according to the International Energy Agency, solar power is the fastest-growing power source in the world.
Simply put, solar power is the usable energy harnessed from the sun that is converted into thermal or electrical energy. Today, it is considered the earth’s cleanest and most abundant resource of energy.
The solar hype, understandably so, makes you wonder how going solar can be so efficient and budget-friendly while giving you “green” energy.
We love solar. Yes, we do! So in this article, we will break down how are solar panels made, and yes, until the very atom of it! Let’s geek out!
A Brief History
Work in solar energy can be traced back as early as 1839. A young French physicist, Edmond Becquerel discovered the conversion of sunlight into solar electric energy known as the photovoltaic effect. This breakthrough led American inventor Charles Fritz to create the first working selenium solar cell in 1883 that would later develop into the solar panel we now know today.
Years went on and advancements in solar cell technology made steady, small steps. The biggest leap came around 1954 when a trio from Bell Laboratories in the name of chemist Calvin Fuller, physicist Gerald Pearson, and engineer Daryl Chapin built the first silicon solar cell.
At first, solar panel systems found mainstream use in space satellites but later on adoption of solar power as a viable source of electricity to power up homes and commercial buildings became popular.
What’s Inside: How Do Solar Panels Work?
A solar panel is an assembly of solar cells that convert sunlight into electricity. But have you ever wondered how it produces electricity?
Solar panels are made up of photovoltaic cells or solar cells, which are composed of silicon atoms. See? I am not kidding when I told you we’ll talk about atoms. The solar cell has two types of silicon atoms: p-type such as boron (which is a positive charge) and n-type (which is a negative charge) like phosphorus.
When light is absorbed and interacts with a solar cell, electrons are now set in motion thus, initiating a flow of electricity. This whole process is known as the Photovoltaic Effect.
In simpler terms, let’s just say that the electricity conversion is achieved thanks to the good semiconductor material, silicon.
A single solar cell generates 0.5V of electricity. As the number and size of a solar cell increases, thus, the voltage. However, silicon alone will not be fully functional to power up your home unless it is paired with metal casing and wiring. So generally, a set of photovoltaics put together form a solar panel.
The more solar panels you have, the greater amount of electricity you generate.
How Are Solar Panels Produced?
A solar PV module is composed of solar cells, glass, EVA or ethylene vinyl acetate, backsheet, and aluminum frame. To learn more about the solar panel manufacturing, first, we need to know the three main types of solar panels:
Mono vs Poly vs Thin Film Solar Panels
- Monocrystalline Solar Panels
Monocrystalline solar panels offer higher efficiency and sleeker aesthetics, thus, is considered the premium solar product. It is produced from a single crystal of silicon making it more efficient than its counterparts. Also known as single-crystalline, it is easily identified by its distinct black hue.
- Polycrystalline Solar Panels
Polycrystalline solar panels also referred to as “multi-crystalline” or many-crystal silicon since it is made up of multiple melted silicon fragments. Due to the number of crystals in each cell, electrons have less freedom to move to result in its lower efficiency but also making it cost less. This solar panel type was the first to be presented in the solar panel market at the beginning of the 1980s. It can be easily identified for its square-shaped polycrystalline and bluish hue.
- Amorphous silicon or Thin Film Solar Panels
A thin-film solar panel is a second-generation solar panel that is non-crystalline and is made up of micron-thick photon absorbing material layers onto a flexible substrate like glass, plastic, or metal. True to its name, thin solar panels are lightweight and flexible but compared to monocrystalline and polycrystalline solar panels it lags in terms of efficiency and performance.
Solar Panel Manufacturing Process: A three-step guide
Mono and poly solar panels dominate the solar panel market and both have a somewhat similar manufacturing process. Here’s a three-step guide on how it goes:
Step 1: Creating Silicon Ingots
Silicon is the key ingredient in making solar panels since pure silicon is a great semiconductor. Luckily, silicon is the earth’s crust’s second most common element. However, pure silicon is too reactive to be found in nature so people obtain silicon dioxide (SiO₂), otherwise known as quartz instead.
To extract silicon, the rocks of solid quartz are heated with carbon at temperatures approaching 2200°C.
Now, remember the silicon atoms awhile ago? Yeah, they are back for the process called doping. Pure silicon is an insulator. It needs to be turned into a semiconductor so it must be given positive (p-type doping) and negative charges (n-type doping).
After intense heating, the silicon cools into cylindrical ingots. One silicon crystal is used for a monocrystalline silicon ingot, on the other hand, multiple silicon crystals are used for a polycrystalline silicon ingot.
Step 2: Cutting Ingots into Wafers
Imagine using a knife to cut onions into thinly-sliced pieces. That’s basically what happens, except in this process a wire saw is used for precision-cutting of silicon ingot called wafers.
The chunky ingots of silicon will be trimmed down into paper-thin slices and will be cut into rectangular or hexagonal shapes to ensure that it will fit together like puzzle pieces.
Once the silicon wafers are ready, it’s time for the combination of boron (p-type) and phosphorus (n-type) called the P/N junction, which is crucial for the proper function of a PV cell.
Now, we’re almost done in this process! Well, almost. Pure silicon is naturally shiny and it reflects as much as 35% percent light from the sun. To reduce the amount of sunlight being lost, an anti-reflective coating – either silicon oxide or titanium dioxide is applied.
Step 3: Building the Solar Panel
The third and final step in manufacturing is assembling the solar panel itself. Solar panels are made up of solar cells soldered together in a matrix-like structure using metal connectors, which allow the electricity to travel between cells and into the solar inverter.
Once the wafers are connected, it is then sealed to a backsheet made of highly durable, polymer-based material to prevent water, soil, and unwanted materials from entering the panel from the back. A thin 6-7mm layer glass is added on top and a junction box to enable connections inside the module is added on the side.
As a finishing touch, manufacturers add a sturdy aluminum frame. The use of a frame protects the panel against impact and weather. It also allows the panel to be mounted in a variety of ways.
Is Solar Panel Production Harmful To The Environment?
Solar energy systems have been proven to be a form of clean, renewable energy that helps combat climate change. However, manufacturing solar panels has environmental drawbacks.
Solar PV cell production involves toxic materials and chemicals such as sodium hydroxide and hydrofluoric acid as well as the involvement of water and electricity in which emits greenhouse gases. Solar panel manufacturing also produces toxic wastes that could reach 78 million metric tonnes by 2050 according to the International Renewable Energy Agency (IRENA).
Does Solar Power Come With High-Environmental Cost?
As the world continues its initiative to fight climate change, the demand for solar energy will be on the rise. There are talks about perovskite as a superior alternative and transparent solar panels, which involve a slightly different production process but all of these are in their early phases. One thing is for sure, the solar industry will keep on upping its technology to lessen the environmental blow of solar panel production.
Can you build your own solar panels?
If you’re an adventurous homeowner and might be wondering if you can build a solar panel system by yourself, well I have good news for you! You can definitely go for a DIY solar installation.
- Building your own solar panel would save you money on the high upfront installation cost.
- If you’re someone who’s up for a challenging DIY project, then a solar installation is the right fit for you. It would require many different stages such as research, planning, installation, etc. but it sure will give you DIY satisfaction once it’s completed.
- It would require more work on your end.
- Risk of roof or damage leaks since solar installation would involve drilling a large number of holes on your roof.
- Well, there are also physical dangers. You will need to get on your roof and connect some wirings.
Of course, DIY solar energy systems won’t be easy but it is definitely rewarding and doable. To know more about DIY solar systems, check our guide.
Arming yourself with the right information about a product you’re interested in, even if it involves scientific explanations, is a sign of being a smart consumer.