A new solar project was just installed in the US.
You can find more information on our web, so please take a look.
Set a timer for 60 seconds and wait. Maybe take a step outside and soak up some sunlight.
Zing!&#;another solar project was just installed.
The sun is shining on the solar industry; the numbers are impressive. Today, there is enough solar capacity in the US to power the equivalent of 23 million homes, according to the Solar Energy Industries Association (SEIA). That&#;s 126 gigawatts (GW), coming from millions of solar systems across the country.
The US solar industry was valued at $33 billion in , employed more than 230,000 people, and continued to grow in power capacity at an average rate of 33 percent per year.
Solar panels generated almost 4 percent of electricity in the US in , up from less than 1 percent in . In some places that number is much higher; for example, 17% of California&#;s electricity generation came from solar in . Almost half of all new energy capacity added to the US grid in came from solar. Even more encouraging, by , the solar industry aims to generate nearly a third of US electricity.
With so many solar panels planned for the coming years, you might be wondering: what exactly are solar panels and how are they made?
There are two types of solar technology for electricity generation. The most common are photovoltaic (PV) panels or modules, which use the sun&#;s light to make electricity. Another technology, concentrating solar power (CSP), uses the sun&#;s heat instead.
The most common type of PV panel is made using crystalline-silicon (c-SI). That technology accounts for 84% of US solar panels, according to the US Department of Energy. Other types include cadmium telluride, copper indium gallium (di)selenide panels, and thin-film amorphous silicon. Because c-SI panels compose most of the US and global market, I focus on them in this blog.
What&#;s in a solar panel? By weight, the typical crystalline silicon solar panel is made of about 76% glass, 10% plastic polymer, 8% aluminum, 5% silicon, 1% copper, and less than 0.1% silver and other metals, according to the Institute for Sustainable Futures. Graphic: UCS.Building a crystalline silicon solar panel is a bit like building a sand castle, because silicon comes from sand! Beach sand is silicon dioxide, aka silica. (If beach patrol put that on a warning sign, I bet no one would step foot on the beach!). Silicon, in the form of silicon dioxide sand and gravel, is the second most abundant element on Earth, next to oxygen.
Before it&#;s used in a solar panel, silicon dioxide must be turned into pure &#;metallurgical grade silicon&#; (MGS). This process uses a lot of energy: producing 1 kilogram of metallurgical grade silicon requires 14-16 kWh of power, which is roughly equivalent to using your home oven for seven hours. Still, over their lifetimes, solar panels emit 25 times less carbon dioxide equivalent per kilowatt hour than coal-powered electricity.
Chemistry break! The recipe for cooking up metallurgical grade silicon is
Add 1 part silicon dioxide (gravel) and 2 parts carbon (sourced from coal, charcoal, or wood chips) to an electric arc furnace
Crank up the heat to degrees Celsius (this is a third of the temperature of the sun!!)
Ta-da! You&#;re left with 99% pure silicon and carbon monoxide (that&#;s from the carbon we added, bonded to the oxygen we removed from the silicon dioxide)
But solar panels are perfectionists; they demand silicon to be close to 100% purity. To achieve that, we need to upgrade the silicon into an even more pure polysilicon metal using a process that involves hydrochloric acid and hydrogen gas. (Fun fact: about 12% of the world&#;s silicon production is currently processed into polysilicon for solar panels.)
Source: UCSAfter adding the acid and gas, we are left with chunks of polysilicon metal, which are typically melted down again in a roughly 5-meter-long cylindrical mold. Boron is added to give the metal a positive electric charge on one side. The hot, melty silicon cools and forms a single crystal (&#;monocrystalline&#;) structure as a cylindrical ingot. Ingots are any material cast into a rectangular shape, like bars of gold.
(Another process is used to make &#;polycrystalline&#; silicon wafers, in which multiple crystals form. This process tends to lead to less efficient panels but can reduce the cost of wafers.)
Next, a wire saw cuts the pure metal blocks of polysilicon into paper-thin, typically 7-inch by 7-inch flat slices called wafers.
Source: UCSThe wafers are heated in an oven and a thin layer of phosphorous is added, giving one side (the opposite of the positive boron side) a negative charge. Next, an anti-reflective coating is added to the wafers because without it these shiny disks reflect sunlight&#;and we want them to absorb it instead. At this stage, the wafers are now capable of absorbing the sun&#;s energy and converting it into electrons. Now we need to add silver metal conductors so those electrons can get turned into an electrical current that devices can use!
Silver&#;the most conductive element in the world&#;intercepts the electrons in the silicon wafers and turns them into current. The silicon wafers now form a conductive solar cell. Each solar panel, usually containing 60 or 72 cells, uses about 20 grams of silver&#;a fraction of the panel&#;s weight but about 10% of its total cost.
Copper metal conductors and wiring connect the solar cells together into one big solar panel, giving it the classic matrix appearance. Copper is a good electrical conductor and very malleable, making it a great material for forming the wiring that moves the current through the panel.
Workers install a completed solar panel. Photo credit: GRID Alternatives.Zap! A solar panel has been made.
Now multiply it by about 60 million for the US alone, each year.
And then speed it up because we need solar to play an ever-growing role in achieving our clean energy and climate goals.
There&#;s a lot that goes into making solar happen beyond building panels, but responsibly accelerating solar panel manufacturing and installation is a critical step in the journey towards a just, sustainable renewable energy future.
Want to learn more about the solar panel supply chain? Which countries are driving PV material mining and PV manufacturing? What does the solar panel repair and reuse industry look like today? How can we recycle solar panel materials and create a lower-waste circular supply chain? Click the links for answers!
Mining Raw Materials for Solar Panels: Problems and Solutions
Solar Panels Should Be Reused and Recycled. Here&#;s How
Why is electricity more expensive than gas?
Everything you need to know about the Warm Homes Plan
&#; The solar cells in traditional solar panels are made of crystalline silicon
&#; Solar cells are stuck onto a clear pane and connected with metal wires
&#; A backsheet and frame are sealed onto the clear pane to form an airtight unit
Making a solar panel is a somewhat complicated process, which involves several steps. This explains why solar panels cost a decent amount of money.
We&#;ll break down how solar panels are manufactured and explain the different steps in this article. We&#;ll also go over how non-traditional types of solar panels are made, and tell you where most solar panels are manufactured.
But if you&#;re curious how solar panels actually work, we&#;ve got you covered, too. Use our guide to find out not only how they work, but how they generate electricity, too.
Solar panel manufacturing involves making solar cells from crystalline silicon (a very pure form of silicon), assembling them onto a clear pane, connecting the cells with wiring, fitting a backsheet over them, and encasing everything in a frame.
Solar cells are the most important part of the solar panel, since they&#;re the part that generates electricity.
The main two types of solar panel used in residential settings are monocrystalline and polycrystalline solar panels.
We&#;ll take a more in depth look at how these two types of panels are made in the sections below.
To make monocrystalline solar cells, a single fragment of crystalline silicon is melted down and moulded into a cylindrical shape, often called an ingot. During this process, the crystalline silicon is also mixed with gallium or boron, which gives it a positive electrical charge.
To make polycrystalline solar cells, the process is more or less the same. The only difference is that several crystalline silicon fragments are melted together, instead of one.
Crystalline silicon is a photovoltaic (PV) material, which means it can convert sunlight into electricity. Other types of solar panels use different PV materials.
The silicon cylinder is then cut into paper-thin wafers. A layer of phosphorus is added to one side of the wafers so that it has a negative electrical charge. The other side (the boron or gallium side) will keep its positive charge &#; this is to control the flow of electrons, and is similar to how a battery functions.
As a last step in this process, an anti-reflective coating is added to the wafers, so that they absorb sunlight instead of reflecting it. At this stage, the wafers are now fully formed solar cells.
Goto ORIENT to know more.
Thin strips of metal, typically silver, are printed onto the front of the solar cells. Next, the solar cells are connected together from the back by thin wires, usually made from copper.
These metal strips and wires are electricity conductors. In simple terms, this means that they gather and move the electricity that&#;s generated when the solar cells are exposed to sunlight.
The solar cells are then stuck face down onto a pane of glass or clear plastic coated with a sheet of adhesive material, such as polymer encapsulant or ethylene-vinyl acetate (EVA). The solar cells end up forming a grid pattern on the pane.
The clear pane serves as a protective front layer, which keeps the solar cells safe from rain, dust, or debris.
Another layer of adhesive materials is added over the face-down solar cells, and a backsheet (the protective backing of a solar panel) is added over that, essentially sandwiching the solar cells in between protective layers.
All the layers are then heated and vacuum pressed together, so that they bond into a tight unit. At this stage, the solar panel is almost finished.
Metal circuit ribbons are attached to the edges of the solar panel, followed by a metal frame, typically made from aluminium. The frame makes the panel sturdier and more resistant.
The circuits that run along the edge of the solar panel are connected to a junction box, which is attached to the back of the panel.
The junction box collects the electricity generated by the panel&#;s solar cells, and regulates the amount of electricity being sent from the panels to the rest of the electrical system they&#;ll be connected to.
With this final step, the solar panel is complete.
The solar panels and solar cells are tested for faults at all stages of the manufacturing process. Engineers regularly check for cracks in the solar cells or panels, and expose them to light to ensure they work.
There are other types of solar panels, beside monocrystalline and polycrystalline. These include thin-film solar panels, organic solar panels, perovskite solar panels, quantum dot solar panels, and &#;zombie&#; solar panels.
The process of sandwiching solar cells between protective layers remains the same, but what the solar cells are made of and how they&#;re made changes depending on the type of panel.
We&#;ll get into how different types of solar panel cells are made in the following sections.
To make thin-film solar panels, the PV material is laid out in several thin layers onto a flexible glass, plastic or metal sheet, instead of being pre-cut into cells, as is the case with monocrystalline or polycrystalline solar panels.
Several different types of PV material are used to make thin-film solar panels. These include cadmium telluride (CdTe) &#; the most common material for thin-film panels &#; copper indium gallium selenide (CIGS), and amorphous silicon (a-Si).
Once the PV material has been laid out, a laser carves rectangular patterns into it to create individual solar cells.
Organic solar panels have solar cells made from &#;organic compounds&#;. These are molecules composed of carbon atoms bonded by other atoms, such as hydrogen, oxygen, and nitrogen.
The result is a very lightweight and flexible solar cell, which can be placed on a wide variety of supportive materials, from glass to flexible plastic. The downside is that organic solar cells are less efficient than typical solar cells &#; only around 10% efficient on average &#; and they degrade much faster too.
Because of this, and the fact that the technology is still fairly new, organic solar panels aren&#;t yet commercially available.
Perovskite is the PV material used in perovskite solar panels. It&#;s a synthetic material that imitates the structure of a mineral with the same name.
It&#;s a relatively new form of technology, and so researchers are still looking for the best way to manufacture perovskite solar panels.
For now, there are two main methods for making perovskite solar cells.
The first method is to coat a standard silicon solar cell with a thin layer of perovskite. This is usually done using a &#;spin-coating method&#;; a few drops of a perovskite solution are poured onto a base (typically a solar cell) which is then spun until there&#;s an even layer of perovskite.
The second, more recent method, is similar to the method used for making thin-film solar panels. Basically, it means coating a sheet &#; made from plastic, glass, or silicon cells &#; with thin layers of perovskite.
In a quantum dot solar panel, &#;quantum dots&#;, which are basically artificial atoms, are the PV material.
The most common method for manufacturing quantum dots is called &#;colloidal synthesis&#;.
This process involves a lot of complex chemistry, but the final result is that the quantum dots are dispersed into a liquid solution, and sprayed or dropped onto a supportive material, such as a glass or plastic pane (the same kind used in other types of solar panels).
Quantum dot solar panels aren&#;t yet in use, since they utilise a relatively new technology to create solar cells. But studies have shown that they can produce solar panels that are potentially 66% efficient.
Zombie solar panels have &#;zombie&#; solar cells, also called dye-sensitised solar cells. These cells are made from organic dyes that can absorb light.
To make them, a conductive mixture, typically titanium dioxide, is layered into a thin square of glass or plastic coated with a conductive material, usually idiom tin oxide or fluorine-doped tin oxide. This is then soaked in the organic dye.
After that, the square is dipped in an electrolyte solution and covered with another layer of glass, this time coated with a different material, typically platinum, carbon, or graphite.
Zombie solar panels aren&#;t commercially available yet, but what&#;s special about them is that they have the potential to generate electricity indoors, albeit in small amounts.
Most solar panels are made in China &#; around 80% in fact, according to the International Energy Agency (IEA).
On top of that, six of the seven largest solar panel manufacturers are China-based companies, among them JA Solar and Aiko Solar, who make some of the most efficient solar panels.
This doesn&#;t mean that solar panels aren&#;t made in other countries. The USA and Canada also have large solar panel manufacturing companies, such as First Solar and Canadian Solar respectively.
Making a solar panel is a complex process that&#;s changing and improving all the time.
Monocrystalline and polycrystalline solar panels, which have silicon-based solar cells, might be the norm today, but maybe not in the future. New and more efficient types of solar panels, such as perovskite and quantum dot solar panels could become the norm in a few years.
That&#;s all good news for you, the consumer, since the more efficient solar panels are, the more electricity they&#;ll generate. Plus, with the cost of solar panels going down, that means you&#;ll break even on your purchase in less time than you would have ten years ago.
Tatiana has used her research skills to turn complex data into easily digestible articles on all things eco &#; from energy-efficient appliances to solar panels.
Before settling back in her native city of London, Tatiana lived in various other cities, across three different countries. She&#;s witnessed varying approaches and attitudes towards tackling the climate crisis in her time abroad, and uses this experience to inform her writing. She&#;s dedicated to opening up the conversation around green energy to a wider audience.
In her free time, Tatiana enjoys cooking with seasonal local produce, or going for long walks in green spaces.
You can get in touch with Tatiana via at
Contact us to discuss your requirements of Poly Solar Cell. Our experienced sales team can help you identify the options that best suit your needs.
More about