174,000 terawatts of energy strike the earth at any moment, even on cloudy days. That is more than 10,000 times what the world uses. Just one hour of sunlight is equivalent to one year’s worth of energy for the whole planet.
Solar panels have been around for less than 70 years, with the first photovoltaic cell having been invented in 1954. Since then, solar panel technology has evolved from that first basic cell that could only convert sunlight into energy at an efficiency of 8%.
Today solar panel efficiency has almost tripled while the price for solar panels has fallen by 70% since 2010. Those are remarkable statistics by any measure.
There are over 350 companies in the world that manufacture solar panels today. But they all seem to make solar panels that have the same blue or black color. Have you ever wondered why? Why don’t they make them red or yellow or even pink? Today we are going to explore those questions and find out why solar panels come in the same colors.
On a side note! If you’re in need of a reliable and high-performance portable solar panel, We strongly recommend the Jackery SolarSaga 100W Portable Solar Panel (Amazon Link).
With a high conversion efficiency and foldable design, this solar panel is easy to transport and set up, making it perfect for outdoor activities like camping, hiking, and RV trips.
The US solar cell technology used in this panel ensures that you get the most efficient and reliable solar charging possible.
There is also a 60W option that is more affordable (Amazon Link)
Why Are Solar Panels Black or Blue?
Solar panels are black or blue because of the way light interacts with the silicon they are made of. 95% of solar panels on the market are made from silicon. Silicon is used because it can absorb most wavelengths of light to produce energy.
After oxygen, silicon is the most abundant material on earth. The abundance of silicon makes it much cheaper as a raw material in the production of solar panels.
In a crystalline silicon cell, silicon atoms fuse to form a crystal lattice. The result is an organized structure that makes energy conversion more efficient. (Source)
Solar panels made from crystalline silicon come in three main variants. These are monocrystalline, polycrystalline, and thin-film. These three materials slightly differ in color. 90% of the world’s solar panels are made from polycrystalline. Also, check out our post on “Which Metal Is Used For Interconnection Of Solar Cells In Solar Panels?“
Monocrystalline solar cells are typically black. You can find them in a dark blue or grey color as well. Polycrystalline solar cells are blue or dark blue. Thin-film silicon cells are grey, brown, or black. The color of the solar panels is influenced by the anti-reflective coating used on them.
What Is an Anti-Reflective Coating?
Raw silicon has a high surface reflection. Applying Anti-Reflective Coating (or AR Coating) to the surface reduces reflection, increasing the light absorption of solar cells.
Anti-reflection coatings on solar cells are similar to those used on other optical equipment such as camera lenses. AR coating improves the light transmittance of a solar panel making it more efficient than if the silicon were absorbing directly. (Source)
Why Are Polycrystalline Panels Blue?
Polycrystalline solar panels are blue because of the way light interacts with the polycrystalline silicon they are made from. The blue color is mostly because of the anti-reflective coating used to improve the efficiency and absorbing capacity of the solar panels.
There are two ways of producing polycrystalline panels. One way involves the slicing of silicone to produce a single crystal cell. This is the same technique used to produce monocrystalline solar cells. The second technique involves depositing a polycrystalline film on a substrate.
Raw silicon is melted and poured into a mold. The silicon does not align perfectly using this process. The result is many individual silicon crystals. That is why polycrystalline solar panels have their speckled look. While this second technique is cheaper it does result in a less pure cell that has lower efficiency. (Source)
Why Are Monocrystalline Panels Black?
Monocrystalline solar panels are black because of how light reacts to the monocrystalline silicon cell they are made from. Like polycrystalline panels, monocrystalline solar panels have an anti-reflective coating that improves their efficiency and absorption capacity.
Solar cells made from monocrystalline are purer. This is because monocrystalline solar cells use one large silicon crystal. Polycrystalline uses many individual silicon crystals that are fused. The use of a single continuous crystal gives monocrystalline its uniform black color.
Producing monocrystalline solar panels is energy-intensive and results in between 40-50% wasted silicon. This makes monocrystalline more expensive to produce than polycrystalline which is why monocrystalline solar panels are more expensive to buy.
The darker black color of monocrystalline solar cells makes them more efficient as darker surfaces absorb more light than lighter surfaces which are more reflective. (Source)
For more on this topic, check out our post titled Which Solar Panel Is Best, Polycrystalline, Monocrystalline, or Thin Film?
Can Solar Panels Be Different Colors?
Solar panels can be made in different colors. The key to changing the color of a solar panel is in using a thicker or thinner anti-reflective coating.
There are solar panels in production that come in red, green, yellow, and even white. There are even patterned and clear solar panels. These color variants are manufactured by small specialist companies.
While you can get them on the market it’s important to know the pros and cons of colored solar panels.
Pros of colored solar panels
- Perhaps the only advantage to color solar panels is their aesthetic appeal. They look good. They will blend better with their environment if you can get a color that matches.
Cons of colored solar panels
- They are more expensive than conventionally colored solar panels. As they are made by smaller companies they are priced at a premium. While it depends on the size and color, they typically cost up to $14 more per panel.
- They produce less energy as they use a thicker layer of anti-reflective coating. They are 15% less efficient than the standard black and blue solar panels. Clear solar panels have an efficiency of only 5%.
The up to 45% reduction in efficiency of colored solar panels means you get less energy at a higher price. It is not the best investment unless aesthetics are very important to you.
Also, find out the impact of heat which could result from dark colors on solar panels and check out our post titled: Do Solar Panels Get Hot (To Touch)? Impact On Efficiency!
What Is the Best Color for Solar Panels?
The best color for solar panels is black. Black absorbs more light compared to any other color. More light means more energy produced.
That is why monocrystalline solar panels which are black, are the most efficient solar panels. Polycrystalline solar panels are blue and thus do not absorb as much light. Color solar panels have even less efficiency compared to both poly and monocrystalline solar panels.
For maximum efficiency, monocrystalline solar panels will produce more energy because of their ability to absorb the most light because of their black color.