As the solar industry has been growing, many homeowners start seeing solar panels on the top of their neighbor’s roofs and notice that lately, solar PV modules have a dark appearance that leads to the conclusion that solar panels are usually black nowadays.
The industry has focused on developing new ways in which solar panels can have increased aesthetics, especially for houses with clay tiles or concrete lightweight tiles, which have a high-end-looking design.
The answer came in the way of the so-called all-black solar panels. These modules have a much darker appearance than other types of solar panels.
This makes them better looking and therefore, they get sold faster and easier for high-end houses.
However, it is wise to ask yourself, are all the panels nowadays black? Are they actually black or do they just look like it? Finally, are the all-black solar panels better than their counterparts?
We will dive into all these questions and find out everything you should know about the new all-black solar modules.
Are All Solar Panels Black?
Historically, there have been always three main types of solar panels: monocrystalline, polycrystalline, and thin-film.
However, the two main options for most applications have always been monocrystalline and polycrystalline ones which is why we are focusing on these two.
Both types of solar panels are made from silicon crystals, however, there is an important difference in their manufacturing.
Why Some Solar Panels Are Black
The process used for manufacturing solar panels is called the Czochralski method and it is applied to all silicon-based technologies.
We won’t dive too much into the method itself, but it basically consists of melting silicon along with other conductor components such as phosphorus and boron at very high temperatures.
Then, a seed-crystal is carefully dipped into the molten silicon and is slowly pulled upwards creating a silicon ingot or crystal in a cylindrical shape that is later sliced into multiple wafers.
The main difference between monocrystalline and polycrystalline modules is that monocrystalline panels are made using a single silicon crystal, while polycrystalline ones are made using multiple silicon crystals.
This is why polycrystalline modules look like they have small irregular pattern shapes inside while the monocrystalline ones look smoother.
Now, this important manufacturing process detail is what makes a difference for the different colors of solar panels.
Blue Solar Panels That Look Black
While polycrystalline cells do have a light blue color, monocrystalline ones have a very dark blue or technically black appearance.
Yes, you read that right! Even the monocrystalline modules are not quite actually black, however, they certainly do look like it (some models more than others do) and as far as anyone is concerned, they are just black.
The reason is that a single-crystal cell (monocrystalline) will have a different interaction with light when compared to the physical interaction between multiple crystals and light. This is the main reason why monocrystalline cells look darker than their counterparts.
Traditional Monocrystalline vs All Black Solar Panels
Now, do you remember which idea we said that the industry came up with to improve the aesthetics of the modules? Yes, that’s right! We were talking about the all-black solar panels. But, are this new technology different from monocrystalline ones?
The truth is that all-black solar panels are based in monocrystalline technology, just as any other monocrystalline solar panel. So, why are they all-black?
Well, the reason is because the traditional monocrystalline modules have a white backsheet and silver frames while the new-all black solar panels have a purely black backsheet and also black frames.
This black backsheet makes the cells look totally black when compare to their white counterparts which may or may not look totally black.
All-black solar panels are manufactured using the same procedures, with the exception that they may use black adhesives around their junction boxes and related electronics.
Probably the best visually available comparison would be between all-black and white monocrystalline solar panels from the X-series models of Sunpower (the top solar panel company in terms of efficiency). This can be seen in the figure below.
Now, aside from the darker look of the solar panel, which you may or may not like (but most probably will), is there any other thing that makes these two types of monocrystalline modules different? In fact, there is.
Believe it or not, those white grid lines that you see in the white backsheet monocrystalline solar panel (the one on the right from figure below) actually do something good in terms of solar power production.
The light that reaches those white grid lines actually gets reflected and generates a “light-trapped” phenomenon in which part of that reflected light is actually used to harvest electricity.
Crazy right? The downside for those all-black modules is that since the backsheet is entirely black, there is no light reflected by grid lines, which means, solar cells can only harvest electricity from the light that actually hits the solar cells.
Efficiency of Black Solar Panels
In other words, all-black solar panels can lose around 3% of electrical photocurrent generation, which translates to about 0.5% of efficiency loss or more.
So, why does this matter? Well, because no matter what you do, there is no way that an all- black solar panel with the same size, wattage, cell type, and manufacturer can match the efficiency of an equal but white backsheet monocrystalline module.
All-black X-series Monocrystalline Sunpower model (left). White backsheet X-series Monocrystalline Sunpower model (right). Source: Sunpower
All Black Solar Panel, Should I go for it?
The thing is that currently in the US, more and more all-black solar panels are being implemented in new systems, especially in those high-end houses that have clay tile, concrete standard tile, or even asphalt composition type roofs.
Many homeowners from these houses, do not want to sacrifice the look of their house by placing panels (much less the light blue polycrystalline ones), especially if they would go in the front side.
For them, the target of the house with solar should be something like the image we can see below, nice dark looking panels with black frames mounted on top of a clay tile roof.
Should you Buy Black Solar Panels?
If you are one of these homeowners, the premium price that you pay on the all-black solar panels so that they look good on your roof, will probably be worth it (yes, the premium is only for the aesthetics and nothing else).
After all, the modules will be there for around 25 years.
However, before jumping to this conclusion, ask yourself these questions
- Is there a big difference between the white and black monocrystalline panel in terms of price and efficiency?
If the all-black module is far more expensive and far less efficient, then the aesthetics must really be placed into balance. For that, you may want to ask yourself the two questions below.
- Are the panels going to be installed in front of the house, in the backside or in a ground mount?
To help you make the decision if you find yourself in the situation mentioned in the previous question, you must know if your panels need to be installed in the front-side roof face for whatever reason (whether that is due to obstructions in other roof faces, or that the front roof side radiation performance is much better).
If they need to be installed in the front-side and you want better-looking solar panels, then the all-black models are probably the best option for you.
If they are actually are going to be installed in a backside roof face, or a roof face that cannot easily be seen from the street, then the plus for the aesthetics highly diminishes. The same applies if it is a ground mount in a backyard.
- Is your house a two-floor model or a single-floor house?
Something that people often forget is that solar panels cannot always be clearly seen from the ground, especially if the modules are mounted on a two-floor house roof.
If the modules are going to be installed on a roof face that doesn’t face directly front, and the house is two-floor and is right next to the other two houses on each side, then it is probable that the panels will not even be clearly seen from the ground.
This may result in white backsheet monocrystalline ones being a better choice.
So! We covered a lot in this article on solar panels’ appearance. Now, we know that there are two big solar panel types out there (polycrystalline and monocrystalline).
We also know that there are different types of monocrystalline solar panels, some of which look totally black, while others have the typical white frame and inner grid lines.
Moreover, we learned that their difference is not only in their colors but also in their performance since the total black appearance reduces the light reflection efficiency and therefore decreases power output.
Nevertheless, what’s most important, we went over some of the considerations you must take when asking yourself the bottom-line question, are all-black solar panels worth it?
Only you can answer that question balancing between costs, preferences, and actual solar power production.