There are several types of solar panels available on the market today, some of them being older but durable, while others being flexible, less durable and more expensive per watt.
Today, mono and polycrystalline solar panels are called traditional solar panels, while the thin film flexible solar panels are called newer panels.
Monocrystalline vs. Polycrystalline Solar Panels
The major differences between these two types of panels are represented by: durability, the way they look, efficiency and size, and cost per watt.
Durability
Both these panels (mono and poly) are very durable because they use an aluminum frame with a tempered glass top cover and protect the solar cells without blocking the sunlight.
Manufacturers provide a warranty of about 25 years for these panels because they resist very well in all types of weather, including high winds and medium sized hail.
The Way They Look
When you look at monocrystalline and polycrystalline solar panels, a few things will stand out right away with their appearance.
Monocrystalline solar panels have a black or a very dark blue color and you easily see how the solar cells or the individual squares were made.
Polycrystalline solar panels have a blue mottled look, they look more like they were made from multiple pieces of silicon pressed together.
Efficiency And Size
Monocrystalline solar cells are made with a higher grade of silicon (solar cells are cut from a single ingot of silicon), so they’re slightly more efficient than polycrystalline solar cells.
Monocrystalline solar panels have an efficiency between 19 and 20 percent, while polycrystalline solar panels have an efficiency between 16 and 17 percent.
Being more efficient, monocrystalline solar panels won’t take as much room as polycrystalline solar panels, so if the space on your roof is limited, now you know what type of solar panels you need.
Cost per Watt
The manufacturing process of monocrystalline solar panels is slightly more expensive, and this is the reason why these panels are more expensive than polycrystalline solar panels.
However, the price of solar decreases year after year, and in 2020, you can get a monocrystalline solar panel at the price of about $0.70 per watt, and a polycrystalline solar panel at the price of about $0.50 per watt (the other components of a solar PV system were not included in these prices).
The Difference Between Traditional Panels (Mono and Poly) and Modern Flexible Thin Film Panels
There is a pretty big difference between traditional solar panels (mono and poly) and modern flexible panels.
Durability
Traditional solar panels (mono and poly) are extremely durable compared to flexible panels that are less durable.
Flexible thin film panels are exposed to micro scratches, cupping as well as tears that can happen to the solar cells because they are not covered by tempered glass to protect them.
Mono and polycrystalline solar panels come with a warranty of 25 years from the manufacturer, while flexible thin film panels come with a warranty of only 10 years.
Efficiency and Size
If traditional solar panels have an efficiency between 16 and 20 percent, flexible thin film panels come with an efficiency of only 12 to 13 percent.
When using flexible panels you will have to buy more modules to reach the desired output of the PV system, and the installation will require a larger roof area (bigger footprint).
In terms of size, traditional panels are bulkier and heavier, while flexible thin film panels are thinner and lighter (this is actually the only advantage that flexible panels have over traditional panels).
If you want more portability, you have to use flexible panels.
Cost per Watt
Traditional panels (mono and poly) cost today around $0.50 and $0.70 per watt, while flexible thin film panels cost between $1.10 and $1.30 per watt.
You have to pay more if you want a solar panel that is less durable, but more flexible and portable.
How to Wire Solar Panels: Series vs. Parallel
We have to start here with the following equation:
Watts (W) = Volts (V) x Amps (A)
You also need to know that the wire size used by your panels is strictly correlated with the amount of amps running through the solar cable, so if you use smaller seize wires, the amount of amps that will run through the wires will also be smaller.
For our example, we will take four 300 Watt panels for a total of a 1,200 Watts (1.2KW) solar array.
Wiring Solar Panels in Series
When you want to wire your panels in series, you have to think to the panels as being connected to form a single larger panel.
Solar array wired in series.
Using our example 1.2 KW solar array, we have four 300 Watts monocrystalline solar panels at 24 Volts and producing 12.5 Amps each.
To wire this solar array in series you will connect each of these 300 Watts panels to obtain a singular 1.2 KW panel (in an electric sense).
To do this, you will take the positive line of the first panel to wire it to the negative line of the next panel, and so on, until you finish wiring them and you get only one positive line free and one negative line free.
When you wire your panels in series, the only thing that changes is the voltage of the system, so by wiring four 300W and 24V panels together, you will multiply the 24V by 4 to get 96V.
1,200 Watts / 96 Volts = 12.5 Amps, and this shows again that wiring the panels in series will only change the voltage of the system.
Wiring Solar Panels in Parallel
When you wire the solar panels in parallel is the exact opposite of wiring them in series, because of those 300W panels will remain separate panels in the system.
Solar array wired in parallel.
You will get individual panels producing individual amounts of energy at the same initial voltage of 24V, and the only thing that will change will be the amperage of the system.
To wire the panels in parallel, the positive and the negative line of each panel comes out on one side (lets say the positive lines on the left side and the negative lines on the right side).
Each of the positive lines will be connected to the positive line of the system, and each negative line will be connected to the negative line of the system (none of them will be connected together).
You will get this way a 1.2 KW solar array that produces 24 Volts and 50 Amps.
Advantages And Disadvantages Of Wiring The Panels In Series And/Or Parallel
We will talk about wire sizing, shading issues and charge controller size.
Wire Sizing
Wire size is strictly correlated correlated with the amount of amps running through that wire.
Solar wire size and amperage.
Each wire is rated for a specific amount of amps, so if your system uses a smaller amount of amps, the size of the wires will also be smaller.
This way, the 1.2KW solar array wired in series will work at 12.5 Amps, so will use smaller size wires, while the same solar array wired in parallel will use larger wire size.
Shading
When you deal with shading in your area, wiring the solar array in parallel will solve the issue because each panel will work independently from the system, so if one panel gets shaded, the other panels will continue to produce power.
However, if your solar array is wired in series, it will act like a single major panel, so if one panel will be shaded, the entire system will be shaded and will stop producing energy.
The Size of the Charge Controller
The higher the amps in the system, the higher the charge controller.
A solar array wired in parallel will need a much larger charge controller than a solar array wired in series.
Conclusion
Now that you know the difference between the different types of solar panels, and you can wire the system to suit your needs, you only have to buy your first solar PV system and start producing free and clean power that will reduce your energy bills and will also make the environment cleaner.
