Solar installers often receive many questions regarding solar systems. Many questions shine upon the topic of solar panels. We recently tackled the question “How Do Panels Work?” and hope you have learned a better idea of the process. We’ll continue to shine the light on panels, specifically exploring the types of solar panels available for your solar system.
Foremost, although various types of panels exist, the main job of a panel is to produce power. As technology improves in solar at an unprecedented rate, solar panels are evolving. This includes better manufacturing (i.e. less carbon emissions during production), better active production (in receiving photons and distributing electrons), and overall more affordable prices. Panels may have assorted characteristics such material make-up and specifications, and each may have pros and cons.
The two main types of panels used in residential and commercial applications are crystalline and thin film. Of the two, crystalline panels comprise the bulk of solar installations. Crystalline panels are either monocrystalline or multicrystalline (aka polycrystalline). The three main kinds of thin film panels are amorphous silicon, cadmium telluride, and copper indium gallium diselinide. A hybrid panel is currently in the works as well; labeled “hetero-junction” panels, they combine crystalline and thin film technology. We shall take a look at the two types of crystalline panels here, with an upcoming blog focusing on thin film panels.
As we mention in the blog, “How Do Panels Work?,” silicon, boron, and phosphosrous are the primary elements in a solar cell. The cells combine to form modules, and modules combine to form the panels. Both monocrystalline and multicrystalline panels utilize the aforementioned elements, albeit somewhat differently.
In the manufacturing process of monocrystalline panels, silicon is doped with boron to form electron holes. A crystal enters the mixture and becomes the solar cell’s structure. Upon being formed, the crystal is pulled from the mixture resulting in a cylindrical, circular shape. The resulting crystal is sliced and combined with phosphorous, completing the cell. Electron flow is enabled once an electrical grid is affixed.
Most monocrystalline solar panels are shaped as rectangles, and this causes manufacturers to cut the cylinder crystals cells into octagon shaped modules. This results in a slight “dead space” when placing monocrystalline modules next to each other. Monocrystalline panels often are manufactured with a black hue and a white back sheet as well.
Rather than the cylndrical, circular shape of monocrystalline panels, multicrystalline panels are often brick or cubed shaped. This shapes is the result of forming the silicon-boron combination in a cube shaped cauldron. The silicon cools and forms many crystals, thus the term “multicrystalline.” Upon cooling, the crystal is sliced and phosphorous and the electrical grid are added, completing the cells and modules.
Unlike monocrystalline cells and modules, multicrystalline can be made into various shapes without much (if any) cutting. This allows cells and modules to be placed closer to each other than monocrystalline modules. Multicrystalline panels are generally marked with a dark blue hue as opposed to monocrystalline’s black hue.
So Which is Better?
Although the process in manufacturing monocrystalline and multicrystalline panels differs, ultimately it comes down to efficiency and price for most. Although monocrystalline is the older, more developed technology in panels, multicrystalline technology has improved much recently and compares reasonably. Both types of panels have pros and cons, and each application for installation is unique. With that being said, please consider the following statement and charts:
Monocrystalline modules are typically more efficient than their multicrystalline counterparts on the cell level because the molecular structure of the ingot is uniform from top to bottom. This characteristic allows the photon to move the greatest number of electrons when in sunlight because the cells are lined up and facing the exact same direction. In a multicrystalline cell, the crystals have various shapes and point in different directions, slightly reducing the efficiency.
—Ryan Mayfield, President, Renewable Energy Associates, “Photovoltaic Design & Installation For Dummies,” p. 106
Of note, the above graphs represent panels in general terms.
In addition to the characteristics mentioned in the above charts, please keep in mind other attributes may need to be explored as well, such as panel specifications. Each panel will feature attributes such as current specifications, voltage specifications, a maximum power point, voltage temperature coefficient, power tolerance, and a series fuse rating. Manufacturers also test panels with respect to temperature, irradiance, and air mass. Bay Area Solar Solutions LLC is happy to work with you in understanding your panels better and will do our best to find a solar panel solution to fit your needs. Whether you prefer monocrystalline or multicrystalline, we will help you choose a panel manufacturer. Two brands that we use and trust are Solar World and Suniva.
Monocrystalline and multicrystalline panels have come a long way over the years and should continue to become more efficient as solar grows. Let’s keep the heart of the solar system burning bright!
Need more information on going green and ready to take the next step? We are here for you at Bay Area Solar Solutions LLC, where your solar needs come first!