We all know installing solar panels will save you money, that part is simple. But when it comes time to purchase your equipment, you will need to decide what type of solar panels you want. There are three basic types of solar panels available for residential systems – monocrystalline, polycrystalline and thin film.
The monocrystalline and polycrystalline panels are the more popular and these are considered “First Generation” solar panels. Both of these types are made with silicon PV cells but the difference is how they are made.
Monocrystalline PV cells are super-thin slices of a silicon crystal called an ingot. The ingots are grown in the PV factories and their natural shape is round so the slices are also round. In the old days, they made the monocrystalline solar panels with the fully rounded cells but this created a lot of “dead” space in the solar panel because the area around the round cells did not produce anything. To make better use of the space in a rectangular solar panel, they started cutting of the rounded edges of the monocrystalline PV cells but they don’t make them completely square because they don’t want to waste too much of the expensive crystal slice. When you look at a monocrystalline solar panel, you can see all the solar cells have rounded corners which means there are small rectangles of the backsheet showing through. When the backsheet is white, these rectangles are very obvious. If the blacksheet is black, then you will have to look very close to see them. These little rectangles between the solar cells are how you can easily identify a monocrystalline solar panel.
Polycrystalline PV cells are made by melting fragments of silicon crystals together. Because they are made in molds, they can be any shape, so they are square to avoid any wasted space in the rectangle of the whole solar panel. The square shape of the solar cell is how you identify a polycrystalline solar panel from the monocrystalline where the cells have the rounded corners.
Thin film solar panels are considered “Second Generation”. There are different types of thin film solar panels but the most popular are amorphous silicon which are made with silicon that is not in crystalline form allowing for flexibility, and the non-silicon Cadmium Telluride (CdTe) and Copper Indium Gallium Selenide (CIGS) solar panels.
Of these three types, the monocrystalline panels are the most efficient which means that you will get the most wattage per square foot with them. Polycrystalline modules come in as a close second on efficiency. When deciding between mono or poly technology, you will look at cost and availability. It often happens the polycrystalline solar panel is only ten watts less for the same size panel but it is quite a bit less expensive which makes it a good choice.
The thin film modules are generally much lower in efficiency and in price. They are typically only used when there is more than enough space to install solar panels which is rare for residential solar. Usually, residential roofs are very limited in space with good sun exposure which is why monocrystalline and polycrystal solar panels dominate the residential solar market.
Hopefully we have taken some of the mystery out of understanding the different solar panel technologies. If you have further questions about which solar panels are right for you, call the experts at GoGreenSolar.com.