First of all, let’s take a look at the components diagram of solar panels.

The very middle layer are the solar cells, they are the key and basic component of solar panel. There are many types of solar cells, if we discuss from the size perspective, you will find three major sizes of solar cells in the current market: 156.75mm, 158.75mm, and 166mm. The solar cell’s size and the number determine the panel’s size, the larger and the more the cell is, the bigger the panel will be. The cells are very thin and easily breakable, that is one of the reasons why we assemble cells to panels, the other reason is that each cell can only generate half volt, which is really far away from what we need to run an appliance, so in order to get more electricity, we wire the cells in series then assemble all the series string into a panel. On the other hand, there are two types of silicon solar cells: monocrystallian and polycrystallian. Generally, the efficiency rate range for a poly cell goes from 18% to 20%; and mono cell ranges from 20% to 22%, so you can tell the mono cells bring a higher efficiency than poly cells, and the same with panels. It is also obvious that you will pay more for higher efficiency which means the mono solar panel is expensive than poly solar panel.

The second component is the EVA film which is soft, transparent and has good stickiness. It protects the solar cells and increases cells’ water and corrosion resistance ability. Qualified EVA film is durable and perfect for laminating.

The other important component is the glass. Compare to regular glass, solar glass is what we called ultra clear and low iron tempered glass. It looks a little white, coated at the surface to increase transmission rate which is above 91%. The low iron tempered feature increases the strength and therefore increase the mechanical and resistance ability of solar panels. Usually the thickness of solar glass is 3.2mm and 4mm. Most regular size panels 60 cells and 72 cells us 3.2mm glass, and large size panels such as 96 cells use 4mm glass.

The types of backsheet can be many, TPT is applied by most manufacturers for silicon solar panels. Usually TPT is white to increase reflection rate and reduce temperature slightly, but nowadays, many customers prefer black or colors in order to get a different appearance.

The full name for frame is anodized aluminum alloy frame, the main reason why we add frame is to increase the mechanical ability of solar panel, therefore helps for installation and transport. After adding frame and glass, the solar panel becomes tough and durable for almost 25 years.

Last but not least, junction box. Standardized solar panels all have junction box include box, cable and connectors. Whereas small or customized solar generator  may not include all. Some people prefer clips than connectors, and some prefer longer or shorter cable. Qualified junction box should have bypass diodes to prevent hot spot and short circuit. The IP level shows on the box, for example, IP68, indicates it has strong water resistance ability and allows it suffer from sustainable raining.