We do not often buy solar panels in our lives or install a solar power plant on our roof. And the right choice of such expensive equipment is both a responsible and difficult task for the buyer.
First of all, it is necessary to pay attention to the technical characteristics of the solar photo module. Also, it is necessary to check the workmanship and the absence of visual defects on the photocells, protective glass, and of course, the frame of the solar module.
How to determine what voltage the modules have?
In recent years, non-standard voltage solar panels have appeared on the market, which is designed to work in sequential high-voltage circuits. With the easy hands of non-professional sellers, there was confusion indicating the nominal voltage of the solar modules.
What to come across for when deciding solar panels for your solar power plant?
Price versus quality
In addition to the fact that not all manufacturers and solar modules are the same, there are several parameters and factors that you should pay attention to when deciding on a purchase, and when choosing a supplier. Only the price of modules should not be a determining factor.
The following factors can cause problems and deterioration of the parameters of solar modules:
The quality of the solar cell – its effectiveness may be different. It depends on many of its parameters – shunt and series resistances, noise currents, reverse resistance, etc. On the quality of production of solar cells and the quality of materials and equipment used in its production. There are known problems at almost every stage of the production of an element. From the quality of silicon used to the quality of contact pastes and solder used.
The quality of the soldering of solar cells. In the case of poor-quality soldering, a local overheating of the contact and its burning out is possible.
The quality of the EVA film, which is located between the elements and the glass. The aging of crystalline solar modules is mainly associated with the aging and clouding of this film. A poor-quality film may begin to cloud and collapse in a few years. A good film will last 30 years or more, while it is clouding (and, consequently, the loss of power by the module) will not exceed 25-30%.
The quality of the module sealing and the quality of the back protective film. The rear film protects the module from humidity. In any module, moisture diffuses through the film. If the film is of poor quality, then there is more moisture than it can escape when heated, residual moisture accumulates inside the module and destroys the contacts and the contact grid of the elements.
The quality of the aluminum frame. Everything is clear here: poor-quality anodizing can lead to oxidation of the frame and its corrosion. Fortunately, this defect is more visual and is unlikely to lead to premature module failure. Although, in some cases, accelerated corrosion of the metal can lead to its destruction under loads.
Recently, solar modules with double glass appeared, i.e., glass was used instead of the back protective film. Such modules have several advantages.
Double Glass Solar Modules
Tolerance means the deviation of the real power of the module from the passport. Tolerance can be either positive or negative.
The temperature coefficient reflects the effect on the output current, and the voltage of the module will increase or decrease the temperature of the module. As you know, the voltage and power of a module decrease with increasing temperature, and the current rises. The lower the temperature coefficient of power change, the better.
Sunlight conversion efficiency