There are many kinds of solar panels, including polycrystalline solar panels and monocrystalline solar panels. From the voltage, the open circuit voltage is 20V, 30V,40V, and so on. As a professional solar controller manufacturer with 12 years of industry experience, orlins technology can provide you free solar power generation system solutions and solar street lamp system solutions to help you choose the most suitable solar panel and solar controller.
1. Choice of single crystal and polycrystal
Of the same power, two solar panels made of monocrystalline silicon are more efficient than polysilicon, have less light decay, but cost more. Therefore, the choice of single crystal or polycrystal is based on actual needs.
2. Power selection of solar panels
Two factors are involved in choosing multiple solar panels. One is that the power of the load is related to the time the load is used. The second is related to local average sunshine time. Load power and time can be used to calculate the number of WH consumed per day, and the number of WH divided by the average sunshine time is equal to the power of the solar panel. This energy must be satisfied at least every day. In order to be able to turn on the light even when the solar panels are not charged at all, the energy charged by the solar panels must be greater than the energy discharged every day. The excess energy is stored in the battery for use in rainy days.
3. Select solar energy controller for battery voltage
Select the appropriate solar panel according to the voltage of the battery. Generally speaking, if PWM solar controller is selected, the working voltage of the solar panel charging the 12V battery is 18V. The open circuit voltage of the solar panel charging the 24V battery is 36V.
If you choose MPPT controller, this problem does not exist, as long as the open circuit voltage of the solar panel does not exceed the maximum input voltage of the controller. As long as the solar panel voltage is greater than the battery voltage can start charging
The above are the types, power and voltage of solar panels. If you can master these three conditions, you can basically determine the specifications of solar panels.