Solar panels are devices that collect solar energy and convert it into direct current. This power supply is used to charge the battery directly using the charge controller.
The size of the solar panel will depend on several factors.
It depends on what you are powering. It can be a 10-watt light fixture or a 100-watt light fixture. The higher the power consumption, the larger the solar panel needs to be.
The geographic location where the solar panels are installed has an impact on the size of the solar panels. A solar system powering a 10-watt lamp would require larger solar panels if installed in Seattle, Washington, compared to Miami, Florida. This is because the sun levels in Florida are much higher than those in Washington state.
The orientation and installation angle of the solar panel will also have an impact on the size of the solar panel. For maximum sun exposure, solar panels should face due south. To maximize the performance of your lighting system in winter (the worst conditions for solar due to longer nights, shorter days, and harsh weather conditions), solar panels should be installed at a 15-degree angle plus the latitude of the installation site. For example, the latitude of Atlanta, Georgia is approx. 33°N, so the proper angle for the solar panel is approx. 48°. If for some reason the solar panels must face east or west, and/or need to lie flat on top of the structure, the solar panels may need to be larger to compensate for the unfavorable positioning of the solar panels.
The amount of time each night needs to be lit also has an impact on the size of the solar panel. A 10-watt light for 14 hours will consume more power than a 10-watt light for 6 hours. The longer the lights stay on, the larger the solar panel needs to be.