Many of the people who contact us don't fully understand how solar lighting systems work, which is understandable! There are often many questions, including whether the system uses batteries, what is a charge controller, how do the lights turn on, and how big are the solar panels? These are good questions, and we'll address them below.
A solar panel is a device that collects solar energy and converts 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 panel is installed has an impact on the size of the solar panel. 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 mounting 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 solar panel positioning.
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.
All solar systems use some type of battery, surprising some. Remember, solar panels absorb energy, not store it. A battery is needed to store the energy that will power the lights when the sun goes down. The size and type of batteries provided by solar systems vary widely. The battery can be a small AA rechargeable battery, a lithium battery pack, or a battery similar in size to a car battery. The size and type of battery will depend on many of the same factors mentioned about solar panel size. The longer the light is on, the higher the power consumption of the light and the larger the battery. All systems we offer come with a lockable weatherproof battery enclosure to accommodate the battery.
Solar systems use a device to help regulate the energy harvested from the solar panels and transfer the energy to recharge the batteries. It can be a piece of circuitry integrated into the lighting kit, or it can be a separate device called a charge controller. The charge controller will manage the power to and from the batteries to prevent them from overcharging or overdischarging. The charge controller will also control when the lights turn on and off. When the sun sets and rises, the solar panel sends a signal to the charge controller, which then turns the lights on or off. Many charge controllers can be programmed to adjust lighting time settings. The charge controller can be programmed to turn on the lights from sunset to sunrise, or it can turn the lights on for a period of time after sunset and then turn off. They can also be turned on a certain time after sunset, then turned off a certain time before sunrise, and then turned on again. We can also implement dimming and motion sensors to save power.
Most solar lights use LEDs as their light source. LEDs are more energy efficient than older light bulbs such as incandescent, CFL, high pressure sodium or metal halide bulbs; this means they can provide more light (lumens) using less power (watts). Lighting styles can vary widely, from decorative landscape lights to floodlights, or to road and parking lot lights.