Like any solar lights, solar street lights also work on the principle of photovoltaic effect. When placed under direct sunlight, solar cells on the panels absorb sunlight and convert solar energy into usable electrical current. This direct current is stored in solar batteries through a charge controller. This energy is used to illuminate solar street lights from dusk till dawn. The current generated by a solar panel depends on the size of the solar cells and the amount of sunlight absorbed by the panel.
How does a solar street light work?
A solar cell consists of layers of negatively-charged electrons and positively charged spaces. When sunlight passes through these solar cells, the electrons are activated and pushed into the positive spaces. This forms an electrical circuit and when the electrons pass through this circuit, direct current electricity is generated. A solar cell is made of a semiconductor material called crystalline silicone and a solar panel is composed of multiple solar cells.
The solar panel is connected to the battery through a charge controller. The role of charge controllers is to protect the battery by regulating the voltage and preventing the backflow of current through the solar cell at night when the charging does not happen. The solar-to-current conversion process stops at night and solar cells stop producing power at nightfall. Photoreceptors on the solar lamp sense the lack of sunlight and start supplying power that is stored in the battery to the light source. Again, at daybreak, the photoreceptors shut off the light automatically.
Do all in one solar street lights and integrated solar street lights work the same way?
Both all in one solar street light and integrated solar street have the same working pattern in terms of the conversion process. The components in both these solar street lights are the same, i.e. monocrystalline or polycrystalline solar panel; lead acid, lithium ion or LiFePO4 battery; PWM or MPPT charge controller and LED light source; however, the solar panel comes as a separate unit for integrated solar street lights and all the components including the panel are integrated into one unit for all in one solar street lights. Solar street lights are designed to work throughout the night providing safety and adding a sophisticated ambiance to the installed area.
Solar street light with infrared motion sensors switch on at dusk and after around 30 seconds, reduce the brightness until they sense movement from any warm objects when they light up to maximum brightness. The lights dim down again when there is no motion identified. Solar street lights with timer-based dimming options work at full brightness for the first four hours and then operate at 20% brightness for the rest of their operation time. This process gets repeated every day as long as there is enough sunlight falling on the panels for the conversion.
On non-sunny days, solar street lights use the stored up energy to illuminate the lights. Once installed, the lights keep working without any hassle and there is no manpower required to switch on and switch off the lights. Solar street lights are being used for a variety of lighting applications and rural areas with less connectivity to a power grid can benefit a great deal from the simple working principle of solar street lights. Also, communities and cities can enjoy the multiple of advantages of solar street lights since the functionality of a solar street light is quite straightforward.