Solar technology was developed in the 17th century and has been in the news ever since for all the good reasons in both developing and developed countries. The traditional street lights consume more energy as they use HD lamps. Solar street lights use LED lamps that consume less energy and require very low maintenance to keep running. Solar technology applications can be found everywhere nowadays as utility platforms to power buildings, vehicles, street lights and other devices. Modern solar lights are automatic and designed to conserve energy to make the operation easy for the users.
Before you invest into solar lighting, it is essential to take a closer look at how a solar street light system is designed and to understand what components are integrated together. A solar street light consists of the following parts:
- Solar panels
- LED light
- Rechargeable battery
- Interconnecting cables
Solar panel or a photovoltaic cell uses solar energy to convert it into electricity to run the solar street light. Poly-crystalline solar panels are commonly used due to their affordability; however, mono-crystalline panels are popular for their high efficiency. The solar panels start their job as soon as the sun is up and the lamp automatically switches off after the sunrise. The amount of power generated is determined by the size of the solar PV modules. The following points should be checked while purchasing a solar street light:
- Number of solar panels
- Type of solar panel
- Total wattage of solar panel
- Mounting position of the panel, on top or side of the pole
When considering solar street light installation, the location of the lights is very important. The lights should be installed in such a way that there is sufficient direct sunlight falling onto the solar panels. It helps to configure the solar panel power and to set up the appropriate angle of solar panel if you know the geographical location of the solar street light project.
LED lamps consume less energy compared to fluorescent and incandescent lamps and are the most common light source used in a solar street light system. LED lights emit zero ultraviolet rays and are well known for their durability and longevity. The LED technology uses less energy and delivers much higher lumens than traditional style light fixtures. The solar light with HPS light fixture consumes more energy compared to modern street lights with LED. The following questions should be asked before selecting your solar street light:
Type of light fixture
- Luminosity per Watt
- Light distribution pattern
- Light level requirements
- Fixture mounting height
- Specific illumination area
Compared to traditional street lights with 5000 to 8000 working hours and a higher failure rate, LED light fixtures are less prone to failures with an average working hours of 50,000. LED lights emit light in a specific direction unlike HD lamps and offer a pollution-free ambience.
Modern street lights use lithium-ion or LiFEPO4 batteries and the capacity of the battery affects the backup power days of the lights. A battery’s function is to store electricity from the PV panel during the day so that it can provide energy for the LED light in the dark. The specifications to look for are:
- Type of solar battery
- Total amperage hours
- Average lifespan
- Battery voltage and capacity
- Charging time
Lithium battery technology is constantly growing and is the perfect choice for solar street lights due to their compact and lightweight features. Lithium batteries tend to charge faster and in today’s solar-powered lights, the batteries do not require any maintenance.
A controller controls the battery from overcharging or undercharging. The main function of a controller is to receive power from solar panels and to charge the battery during the day which helps in supplying power to the LED fixture during the night. PWM or MPPT controllers are used in a solar street light system. You need to check the following while selecting a solar street light:
- Type of solar controller
- Capabilities and functions
- Mounting and installation
- System connections
Controllers offer reverse current protection and multistage charging. The controllers used in modern solar street lights lower the amount of power applied to the batteries when the batteries are charged fully and convert excess voltage into amperage, thereby extending battery life.
While some of the solar street lights can be fixed on walls, most of the lights are installed on poles. Since the panel and lighting fixture with in-built battery are mounted on top of the pole, for every street light a strong pole is essential. The construction material used to manufacture a pole typically is thermally galvanized steel. To reduce transportation and logistics costs and to lessen the challenges during installation, the poles are carefully designed. You need to discuss with your dealer about:
- Type of pole material
- Placement of pole
- Height and diameter of pole
There are cables to connect the LED light and solar panel which are to be fixed on the top of the pole. Depending on the height of the pole and the current that is being carried to the light, the size and length of the cable could vary. Before hoisting the pole, the entire fixture is attached to the pole and cables are connected. Your dealer must specify in detail about:
- Installation guide with exact technique for the interconnecting cables
- Specification of the interconnecting cables
Only when all the above components are interconnected into one integrated system, the solar LED light system design can be completed. All-in-One solar street lights detect movement and light up the LED with the help of motion sensors. Integrated solar street lights operate at full brightness for the first few hours of the night and then at a lower level until sunrise. Both the motion sensor and the dimming features help conserve energy during the night. It is crucial to understand individual components and functioning to design a solar street light system and to get maximum performance out of it.