Integrated solar street lights are well known for their enhanced efficiency and intelligent operation. They are also known as split or all in two solar street lights. Most of the latest designs have solar panel as one unit and luminary with in-built battery as a separate unit. However, integrated lights that use lead acid batteries have a battery box that has to be attached to the pole separately. Integrated solar street lights are widely used to illuminate any large open spaces including public roads and streets, parks, private gardens, parking lots, playgrounds, or any remote areas that have no access to a power grid.
Integrated solar street lights turn on and off automatically by sensing the sunset and the daylight. They are powered by solar panels where photovoltaic cells convert solar energy into direct current and stores up the energy in batteries to power the lights at night. The controller works as a regulator and controls the reverse power flow. According to The Ministry of New and Renewable Energy, there are two models of integrated solar street lights available, where Model-I works from dusk to dawn at full brightness and Model-II functions at 100% brightness the first four hours and then at a lower level until sunrise.
Some of the integrated solar street lights use lead acid batteries and due to their relatively large size, they need to be placed separately in a battery box and cannot be integrated into the luminary unit. Modern integrated solar street lights mostly use LiFePo4 battery because of its high efficiency and due to its compact size, it can be attached into the luminary. LifePo4 batteries offer a longer lifespan and constant output power and require less maintenance compared to lead acid batteries.
MPPT (maximum power point tracking) or PWM (pulse-width modulation) controller is used in integrated solar street lights to control and regulate the current flowing from the panel. PWM controllers are relatively cheaper but MPPT controllers are high on demand as they are more efficient and sophisticated comparatively.
Integrated solar street lights use monocrystalline or polycrystalline solar panels. Due to their silicon purity, monocrystalline solar panels are more expensive and highly efficient in their performance while polycrystalline solar cells are more affordable.
LED lights are popular for their high luminosity with lower energy consumption and instantaneous illumination. LED lights work the best for street lighting due to their great color rendering index and are capable of functioning even on low voltage and in different operating temperatures. LED lights support the integrated solar street lights to run their dimming option, extending the life of the luminary.
Installation and maintenance
Integrated solar street lights can either be fixed on a pole or a wall. Before erecting the pole, the solar panel and the luminary must be fixed into the arm and then the arm must be attached to the pole. If the light is fixed on a pole, a flat ground should be selected to place the pole. The pole can be secured to the ground using concrete. The panel and luminary are connected using the wires given. The installation process is very simple and can be completed by following the instructions of the manufacturer using only basic tools and minimum manual labor.
The location of the light installation is crucial as the panels require maximum direct sunlight to operate throughout the night. Since integrated solar street lights have solar panels as an independent unit, at the time of installation, direction of the panels can be conveniently adjusted according to the direction of sunlight. If multiple street lights are being installed, they must be fixed at an even distance to provide adequate brightness to the entire area uniformly.
Integrated solar street lights are eco-friendly and operate using brilliant, integrated technology. Their function is completely automatic in nature, so there is hardly any manual operation or maintenance required after installation. The solar panels are typically fixed at a tilted angle to avoid water stagnation. Rain water washes away most of the dirt accumulated on the solar panels; however, doing basic cleaning and maintenance once in a while helps to increase the efficiency and brightness of the lights.
Advantages of solar integrated street lights
- There are two cost-effective and energy-efficient models of solar integrated street lights available with dusk to dawn feature.
- Since the solar panel comes as a separate unit, the panel direction can be changed to absorb maximum sunlight.
- Dimming option helps to save energy and in areas where night-long illumination is not required, lights with dimming option can be used.
- Solar panels can be fixed at an angle to avoid water stagnation and increase efficiency of the lights.
- The lights are charged at a faster rate since the solar panels are bigger.
- Integrated solar street lights perform even during rainy days and low sunlight days and even with low voltage.
Integrated solar street lights are available in different wattages and designs. The lights are weatherproofed to withstand any type of climatic conditions. Most of the manufacturers and dealers offer a minimum of 1 to 2 years of overall warranty and the solar panels have a lifespan of 25 to 30 years.