Solar steel lights consist of 3 parts. The panel, the battery package, and the light source. The solar panel consists of silicon wafers arranged in the form of a grid. They collect solar energy and convert it into electrical energy.
The joints are made of silver to reduce losses during transmission. Manufacturing and extraction of silicon are quite costly. Silver being precious, adds to the total cost of the solar panel. The battery package stores electricity during the day and discharges at night. The battery package is also expensive but not as the panel itself. There is also a small electronic chip that provides overcurrent protection and controls the battery cycle. Monocrystalline panels are present inside a solar panel. The controller deals with electronics. The battery discharges power into the panel. They absorb the energy emitted by the sun during day time. The battery stores the electrical energy after converting solar energy.
The last part is the bulb. It can either be a sodium vapor lamp providing yellow light or a mercury vapor lamp providing white light. Nowadays, people prefer LED lamps due to their lower cost and energy consumption, but they’re neither as bright as the vapor-based bulbs nor do they last as long. LED bulbs light up street lights hoisted at the sides of highways, while vapor-based lamps brighten desolate areas where there is only one lamp covering large areas.
The initial cost to acquire them from a Solar street light manufacturer is high. They provide free energy and do not require maintenance for years. Users would have saved more than the money they spent on it, making them more attractive.
Unlike powered street lamps, there is no need to draw transmission cables along the side of the road. This costs manpower along with the cost of the cable. As this is a mode of clean energy, there are also incentives given by the government in the form of subsidies and waiver of installation charges. The smart lights today are even better. They have sensors that can detect light intensity to increase or decrease the luminosity of the lamp.
It can also be programmed to turn on and off at a particular time, leading to less wastage and more savings. Overall if the initial investment charges are ignored, all in one solar street light or vapor-based lights are nothing short of a boon in disguise.