Modern solar street lights are automatic, energy-efficient and designed to make the operation easy for the users. To understand the making of a solar street light, it is important to know the main parts of a solar street light system. According to the system type and applications, different components should be selected. Following is a brief mention of basic features of each part of a solar street light.
Solar Panel:
Solar panel or a photovoltaic module is an assembly of solar cells mounted in a framework. This helps to convert solar energy into usable direct electricity in order to run the solar street light. Polycrystalline solar panels are more popular and affordable and monocrystalline solar panels are well known for their high efficiency. The amount of electricity generated is determined by the size of the solar panel.
Rechargeable Battery:
The converted electricity gets stored in a rechargeable battery which is later used to light up the LED at night. Traditional solar lights used lead acid batteries; however, the latest solar street light designs have in-built lithium-ion or lithium iron phosphate (LiFEPO4) batteries. Lithium batteries charge faster, do not demand any maintenance, are compact and lightweight.
Charge Controller:
The converted electricity gets stored in a battery through a charge controller. The main function of a controller is to prevent the battery from overcharging and undercharging. It protects the battery by regulating the voltage and prevents the backflow of current when the conversion process stops at dusk. In a solar street light, PWM or MPPT controller is used and the controller must have enough capacity to handle the current from PV array.
Light Source:
LED lamps consume less energy and provide much higher lumens compared to fluorescent and incandescent lamps. They emit zero ultraviolet rays and need no warm-up time to switch on. You should consider the luminosity per watt and light distribution pattern while purchasing your solar street light. LED lights are less prone to failures and have an average lifespan of 50,000 working hours.
Pole:
Many modern solar lights can be effortlessly fixed on walls; however, if used for illumination of a larger area and if the panels used are heavier, they must be installed on poles. Thermally galvanized steel is used to construct light poles and the preferred height is 5 meters and above. The lighting unit is mounted on top of the pole and the erected pole must be secured at the base with concrete.
Interconnecting Cables:
For an integrated solar street light, the solar panel is an independent unit and in order to connect the luminary unit and the panel, there is some cabling required. The size and length of the interconnecting cables may vary depending on the height of the pole and the current that is being carried to the light. Technical guidelines must be followed to connect the cables precisely.
All the components are attached to the pole with the help of aluminium brackets and frames and the brackets are usually powder coated or anodized. All the components used are weather-resistant, rust-free and waterproofed. With the ongoing advancement in solar technology, there is a huge range of solar street lights available now for highways, streets, gardens, parking lots, play areas, residential properties, etc.
Solar street lights are independent outdoor lighting units that can operate by sensing the presence and absence of sunlight. The new-age all in one solar street lights have motion sensors attached to them where they can sense movement and glow up and remain dim otherwise. Integrated solar street lights are designed to work at full brightness for a few hours and then at a lower level until morning.
The making and specifications of each solar street light are different and you need to ask yourselves a few questions before you choose a light:
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What kind of area do you need the solar street light for?
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What is the size of the area and its length?
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What are your lighting requirements (domestic/commercial, night-long illumination, with/without motion sensor)?
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Are you looking for any special lighting features?
- What is your total budget?