If you’ve ever walked any street anywhere in the city, chances are you’ve come across street lights. These public infrastructures are very handy light sources, especially at night when there isn’t much light around, and these can at least help you navigate while walking, driving, or even commuting. Interestingly, however, if you see street lights in various rural areas or areas, you can swear there isn’t any grid. That is how the matter? In this case, you’ve likely encountered solar powered street lights.
What are solar powered street lights?
The sun is one of the most abundant renewable energy sources. Solar cells or photovoltaic cells make it easier to harness this infinite and free energy source. You may have seen solar panels attached to the poles of some street lights. These street lights are undoubtedly solar powered and are experiencing full autonomy from the grid.
Solar powered street lights are powered by solar panels integrated or mounted on poles. It has a smart rechargeable battery that powers the LED lights.
Solar powered street lights are one of the latest technologies to support green initiatives. They are environmentally friendly, smart and economical lighting solutions. Solar LED street lights help provide a good living environment while reducing operating and energy costs. Globally, some countries have converted traditional street lights to LED street lights, and achieved good results.
Are solar powered street lights worth the investment? Solar powered street lights are as efficient as solar power is extremely efficient, especially now that the world is pushing for a greener energy system to avoid the adverse effects of climate change. According to World Energy, the global average annual amount of solar radiation alone can generate as much energy as 140 cubic meters of natural gas, 200 kilograms of coal or a barrel of oil. This means that, with the right optimization process, solar energy can indeed replace the modern energy we have today.
Basic operation of solar powered street lights:
The basic operation of solar powered street lights is to automatically turn on and off by setting specified parameters in the controller of its control circuit.
When dusk comes, the voltage drops to about 5V. This signals the LED light to turn on and use the power stored in the battery. As dawn approaches, the voltage rises until it exceeds 5V, which causes the LEDs to turn off. At this point, the battery will be charged again. This process is repeated every day.
Of course, solar powered street lights have some complex features that make them a smart lighting solution. In the chapters that follow, we’ll discuss how each component helps solar powered street lights work efficiently.
Solar LED street lights are one of the many classifications of existing solar powered street lights. In addition to solar LED street lights, other types include:
Sodium vapor street lights use sodium as the main light source. Sodium held in an excited state can release the light it has stored, thanks to solar panels that absorb sunlight during the day. The battery can receive the converted electrical energy – due to its rechargeable nature, sodium-based street lights do not require any wiring. This makes them suitable for squares, parks, residential areas, public spaces and streets.
Street lights based on induction technology use lamps without filaments, thus preventing the lamps from breaking down more quickly. This at least helps the lamps have a longer lifespan. Using this technology, lamps can be used for up to 10,000 hours. Induction-based street lights also have lower maintenance costs and generate less heat.
How do solar powered street lights work?
Smart solar LED street lights are modern integrated solar street lights with enhanced features and components to control, manage and provide an effective lighting experience.
The smart street light adopts a modular design, which is easy to install and maintain. They usually have a degree of protection up to IP65.
Solar powered street lights work as follows:
1. Solar panels collect solar energy
Photovoltaic modules or solar panels detect and absorb sunlight. Currently, there are two popular types of solar panels used in the solar industry. These are monocrystalline and polycrystalline solar panels.
Monocrystalline solar panels are widely used in solar powered street lights technology because it captures solar energy efficiently, even in cold weather.
The solar panels are mounted on top of the light poles via aluminum brackets. Some designs have a range of flexibility by making the panels adjustable. This is to enable the different solar panel positions to be used more efficiently.
2. Rechargeable batteries convert solar energy into electricity and store it
Solar powered street lights have rechargeable batteries. From solar panels, the energy captured from the sun will be used for rechargeable batteries. The battery stores energy during the day and uses it to power the LED lights at night.
Rechargeable batteries are a type of deep cycle battery designed to maintain continuous current for longer periods of time. Therefore, it can effectively discharge current from time to time without losing its efficacy. Solar street light batteries are designed to be charged for more than a day. A typical design margin is 5 days to maintain lighting during winter and rainy seasons.
The solar lighting industry uses two types of deep cycle batteries. These are lead acid and lithium batteries.
3. Smart controllers regulate stored energy and communicate electronically with other devices
The stored energy is regulated in an intelligent controller. Smart controllers help control the flow of voltage and current to prevent overcharging the battery. This component is actually installed between the solar panel and the rechargeable battery to be able to accept signals from both components. The intelligent controller manages the signals to regulate the amount of voltage and current coming from the panel.
There are two main types of smart controllers used in solar lighting technology. These are PWM and MPPT. Modern solar LED street lights are equipped with MPPT charge controller as it is a more reliable charge controller than PWM.
As the core component of solar powered street lights, its role is to control the following:
- Dusk to Dawn Control
- time control
- motion sensing
- LVD disconnect
Dusk to Dawn: Voltage is monitored and metered. When the controller detects that the input voltage is low, the LED light will automatically light up. When the voltage increases, it will signal to turn off the LED light.
Time control: The MPPT controller also starts the dimming action and light intensity of the solar street light. For example, at certain times of the day, LED lights can project different levels of illumination, as follows:
6-7pm – 70% brightness
8pm to 10pm – 100% brightness
11pm-5pm – 30% brightness
When the sensor detects a person, it automatically turns to 100% brightness, even at any time of night. Therefore, energy use is conserved.
Motion Sensor: Motion sensor can be microwave or infrared. Infrared motion sensors detect the heat of an object or person, while microwave sensors let reflected signals into the sensor.
Motion sensors are able to detect people within a certain distance before turning on the LED lights. This can be a distance of 5m to 6m.
Low Voltage Disconnect (LVD) Prevention: Overcharging can negatively impact battery performance and its lifespan. The intelligent charge controller prevents overcharging by monitoring low voltage and overcharging.
4. Remote Management Software (RMS)
Remote Management Software (RMS) sends a signal to your device to monitor street lights remotely
Remote management software enables active monitoring of light level performance to avoid excessive power usage and greater costs. It provides a complete report on the operational status of the solar powered street lights system. This also allows the owner to monitor and control each light fixture with remote access via phone, PC or tablet.
5. LED lights for street lighting from dusk to dawn
Finally, the stored energy is used to power the LED lights when night falls. Manufacturers use LED lights because it is the most energy-efficient light source.
Note that the LED lights on solar powered street lights only glow from dusk to dawn, usually for 12 hours. Also, adjust the brightness during these times. As mentioned above, light intensity is highest during peak hours. The dimming effect kicks in after peak hours, but it automatically adjusts to full brightness whenever the sensor detects a person.
Solar powered street lights are used with LED lights, such as light-emitting diode lights. Therefore, LED-based lamps have special compounds that emit light when direct current from the source battery is passed through it. LED street lights are practical because many companies have LED lights in different styles, shapes, and sizes. Its durability also means it can last up to 50,000 hours. It also tends to be much smaller than other lamps since it requires very little current to operate. Likewise, the solar panels required to make solar powered street lights work are much smaller, thus reducing construction costs.
Solar powered street lights rely on the photovoltaic effect, which enables solar cells to convert sunlight into usable electricity. This is done when negatively charged electrons push solar energy into positively charged spaces in the cell.
This process allows the transfer of solar energy into electrons – into direct current. Similar to how electricity-based gadgets work, the wires from the solar cells are then connected to the batteries to transmit fresh direct current from sunlight.
When night comes, the solar cells will stop the conversion process as the sunlight disappears. The photoreceptor will help turn off the solar cell when there is not enough sunlight to convert it. This is when the battery starts powering the LED light through the other wiring.
We hope this article helped you understand how solar powered street lights work. You can see how amazing this smart technology is compared to traditional street lights and older versions of solar powered street lights.
Bbier is a solar powered street lights manufacturer located in China. Please feel free to contact us for more information about solar powered street lights. We are also happy to accept quotation requests.