Solar Led lights are self-powered fixtures that generate and use their own electricity without relying on external sources such as the grid or generators. These are portable and suitable for a variety of applications without restricting them to the wired electrical circuits.
The solar LED lights are designed to run off the batteries that the solar panels charge during the day. Since the lights are necessary when there is no daylight, they must rely on stored energy. They, therefore, have batteries that store the energy the PVs capture during the day and then discharge this during the night.
The lights are ideal for outdoor applications since they rely on the sunlight to charge the inbuilt or external batteries.
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Main components of a solar LED light
A basic solar LED light consists of the following four components.
- A solar panel to convert sunlight into electricity
- A battery to store electricity during the day and feed this to the bulbs during the nights.
- Controller board and optional sensors
- LED bulbs to provide the light
How do the solar LED lights work?
The solar panel connects to a charger and a circuit to regulate the electricity and store it in the battery without causing any damage. From the battery, the LED solar light has a driver or control circuit to ensure that the bulbs get the correct amount of electricity. Some advanced systems may have sensors and remote control circuits. This enables automatic turn on and off of the LED lights or even dimming depending on the requirements.
In some lights, a solar panel is usually a separate unit. This makes it easier to place it in a position and orientation that ensures that it receives full sunlight and maximum conversion throughout the day.
While some lights have manual controls, others include photosensors and dimmers to automatically turn the light on or off depending on the daylight. But for such an automatic function to work efficiently, the light sensors need to be placed in a location where there is no other source of light.
Sizing the PV panel, battery, and output light requirements
There should be a proper matching of the storage device in relation to the power requirements as well as the PV rating. As such, the solar panal must have adequate capacity to fully charge the battery in use. Similarly, the battery should have enough storage capacity or rating to power all the LED bulbs throughout the entire night or period they user needs lighting.
Ideally, the solar panels should charge the battery to the maximum. However, this may not happen during the seasons with short days or heavy overcast. Using batteries that can provide slightly longer periods of light ensures that they do not exhaust their charge completely and can survive days when the battery doesn’t get the full charge. In addition, optimizing the battery helps in reducing the consumption hence prolonging its energy.
Most often, the batteries can last for over 10 hours, but some applications do not require all these hours. This means that the lights will still operate all the times including when the days are shorter.
What determines light levels and battery charge?
The solar LED light converts the sunlight energy into electricity during the day. The light then stores the energy in the integrated battery. During the night when there is a need for light but no sunlight, the battery supplies power to the bulbs, hence providing the necessary illumination. The duration of the light depends on the size of the battery and amount of charge it holds stores during the day as well as the total power consumption by the bulbs.
The amount of charge is dependent on the size of the panel and sunlight falling on the PV. Other factors that influence the amount of electricity the light generates include weather, position, and orientation of the solar panel, its efficiency and more.
If powering several high wattage bulbs, the fixture will require a relatively powerful PV and bigger battery capacity.
Extending battery charge
There are several ways of extending the battery charge and ensure it provides energy throughout the night. For example, automating the light using sensors and intelligent controllers make provides more and efficient control.
The automation includes using daylight sensors to turn on the light when it becomes and off when the day. Others are motion or activity sensors which work in conjunction with dimmers to adjust the level of lighting depending on the presence or absence of a person. For example, the light can be programmed to provide less light when there is no activity. When it detects a person or activity, it can then adjust the light to full brightness.
Advantages of solar LED lights
- The lights do not depend on the grid and can work anytime without fear of outages.
- Since they do not consume electricity from the utility company network or standalone generators, it has minimum running costs.
- Flexible design to cater a a wide range of environments and light requirements.
- Since they do not require the grid, they are portable and can be installed anywhere including remote areas. This helps in providing light to almost any location.
- The solar LED lights rely on renewable energy and thus environmentally friendly. They have no demand for electricity from generating plants and do not emit a lot of heat to their surroundings.
- No interdependencies with other systems. Since the lights are self-powered, their operation does not require other equipment or system to work. In the grid systems, a problem in a different section may trip the entire circuit and cut off areas with no issues. For the solar LED lights, a failure in one does not affect the other lights.
- No cable cost, installation labor or theft. Cost of laying and maintaining cables and associated accessories can be high, especially in remote areas and where there is a great distance to cover. This is not necessary with the solar LED lights since they are independent and only requires a source of light.
Disadvantages of solar LED lights
- They are expensive because of their construction. Since the solar LED light consists of a solar panel and a battery, they are more costly compared to the standard lights.
- Since they are usually standalone without any form of wiring and can be installed anywhere, they are easy to steal. Because of their higher monetary value, they are very appealing to thieves.
- Risk of dust, moisture or snow covering the horizontal surface of the PV, hence reducing the light to energy conversion and lamp’s performance. To avoid these, the lights require regular cleaning, which can increase operational costs.
- The rechargeable batteries may require a few replacements over the light’s service life, and this will increase operational costs.
- The solar LED light has more potential points of failure. Although the LED bulbs and solar panels have long lifespans, of over 50,000 hours, the other components such as the battery and charger unit may not. This increases the possibilities of failures that can make the light non-functional.
Types and applications of solar LED lights
There is a wide variety of solar LED lights with different designs and capabilities to suit almost any indoor or outdoor application. Although they are mostly used for outdoor environments, they are also suitable for normal and emergency indoor lighting. This is especially improtant in areas without grid or other sources of electricity.
Typical fixtures include solar LED light lanterns, solar LED floodlights, Solar-powered LED lamp posts, decorative solar LED lights, Solar LED spotlights, Solar LED streetlights and more. These are used in applications and areas such as:
- Areas with no grid electricity
- Street lights
- Pathway lights
- Farm lights
- Group houses
- Military lights
- Schools and college
- Remote area lights
- Sidewalk lights and more
Conclusion
Solar LED lights are great for outdoor lighting and other areas with no electricity. The lights generate and store their own energy which is then used during the night. It is also applicable for indoor applications but will require mounting the PV panels outside where they can receive sunlight.
The solar lights have several advantages, including but not limited to no grid electricity consumption, no wires, and easy installation, better for the environment and low operational costs.
