There is more awareness in the world now regarding the benefits and necessity of using renewable energy. Some of the reasons behind this thought are the need to conserve the environment and the high expense of other source of energy. Solar market has been growing rapidly and solar energy is one of the most accessible and popular types of natural energy. Solar power now has a wide range of application both in the commercial as well as residential premises.
Solar lighting technology has been developing gradually and customers seeking for eco-friendly lighting solutions are being attracted to the modern designs of solar lighting systems. Solar street lights are perfect for outdoor illumination and are cost effective with easy installation techniques. As a customer, it is crucial that you familiarize yourself with all the areas of solar street lighting before making the purchase. Since you will be given the choice to choose from a variety of solar products by your dealer, it is better to avoid confusion and have clarity of what your needs are.
Solar street lighting vs. traditional street lighting
Solar lighting definitely has a lot of advantages over traditional outdoor lighting. The biggest highlight of solar power is that the lights are charged with free energy and with the latest advancement in technology, the lights can hold their charge for long periods of time. This is a very important factor for outdoor lights during non-sunny days when there is less time and less sunlight for the lights to charge up.
Unlike traditional outdoor lighting, there is no underground cabling or trenching required to fix solar lights and in fact, the installation process is quite simple for solar street lights. A lot of money can be saved on operation and maintenance as the lights require no manual intervention once they are installed. Compared to conventional energy sources, solar energy does not produce any harmful emissions to damage the environment.
Factors to consider:
Solar street lights are used to illuminate private residential areas as well as public spaces or institutions and here are a few points that you should consider while choosing the best solar street lights:
Type of solar street lights
All In One solar street lights are a compact, new-age form of lighting that have solar panels, charge controller, battery and LED integrated into one single unit. These lights use motion sensors and switch on in the evening and after a time delay of 30 seconds, the lights automatically dim down and continue lighting with 20% brightness. Infrared waves from moving objects are detected by the motion sensors and lights are turned on electronically to 100% brightness. When there is no activity detected in the area after the time delay, the lights are adjusted to a dim mode of 20% automatically.
Integrated solar street lights or split solar street lights have the solar panel as a separate unit while the battery and the luminary are integrated into one unit. These lights do not operate with motion sensors; however, there are two models available to choose from. Model-I operates at full brightness from dusk to dawn and Model-II also operates from dusk to dawn but the first four hours at 100% brightness and then at a lower level of brightness until sunrise.
Area to be illuminated
Solar street lights are being used not only in urban areas but to light up rural areas too. Solar street lighting can be used for decorative purpose as well as to provide a sense of safety where there is lack of grid electricity. Solar street lights can be installed to cover any large area, both in your private landscape or a public space. A distance of 10 to 15 meters is suggested between poles to have equal and sufficient distribution of lights.
Public street lighting, park lighting, roadway lighting, dock lighting, fence lighting, sidewalk lighting, farm and ranch lighting, perimeter security lighting, and residential property lighting are a few of the areas where solar street lights are used usually. Ensure that the area where you are planning to install the solar street lights gets sufficient amount of direct sunlight and is not covered by tall buildings or trees.
Light source and light efficacy
Most traditional streets use high intensity discharge (HID) lights and when the temperature and pressure increase within the bulb, these lights tend to emit UV radiation along with light. Though the lights are very bright for public lighting, they need to be replaced every few years and are not energy efficient, so this type of light source is not a good option for solar lighting.
Light emitting diodes (LEDs) are the best choice for solar street lighting as they use small microchips to create visible light in the diode. This method is very efficient and the LED bulbs do not burn out like other light fixtures and instead, LEDs experience lumen degradation and slowly start dimming over time. Nonetheless, this is a slow process and LEDs do not need replacement for many years after installation. When the solar street lights are being placed for safety, the high-performing LEDs that produce over 120 lumens make a big difference in your landscape.
You need to be aware about the lighting efficacy of the LED you have chosen. This is measured in lumens per watt (lm/w). Lighting efficacy rating is important as it helps you understand how much light is generated compared to energy consumed. This is calculated by dividing total light output (lumens) by input power (watts). Higher lumen does not mean they are the best always so you must pay attention to how well the luminaire focuses its light.
Power storage
Solar street lights operate with the sun’s energy collected by photovoltaic cells. The solar energy is converted into electricity and stored in a battery which is later used to light up the LED. It is essential that you look for a solar panel and battery combination that can offer a large milliampere hour (mAh) capacity. You need to talk to your dealer to understand the ratio between the solar panel and battery while looking at luminaire energy draw. The panel must be sufficient enough to charge the battery and the battery must have enough capacity to run the light for multiple hours. Good power storage means less time to charge the battery fully, this helps the lights to continue to operate with even a few hours of sunlight.
Battery, solar panel and controller
Lithium ion or LiFePO4 batteries are used in modern solar street lights due to their compact size along with many other advantages in comparison with traditional lead acid batteries. Polycrystalline solar panels are commonly used; however, there are solar street lights available with monocrystalline panels too. Both are available in standardized 60, 72 and 96 silicon cell variants. PWM or MPPT charge controllers are used to regulate the flow of electricity going from the PV panels to the batteries.
Distribution pattern
There are mainly two distribution patterns, symmetrical and asymmetrical. Symmetrical lighting pattern can deliver in a condensed or even circular pattern. This is mainly used in landscaping. Asymmetrical lighting is used to brighten pathways and is ideal in safety applications as they are delivered in a narrow and elongated form.
It is always better to go for a trial before purchasing the product. You may ask your dealer regarding any kind of queries related to solar street lighting. It is important to understand that the brightness of the light will depend on the amount of sunlight it is exposed to but the quality of components used in the solar street light also matter in terms of efficiency of the product. Also, remember to check the certificate of authorization to confirm that the panels have met their specifications and have been tested.