The facts: what it is, how it works, and why it's the future
Not sure if you should make the switch to solar lighting? Have you heard about it, but don’t know what it is exactly and whether it’s worth having? Then you’ve come to the right place. In this article, you’ll find useful information, advantages, disadvantages, and a reflection on why public solar lighting is the future of global public lighting.
Night lighting of public areas of cities, streets and even roads, is probably a necessary evil these days. It ensures traffic safety, and at the same time increases our sense of personal safety when we are out and about at night. And in the winter months, when we are surprised by solid darkness at around five in the afternoon, we simply cannot avoid it. But on the other hand, public lighting is extremely wasteful of electricity. It is one of the largest consumers in individual municipalities, which also means a high monthly amount to cover the cost of the electricity used. Not to mention environmental pollution. Let’s take the United States of America as an example, where there are approximately 26 million classic street lamps, which together consume the same amount of electricity as 1.9 million households and generate the same amount of greenhouse gas emissions as 2.6 million cars.
That is why solar street lighting is a big step forward in the global transition that is leading us away from fossil fuel consumption. When we learn about solar public lighting together, we will understand how much its implementation would alleviate the energy-overloaded global system. The transition to LED lighting assemblies instead of traditional ones means a significant improvement in the efficiency of public lighting, and the global leap to solar-powered LED lighting represents an improvement in the public lighting system that is still unimaginable to many. But many cities on this planet are already enjoying the privileges that solar LED lamps bring. For example, the research, which you can view at the link, finds that the Ugandan cities of Kampala and Jinja have benefited greatly from the introduction of public LED solar lighting, which offers them a significantly cheaper and also sustainable solution for lighting public places.
What are solar street lights?
If you see a solar panel on a street lamp, it is definitely a solar lamp. They are often installed as a novelty where a classic street lamp used to stand, usually on an existing lighting structure (pole or candelabra). Or maybe you noticed it along a walkway where there was no lighting before because there is no electricity network in that place?
Components of a solar LED road lamp:
- solar panel: solar cells collect and convert solar energy into electricity.
- lighting system: the most common light source for solar lamps is LED diodes connected in LED light assemblies. LED systems are approximately 50% more efficient than their counterparts, such as traditional high-pressure sodium lamps. LEDs also provide high brightness and lower energy consumption.
- rechargeable battery: the energy produced and accumulated by the solar panel during the day is stored in the battery, where it is available for use at night.
- pole (candelabrum): solar lamps are installed on suitable poles, which are mostly sold separately from the lamp. The solar panel is installed on the top of the pole or lamp, or even better if it is already integrated into the construction of the solar lamp (these are “all-in-one LED street lights”).
The biggest advantages of solar LED street light:
- Installation anywhere outside, even where there is no electrical wiring: along roads, highways, streets, along various paths (pedestrian, cart tracks, etc.), in parking lots, bus stops, in city centers, parks, near traffic signs and pedestrian crossings, for lighting billboards, etc.
- Economy: solar LED lamps have practically no operating costs. After installation, you can leave more or less everything to sunlight.
- Since they operate with an LED lighting system, there is no need to change bulbs frequently.
- Certain tax breaks and state subsidies are also available for the new establishment of public solar lighting systems.
- Minimal risk of accidents: because solar lamps are not connected to the electricity grid and do not have external wiring, maintenance personnel are safer during installation and repairs, or at much lower risk of potential accidents.
- Environmentally friendly: solar lamps depend solely on the sun or solar energy to operate. The carbon footprint associated with public lighting is eliminated in this case.
- Independent of the electrical grid: solar lighting can be installed in remote places that are not connected to the electrical grid. So we can illuminate every dark corner of this world! Since we do not need to connect to the electrical grid for installation, the lights will also light up where there is no electrical wiring, and if there is, they will light up even when there is a power outage.
What should you pay attention to before buying solar LED street lights?
- Solar LED lights are more expensive than traditional street lights, but the initial installation cost is not necessarily higher than that of traditional lights, as solar lights do not require electrical wiring, which also represents a large initial investment.
- Snow or dust accumulation on the solar panel: if there is no maintenance (cleaning) in such conditions, the accumulation of solar energy is reduced or completely stopped.
- During cloudy and rainy periods, when there is less sunlight, it happens that the battery is not charged and the light does not light up until the first new appearance of sunlight. However, there are already solutions to this problem. You can find more about this at the link: Solar LED street lighting – high-performance and more environmentally friendly (maitim.si)
- Battery replacement: when the battery life is exhausted, it must be replaced with a new one, this is a maintenance cost that must be added to the initial purchase investment.
Curious how they work?
The operating system of solar street lights is the same or similar to other systems that include solar panels. The solar panel cells collect solar energy during the day. They convert the collected energy into electricity, which is stored in the battery. When the light begins to fade at sunset, the voltage of the solar panel drops below 5V, and the LED lighting assemblies gradually begin to light up. They shine throughout the night and consume the energy stored in the battery. The cycle repeats the next day.
Why LED?
LEDs and LED light assemblies have some wonderful properties that put them in an advantageous position when compared to conventional light bulbs. LED lights consume significantly less energy than any other commercially available lighting technology. The typical efficiency of an LED source, or its luminous efficacy, is between 80 and 130 lumens / watt. In addition, LED lights emit light in a directional manner, while classic light bulbs shine in a 360° circle. The LED light assembly thus eliminates the need to redirect the light, which leads to much lower losses than occurs with conventional light bulbs. The comparison is best explained by the illustration below:
Traditional fluorescent bulb: light shines in all directions, creating unnecessary energy loss.
The LED light source emits light in a specific direction, thus preventing unnecessary energy loss.
LEDs also have a much longer lifespan than other lighting technologies. You can bet that an LED light fixture will last for 50,000 hours or more. They can also offer very high quality light, few problems and low maintenance costs. Since LED light fixtures are more efficient than traditional bulbs, solar panels can also be smaller.
In addition, manufacturers are installing light sensors in solar LED street lights that detect different levels of light radiation at different times of the day. This ensures energy savings; for example, at sunset, when it is not completely dark, and towards morning, when it is already day, the lights use less light power. Now, even better, certain solar LED lights offer a motion sensor and different modes of use, which means that in the selected energy-saving mode, they only light up at 100% power when they detect movement. When the surroundings are still, certain lighting units are turned off, thus saving energy. The options are different, including, for example, 5 hours of operation at full brightness (evening) and then in the early morning hours until sunrise at 70% brightness until the sensor detects movement. Then, when it is idle again, it returns to 70% lighting power. To avoid complete darkness, motion sensors ensure that the lamp emits enough light even when there is no one nearby (yet).
Two types of solar LED lights: all-in-one and with separate solar panels
Thanks to developing technologies, the components of LED solar lights and batteries are becoming smaller and smaller. The smaller physical size of the components means that the lights can be assembled into smaller, integrated, compact lighting units in production.
All-in-one solar lights do not require wiring and are easier to install. When installing, the person does not need specific technological skills.
Due to the low energy consumption of LED lighting assemblies, solar street light systems have already extended their autonomy to 5+ days for cases when there is no sun during the day and the battery is not charging. Even in areas with intense rainy periods or lower levels of light irradiation, they gain a lot by installing solar systems. And here the technologies are still developing.
If we compare all-in-one solar LED lights with those that have solar panels separate from the lighting unit, all-in-one models are more resistant to extreme weather conditions, such as strong gusts of wind, due to their exceptional compactness. If the solar panel is separate from the light, it is more exposed and subject to damage due to difficult weather conditions.
In addition, compact systems are easier to transport, and transport is significantly cheaper. Since more compact all-in-one solar lights take up less space, storage costs are also lower than lights with a separate solar panel.
Price ranges of solar LED street lights:
A moment of truth. It is true that solar LED lamps are more expensive than conventional ones. The initial investment in the lamp itself can be up to 50% higher than for classic street lamps. However, other very important factors must also be considered. In the long run, solar LED lamps are actually significantly cheaper. And street lighting arrangements must be viewed in the long term.
Once solar LED lighting systems are installed, you will no longer receive any bills for the electricity consumed. Assuming that a street lamp lights up on average 4,000 hours per year and the average cost is 10.05 cents / kWh for an individual lamp, the costs associated with lighting for different lighting systems are as follows:
- High-pressure sodium lamp: approx. €350
- Mercury lamp: approx. €350
- Compact fluorescent lamp: approx. €52
- Metal halide lamp: approx. €70
- Solar LED light: €0
The good news is that you won’t need a trenching company to connect your solar lights to the grid. You can easily deduct this cost, which can be sky-high. Maintenance costs are also minimal compared to traditional lighting systems.
How to choose the best solar system?
Here is a list of things to consider before deciding to buy a specific model of solar lamp:
Luminous efficiency:
How do you know that you didn’t order a solar light that could light up an entire stadium when all you need is a solar light that will light up your garden? First of all, you need to check the luminous efficacy specification, which is usually expressed in lumens per watt (W). The lumens (lumen/W) tell you how much visible light the chosen light will emit. In the diagram below, you can see an example of a headlamp and how much light it emits based on its lumens (a higher lumen means more light emitted from the light source). So, the higher the lumens, the brighter the light emitted and the further it will reach.
Here are some recommendations for lumens for outdoor lighting:
- Light paths and roads: 100 – 200 lumens
- Stairs: 12 – 100 lumens
- Spotlighting: 700 – 1300 lumens
- Carports: 30 – 40 lumens
Battery:
Battery selection is key to ensuring you don’t get caught in total darkness in the middle of the night. Since sunlight is only available for a limited time during the day, batteries need to recharge as quickly and efficiently as possible. When used outdoors, a flashlight’s battery should last at least 10 hours at full brightness.
Resistance of the lamp to weather conditions (strong gusts of wind, heavy rain, snow, rust, heat, etc.):
A high-quality solar LED light must be resistant to all weather conditions. It must be waterproof, resistant to extreme heat, and resistant to rust and corrosion.
Sensors:
Make sure the lamp has a sensor for automatic on and off. It is also great if the lamp has a motion sensor, which ensures that the lamp only turns on fully when movement is detected, and then returns to energy-saving mode (lights at a lower power).
For all additional information and advice about solar LED street lighting, you can also contact the telephone number +386 1 830 33 60 or the mobile number +386 41 618 253. You are also invited to view the offer at the link:
