Solar lighting, especially solar street lighting, is a field with high technological content and strong professionalism; solar lighting industry, with its clean and green characteristics and the effect of caring for the earth, should be an industry worthy of respect. Solar street lights should be durable goods and asset products.
However, in recent years, due to the vicious low-price competition of some suppliers who lack integrity, the solar street light market is being led to an embarrassing situation full of misleading information, disorderly competition, and even dirty fraud. The price of solar street lights with the same wattage may differ by 10 times; even if the appearance is similar, the price will also have a gap of 2 to 3 times. This is the current state of chaos in the market.
Solar street light is a complex system, but this is only for the manufacturer’s manufacturing process; for dealers, contractors, installers and users; it is actually very simple to distinguish the pros and cons of solar street lights! After getting the samples from different manufacturers, according to this strategy, disassemble it and look at each accessory, and you will have a 60% chance of seeing the truth.
The difference between high-priced and low-priced products is mainly reflected in the following aspects:
1 solar panel
1. Power & Size: Generally speaking, the power of a solar panel depends on its size; when the prices of two solar street lights differ greatly, first compare their solar panel sizes.
2. Type & Efficacy: The efficiency of monocrystalline solar panels is higher than that of polycrystalline solar panels; with the same size, the power of monocrystalline solar panels is 20% higher than that of polycrystalline.
√Professional solar street light 20W
√Monocrystalline solar panel power: 35~40Wp √Solar panel size: 820*272 mm
× Low price solar street light 20W
×Solar panel power: 7~8Wp
× Solar panel size: 270*220 mm
3. Quality problems & potential defects: The above two products can be distinguished from each other even through product pictures. The battery color of the solar panel is dark and light, and the welding process of the solar panel is high and low, which can be recognized by the naked eye. Even so, solar panels with the same size and appearance still have great differences in quality, power, and service life. The most effective and reliable way to test the quality of solar panels is to use a solar simulator (IV tester: to test the power of the solar panel), a solar cell defect tester (EL tester), similar to an X-ray inspection of the solar panel, To detect potential defects in solar panels.
Two controllers
1. Type of controller: MPPT or PWM? Usually, MPPT controllers are more efficient than PWM, and cost more.
2. IP grade: IP: Refers to the waterproof grade of the controller, which plays a decisive role in the service life of the controller. The bare-board controller without waterproof treatment on the right side of the figure below has a much lower service life than a controller with a high waterproof level.
3. Maturity of technology: Generally speaking, the more projects a supplier participates in, the more experience and reference data, the more mature the technology.
4. Aging and manufacturing process: There will also be suppliers who use controllers with similar appearance, as shown in the picture above on the left; but if the technology is not mature, there is still a big difference in quality. The best way is to choose a supplier that has standard operating procedures in the manufacturing process and is well-aged. In the case of not being able to visit the factory, let the supplier first provide: photos and videos of the workshop; or through video calls to understand the manufacturing process of the factory; do some research on the supplier and learn about the products from their existing distributors and service feedback. Always remember, don’t look at advertisements and prices for this product, but look at word of mouth!
three batteries
The battery is the key to affect the cost and the supplier’s quotation. It is the deepest part of the solar street light. Most unscrupulous merchants make huge profits through low-priced and inferior batteries.
1. Types of batteries: There are currently two types of batteries most commonly used in the market: lithium iron phosphate batteries (LiFePO4), and ternary lithium batteries (Li(NiCoMn)O2.
Due to the high temperature inside the lamp, lithium iron phosphate batteries are the best choice for solar street lamps. Especially for installation areas where the annual maximum temperature is higher than 40°C, lithium iron phosphate batteries are the only feasible solution.
2. Battery capacity: battery capacity is the gray area where the cost of solar street lights is the largest. Buyers have no way to effectively detect battery capacity, which provides unscrupulous merchants with an opportunity to falsely report battery capacity, deceive buyers, and make huge profits.
3. Battery grade/quality: Even if both suppliers use lithium iron phosphate batteries with the same capacity, but the battery grade/quality is different, there will be huge differences in cost, product quality and lifespan.
4. Waste batteries: The currently popular low-priced products may also claim to use lithium iron phosphate batteries. When the price is too low, it is very likely to use waste batteries eliminated from electric vehicles. In short, solar street lights with a system voltage lower than 12V use waste batteries. The cost of used batteries is lower than that of lead-acid batteries. The service life of such street lamps is unknown.
Four LEDs
1. LED chip & LED light effect: Different suppliers use different LED lamp beads, and the cost is also different. Take the 3030 chip as an example. For chips of the same size, the manufacturers are different, and the light efficiency, light decay and service life of the chip are very different. It is recommended to choose suppliers who purchase brand-name chips, such as: PHILIPS, CREE, SEOUL, OSRAM. Naturally, each manufacturer will claim to purchase brand-name chips; then please provide a copy of the purchase order as a verification basis!
2. Number of LEDs: At present, there is a wrong trend of thought: the more LED beads, the higher the wattage of the lamp. So everyone started counting the lamp beads. In fact, adding lamp beads is almost meaningless to increase the brightness (luminous flux) of the lamp. Taking Philips 3030 lamp beads as an example, when the driving power is within 0.5~0.7W/piece, the luminous efficacy of the lamp beads is in the high luminous efficiency range. Therefore: it is the actual electric power that determines the illuminance of solar street lights, not the number of LED lamp beads.
√ High quality 80W solar street light
√ Equipped with: 4*36 LED in one module
√ Total: 144 Philips 3030 lamp beads
× Low price 200W solar street light
× Equipped with: 4*56LED in one module
×Total: 244 lamp beads
I just want to ask: How can a 15W solar panel drive a 200W lamp?
3. Radiator: A reasonable cooling and heat dissipation device is very necessary for the LED light source. The LED module without heat sink will rapidly decay and age, the brightness of the lamp will drop rapidly, and the service life will be greatly shortened.
4. Aluminum substrate: SMT patch, aging: the basic circuit board of the aluminum substrate LED module, the LED light source is welded on the aluminum substrate through SMT technology, and it is also the first and most basic structure of LED heat dissipation. Different quality MCPCBs cost 2 times or even more. Aging is a key process for all electronic products, and it is also applicable to LEDs. However, the vast majority of suppliers in the market currently do not do burn-in, or the burn-in time is much lower than the industry standard of 12 hours. I even mistakenly thought that assembling the LED module on the solar street light and turning on the light for several hours is called aging.
5. LED lens and light distribution: A professional solar street light should have a professional IES design light distribution, and the IES type meets the project requirements.
6. Performance: Brightness & Light Distribution When people buy solar street lights, what they buy is not the lamp itself, but the light it emits. Therefore, the core focus should be on: compare the luminous flux (LM) of the lamp, that is, the brightness, rather than the so-called wattage (W)! An illuminance meter and some simple testing methods can hide the lies of unscrupulous merchants:
(1) Put the No. 1 lamp in the darkroom, use an illuminance meter, measure the illuminance value from different angles and different lamp distances, and record it.
(2) Turn off light #1; measure another supplier’s light #2. Use the same method, at the same location, distance, measure and record.
(3) Compare the data of the two lamps.
Some smart suppliers will make the lights very bright in the first few hours of lighting to deceive buyers.
In order to avoid being deceived, it is recommended that you: keep the light on for 12 hours; and, do a test every 2 hours to collect data for comparison.
five shells
1. Materials: High-quality solar street lights use aluminum alloy casings, and low-cost street lights use iron or plastic materials.
2. Screws & bolts: 304 stainless steel screws and anti-corrosion bolts are used for high-quality solar street lights; 316 screws are used for street lights installed by the sea.
3. Shape & size: For professional solar lighting projects, the focus should be on the rationality and stability of the lamp body structure, not the shape of the lamp; there is no need to be overly entangled in the shape or spend too much on the appearance. When purchasing street lamps, relative brightness, quality, lifespan, and appearance should always be the last considerations.
6. Durability & Warranty:
At present, too many suppliers make random promises in order to make quick money in the short term, such as “8-year warranty” and so on. Buyers should be more vigilant. For suppliers who are indeed interested in cooperation, it is recommended to conduct background investigations from the following aspects:
1. Industry experience
2. Technical background
3. Quality assurance system
4. Successful case reference
5. Contact the customers or distributors that the supplier is serving to learn about customer feedback.
Post time: Feb-15-2023