The service life of solar street lights is generally 2-5 years. Although it is technically possible to achieve a service life of 10 years, because the initial cost is too high, instead of designing a long battery life, it is more cost-effective to replace the battery every five years. This is different from the battery technological breakthroughs and is also related to the year-by-year decrease in costs.

When we talk about the service life of solar lights, we usually refer to the entire light. Next, let’s take a look at the service life of different components such as photovoltaic panels, batteries, LED lights, controllers, and light housings.

The Lifespan Of Each Component

Solar Panel

Solar panels are engineered to withstand the test of time, with manufacturers typically offering warranties spanning 25 to 30 years, and in some cases, even up to 40 years. Despite this impressive longevity, solar panels experience a gradual decline in efficiency over their lifespan, a phenomenon known as solar panel degradation.

Laboratory results indicate that the average solar panel degradation rate is approximately 0.5% per year. This means that over time, solar panels may produce less electricity than they originally produced, perhaps as little as 2% after four years and less than 10% after 10 years.

The life of photovoltaic panels is much longer than that of solar LED lights. It should be noted that regular cleaning is required during use to reduce the degradation rate.

Battery

Solar lights mostly use lithium iron phosphate batteries, and according to current technology, the lifespan of new batteries is 5-10 years. However, the actual lifespan of solar batteries in the market is generally 2-5 years. The battery lifespan is more based on cost and the lifespan of other components (if a driver can only be used for 3 years, it is not necessary to use an expensive battery with a 10-year lifespan).

Taking two types of battery systems, 3.2V and 12.8V, as examples: Solar light batteries with a voltage of 3.2V typically use recycled battery cores, which are often recycled from electric vehicles and termed “graded” batteries, with a lifespan of 1-3 years. “Graded” batteries are relatively inexpensive.

Solar batteries with a voltage of 12.8V generally use brand-new cores, with a lifespan of 3-5 years. The 12.8V battery system connects four 3.2V batteries in series, requiring higher stability for each battery, thus necessitating the use of new cores, despite the higher price, they have smaller voltage tolerances.

“Graded” batteries typically have a cycle life of about 800-1300 cycles, while brand-new LiFePo4 batteries have a cycle life of over 2000 cycles, with one cycle representing a complete charge-discharge cycle.

Our GCOTS solar street lights are designed to work continuously for 12 hours after being fully charged and can work continuously for 2 days under cloudy or rainy conditions. Once the working mode is set, if a 36Ah battery discharges 12Ah overnight and is fully charged the next two days, working continuously for 12 hours each night, then a total of 36Ah of electricity is used in these three days, equivalent to one day’s electricity—a complete cycle.

The working mode determines how much discharge the solar light undergoes within a certain working time, so the battery life is related to the number of battery cycles and the set working mode.

The price of batteries is relatively high, and the cost will gradually decrease as technology advances, so replacing a new battery after a few years will be more cost-effective than investing in a larger-capacity battery at the beginning. From a cost perspective, this is why most solar light batteries have a service life of 2-5 years.

LED Chips

Many LED chips can actually last close to 100,000 hours if operated correctly. Although the circuits and resistors inside the LED will gradually age due to long-term use, high-quality LED chips can still be used for 5-8 years.

Good heat dissipation performance can prolong the LED chips’ use time. This performance is influenced by both the lamp’s structure and the LED chip’s performance. For example, SMD3030 has a larger package size compared to SMD2835, providing more internal space and better heat dissipation efficiency. Therefore, under the same power conditions, SMD3030 has a longer lifespan.

Controllers

Whether it is a PWM or MPPT controller, the current shelf life provided by the factory is 2-3 years, and the designed service life of the product is 5-10 years, which varies according to different usage conditions.

Light Housings

The lifespan of aluminum and iron solar light housings may vary depending on factors such as material quality, installation environment, and maintenance level. Generally, compared to iron housings, aluminum housings tend to have a longer lifespan because aluminum is more corrosion-resistant and rust-resistant.

The lifespan of aluminum housings can reach 10 to 20 years or longer, especially if they are properly maintained and protected from harsh environmental conditions (such as exposure to saltwater or extreme temperatures). On the other hand, iron housings may have a shorter lifespan due to susceptibility to rust and corrosion, which can lead to performance degradation over time.

To extend the lifespan of aluminum and iron solar light housings, it is necessary to apply high-quality protective coatings through surface spraying and to conduct regular maintenance. This includes cleaning the housing to remove dirt and debris and checking for any signs of damage or corrosion. Additionally, proper installation in suitable locations helps prevent premature deterioration and ensures longevity.

For the moment, the industrial supporting facilities in the solar LED lighting industry are quite mature. Whether it is photovoltaic panels, batteries, LED chips, lamp housings, or spare parts such as screws, wires, and waterproof glue, they can be used for many years. However, taking into account the initial investment cost, future technological progress and cost reduction, the current design of a product life of 2-5 years is more in line with the needs of most application scenarios.