In recent years, there has been a sharp increase in the use of solar panels, which has brought a range of benefits to homeowners looking to harness solar energy, including reduced energy costs, increased home value, and a smaller carbon footprint. However, the upfront cost of solar panels is also quite high. Naturally, before making a significant investment in solar panels, homeowners want to know how many years they can expect to use them.
In this article, we will answer questions about the lifespan of solar panels, the factors that can affect their lifespan, and how to make them last longer to capture the most sunlight and get the most value out of them.
structure of solar batteries
The tempered glass protects the main power generation body (such as the battery sheet) and must have high light transmittance (generally above 91%) and be super white tempered.
EVA (ethylene vinyl acetate) is used to bond and fix the tempered glass and the main power generation component (such as solar cells). The quality of transparent EVA directly affects the lifespan of the solar panel. EVA exposed to air can age and turn yellow, which will affect the transparency of the panel, and thus the power generation quality. In addition to the quality of EVA itself, the laminating process of the panel manufacturer also has a significant impact. For example, if the adhesion of EVA is not up to standard or the bonding strength between EVA and tempered glass/backsheet is insufficient, it will cause premature aging of EVA and affect the lifespan of the batteries panel.
crystalline silicon and thin-film solar cells
The mainstream power generation components on the market are crystalline silicon solar cells and thin-film solar cells, each with its own advantages and disadvantages. The equipment cost of crystalline silicon solar cells is relatively low, but their consumption and cost are high. However, their photoelectric conversion efficiency is high, and they are suitable for generating electricity in outdoor sunlight. The equipment cost of thin-film solar cells is relatively high, but their consumption and cost are low. However, their photoelectric conversion efficiency is only slightly more than half that of crystalline silicon solar cells, but their low-light performance is excellent, and they can generate electricity even under normal light, such as the solar cells on calculators.
The sealing effect of silicone gel is used to seal the intersection of the module and the aluminum alloy frame, and the intersection of the module and the junction box. Some companies use double-sided adhesive strips or foam to replace silicone gel. However, silicone gel is widely used in China due to its simple process, convenience, easy operation, and low cost. Generally, materials such as TPT and TPE must be resistant to aging. Most module manufacturers offer a 25-year warranty. Tempered glass and aluminum alloys generally do not pose any problems, and the key lies in whether the backplane and silicone gel can meet the requirements.
The aluminum alloy protective laminated parts play a certain sealing and supporting role.
The junction box protects the entire power generation system and acts as a current transfer station. If a short circuit occurs in the module, the junction box will automatically disconnect the short-circuited battery string to prevent the entire system from being burned out. The most critical component in the junction box is the selection of the diode, which varies depending on the type of battery sheet in the module.
What affect the lifespan of solar battery?
There are several factors that can affect the lifespan of solar panels and increase or decrease their efficiency. Here are some of the main factors:
Quality: The quality, materials, and type of solar panels you install will affect their effectiveness and lifespan. Although cheaper materials may be more affordable, they may also degrade faster.
Climate: Extreme weather can shorten the lifespan of solar panels. If you live in an area with cold, heavy rain, snow, and hail, you may find that your solar panels degrade faster.
Installation: The way your panels are installed, as well as the rack system they are mounted on, can affect their degradation rate.
Maintenance: Like anything valuable that you purchase, solar panels can last longer with proper maintenance. If the panels are dirty, have debris on them, or are not maintained regularly, they may degrade faster.
Definitive study results on solar lifetime
According to NREL research, the degradation rate of solar panels is about 0.5% per year, which means that after 20 years of use, solar panels will still be able to generate about 90% of their new power.
Based on these research results, solar panel manufacturers typically offer warranties of around 25 years or longer. For newer or well-built systems, solar panels can last up to 30 years.
Although the warranty period for solar panels is typically 25 years, it is enough to meet your expectations in terms of time. However, studies have shown that solar panels will still operate at lower efficiency for a long period of time after the warranty period expires.
let’s make an example:
We assume that a 0.5% efficiency loss each year, and a 25-year warranty period for solar panels, your panels should still produce energy at 75-87.5% of their rated output when the warranty period ends.
Photovoltaics (PV) System Lifespan Research
Photovoltaic module output power attenuation:
The attenuation rate of photovoltaic modules refers to the ratio of output power to nominal power under standard test conditions (AM1.5, module temperature 25°C, irradiance 1000W/m2) after the photovoltaic module has been running for a period of time.
Output power attenuation of crystalline silicon photovoltaic modules:
The first stage is called the initial light-induced attenuation, that is, the output power of the photovoltaic module drops by 1% to 2.5% in the first few days of use, but then tends to stabilize.
The second stage is called the aging decay of components, that is, the extremely slow power decline in long-term use. The main reason is related to the slow decay of the battery and the performance degradation of the packaging material. Manufacturers of crystalline silicon components generally provide a 25-year power warranty. It is generally promised that the power will not be lower than 90% of the initial value at the end of the 10th year, and not lower than 80% of the initial value at the end of the 25th year.
In the third stage, PID potential energy induces attenuation (cells discharge to the frame of the module, that is, weak leakage occurs in the packaged photovoltaic module)
In fact, 78% of the systems tested had a decay rate of less than 1% per year. This means that after 25 years of use, about four out of five solar panels are still operating at 75% efficiency or better. At this point, it can be estimated that your solar panels will still produce a certain capacity of energy long after the warranty period ends.
How to Make Solar Batteries Last Longer?
As you can see, some factors that cause solar panel degradation are controllable, while others are not.
Fortunately, here are some tips to make your solar batteries last longer:
- Use high-quality batteries: When it comes to solar batteries, you get what you pay for. Investing in high-quality batteries may cost more upfront, but it can save you money in the long run. High-quality batteries tend to have longer lifespans and can withstand harsh weather conditions better.
- Choose the right battery type: There are different types of batteries that you can use for your solar panel system, including lead-acid, lithium-ion, and flow batteries. Each type has its advantages and disadvantages, and it’s important to choose the right type that suits your needs.
- Maintain the batteries regularly: Regular maintenance is crucial for the longevity of your solar batteries. You should inspect the batteries at least once a month and check for signs of damage, leaks, and corrosion. You should also clean the batteries and keep them in a cool, dry place.
- Avoid overcharging and over-discharging: Overcharging and over-discharging can damage your solar batteries and shorten their lifespan. To avoid overcharging, you can install a charge controller that regulates the charging process. To avoid over-discharging, you can set up an automatic shut-off system that disconnects the batteries when they reach a certain level.
- Keep the batteries cool: High temperatures can damage your solar batteries and reduce their lifespan. You should keep your batteries in a cool, well-ventilated place. If your batteries are located in a hot environment, you can use a cooling fan or a heat shield to protect them.
By following these tips, you can extend the lifespan of your solar batteries and get the most out of your solar panel system.
When should I replace the solar battery?
A good solar battery will last 20 to 30 years, but there isn’t necessarily a date when you should replace it immediately. It is more important to pay attention to their productivity. If your solar cells are still in good shape and producing enough power, they probably don’t need to be replaced. On the other hand, if you notice that your electricity bills are going up because your solar panels are no longer functioning, it may be time to replace them.