Service life of solar panels. Solar battery: overview, types, characteristics Service life of solar panels

Before we begin, I would like to immediately provide the payback figures for this system for the Russian mid-latitude climate. For example, in Crimea, such a system will pay for itself in 10 years or more, but in the Moscow region, the payback time for this system can be even longer than 10-15 years. And if you buy expensive equipment, there is no payback at all, only independence from the central electricity supplier. I would recommend purchasing a small kit in case there are frequent power outages to compensate for this inconvenience, but in the Moscow region it is often cloudy and there is practically no use for this system. Install a good generator with automatic start and an uninterrupted power system.
In Europe and other developed countries, it has become fashionable to use alternative energy sources such as solar energy. Germany is a leader in the use of this type of energy. In general, Germany has always been distinguished by its thirst for technology, and for this we have great respect, well done. In Russia they are also trying to use solar panels, but unfortunately the efficiency of this type of energy in our latitudes is minimal, unlike those countries where it can be sunny every day. However, to complement smart home This energy option is quite acceptable.
Practice shows that the service life of solar panels can exceed 20 years. Solar stations in Europe and the USA have shown a 10% decrease in module power over the course of 25 years. Based on these statistics, we can talk about the real service life of solar monocrystalline modules for more than 30 years.
Polycrystalline modules typically last more than 20 years.
Amorphous silicon modules have a service life of 7 years (first generation of thin-film modules) to 20 years (second generation of thin-film modules). Thin film modules can lose from 10 to 40% of power in the first 2 years of operation. Due to this, about 90% of the PV module market currently consists of crystalline silicon modules.
But monocrystalline modules are only an energy receiver. The main problem is energy accumulation. Batteries have a service life of 2 to 15 years, and power electronics have a service life of 5 to 20 years. So there are no completely autonomous “set it and forget it” systems yet.
Manufacturers often provide a guarantee for modules from 10 to 25 years, with a guarantee that the power of the modules will decrease by no more than 10%. Warranty for mechanical damage from 1 to 5 years.
Crystal modules are market leaders. Installation in private homes began in the 50s, and mass use began in the late 1970s. - We can draw conclusions about the durability of these modules.
The service life of crystal modules is about 30 years. Manufacturers themselves perform accelerated tests on the operation of solar modules to assess the actual service life of the modules. An interesting point is that the solar cells themselves in solar modules have an almost unlimited service life. But the production of modules decreases over time. This is the result of the destruction of the film for sealing the module and the destruction of the rear surface of the module, as well as the gradual clouding of the EVA film layer located between the glass and the solar cells.
Manufacturers can give the most optimistic forecast - deterioration of no more than 20% over 25 years. However, measurements taken on modules actually operating since 1980 show that their output has decreased by no more than 10%. Many modules still work with the parameters declared during production (i.e., there is no degradation). Therefore, we can safely say that the modules will operate for at least 20 years, and with a high probability will provide high performance even 30 years after the start of operation.

Derek Markham, a solar energy specialist at CleanTechnica, answers a question that interests the vast majority of those planning to acquire their own solar installation - How long is the life cycle of solar panels?? Or, in other words - how long can you use them??

When we decide to install a solar system, the most common question is usually “how much do solar panels cost?” Or “How much do solar panels cost?” This is natural, because for many of us, our own solar power plant is not only an environmental issue and reducing harmful emissions into the atmosphere, but also a financial issue, which, in the end, comes down to talking about our wallet, writes Ecotown.

Most solar modules that are used in home power plants have a warranty of about 25 or 30 years. This means that they are guaranteed to last for decades - unlike most other equipment that we often buy. In addition, the end of the warranty period of a solar panel does not mean that it will immediately “die” and will need to be replaced. It will continue to work, but its effectiveness will decrease somewhat every year. In fact, some older models of solar panels have been producing electricity for over 40 years and have no intention of dying. Moreover, their expected service life is still tens of years.

Several years ago, the National Renewable Energy Laboratory (NREL) conducted a study of the rates of "photovoltaic degradation" on a sample of 2,000 solar power plants. According to the study, on average a solar panel loses about half a percent (0.5%) of its operating efficiency per year. This means that at the end of the 25-year warranty period, your solar panel will operate at a still high level of efficiency - 88% of the original. However, not every panel reduces its efficiency by 0.5% annually. As evidenced by the performance of some solar modules that have been operating for more than 30 years under the sun's rays, their efficiency exceeds that indicated in their documentation.

These decades of solar panel life make the economics of solar power plants even better, since most systems will pay for themselves within the first ten years and continue to provide clean energy to their owner for many years to come, so the question " how long do solar panels last?"may simply not be entirely correct.

Obviously, a more correct question would be " What are the expected costs of maintaining and replacing parts of a solar power plant?", since solar panels will need to be replaced in the near future, however, the situation with an inverter (a device that converts direct current from the panels into alternating current, which can be transmitted to the general network) is completely different. The average operating time of an inverter is 10-15 years. However, its efficiency does not decrease gradually, as in a solar panel. One day it simply stops working. This is usually what happens with the so-called central inverters. However, at the same time, there is a good alternative - micro-inverters that can be installed on each individual solar panel. should be higher than traditional inverters and can reach up to 25 years.

Even taking into account the replacement of an inverter (or several, if micro-inverters are used) and the realities of the Ukrainian economy, an investment in a solar system is one of the most profitable investments.

Reference. Solar panel - several photovoltaic converters (photocells) combined into a module - semiconductor devices that directly convert solar energy into electricity with DC, in contrast, for example, to solar collectors, which heat the coolant liquid.

Before installing an autonomous power supply, two questions usually arise: “How long will the system last?” and “How long will it take to pay off?” After all, the feasibility of spending on purchasing and installing an autonomous circuit depends on the answers to these questions. The lifespan of solar panels varies. It depends primarily on the type of panels themselves.

Service life

As practical tests have shown, the service life of solar panels is at least 20 years. After a certain amount of time (15-20 years, depending on the type and characteristics of the photocells), a slight decrease in power is observed, which continues in the future. As a rule, batteries based on monocrystals last up to 30 years, and those based on polycrystals – 20-25 years. Thin film batteries The latest generation also lasts about 20 years.

The standard warranty for most solar panel manufacturers varies widely, from 10 to 25 years. This scatter is associated with the characteristics of the photocells themselves, their type (poly-, mono-), class (“A”, “B”, “C”), the quality of the protective front covering, etc.

Manufacturers guarantee that during this period the power of their products will decrease by no more than 10%. A drop in power by a more significant amount is fraught with a critical reduction in the output of the entire system, since every watt of energy produced is very important for solar power plants. Amorphous silicon batteries, as a rule, lose 10-40% of power in the first seasons, after which their production “freezes” at this level.

What affects service life

The standard design life of crystalline solar panels is 30 years. To find out the rate of actual aging of elements, whole series of various kinds of tests are carried out. They show that the photocells themselves have a very long service life; their degradation after several decades of use is minimal.
The decline in the performance of solar panels is associated with three factors:

• destruction of the film sealing the module;
• clouding of the film layer between the photocells and the protective glass;
• destruction of the back film of the solar battery.

To seal solar panels (as well as as a film layer), EVA film (ethylene vinyl acetate, the so-called “ethylene vinyl acetate”) is used. The back side of the panel is usually a polyvinyl phosphate film.

Such film protection is necessary to protect the photocells and solder joints of the panel from moisture. Under the influence of UV rays from the solar spectrum, films are gradually destroyed, they lose their elasticity and are more easily susceptible to mechanical stress. As a result, the tightness deteriorates and moisture begins to seep into the panel more actively.

In addition, the EVA film between the glass and the photocells also loses its optical transparency, which leads to a decrease in the absorption of sunlight. And due to microdroplets of moisture, solder joints gradually begin to corrode, which leads to an increase in contact resistance, its overheating and subsequent destruction.

As a rule, manufacturers guarantee the deterioration of their solar panels by no more than 20% over 25 years. However, this applies only to reputable companies that carefully monitor product quality. Less conscientious companies save on everything when assembling panels in order to set the final price of the product as low as possible.

Such savings lead to the fact that low-quality (or unsuitable for the specific conditions of solar panels) materials are used for sealing. As a result, contact destruction can be observed as early as the next season, which leads to a sharp drop in power (up to 30-40%). This phenomenon can be observed especially often on cheap garden lamps with photo batteries.

Additional factors

The service life is also affected by the quality of the EVA film itself, as well as the protective laminating coating. Poor-quality coating causes noticeable shrinkage already in the first season. This leads to almost complete depressurization of the panel, a sharp decrease in efficiency and failure of the product.

Another aspect is the thickness of the connecting conductors and busbars. It must be sufficient to pass currents of exactly the power stated in the solar panel passport. Moreover, the thickness of the bus must be greater than that of the conductors connecting the photocells to each other. If the tire is too thin (which is often found in cheap panels from little-known companies), then it will soon fail.

It also affects the service life and quality of solder joints. Poorly performed soldering is destroyed very quickly and without corrosion, since such contacts themselves overheat greatly. Therefore, the reliability of solder connections is an indispensable condition for long-term performance.

Payback period

The payback period for solar panels depends on several factors:

• Type of equipment (poly- or monocells, single- or multilayer solar battery structure). The initial costs depend on this, since the cost of different types of solar panels varies quite a lot.
• Number of installed panels. That is why it is very important to carry out an accurate calculation of the entire system in advance.
• Geographic latitude, or more precisely, the amount of insolation: the more sun hits the working surface of the module, the more energy it generates and the faster it “recovers” costs.
• Energy prices in the region. The cost of a kilowatt-hour of electricity will determine the difference in the cost of energy generated by the sun and energy received from the central power grid. In other words, how much more profitable is it to generate “solar electricity”.

On average, for a private house the payback period is 2.5-3.5 years in Central European countries and 1.5-2 years in Southern European countries. For Russia, this indicator varies on average from 2 to 5 years. However, it must be remembered that with the improvement of manufacturing technologies, the efficiency (energy production) of panels increases, which means that the payback period is gradually decreasing.

Today, solar panels can provide electricity to an entire house or a separate industrial facility. They can act as both the main and additional sources of energy. Due to their long service life - up to 50 years - and quick payback, you can forever forget about the costs associated with current consumption from shared network. However, if operating rules are not followed, solar modules may become unusable ahead of schedule. What you need to know about how solar panels work?

First of all, the service life is determined by the quality of solar panels, what material they are made from and the type of technological process.

• Monocrystalline ones are considered the most durable. Their efficiency indicator decreases by 2-3% after 25 years of operation, and the total service life can reach up to 50 years.
• Polycrystalline ones are not much inferior to monocrystalline ones and can last more than 20 years without major losses.
• Modules made of amphora silicon, which are presented in the form of a thin film, differ in service life depending on the production process. First generation panels will quickly reduce their declared performance, and after 5-7 years the efficiency may drop to 15%, while second generation panels will work flawlessly for up to 20 years.

Batteries tend to degrade during the first 5 years; during this period they lose the greatest percentage of power. This is especially true for thin-film modules. Therefore, manufacturers put in technical specifications designs a certain percentage of power reserve. It can reach up to 15%. The situation with silicon modules is much better; they can lose only 1% efficiency over 10 years.

More detailed information about the degradation values ​​of each type of solar battery can be found in the table.

In addition to the quality, material and technological features of each solar module listed, a special place in the service life is occupied by compliance with operating rules. To maintain efficiency at the original level, it is necessary to regularly clean the panels from dirt, dust and snow, use a controller to stabilize the energy and a high-quality service device - an inverter and battery.

What happens to batteries at the end of their service life

There is no clear answer to this question. Due to the fact that some batteries can last up to 30 or even 40 years, there are no reliable statistics in this industry due to the recent popularity of solar systems. Manufacturers, depending on the type and quality of the solar panel, provide a warranty period of 10 to 25 years. That is, the battery should definitely last 25 years.

Based on practice, the following data has been recorded:

• The world's very first panel is still in operation today and has been around for over 60 years.
• For example, a solar battery from the manufacturer Kyocera has served for 30 years, and its performance has remained virtually unchanged from the declared ones.
• Arco Solar is also as good as new models even after 25 years of service.

Most of the modules of various types - polycrystalline, monocrystalline, amphora and others, thanks to modern technologies are stable in their work and provide high performance indicators.

If we look at the instructions and properties of individual solar panels, then deterioration in performance occurs after 10-15 years of operation. And then, during this period the values ​​are critically small, which does not particularly affect the overall electricity generation. Typically degradation does not exceed 2-5%. Closer to 20-25 years, the percentage decrease in efficiency can exceed 5%, but this is very rare, especially when operating rules were not followed.

Therefore, we can safely say that if you purchase a solar system made from high-quality modules, they will reliably serve you both after 10 years and after 30 years. And this is far from the limit. Under such conditions, they are of particular benefit, especially after the payback period has arrived and you can receive electricity absolutely free.

Service life for different manufacturers

A high-quality solar battery from a reliable manufacturer can last more than 20 years. If you do not want to encounter problems in 5-7 years and at the same time want to fully provide yourself with electricity, then you will have to invest significantly in the purchase and installation of a solar system. Below we have presented you with a graph where you can see the performance of panels from different manufacturers.

All solar batteries undergo accelerated testing and are practically unlimited in service life; after 10 years, performance may only decrease slightly.

The graph shows that almost all presented batteries from different trusted manufacturers are guaranteed to work for at least 25 years. And this is only based on the data provided, but in fact they can last 40 years. The only thing you need to take into account is the percentage of power drop over time. Silicon modules, namely monocrystalline ones, are considered the most durable. They have been working flawlessly for 30 years and with degradation of no more than 5%, which does not particularly affect the overall output over such a long time.

The result of a decrease in the efficiency of panels even of high-quality production from proven brands is associated with a number of factors. Firstly, over time, the tightness of the film is destroyed, which can lead to moisture getting inside the structure, and secondly, under the constant influence of bright sunlight, the film layer darkens over the years. It is also impossible not to note the damage to the rear surface of the panel over many years of use. It is impossible to notice any changes immediately; in fact, this only leads to a decrease in power.

How to increase service life

The performance of the solar system depends on many factors. You can maintain the service life declared by the manufacturer and increase it using the following actions:

• Regularly clean the modules from snow, dirt, and dust, as the sun's rays are more difficult to penetrate the photocells.
• Make sure there is no darkening of the panels.
• If you are installing a solar system in a hot climate zone, then try not to place the panels next to each other so that air circulates between them, since when the modules overheat to a critically high temperature, the solar cells wear out faster.
• Use reliable and correct ones.

Particular attention should be paid to special protection against physical damage. Most often, damage to the surface of modules is associated with falling branches from trees, hail, and scratches from foreign objects. If the integrity is damaged or there are deep scratches, if moisture gets inside, a short circuit may occur, not to mention corrosion of the contacts. Here it is sometimes advisable to install wind-breaking structures.

What is the lifespan of other solar power system components?

In addition to batteries, the solar system is also connected to other mandatory devices, without which it will not be possible to obtain alternating current with the required voltage. An additional inverter and battery are connected to the system. The battery life ranges from 3 to 15 years, this discrepancy is due to different types devices. On average, a battery from a reliable manufacturer can last 10 years, and an inverter may require replacement after 12-15 years.

Solar panels have been field tested in many installations. Practice has shown that the service life of solar panels exceeds 20 years. Photovoltaic plants operating in Europe and the USA for about 25 years have shown a decrease in module power of approximately 10%. Thus, we can talk about the real service life of solar monocrystalline modules of 30 years or more. Polycrystalline modules typically last 20 years or more. Amorphous silicon modules (thin-film or flexible) have a service life of 7 (first generation of thin-film technologies) to 20 (second generation of thin-film technologies) years. Moreover, thin-film modules typically lose 10 to 40% of their power in the first 2 years of operation. Therefore, about 90% of the PV module market currently consists of crystalline silicon modules.

Other system components have different service lives: batteries have a service life of 2 to 15 years, and power electronics have a service life of 5 to 20 years.

Many manufacturers provide a warranty on their modules for a period of 10 to 25 years. At the same time, they guarantee that the power of the modules will decrease by no more than 10%. The warranty for mechanical damage is usually given for a period of 1 to 5 years.

Crystalline modules have the most extensive operating experience. They began to be installed in the 50s of the last century, and mass use began in the late 1970s. Therefore, it is already possible to draw some conclusions about the durability of such modules.

The design life of crystalline modules is typically 30 years. Manufacturers perform accelerated tests on the operation of the module in order to evaluate its real service life. The solar cells themselves used in solar modules have an almost unlimited service life and show no degradation after decades of operation. However, the production of modules decreases over time. This is the result of 2 main factors - the gradual destruction of the film used to seal the module (usually ethylene vinyl acetate film - EVA) and the destruction of the rear surface of the module (usually polyvinyl phosphate film), as well as the gradual clouding of the EVA film layer located between the glass and solar cells.

The module sealant protects the solar cells and internal electrical connections from moisture. Since it is almost impossible to completely protect the elements from moisture, the modules actually “breathe”, but this is extremely difficult to notice. Moisture that gets inside is removed outside during the day when the temperature of the module increases. Sunlight gradually destroys the sealing elements due to ultraviolet radiation, and they become less elastic and more susceptible to mechanical stress. Over time, this leads to deterioration of the module's moisture protection. Moisture that gets inside the module leads to corrosion of electrical connections, an increase in resistance at the point of corrosion, overheating and destruction of the contact, or a decrease in the output voltage of the module.

The second factor that reduces module production is a gradual decrease in the transparency of the film between the glass and the elements. This reduction is not noticeable to the naked eye, but leads to a decrease in the module's power due to the fact that less light reaches the solar cells.

Maximum deterioration is usually guaranteed by manufacturers to be no more than 20% over 25 years. However, measurements taken on modules actually operating since 1980 show that their output has decreased by no more than 10%. Many of these modules still work with the parameters declared during production (i.e., there is no degradation). Therefore, we can safely say that the modules will operate for at least 20 years, and with a high probability will provide high performance even 30 years after the start of operation.