F.A.Q. about boilers and heating

Have been field tested on many installations. Practice has shown that the service life exceeds 30 years. Photovoltaic plants operating in Europe and the USA for about 25 years have shown a decrease in the power of modules by about 10%. Thus, we can talk about the real service life of solar monocrystalline modules for 30 years or more. Polycrystalline modules usually operate for 20 years or more. Amorphous silicon modules (thin-film, or flexible) have a lifespan of 7 (first generation of thin-film technologies) to 20 (second generation of thin-film technologies) years.

Solar modules usually degrade faster in the first 2 years of operation. Thin-film modules lose 10 to 30% of their power in the first 2 years of operation, so usually new ones have a power reserve of about 15-20%. Crystalline silicon modules currently account for about 90% of the PV module market. their degradation is much less and their service life is longer than that of other types of solar modules (see table below).

How quickly do solar panels degrade / lose their efficiency?

Typical power degradation of solar panels is 0.5% per year. As noted above, thin film solar panels (a-Si, CdTe and CIGS) degrade faster than mono and polycrystalline panels. Below is a table with data on solar panel degradation produced before 2000 and after 2000. :

What is the expected lifespan of solar panels?

Below is a graph of a typical solar panel power guarantee from various manufacturers:

As you can see, the majority of manufacturers guarantee the operation of solar modules for 25 years, while the power reduction will not exceed 20% by the end of this period.

Many manufacturers give a guarantee for their modules for a period of 10 to 25 years. At the same time, they guarantee that the power of the modules in 10 years will decrease by no more than 10%. Mechanical damage is usually guaranteed for a period of 1 to 5 years.

What will happen to my solar panels after 25 years of use?

We honestly don't know. There is still no sufficient statistical data on this issue, since PV is a fairly young industry, and the vast majority of modules are currently in operation. made less than 10 years ago. However, the data that exist suggests that solar panels will work much longer than the 25 years promised by manufacturers:

• The 33W solar panel (Arco Solar 16-2000) actually performs better than its specs promised after 30 years of operation.
• The world's first solar panel has been in operation for 60 years.
• Kyocera has reported on solar installations that continue to operate successfully and reliably after 30 years of operation.

The maximum deterioration is usually guaranteed by manufacturers to be no more than 20% over 25 years. However, measurements carried out on the modules actually working since 1980 show that their production 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 work for at least 20 years, and with a high probability they will provide high performance even after 30 years from the date of their start.

Modern solar panel technology has improved dramatically, and the solar panels that are now being marketed are even more reliable, stable and efficient.

All this means that if, when calculating the payback of solar power plants, the service life of solar panels was 20 years, then they will then generate electricity for free.

We are confident that high-quality solar panels will work to generate electricity in 30-40 years after installation.

What can be done to increase the lifespan of solar panels?

• Avoid physical damage to the panel (i.e. falling trees, branches, being blown off by the wind, scratching the module). The more scratches on the surface of the module, the less its effectiveness. In the worst case, moisture and water can get between the glass and the protective film and cause a short circuit and / or corrosion of the solar cell contacts.
• Regular maintenance and cleaning is very important. See Best Way to Clean Solar Panels.
• The more severe the climatic conditions in which solar panels operate, the faster they will degrade. Therefore, in some cases it makes sense to install wind barrier structures.

What is the lifespan of the other components in the solar power system?

Other components of the system have different lifespan: batteries have a lifespan of 2 to 15 years (average 4-10 years), and power electronics from 5 to 20 years (average 10-12 years)

Continue reading

How to choose the right solar cells and modules First of all, you need to pay attention to the technical parameters of the solar module. The main ones are listed below. Also, you need to check the workmanship and the absence of visual defects on solar cells, glass, protective film and frame ...

One of the main criteria when buying any product is its expiration date, because over time, any device fails. This rule also applies to solar panels. Their cost today is quite high, and from how long the batteries last, it will be possible to judge whether they will have time to pay for themselves or not.

You already know from our previous articles that a solar power supply system consists of 4 main elements: solar panels, a battery, an inverter, and a charge / discharge controller. Their service life is different. The most "resistant" component is considered to be SB, but in any case it all depends on the type of panel, manufacturer and many other factors.

Service life depending on battery type

Depending on the material on the basis of which the photocells are made, the shelf life of the panels also varies. The most common option is silicon SB, but there is no definite figure here either. For solar cells made of polycrystalline silicon, the service life is about 20 years or more, for monocrystalline - from 30 years or more, but batteries made on the basis of amorphous silicon will last no more than 10 years.

But that's not all the pitfalls. Few people think that over time, the power of the modules gradually decreases. Amorphous panels will lose from 10 to 40% of their initial power in the first two years of operation, for crystalline batteries this figure is much less - 10% in 25 years. Most manufacturers give a 10-25 year warranty for their products. It turns out that with proper operation, the minimum shelf life of solar panels will be at least a quarter of a century. Agree, not every device can boast of such indicators. And what is important, all these figures were obtained not in laboratory conditions, but as a result of testing the SB, installed back in the 70s and 80s.

Factors affecting service life

It is impossible to calculate the life of solar panels with an accuracy of a year. There are many factors that affect the indicator in question. Sudden temperature changes, excessive heating of solar panels - all this can shorten their life by several years. Moreover, the photocells themselves are practically eternal, other components of the panels are destroyed:

• The back surface of the module.
• Film used for sealing.
• EVA interlayer between photocells and glass.

Under the influence of ultraviolet radiation, the sealant layer is destroyed, which is used to protect elements and electrical connections from moisture. This process leads to a decrease in the elasticity of the photocells and, as a result, to mechanical damage. The clouding of the EVA interlayer causes a decrease in the efficiency of solar cells, as less light hits the photocells. If you plan to make a SB with your own hands, remember that the sealant increases the life of the panel. By covering the modules with ordinary silicone, you will make them more durable, this will allow the panels to withstand sudden temperature changes and other harmful external influences.

Cost is not always an objective quality criterion, but you shouldn't ignore it either. When purchasing cheap Chinese panels, you should be prepared for the fact that their shelf life will be significantly shorter than that of batteries manufactured in reputable factories. Even small gaps in the frame or inaccurately soldered elements should be perceived by you as a strong argument in favor of abandoning such modules.

Russian scientists to the forefront ...

Solar energy in Russia is developing very slowly, but this does not prevent our scientists from making innovative discoveries in this area. This time the Krasnoyarsk scientists distinguished themselves by presenting the Security Council, the service life of which reaches 100 years. As you understand, this is 3 - 4 times more than that of existing analogues. The developed modules have received the quite logical name "VEK".

And what is most interesting, the technology they proposed is much more profitable in terms of financial costs. It turns out that the Krasnoyarsk security forces will not only live longer, but will also be cheaper. Pros alone. The developed technology was awarded the “For Successful Promotion of Innovations in Solar Energy” award at a competition held in Moscow.

The article was prepared by Abdullina Regina

More about how solar panels work:

Before installing an autonomous power supply, two questions usually arise: "How long will the system last?" and "How long will it pay off?" Indeed, it is on the answers to these questions that the expediency of the costs of purchasing and installing an autonomous circuit depends. The lifespan of solar panels varies. It depends primarily on the type of panels themselves.

Terms of service

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, single crystal batteries last up to 30 years, polycrystalline batteries - 20-25 years. The latest generation of thin-film batteries also last about 20 years.

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

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

What affects the service life

The standard design life for crystalline solar panels is 30 years. To find out the rate of real aging of elements, a whole series of different 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 drop 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.

For the sealing of solar panels (as well as for the film layer), an EVA (ethylene vinyl acetate, so-called "ethylene vinyl acetate") film is used. The back side of the panel is usually a polyvinyl phosphate film.

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

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

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

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

Additional factors

The service life is also influenced by the quality of the EVA film itself, as well as the protective lamination coating. A poor-quality coating gives a noticeable shrinkage already in the very first season. This leads to an almost complete depressurization of the panel, a sharp decrease in efficiency and product failure.

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

It also affects the life and quality of the soldered joints. Poorly performed soldering will break down very quickly and without corrosion, as these contacts themselves overheat. Therefore, the reliability of soldered joints is an indispensable condition for long-term performance.

Payback period

The payback period for solar panels depends on several factors:

• Equipment type (poly or monocells, single or multi-layer solar cell structure). The initial costs depend on this, since the cost of solar panels of different types varies quite a lot.
• The number of panels to be installed. That is why it is very important to carry out an accurate calculation of the entire system in advance.
• Geographic latitude, more precisely, the magnitude of insolation: the more sun hits the working surface of the module, the more it generates energy and the faster it “recoups” 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 the energy received from the central power grid. In other words, how much more profitable it is 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 in the average range 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.

Using energy from the sun is an alternative to non-renewable energy sources. Modern technologies make it possible to use solar panels for street lighting, heating and lighting of small houses. Today it is no longer uncommon for solar panels for summer cottages, which allow to provide the economy with electricity in the summer.

Solar panels

A device that is a large number of photovoltaic converters connected into a single system is a solar battery.

For a solar battery, it is important to have direct sunlight, the energy of which is converted into electric current.

Batteries are installed in areas where sunny days are most of the year. True, the geographic latitude also affects the efficiency of solar panels. After all, the farther from the pole, the more powerful the sun's rays. But even in central Russia in winter, solar panels reduce the consumption of electricity from public networks, and in the summer there is an opportunity to even sell its surplus.

Solar cells are monocrystalline, polycrystalline and thin-film.

Crystals directed in different directions in polycrystalline batteries reduce dependence on direct sunlight. Such batteries are most common today, they are used to illuminate public buildings and private houses. It is often already found and it is of the polycrystalline type.

Solar panels for summer cottages

Until recently, the main argument against the installation was their cost. Today, domestic industry is starting to produce these products, prices are getting lower, the choice is wider, and service is more affordable.

Modern technologies are quite capable of coping with the lighting of the site and ensuring the operation of household appliances. True, this requires a battery pack and also a charge controller and an inverter that converts direct current into alternating current.

Today you can buy a ready-made set of solar mini-power plants for a summer residence or a small house with an autonomy of work for 24 hours. The power of such a power plant is 235 W with a battery power of 2.4 kW * h.

Solar Batteries

Rechargeable batteries are an important piece of equipment in a modern solar system.

On bright sunny days, solar panels generate significantly more electrical energy than electrical appliances consume, and at night, when lighting is especially important, they do not work at all. This means that it is necessary to accumulate and store electricity for its subsequent use.

Rechargeable and designed for uniform and uninterrupted power supply.

Also, accumulator batteries cover peak loads, which are too large for PV modules, use the accumulated energy in the dark, compensate for the difference between the generated and consumed energy in cloudy weather.

Battery connection methods

Most often, one battery is not enough for the full operation of a solar power plant, and you have to use several batteries of the same type. Experts believe that they should generally be from the same batch.

To increase the total capacity of the system, three methods of connecting (switching) the battery are used.

When connected in parallel, the capacities of all batteries are added, and the total voltage is equal to the voltage in one device.

A series connection, on the other hand, allows all voltages to be summed up, and the capacity remains equal to the capacity of one battery in the circuit.

The most productive is the combined series-parallel connection, in which both voltages and capacities are summed.

True, with such a connection, the batteries are subject to imbalance, that is, the total voltage will be constant calculated, but for each individual battery, its readings will change. This phenomenon leads to the fact that some of the batteries are undercharged, and some are charged above normal, and the resource is depleted prematurely.

Therefore, the complete set of each solar system necessarily includes a solar battery charge controller and jumpers, with the help of which the mid points are connected to self-equalize the voltage in the battery.

Features of batteries for solar systems

A battery pack for a solar cell must meet a variety of requirements. It must withstand a large number of charge / discharge cycles. In this case, the self-discharge should be minimal, and the value of the charging current should be large, and the operating temperature range should be wide.

Today manufacturers are already producing special storage batteries, the so-called solar batteries, which fully meet these requirements.

A set of solar panels with such devices and a charge controller allows you to store energy and store it with maximum efficiency. A grid inverter - to convert it to connect household appliances and lighting.

Criterias of choice

You need to choose according to several parameters.

The most important of these is capacity. Based on the required power consumption, the calculated capacity indicator is calculated, increases by 35-50%, and already one or more devices for parallel connection are selected based on it. A battery with sufficient capacity holds energy up to 4 days.

Duration of discharging and charging. Of the two devices with the same capacity rating, the one that requires a shorter charging time is preferred.

The capacity of a lead-acid battery depends on the mass of lead in it, therefore, the greater the mass of the battery, the higher its real capacity. When choosing, you need to pay attention to the weight and dimensions of the device.

Manufacturers set a range of operating temperatures and service intervals for their products, and you should also pay attention to these indicators.

The accompanying documents always indicate the period of use of the battery, the number of discharge cycles (the larger this indicator, other things being equal, the better) and the amount of self-discharge per month.

When calculating the parameters of the storage battery, it is necessary to take into account the energy losses during its storage and transformation. The efficiency of modern devices for solar systems is about 85%.

Types of solar batteries

Conventional car batteries are not designed for a large number of cycles and are characterized by significant self-discharge. For solar stations, completely different devices are used.

1. AGM-batteries, in the construction of which the electrolyte is in a bound state between the absorbent glass mats. Such a device can be operated in any position; at a low price and a charge depth of about 80%, it can withstand up to 500 cycles and has a high level of charge.

The service life is not so long - 5 years, and the operating temperature range is limited to 15-25 ° С, but they are quickly charged - it takes less than 8 hours for full recovery, can be transported in a charged state and operated in a room with insufficient ventilation.

AGM batteries quickly fail due to overcharging, but they tolerate undercharging quite satisfactorily.

2. The solar gel battery can also work in any position. The jelly-like gel electrolyte is trapped in the pores of the silica gel, which acts as a separator for the plates. The indisputable advantage of this design is that the electrodes do not crumble, because all the free space is filled with gel, which means that the possibility of a short circuit is excluded. In addition, they can withstand full discharge and a significant number of cycles, about one and a half times more than similar AGM batteries. But their price is much higher.

Despite the price, gel batteries are more economical, do not need maintenance, they can be in a completely discharged state without damage for several days, energy losses in them are insignificant due to low self-discharge.

3. OPzS batteries, the so-called maintenance-free filling devices with liquid electrolyte, are specially designed for low current discharge. They can withstand a very large number of deep cycles, are used, as a rule, in high-power expensive solar systems, and are quite expensive themselves.

Solar charge controller

Electronic devices are designed to control and adjust the charge level on the battery. It is they who protect the battery from both complete discharge and overcharge.

Charge controllers are very important elements of solar panels. They provide multi-stage battery charging, automatic shutdown when the battery is fully charged and at minimum charge - loads, connecting photo modules when the battery needs to be charged, and reconnecting loads after charging.

The cheapest and most primitive type of On / Off controllers disconnects solar panels from the battery when the voltage reaches the limit value, preventing the batteries from fully charging and thereby reducing their resource.

PWM controllers operating on PWM (pulse width modulation) are technologies that are economical and efficient in areas with high solar activity. They stop charging, allowing the battery to fully charge. Such devices are installed in low-power, up to 2 kW, systems with a low-capacity battery.

MPPT controllers manage maximum energy peaks. They are most effective in solar systems, but they are also much more expensive than other models.

Solar Battery Manufacturers

There are not many manufacturers of this type of product on the Russian market.

CSB Battery Co., Ltd (Taiwan) offers lead-acid batteries, manufactured according to a service life of up to 10 years, designed for a voltage of 12 V, with a capacity of 26 to 100 A * h at a price of 2.6 to 8.2 thousand rubles.

About the same batteries are produced by Shandong Sacred Sun Power Sources Co., Ltd (China).

HAZE Battery Company Ltd (UK) supplies gel batteries with a service life of up to 12 years, an operating voltage of 12 V, a capacity of 15 to 230 A * h and a temperature range of -20 to +50 ° C at prices from 7 to 28 thousand rubles ...

SSKGroup (Russia-Belgium) produces reliable gel batteries for solar panels with a flame arrester with a service life of 15 years, with a capacity of 100 to 180 A * h at prices ranging from 11 to 19 thousand rubles.

Solar cell manufacturers

The main manufacturers of solar panels have long been Japan, Germany, the United States and China. Russian solar panels are assembled from materials produced in these countries. The most popular domestic solar panels with an affordable price are made from polycrystalline silicon produced in Germany and the USA.

Today, Russian manufacturers not only produce solar modules, but also develop new ones, such as, for example, Kvant in Moscow.

The Krasnodar company "Solar Wind" produces not only modules, but also ready-made home solar stations. Designs ready-made solar systems and SolarInnTech from Zelenograd.

There is more and more equipment for solar systems on the domestic market, including ready-made standard projects. But with some engineering skills and perseverance, you can independently calculate the system for specific operating conditions and select the necessary equipment: solar panels, batteries, controllers from different manufacturers in a wide price range. At the same time, you can save on some components by assembling them yourself from scrap materials, for example, a controller.

Solar panels can be bought for power supply of a private house, summer house or other premises. The complexity of their choice lies in the need to create a balanced system of different elements. These include: photo panels and battery, inverter and controller.

How the solar battery works and works

The solar battery is an independent source of electricity. The device consists of a series of semiconductors that convert solar radiation into current. The size of absorbent panels varies from a couple of millimeters to several meters.

The battery consists of two layers with different conductivity. Solar energy knocks out electrons from the cathode and they fall into the wastelands of the anode. It turns out their cycle. Historically, the first solar cell was selenium. But its performance was low.

In 1954, representatives of the US telecommunications company proposed replacing it with silicon. And after 4 years, a satellite was launched on a photocell from it. The efficiency of monocrystalline material is 17%, and that of polycrystalline material is 15%.

Since the production of the first solar panels, their cost has dropped significantly.

For a long service life, the device elements are shunted by diodes. Which reduces the final resistance of the circuit. Usually they are placed on every quarter of the battery length. This design is especially important when some of the panels are in the shade. Diodes do not allow them to turn into current consumers.

The accumulated electricity is stored in the battery. The voltage of which is less than the incoming potential. The charging process and its speed are checked by a special controller.

Lead and gel energy storage devices are considered effective. Their service life is 10-15 years.

The excess current is absorbed by the resistor. Inverters are used to convert DC voltage to AC voltage.

The performance of a solar cell depends on the angle of its inclination and the cardinal direction in which it is directed. So, the maximum result will be from such a placement of the device:

• south at an angle of 30 ° - 100% efficiency,
• south-east / south-west at an angle of 30 ° - 93%,
• to the east / west at an angle of 93 °.

Benefits and Effectiveness of Autonomous Devices

They buy solar panels for summer cottages, private houses, hotels in resort towns. Users note a number of their competitive advantages:

• inexhaustible source of energy,
• general availability in any area,
• environmental Safety,
• noiselessness of the system,
• long service life up to 25 years,
• state support for the development of alternative sources of electricity in European countries,
• the ability to mount additional panels to expand the system,
• low probability of breakage,
• free energy itself,
• system autonomy.

Disadvantages of solar panels for home

The use of solar panels comes with a number of disadvantages:

• high cost of the system,
• the need for a one-time deposit of a large amount,
• low performance compared to traditional power supplies,
• the need for space for placing additional components,
• long payback period,
• the need for constant care,
• battery disposal problems,
• the likelihood of theft of expensive equipment,
• inefficiency in winter, foggy and cloudy seasons.

When solar panels are advisable

The cost of an autonomous power supply depends on its capacity and performance. And the larger it is, the lower the price of units of its components.

Powerful solar panels can be purchased from $ 330 to $ 530. In order to provide a house for 4 people with electricity, it will be necessary to invest 15-25 thousand cu.

In Western Europe, the demand for alternative sources of food is higher, because there is a higher wealth of people. In addition, there is the possibility of transferring the accumulated energy to the general network. At the same time, the purchase price from the state is higher than the tariffs for consumption.

It is advisable to use the power of solar panels with a lack of electricity in the region. For example, in a resort town, where consumption restrictions are introduced during the “season”.

Or the home is away from the power source. And laying a network of wires is more expensive than the cost of batteries.

It is better to use the energy of the sun when fog and bad weather do not obstruct its flow. For example, in the south of the country on a hill.

For more efficiency of the solar panel, follow the installation instructions that come from the manufacturer.

Autonomous power supply modes

When choosing a solar power supply system, it is necessary to consider the maximum power required from it. It is calculated by summing the power of all household tools and other electrical consumers. You also need to determine the average daily rate. It depends on the mode of autonomy from the general network.

Complete replacement of the usual power source, accompanied by a disconnection from the city power supply. The required amount of power is determined by the meter readings for previous periods. At the same time, it is advisable to take into account possible future electrical consumers, the groundwork for which is better done in advance. Usually you need at least 600 kW per month to provide a house for 3-4 people.

With partial power supply, the main power comes from the network, the rest - from solar panels. Devices, devices and systems requiring more than 2 kW / h or 5 kW / day remain on a traditional power source. For example, underfloor heating, electric boiler, washing machine, heater, iron. This mode will require 2 - 2.5 kWh.

Moderate electricity supply changes the way you live. Capacious work, like a big wash, is performed periodically 1 - 2 times a month. During a period of high sun activity. Water heating is also limited to hourly supply. The system requires 150 kW per month with a possible average energy consumption of 4 - 6 kW / h. Peak power can reach 10 kW / h.

Basic mode uses 100 kW per month. The owners are in a state of energy saving, constantly monitoring the switching on of the light and other current consumers. Work requiring a lot of power is carried out before lunch. So that the battery accumulates a sufficient amount of charge until the evening.

Emergency mode is used in emergency situations and for several days. After that, it is supposed to restore the usual level of power supply from the network. It is used to provide the basic needs of the residents of the house. The average energy consumption per day does not exceed 2 kW with a peak value of 6 kW / h.

After determining the level of energy required, you can proceed with the selection of a specific solar array system.

Selection of solar panels

Solar panels have the following characteristics:

• the size,
• material of manufacture,
• power,
• nominal voltage and at peak power,
• current at maximum power,
• short-circuit current,
• operating temperature range,
• lifetime.

When choosing photocells, it is necessary to take into account all of the above indicators.

To achieve the required voltage level, the panels are connected in parallel in blocks. It is important to understand that elements of the same type are used to combine. But, if the choice is between a large battery or a pair of small ones, then it is better to give preference to the first option. Since there are no additional connections in it, which increases the reliability of the structure.

Typically, panel sizes are 1 - 2 m² at 220 - 250 watts.

Modern batteries are made from silicon.

How much a solar cell costs depends on its type. Photo panels are mono- and polycrystalline. The first ones are distinguished by a greater efficiency at the level of 17.5% with a comparative indicator of 15% of the analogue. But their cost is higher. But in the finished structure, when converting the energy received into costs, the cost of 1 Watt is approximately equal. The service life of the panels is the same. But the activity of the sun is not constant in different periods of the year. Therefore, it is preferable to purchase monocrystalline solar cells.

The rated voltage is the measure for which the device is designed under normal operating conditions. At the same time, the maximum is higher by 5 - 10%.

In the case of solar panels, give preference to 24-volt panels. A higher indicator is rare. And 12V devices are designed for small systems. They are usually used for architectural reasons when space for a battery is limited.

The installation is capable of operating at a certain temperature. The optimal solution is the range from -40 ° C to + 90 ° C.

According to consumer reviews, solar panels function properly for 20-25 years. Moreover, their efficiency decreases by 7 - 8% every 10 years.

Choosing a controller and inverter

The controller is mounted between the solar panel and the battery. It controls the level of voltage coming from the photo panels, depending on the charge level of the energy storage. So at 100% accumulation, overcharging is prevented by disconnecting the voltage supply to the battery.

Expensive technologies track changes in incoming flows and balance them. This is how the maximum possible battery performance is achieved at any time of the day or season. Maximum Power Point Tracking controllers are useful in large systems. And when providing energy to a private house, a rather simplified model. For example, PWM type.

Such devices with a battery charge level of 80% or more reduce the voltage of the solar battery and maintain it. In comparison, ON / OFF controllers, which are the cheapest equivalent, simply turn off the system.

It is also important that the control unit can compensate for the temperature and assume the choice of the type of battery.

Manufacturers of solar panels, when abandoning the controller, recommend constantly measuring the battery charge with a voltmeter. And, if necessary, manually turn off the system. Because overcharging decreases the lifespan of the drive.

The inverter converts DC voltage to AC voltage. The input voltage should be related to the power of the device. So with its power of 600 W, U \u003d 24 V is sufficient, and accordingly 48 V with higher power.

If we talk about the types of inverter, then the least trouble will be a sinusoidal device.

An indirect indicator is the weight of the equipment. Since the transformer is notable for its significant mass, then conventionally 1 kg of the inverter goes to 100 W. Therefore, a high-quality 1000 W converter weighs 8 - 10 kg.

The rated output power must be equal to the power of all electrical consumers.

Battery selection

The battery should be chosen based on the amount of energy that it will store. For this, the daily energy requirement for different consumers is determined. This makes an additional 10% adjustment for conversion losses in the inverter.

If solar panels will be an autonomous power source, then the maximum possible amount of battery charge is important. And in case of backup or emergency mode of the system, it is necessary to give preference to batteries with a long service life.

Starter batteries require constant maintenance and are used with low system power. Gel counterparts are less demanding to maintain and can store more energy. Sealed and flooded batteries provide long run times at high power levels. AGMs are primarily used for standby power saving mode.

With the same characteristics, the heavier counterpart will have the best real performance.

Solar battery maintenance

Solar panels require more maintenance than a fixed grid. Their surface must be systematically cleaned of dirt. Such as bird droppings, dust, traces of precipitation. Since dirty panels absorb less solar energy.

For cleaning it is enough to wash them with a stream of water from a hose. And to remove snow, use a stick like an old mop with a rubber layer.

It is also necessary to cut off tree branches that cast shadows on the surface of the batteries. Ideally, it is better that there are no tall plantations in the adjacent territory of the house at all.

Check the condition of the system mounts twice a year. Change them if necessary.