Long-livers of solar power supply systems. How to buy a solar panel that will last a long time How long do solar panels last

Main elements solar battery for a private house is a photovoltaic panel (not to be confused with a solar water heating plate) and a converter. A photovoltaic panel converts solar energy into electrical energy.
The converter converts electricity into direct current generated by solar energy into a 230 V, 50 Hz power supply. Solar panels for a private house They are placed on the roof of the building, on the roof slopes facing south, and connected in a row to make them more tense.

The inverter is best located in the room where the main switchboard with circuit breakers is located, it can also be located in a second room or on the outer wall of the building.
The amount of electricity produced solar panels depends on the intensity of solar radiation present on them, on the time of operation from the sun and on the correct installation of the panels.

What do you need to know before deciding to install a solar panel in a private home?

Make sure the roof surface is where we want to install the system facing south and that it is not overshadowed by other objects, chimneys, trees.

Avoid shading photovoltaic panels. Make sure the roof is large enough to accommodate solar panels.

Thus, for a power of 1 kW, 8-10 m2 of free surface is required.
The most frequently asked questions about installing solar panels for a private house:

What factors affect the efficiency of solar cells?

- roof direction - under optimal conditions, the modules should be oriented to the south.

If this is 100% impossible, then the principle works: the closer to the south, the greater the performance of the photovoltaic system;
- roof slope - power generation with a battery will be greatest when the sun hits the solar cells at right angles.

What is the life of a solar panel and what does it depend on?

The optimum angle of photovoltaic panels for moderate widths is 30-40 °;
- Shading - architectural and environmental factors that lead to the formation of shadows belonging to solar cells, lead to a reduction in the amount of electricity generated and should be avoided;
- device performance - an improperly designed or manufactured installation may result in loss of capacity or irreparable damage.

Where is the solar connection point for a private house, for an electric meter or in front of it?

s the output connects to the converter on the meter at any point in the internal wiring in the house, or even better - immediately to the meter, so that it will generate electricity to power equipment and farm buildings with electric power supply.

Are solar panels producing power in a single phase or three phase version?

Three-phase systems are used for power in excess of 5 kW.

Can a solar panel be a backup power source in a building in the event of a utility power failure?

When the voltage in the mains supplying the building disappears, the solar installation is shut down. The restart is performed automatically when the mains voltage is displayed.

Of course, it is possible to expand its functions by installing a battery. Then, in the event of a power failure, it can switch to a backup power source that can be used until the battery is depleted.

However, this decision comes with a significant increase in installation costs.

When does a photovoltaic solar cell generate electricity?

Very strong clouds and fogs at night, completely covered with snow photovoltaic plates, without stress in the construction network.

Is snowfall interfering with the installation?

The passage of current through the solar cells during operation causes the surface to warm, which melts the snow on the slabs and restores normal conditions for the plants.

How does the outside temperature affect the performance of the device?

Photovoltaic panels have a negative temperature coefficient.

This means that at a lower ambient temperature, the higher output voltage, the higher the output power.

What is the robustness of a photovoltaic system?

Unlike other energy sources, solar cells do not have moving elements, which is a decisive factor in their sustainability.

Photovoltaic panels provide a decrease in performance after 25 years of operation, no more than 15%.

What should you do when buying your own PV system?

The decisive condition for the purchase of the device is right choice company offering the sale and installation of the device.

We must not forget that about 70% of the production comes from China. Companies claiming to manufacture wafers in Europe overlook the fact that in most cases the installation is carried out using imported silicone elements from China. The most important element of the battery is the inverter, which is mainly produced in Germany.

It is also important to accurately and correctly select the remaining components of the device, as it must last at least 25 years.

How long does it take to install and integrate solar panels into a private home?

Complete installation of the system for a private house and its download usually takes 2-3 days. Prepare an appropriate installation project in advance and sometimes wait a few days for the corresponding components to be delivered.

What happens to the surplus of electricity generated?

The electrical energy generated by solar panels must first be used in the home.

In case of excess energy, it must be used for own needs, but not sold (cost per kilowatt-hour, it is very high, and no one will buy). This energy is sent to additional users such as an electric boiler for heating water, air conditioners, or other devices. For example, in a house with good solar panels on a sunny day, the excess electricity to heat is able to supply approximately 150 liters of water at temperatures between 10 ° C and 60 ° C.

Can a photovoltaic system replace a solar water heating installation?

Yes, of course, there are many arguments in favor of such a solution, especially if we plan to build new house, hut or villa.

Do not install equipment with outdated and less efficient technology. The main argument here is high profits and economic feasibility.
For the same financial installation costs, we get about 50% more energy, and this is electricity that can be used in any form, including for heating and hot water or air conditioning in the summer months.

Another convincing argument for such a decision has a negative temperature coefficient, reflecting the physical properties of a silicon photovoltaic cell, which increases the efficiency of photovoltaic systems, the lower the ambient temperature, which gives a certain advantage over the installation of solar water heating during the winter.

How do solar cells work in a private house in the case of using additional heating of water for domestic purposes?

Renewable energy sources (RES) are unpredictable and dependent on natural changes, so they cannot be considered the main source of power.

Therefore, the solar panel should be considered as an auxiliary source for the preparation of hot water for domestic purposes. The water heats up if the energy produced in the factory meets the needs of all players for home receivers (priority), and the excess energy will be generated at the same time. If this surplus electricity is not used, it will enter the company's power supply (note that the power meter does not rotate in the opposite direction, as it is equipped with a brake).
Thanks to the use of a special filter, this excess can be sent to an electric water heater or to another receiver.

A properly designed and constructed solar panel for a private house can provide up to 50% of the energy consumed.
The use of a special energy filter to use its surplus and direct it for heating, space heating, air conditioning allows up to 80% of the generated energy.

The main advantages of using solar panels in a private house:

- reduction of electricity payments;
- battery operation even in cloudy conditions using diffused sunlight;
- the largest energy production occurs simultaneously with the demand for electricity in the economy (the area with the highest cost of kWh of electricity), and there is the possibility of additional savings;
- the modular nature of the installation allows you to increase its throughput, while balancing the amount of investment;
- protection of the environment and the environment, since solar cells in a private house do not emit CO2 and noise in general, they have no moving parts;
no need for maintenance - the device is designed for automatic operation for at least 25 years;
- Reliability - 5-year hardware warranty and 25-year warranty guarantee peace of mind and confidence in the accuracy and adequacy of financial investments.

The most efficient solar panels for the home today are not something extraordinary and new, but just a great alternative source of energy.

What you need to know about solar panels for home: their choice, placement and use

But the more devices of this type appear on the market, the more often people ask the question: which one should you choose? Which solar panel is the most efficient? But for everyone, this concept sounds as if it is different, since it is characterized by a number of individual needs, and we will talk about this further.

To begin with, the main question should not be “What are the most efficient solar panels?”, But “ Where is the optimal combination of price and quality?»For example, on the roof of your house or business there is free space, on which you can place about a dozen solar panels, and you yourself are faced with a choice: buy devices with the first class of energy efficiency, that is, "A", or give preference to cheaper, but less efficient panels of class "B"?

Perhaps the answer will surprise you, but the second option will be more appropriate in most cases. Simply put, our main task now is to determine which of the solar energy sources is most beneficial to use in a given situation.

Models of the most energy efficient solar panels

Sharp... The efficiency indicator for the models of this company is 44.4%.
Sharp is considered the absolute world leader in solar panels. These devices are quite complex, the solar modules are three-layer here, the manufacturers have spent several years on the development of the technology for their creation, during this period they have carried out a lot of research and testing of their own products.

There are other simplified models as well. Some Sharp panel technology provides them with an efficiency of 37.9%, which is also a lot. The price of the devices is lower due to the fact that they do not use technical devices to concentrate sunlight on the module.
Panels from the Spanish Research Institute (IES)... The efficiency of their work is 32.6%.
Such modern solar panels with high efficiency are devices with two-layer modules, the cost of such an energy source is low compared to the previous manufacturer, but for ordinary residential buildings it is still too expensive and in some way meaningless.

In fact, this list can be continued for a long time, taking into account increasingly cheaper models with a decreasing efficiency index.

But everything remains standard: high efficiency - the corresponding price, low efficiency - is cheap. It happens that quite unpretentious models are offered at a ridiculous cost, you will notice this when choosing, but let's return to our topic.

Famous companies for the production of solar modules

There is an opinion that today less and less time is devoted to the study of the operation of solar panels, and the study of certain solar cells, which are the main components of any alternative battery, has come to the fore.

But this is the point that no one will be interested in panels with weak solar modules, this is what most buyers pay attention to in the first place. In the long-established market of these same modules, leaders have already been determined, it is worth mentioning about them.

We will be one of the first to recall devices with an efficiency of 36%, they are produced by a company Amonix, whose products are available in almost every store with goods of this kind. For domestic purposes, such modules from Amonix are usually not used, since they are produced using special concentrating devices.
You cannot pass by solar modules with an energy efficiency of 21.5%, their manufacturer is a well-known American brand. Sun power, which has been on the market for quite some time.
To some extent, this enterprise has managed to set a kind of efficiency record. For example, the Sun Power SPR-327NE-WHT-D was voted best after field testing. Moreover, the next two positions in the ranking of the list of the best were also taken by the products of this company.
Let us also recall the thin-film modules with an efficiency of 17.4% - a product from Q-Cells.
The devices of this German company at some point ceased to be popular and in demand, Q-Cells went bankrupt, but then it was bought by the Korean company Hanwha and today the brand's modules are gaining momentum in terms of sales again.
Moving on, that is, towards solar modules with less efficiency.
16.1% give us devices from First solar, they are produced on the basis of a special cadmium-tellurium transformation. Appliances of this type are not installed on residential buildings, but this in no way affects the company's turnover, and they are very wide.

First Solar is more popular in the American market: the company itself is from the United States. Modules of this brand are used in many industries, so that the company has excellent momentum and gained universal recognition, because it creates a really reliable product.
As the last of the examples here will be solar modules with an efficiency of 15.5% from a company called MiaSole.
Devices of this brand are recognized as the best among flexible modules. Yes, this type of personalized device is sometimes simply necessary for installation in certain structures.

When you are looking for high-power solar panels for your home or large production workshop, focus not only on the price / quality ratio, but also on the brand. Manufacturers who have proven themselves to be the best should be trusted in such serious matters. If you are not an expert in assembling and installing solar panels, then no matter how carefully you approach the choice, it is impossible to examine each model for strength, durability, economy and other parameters, so it is better to trust the name.

To date, many experiments have also been carried out, their results can definitely help you.

When looking for solar panels, be guided also by your own needs and ability to pay - there is no need to install a device on a residential building, the development of which was made for NASA.

SOLAR BATTERIES FOR HOME. HOW TO CHOOSE EQUIPMENT?

The question of choosing solar panels for a private house is quite difficult. To determine what equipment you need, answer yourself a few questions:

1. Panel type

Photo of panels of three types

Is there a space limitation?

If yes, it is better to choose solar panels made of monocrystalline silicon.

This type of panel has the highest efficiency. These batteries can take up less space at the same wattage as polysilicon panels. A monocrystalline silicon solar cell is easy to recognize - it consists of black pseudo-squares. If there is no space limitation, take solar cells made of polycrystalline silicon - they are cheaper and work a little better in cloudy work due to the fact that solar cells have different orientations of silicon crystals.

Appearance solar battery made of polycrystalline silicon - smooth squares of bluish color with different shades. If you have special conditions for placement (for example, a curved roof or a polycarbonate roof), then you can pay attention to flexible solar panels made of amorphous silicon.

They are glued to any surface and do not require additional metal structures. Plus, these batteries work very well with ambient light.

Therefore, if sunny days are rare in your region, you can take a closer look at these panels. Another option is micromorphic silicon solar cells. This is a new generation of amorphous solar cells operating in both the visible and infrared regions. Practice has shown that such panels give a large total annual output in comparison with classic ones. In addition, such panels are less demanding on the angle of inclination and orientation to the cardinal points.

They are also cheaper because less silicon is used in production.

Let's compare the cost of solar panels for home and summer cottages. We quote prices in dollars, since even Russian panels are made from imported raw materials.

The cheapest are amorphous or micromorphic silicon panels. Their price is $ 0.7-0.9 per watt.
In second place are polycrystalline solar panels with a price of $ 0.9 - $ 1 per watt.
Well, the most expensive are monocrystalline silicon modules.
Their price is 1.1 - 1.3 dollars for 1 watt of power.

2. The power of the panels.

To determine the power of solar panels, you need to determine the average energy consumption in your home (for example, from electricity bills), and then decide what percentage of this amount you want to compensate using alternative energy sources. Let's say you consume 300 kWh of electricity per month. This is approximately 10 kWh per day and 3600 kWh. For Crimea, we can assume that solar panels with a capacity of 1 kW generate an average of 1300 kWh per year.

(about 110 kWh per month). If a calculation is made for the summer, it is considered that the panel gives off its rated power 6 hours a day (a 250 W solar battery will produce 250-6 = 1500 W * h per day, provided that the weather is sunny). Then, for full compensation, you need to install 3 kW panels (12 panels of 250 W each, 1.65 sq.

each). If it is not possible to install 12 panels at once, you can put half, and then add. There is no need to change the equipment!

3. Inverter type

Is there a 220 V network?

If not and will not be, then choose a stand-alone inverter.

In such a system, solar panels will charge the batteries, and at the same time, energy will be consumed by various loads. It is also recommended to stock up on a generator that can charge the battery if a particularly cloudy week comes out and there is not enough solar energy. If there is a network, then the following question arises: do you need power supply redundancy, or do you just want to save money? If the goal is simply to save money, it is enough to install a network inverter. It doesn't need batteries.

The energy generated by solar panels is converted to 220 V and immediately consumed by consumers in the house. Somewhat more interesting is the system, which also stores energy. It uses a hybrid inverter. Its main feature is joint work network and solar panels. In this case, you can choose one of two priorities for the main source of energy. If you choose a network, then the inverter will take no more than the allowed power from the network, and if it is not enough, it will take the required amount of energy from alternative energy sources and batteries.

If we prioritize solar panels, then the inverter will take maximum energy from them, and if not enough, take a little from the grid.

4. Power of the inverter.

The power of the grid inverter is selected equal to or slightly higher than the power of the array of panels.

For hybrid and standalone, the calculation is a little more complicated. To find out how much power the inverter is needed in your system, you need to calculate the total power of electrical appliances that can be turned on at the same time in your house.

Let's say you have the following electrical appliances at home:

10 bulbs (housekeepers) 20 W = 200 W each,
Refrigerator class A +, 300 W,
Pump, 500 W,
LCD TV 32 ″, 70 W,
Charger mobile phone, 5 W,
Laptop, 60 W,
Vacuum cleaner, 1500 W,
Microwave, 2000 W,
Electric kettle, 1800 W,
Air conditioner, 1500 W.

In total, we get 7935 watts.

Additionally, you need to take a margin of at least 20% and get 9500 watts. The closest model in the MAC Energy line of inverters is 12 kW.However, if you do not turn on the vacuum cleaner, microwave oven and electric kettle at the same time, then the maximum total power will already be 4600 W + 20% = 5500 W - you can take an inverter with half the power - 6 kW.

5. Type of charge controller

There are only 2 types to choose from: PWM and MRRT. The difference between them is that the MRPT controller takes up to 20% more power from the solar panels compared to the PWM controller. Moreover, its cost is 2-3 times higher. To help you make your choice, do a simple calculation.

If you have installed solar panels with a capacity of 1 kW at your home, then the MRPT controller can remove all 1000 W from them, while the PWM will "master" only 800 W. In order for it to catch up with the power of the MRPT controller, you need to add another 200-250W panel.

Of course, the 20% gap between controllers does not hold 100% of the time. However, solar panels have been in operation for more than one year, and the difference of 20% over 20 years can be quite large. What is more profitable for you - add batteries or pay extra for a more advanced controller - it's up to you. From experience, I can say that with a panel power of more than 1 kW, it is already more profitable to install an MPPT controller.

The power of the charge controller The power of the charge controller must be selected according to its passport data (it indicates what power it can pump through itself into the battery).

This power should be greater than the power of the battery array installed at your home (in the country). It is also desirable (for PWM controllers) that the battery voltage class matches the battery voltage. Then there will be less losses on voltage conversion inside the controller. There is no such limitation for MPPT controllers. On the contrary, it is better to build up a lot of tension. Then, even in the most cloudy weather, the controller will be able to maintain its operability and remove power from the battery.

Battery Type Lead acid is the most readily available battery type for solar-powered systems. Of these, you can choose between sealed (AGM, GEL) and serviced (traction, OPzV). It makes sense to put the first ones when it is planned to use the battery in the buffer mode (rare deep discharges during power outages, shallow discharges during operation (adding power)). Another advantage is their tightness - they can be installed in any room, there are no special requirements for ventilation.

Serviced batteries must be installed in a room with ventilation, since hydrogen can be released from such batteries during operation. However, such batteries have a very long service life - from 1500 100% discharge cycles. Therefore, it is advisable to install them in such systems where constant cyclic operation is planned from the battery (autonomous systems without a 220V network). You can also install car starter batteries, but they do not tolerate the discharge of small currents well and have a large self-discharge.

Therefore, their lifespan in solar-powered systems is very short.

8. Battery capacity About the capacity we can say: the more, the better.

However, you can calculate the minimum required number of batteries. To do this, you need to determine how many and what electrical appliances should work in the event of a power outage and multiply this amount of energy by the desired battery life. For example, lamps (3 x 20 W * h), TV (70 W * h), laptop (60 W * h), refrigerator A + (40 W * h per hour) must work for 6 hours.

Longevity of solar power systems

The total consumption per hour will be: 60 + 70 + 60 + 40 = 230 W. For 6 hours, you will need 230 * 6 = 1380 W * h (V * A * h) Then the capacity of the battery will be 1380 V * A * h / 12 V = 115 A * h. In order to prevent 100% discharge and increase the battery life, it is better to double the capacity and take a 200 A * h battery. Such a battery can store 2400 W * h of "solar" energy.

You can also call us and ask any question to our engineers. We work from Monday to Friday from 9 am to 6 pm without a break.

This article about solar panels for the home was written by Yegor Moiseev

Calculation of solar panels

Welcome to the site e-breeze.ru, today I want to tell you about how many solar panels you need for a house or a summer residence, a private house, etc.

This article will not contain formulas and complex calculations, I will try to convey everything in simple words understandable for any person. The article promises to be not small, but I think you will not waste your time, leave comments under the article.

The most important thing is to determine the number of solar panels, you need to understand what they are capable of, how much energy one solar panel can give in order to determine the required amount.

And you also need to understand that in addition to the panels themselves, you will need batteries, a charge controller, and a voltage converter (inverter).

Calculating the power of solar panels

To calculate required power solar panels need to know how much energy you are using. For example, if your energy consumption is 100 kW * h per month (the readings can be viewed on the electricity meter), then accordingly you need the solar panels to generate such an amount of energy.

The solar panels themselves generate solar energy only during daylight hours. And they give out their passport power only when there is a clear sky and the sun's rays fall at a right angle. When the sun falls at angles, the power and power generation decrease noticeably, and the sharper the angle of incidence of the sun's rays, the greater the drop in power. In cloudy weather, the power of solar batteries drops by 15-20 times, even with light clouds and haze, the power of solar batteries drops by 2-3 times, and all this must be taken into account.

When calculating, it is better to take the working time, in which the solar panels operate at almost full capacity, equal to 7 hours, this is from 9 am to 4 pm. Of course, the panels will work from dawn to dusk in the summer, but in the morning and in the evening, the output will be very small, in terms of volume, only 20-30% of the total daily output, and 70% of the energy will be generated in the interval from 9 to 16 hours.

Thus, an array of panels with a capacity of 1 kW (1000 watts) for a summer sunny day will give out 7 kWh of electricity for the period from 9 to 16 hours, and 210 kW * h per month.

Plus another 3 kW (30%) in the morning and evening, but let it be a reserve as partly cloudy is possible. And our panels are permanently installed, and the angle of incidence of the sun's rays changes, from this, naturally, the panels will not give out their power at 100%.

I think it is clear that if the array of panels is 2kW, then the power generation will be 420kW * h per month. And if there is one socket for 100 watts, then it will give only 700 watts * h of energy per day, and 21 kW per month.

It's nice to have 210kWh per month from a 1kW array, but it's not that simple.

At first there is no such thing that all 30 days in a month are sunny, so you need to look at the weather archive for the region and find out how many cloudy days by month.

As a result, probably 5-6 days will definitely be cloudy, when solar panels and half of the electricity will not generate. So you can safely delete 4 days, and you get not 210kW * h, but 186kW * h

Also you need to understand that in spring and autumn daylight hours are shorter and there are much more cloudy days, so if you want to use solar energy from March to October, then you need to increase the array of solar panels by 30-50%, depending on the specific region.

But that is not all, there are also serious losses in batteries, and in converters (inverter), which must also be taken into account, more on that later.

About winter I will not say this yet, as this time is completely deplorable in terms of power generation, and here, when there is no sun for weeks, no array of solar panels will help, and you will either need to be powered from the network during such periods, or install a gas generator. The installation of a wind generator also helps a lot, in winter it becomes the main source of electricity generation, but of course, if there are windy winters in your region, and a wind generator of sufficient power.

Calculation of battery capacity for solar panels

This is what a solar power plant looks like inside a house.

Another example of installed batteries and a universal solar controller

The smallest battery capacity reserve, which simply needs to be such to survive the dark.

For example, if you consume 3 kW * h of energy from evening to morning, then the batteries should have such a supply of energy.

If the battery is 12 volts 200 Ah, then the energy in it will fit 12 * 200 = 2400 watts (2.4 kW). But batteries cannot be discharged 100%... Specialized batteries can be discharged to a maximum of 70%, if more then they quickly degrade. If you install conventional car batteries, then they can be discharged by a maximum of 50%.

Therefore, you need to install two times more batteries than required, otherwise they will have to be replaced every year or even earlier.

Optimal battery capacity reserve this is the daily supply of energy in the batteries. For example, if you have a daily consumption of 10 kW * h, then the working capacity of the battery should be exactly that. Then you can easily survive 1-2 cloudy days without interruption.

At the same time, on ordinary days during the day, the batteries will be discharged by only 20-30%, and this will prolong their short life.

Another important thing to do this is the efficiency of lead-acid batteries, which is approximately 80%. That is, the battery, when fully charged, takes 20% more energy than it can then give.

The efficiency depends on the charge and discharge current, and the higher the charge and discharge currents, the lower the efficiency. For example, if you have a 200Ah battery, and you connect a 2kW electric kettle through an inverter, the voltage on the battery will drop sharply, since the battery discharge current will be about 250Amps, and the energy efficiency will drop to 40-50%. Also, if you charge the battery with a high current, then the efficiency will sharply decrease.

Also, the inverter (energy converter 12/24/48 to 220v) has an efficiency of 70-80%.

Taking into account the losses of the energy received from solar batteries in the batteries, and on the conversion of direct voltage to alternating voltage 220v, the total losses will be about 40%.

This means that the reserve capacity of the batteries needs to be increased by 40%, and also increase the array of solar panels by 40% to compensate for these losses.

But that's not all the loss.

Solar panels lifespan

There are two types of solar charge controllers, and you can't do without them. PWM (PWM) controllers are simpler and cheaper, they cannot transform energy, and therefore solar panels cannot give all their power to the battery, maximum 80% of the rated power.

But MPPT controllers track the point of maximum power and convert energy by lowering the voltage and increasing the charging current, as a result, increasing the efficiency of solar panels up to 99%. Therefore, if you install a cheaper PWM controller, then increase the solar array array by another 20%.

Calculation of solar panels for a private house or summer cottage

If you do not know your consumption and are just planning, say, to power the dacha from solar panels, then consumption is considered quite simple.

For example, a refrigerator will work in your country house, which, according to the passport, consumes 370 kW * h per year, which means that it will consume only 30.8 kW * h of energy per month, and 1.02 kW * h per day. Also, light, for example, you have energy-saving light bulbs, say 12 watts each, there are 5 of them and they shine on average for 5 hours a day. This means that your light will consume 12 * 5 * 5 = 300 watt * h of energy per day, and in a month it will "burn" 9kW * h.

For example, you get 70 kW * h of energy per month, add 40% of the energy that will be lost in the battery, inverter, etc. So we need solar panels to generate about 100 kW * h.

This means 100: 30: 7 = 0.476 kW. It turns out you need an array of batteries with a capacity of 0.5 kW. But such an array of batteries will be enough only in summer, even in spring and autumn, during cloudy days, there will be power outages, so it is necessary to double the array of batteries.

As a result of the above, in a nutshell, the calculation of the number of solar panels looks like this:

assume that solar panels work only 7 hours in summer with almost maximum power

calculate your electricity consumption per day

Divide by 7 and you get the required power of the solar array

add 40% to the losses in the battery and inverter

add another 20% if you have a PWM controller, if you don't need MPPT

Example: Consumption of a private house 300 kW * h per month, divide by 30 days = 7kW, divide 10kW by 7 hours, we get 1.42kW.

Add to this figure 40% of the losses on the battery and in the inverter, 1.42 + 0.568 = 1988 watts. As a result, a 2 kW array is needed to power a private house in the summer. But in order to get enough energy even in spring and autumn, it is better to increase the array by 50%, that is, another plus 1 kW. And in winter, during long cloudy periods, use either a gas generator or install a wind generator with a capacity of at least 2 kW.

Cost of solar panels and batteries

Prices for solar panels and equipment are now quite different, one and also products can differ at a price at times from different sellers, so look for cheaper ones, and from time-tested sellers. Prices for solar panels are now on average 70 rubles per watt, that is, an array of 1kW batteries will cost about 70t.rub, but the larger the batch, the more discounts and cheaper delivery.

High-quality specialized batteries are expensive, a 12v 200Ah battery will cost an average of 15-20t. Rubles. I use such batteries, it is written about them in this article Batteries for solar batteries Automotive batteries are twice as cheap, but they must be installed twice as many so that they last at least five years. And also car batteries cannot be installed in residential premises, since they are not sealed.

Specialized ones with a discharge of no more than 50% will last 6-10 years, and they are sealed, do not emit anything. You can buy it cheaper if you take a large batch, usually sellers give decent discounts.

The rest of the equipment is probably individual, inverters are different, both in power, and in the shape of a sinusoid, and in price.

Also, charge controllers can be as expensive with all functions, including communication with a PC and remote access via the Internet.

E-VETEROK.RU wind and solar energy - 2013

Mail: [email protected] Google+

With the help of an autonomous solar installation, you can provide energy to all electrical appliances in your home. The main thing is to understand and correctly assess the needs of your household and the capacities that you need to install.

Home solar system components.

A home photovoltaic system usually consists of 6 basic elements:

Calculating the number of solar panels and batteries in 6 steps

1. Energy consumption calculation. The first step is to draw up a specification, that is, technical description systems. First, you need to make a list of all the electrical appliances in the house, find out their needs and put them on the list.

Below are indicative data on the average power values of some devices. These are rough estimates. In order to calculate the power consumption of a system with an inverter (for AC appliances), you need to make corrections for each appliance. Inverter losses can be up to 20%. The refrigerator, the compressor at the time of start-up consume power 5-6 times more than the rated power, therefore the inverter must withstand short-term overloads 2-3 times higher than the rated power. If there are a lot of devices with high power, then for a cheaper and optimal choice of an inverter, separate switching on of such devices during operation should be provided.

In the network I came across a thesis of Zezin Denis Anatolyevich from 2014 on the topic

DEGRADATION PROCESSES IN THIN FILM SOLAR CELLS

The last chapter is presented to your attention, where the life cycle of a solar power plant and some conclusions are estimated.

[...] Next, a simple solar station was simulated. When creating a layout of the station, it was required to obtain a given power (from 1 to 100 MW) using a standard module (60 single-crystal plates, soldered in the form of two strips of 30 elements each), with a power of 150 W (15 V, 10 A). In this case, the maximum DC voltage should not exceed 1 kV (the requirements of the rules for the operation of power plants in the European Union were used).

In order to meet these requirements, the solar modules were connected in series until the maximum possible voltage was obtained, the missing power was generated by similar chains of modules connected in parallel due to the generated current.

The reliable operation of the modules is determined by the reliability of the solar cells themselves, as well as the soldered joints that provide electrical contact between the cells. When connecting modules in chains, it is necessary to use plugs, since the external leads, unlike solder joints, are in direct contact with the environment. In addition, each such circuit is equipped with an inverter, which is necessary for converting direct current into alternating current. For these reasons, the trouble-free operation of a solar power plant also depends on the reliability of the plugs and inverters.

When calculating the reliability, it was assumed that all the necessary electrical connections and equipment (solder joints, plugs and inverters) obey an exponential distribution law. That is, their refusals were considered only as sudden, the intensity of which does not change over time.

Mean time between failures for each element of the model were chosen close to real ones: soldered connection - 105 [h] (~ 10 years), plug and inverter - 5 * 104 [h] (~ 5 years).

The figures show the simulation results. On these graphs, you can see that due to the large number of modules connected in parallel, the probability of failure-free operation of a solar power plant, close to 100%, takes place over a longer period of time. Then there is a rapid decrease in the probability of no-failure, proportional to the number of elements. This behavior of the system resembles a redundant IC.

Probability of failure-free operation of the standard module and solar power plants

Probability of failure-free operation of solar power plants of different capacities

One of the features of solar power plants is the requirement for a large amount of free space. At the same time, the transport possibilities limit the size of one photovoltaic module. As a consequence, to build a power plant with a capacity of, for example, 100 MW from standard modules with a capacity of, say, 100 W, it is necessary to form a million connections. In addition, each solar module also consists of 20-60 solar cells, which also need to be connected. The demand of modern solar power plants for a large number of connections resembles a similar need for electronics in the transition from wall-mounted to integrated technology.

As measures to improve reliability, it is possible to propose the use of "smart modules" - devices that, by their intended purpose, perform the same function as solar modules, however, they are equipped with additional electronics that provide short-circuiting of failed elements. Such a system is necessary, since one failed element turns off the entire chain of modules. Of course, at large power plants, a large number of parallel connections allows you to postpone the moment of power plant exit, but power losses will accumulate. Similar systems now they are only being developed in the context of ensuring battery operation in conditions of partial shading (for example), since poorly lit ones are actually not working. Such developments can be useful for ensuring the reliability of solar panels.

As an additional and alternative source of energy, solar panels are actively used not only in industrial but also in domestic conditions. But before installing such a source of electricity for himself, it is important for the buyer to find out how to choose the solar panels that are optimal in terms of characteristics and power for the home, because the price of ready-made kits varies in a fairly wide range.

The use of solar panels in the middle lane - it is also possible to use free energy here

Where are solar panels most commonly used?

The field of application of solar panels is huge. Already now they are successfully used for power supply of private and apartment buildings, farms, including for lighting and heating greenhouses, buildings, lighting of the local area, powering devices.

Most often, they think about autonomous power supply in the following cases:

If the area is not electrified, solar panels for a private home will be much cheaper than using liquid fuel generators.

In rural areas, electricity is often cut off, and people are literally left without electricity. By turning on the autonomous power supply, you can live in the usual comfort for a long time, especially since a battery is always included with solar panels.

In apartment buildings, solar modules are also used as backup, and there are projects that involve the use of solar energy for hot water supply.

As a rule, in documents for equipment, a shelf life of 20 to 25 or even 30 years is indicated. However, many devices continue to function after the period specified by the manufacturers. For example, the world's first solar battery has been operating for over 60 years, and over the years, the production technology has been significantly improved.

The prototype of the solar battery was developed at the end of the 19th century.

Obviously, only one drawback can be singled out - with constant operation, the capacity of the equipment decreases, nevertheless, these indicators are insignificant: for 10 years, no more than 10%.

Prevent physical damage such as falling trees, being blown off by wind and scratching sensing elements. The efficiency of the device depends on the latter.

Carry out regular maintenance: maintenance and cleaning.

Install wind barriers if necessary.

In addition to modules, the system includes the following components: rechargeable batteries and power electronics. The service life of the first devices is from 2 to 15 years, the second - from 5 to 20 years, depending on the characteristics, intensity of use and careful maintenance.

General characteristics and availability of purchase

The equipment is not harmful to the environment and provides a stable power supply without voltage surges. And, most importantly, it supplies free energy: for which utility bills do not come.

The appearance of solar panels has changed little after their invention, which cannot be said about the internal "filling"

The solar module converts light into electrical energy, generating constant current. The area of the panels can be up to several meters. When it is necessary to increase the capacity of the system, the number of modules is increased. Their effectiveness depends on the intensity of sunlight and the angle of incidence of the rays: on the location, season, climatic conditions and time of day. In order to correctly take into account all these nuances, the installation must be performed by professionals.

Monocrystalline. They consist of silicone cells that convert solar energy. They are distinguished by their compact size. In terms of their performance, they are the most efficient (efficiency up to 22%), which affects their price - this is the most expensive type of solar panels.

Polycrystalline. They use polycrystalline silicon. They are not as efficient (up to 18% efficiency) as monocrystalline solar cells. But their cost is significantly lower, so they are available to the general public.

Amorphous. They have silicon-based thin-film solar cells. They are inferior to mono and polycrystals in terms of energy production, but they are also cheaper. Their advantage is the ability to function in diffuse and even low light.

Polycrystalline Solar Panel

The system also includes the following components:

An inverter that converts DC to AC.

Accumulator battery. It not only accumulates energy, but also neutralizes voltage drops when the light level changes.

Controller for battery charging voltage, charging mode, temperature and other parameters.

In stores, you can buy both individual components and entire systems. In this case, the power of devices is determined based on specific needs.

Functioning, types of converters and their comparative energy efficiency

Converters or inverters are key components of solar panels. They transform the direct current generated by the module into alternating voltage 220 V, which is necessary for the operation of electrical appliances. Inverters are available in capacities ranging from 250 to 8000 W. When buying, it is recommended to take into account the highest network load and correlate voltage and power. The following parameters are considered optimal: 12 volts and 600 watts, 24 volts at 600-1500 watts, 48 volts if the power is more than 1500 watts.

Inverter, on a schematic diagram of the operation of solar panels

Autonomous. Before choosing an inverter, you need to determine which devices will be powered by it, and calculate their total maximum power per unit of time. It is recommended to take the power of the inverter a little more. Some household electrical appliances, when turned on, create a sharp increase in voltage, due to which the device may fail.

Synchronous. They store energy, and the surplus is transferred to the electrical network. In the event of a shortage of electricity generated by the system, the converter will "borrow" it from common network... The use of a synchronous model will avoid power outages.

Multifunctional devices have combined the advantages of the first and second types.

Depending on the shape of the output voltage signal, there are several types of converters that differ in application and cost:

With sinusoidal signal. Create current High Quality, which affects their cost. Large household appliances work from them: refrigerators, boilers, air conditioners.

Rectangular. Lighting fixtures are connected to these inexpensive inverters. Most household appliances are not compatible with them.

Pseudosinusoidal. Their advantage is the ability to connect almost all home appliances. But the signal quality is reduced compared to the first type, so they are cheaper.

The ribbed shape of the inverter is needed for the most efficient cooling

The cost of the kit and the main technical characteristics, payback period

Prices for ready-made kits generally range from 30,000 to 2,000,000 rubles. They depend on the devices that make up them (on the type of batteries, the number of devices, manufacturer and characteristics). You can find budget options costing from 10,500 rubles. The economy kit includes a panel, a charge controller, a connector.

Standard kits include:

* Provided in extended configuration.

Standard set of equipment

Specifications indicate in the application manual:

The power and dimensions of the panels. The more power you need, the more profitable it is to buy larger batteries.

The temperature coefficient shows how much temperature affects power, voltage and current.

The principle of operation of a solar power plant at home

A solar power plant is a system consisting of panels, an inverter, a battery and a controller. A solar panel converts radiant energy into electricity (as mentioned above). Direct current flows into the controller, which distributes the current to consumers (for example, a computer or lighting). The inverter converts DC to AC and powers most electrical household appliances. The battery stores energy that can be consumed at night.

How solar energy is used to generate heat

Solar systems are used to heat water and heat the home. They can provide heat (at the request of the owner) even when the heating season is over, and provide the house with hot water for free. The simplest device is a metal panel that is installed on the roof of a house. They store energy and heat the water that circulates through the pipes hidden underneath. The functioning of all solar systems is based on this principle, although they may be structurally different from each other.

Solar collectors consist of:

According to the type of design, flat and vacuum collectors are distinguished. In the former, the bottom is covered with heat-insulating material, and the liquid circulates through glass pipes. Vacuum collectors are highly efficient because heat losses in them are minimized. This type of collector provides not only solar heating of a private house - it is convenient to use for hot water supply systems and swimming pool heating.

How the solar collector works

The most common in Russia is the products of Chinese manufacturers, due to the relative cheapness compared to products manufactured in other countries. For example, solar panels from China are almost twice as cheap as German ones.

The most common products on the shelves are Yingli Green Energy and Suntech Power Co. HiminSolar panels (China) are also popular. Their solar panels generate electricity even in rainy weather.

The production of solar panels is also established by a domestic manufacturer. This is done by the following companies:

LLC "Hevel" in Novocheboksarsk;

Telecom-STV in Zelenograd;

Sun Shines (LLC Autonomous Lighting Systems) in Moscow;

JSC "Ryazan plant of cermet devices";

CJSC "Termotron-zavod" and others.

You can always find a suitable option at a cost. For example, in Moscow, you can order and buy ready-made sets of solar panels - at a price of 21,000 to 2,000,000 rubles. The cost depends on the configuration and power of the devices.

Solar panels are not always flat - there are a number of models that focus light at one point

Battery installation steps

To install the panels, the most illuminated place is chosen - most often these are the roofs and walls of buildings. For the device to function as efficiently as possible, the panels are mounted at a specific angle to the horizon. The level of darkness of the territory is also taken into account: surrounding objects that can create shadow (buildings, trees, etc.)

The panels are installed using special fastening systems.

Then the modules are connected to the battery, controller and inverter, and the entire system is adjusted.

For the efficient functioning of the equipment and a long service life, a correct installation is a prerequisite, which only experienced specialists can do.

Despite the complexity of connection and calibration, the work period is short - with the appropriate tools, competent installers will spend about half a day on everything.

For the installation of the system, a personal project is always developed, which takes into account all the features of the situation: how the installation of solar panels on the roof of the house will be carried out, the price and terms. Depending on the type and scope of work, all projects are calculated on an individual basis. The client accepts the work and receives a guarantee for it.

Installation of solar panels must be done by professionals and in compliance with safety measures

As a result - the prospects for the development of solar technologies

If on Earth the maximum efficient operation of solar cells is interfered with by air, which in a certain degree scatters the radiation of the Sun, then in space such a problem does not exist. Scientists are developing projects for giant orbiting satellites with solar panels that will operate 24 hours a day. From them, the energy will be transmitted to ground receiving devices. But this is a matter of the future, and for existing batteries, efforts are aimed at improving energy efficiency and reducing the size of devices.

Solar panels for home: characteristics, cost of the kit and installation

Solar panels for home: where are they used, what is the principle of operation, service life and general characteristics of the device, equipment and cost of equipment.

Solar panels lifespan

A few years ago, there was no particular choice of modules from a Ukrainian manufacturer for a buyer. The price for solar modules from Ukrainian manufacturers was higher than for any imported modules.

Even now, the situation has not changed, but subsidies of the photovoltaic industry by the Chinese government have greatly improved the quality of solar cells and modules produced in China and reduced their prices. Now about 80% of solar cells on the world market are made in China or by Chinese manufacturers. Europe and the United States were so inundated with Chinese products that many local solar cell and module manufacturers were bankrupt. A number of solar cell and wafer manufacturers have gone bankrupt or shut down production. a similar situation for solar silicon producers. All over the world, the pressure from Chinese manufacturers is felt very strongly. So much so that the United States and the European Union have taken measures to restrict the import of Chinese-made PV modules into their domestic markets.

There are more and more Chinese and pseudo-European modules on the Ukrainian market. Unfortunately, not all Chinese modules are of acceptable quality. High-quality modules that meet all international standards are now being produced in China; the quality of such modules is better than those produced in Ukraine at the present time. This has been made possible by the Chinese government's massive investment in solar energy.

Therefore, the buyer was faced with the question - how to distinguish good modules from bad ones? Why are some modules cheaper than others? What is the threat of the cheapness of the modules and will the buyer lose more in the future than he will save when buying?

Indeed, the answers to these questions are not obvious to the layman. All modules produce electricity by converting sunlight - so why buy more expensive? Here the situation can be compared with cars - you can get from point A to point B by different cars. Both can be of the same size and motor power. But one after a few kilometers will lose speed and will not be able to go fast, will begin to break down after every kilometer, etc. The other will travel all the way as it did at the beginning. As a result, on the first one, you risk not reaching your destination, while constantly repairing it, even cyclists will overtake you. Eventually, halfway through the journey, you will be forced to buy another car. In another, more expensive (and better) car, you will reach the end without even noticing the path.

With solar panels, the situation is similar - it is almost impossible for a layman to determine if a module is good. The specifications will say that it delivers its nameplate power under standard test conditions. The look will be good too. The difference becomes noticeable after several years of operation. Also, different modules can work differently at illumination lower than 1000W / m2.

What to look for when choosing solar modules for your solar power system?

Price versus quality

In addition to the fact that not all manufacturers and solar modules are the same (this is discussed in the related article on the quality of solar cells), there are a number of parameters and factors that should be considered when making a purchase decision and when choosing a supplier. The price of the modules alone should not be the determining factor.

Problems and deterioration of the parameters of solar modules can be caused by the following factors:

The quality of the solar cell - its efficiency varies. It depends on many of its parameters - shunt and series resistances, noise currents, return resistance, etc. Much depends on the quality of production of a solar cell and the quality of materials and equipment used in its production. Problems are known practically at every stage of cell production - from the quality of the silicon used to the quality of the applied contact pastes and solder. We will not consider these problems in this article, this is a subject for a separate large article.
Soldering quality of solar cells. In case of poor-quality soldering, local overheating of the contact and its burning out is possible. It is better to choose modules in which the elements are soldered by a robot - in them the spread in the quality of soldering will be minimal
The quality of the EVA film, which is located between the elements and the glass. Aging of crystalline solar modules is mainly associated with aging and cloudiness of this film. A poor-quality film can begin to grow cloudy and deteriorate after a few years. A good film will last 30 or more years, while its haze (and, consequently, the loss of power by the module) will not exceed 25-30%
The quality of the sealing of the module and the quality of the back protective film. The back film protects the module from moisture. In any module, moisture diffusion occurs through the film. If the quality of the film is good, then all moisture that gets inside the module, when it is heated in the sun, is removed outside. If the film is of poor quality, then more moisture gets in than can be released during heating, residual moisture accumulates inside the modules and destroys the contacts and contact grid of the elements. This leads to premature failure of the module.
The quality of the aluminum frame. Everything is clear here: poor-quality anodizing can lead to oxidation of the frame and its corrosion. Fortunately, this defect is more visual and hardly leads to premature module failure. Although, in some cases (for example, when installing modules on masts, where strong wind loads are possible or where the environment is aggressive), accelerated corrosion of the metal can lead to its destruction under loads.

How to determine what voltage the modules have?

In recent years, modules with non-standard voltages have appeared on the market, which are designed to work in series high-voltage circuits. WITH light hand non-professional sellers of solar panels - both Russian and Chinese - there was confusion about the nominal voltage of solar modules. We will give some tips on how to determine what voltage a solar panel has.

The voltage of a solar panel is determined by the number of solar cells connected in series. Each solar cell has an operating voltage of just under half a volt. Currently, there are modules with the number of elements 36.48, 54, 60.72 and 96. The most common modules with the number of elements 36, 60 and 72. At 48, 54 and 96 elements are much less common. The table below shows the main voltages of these solar panels.

1ТММ - point of maximum power

2 is due to the possibility of charging when connected to the battery directly or through a PWM controller. The rest of the modules can be used to charge batteries, but with the mandatory presence of an MPPT controller.

When purchasing modules for an autonomous system with batteries, pay attention to the voltage of the module. Recently, high-power modules (220-270 watts) with a non-standard voltage of about 20V have been mass-produced. These modules are usually used in conjunction with on-grid photovoltaic inverters or MPPT charge controllers. If you want to reduce the cost of the system at the expense of a less expensive PWM controller, choose modules with a nominal voltage of 12 V or 24 V.

Tolerance means the deviation of the real power of the module from the passport. Tolerance can be either positive or negative. For example, a 200W rated power module can have a power of 195W; this will mean that this module has a negative tolerance. Positive tolerance means that the solar panel is not only guaranteed to have an output power of 200W under standard test conditions, but even more.

The temperature coefficient reflects how an increase or decrease in the temperature of the module will affect the output current and voltage of a module. As you know, the voltage and power of the module decrease with increasing temperature, and the current increases. The lower the temperature coefficient of change in power, the better.

Sunlight conversion efficiency

With this it is clear - the higher the efficiency, the smaller the area of the modules will be required to generate the same power and energy.

The total amount of energy expended in the manufacture of the module

Another parameter to look out for is the total amount of energy that could have been expended in the manufacture of a solar module - from mining silicon to shipping finished goods to the store. This parameter reflects how energy-intensive was the production of the module and how quickly the solar module will generate the same amount of energy that was spent on its production (the so-called energy payback).

The declared lifespan of a solar panel is important for several reasons. It can reflect the confidence of the manufacturer in the quality of the manufactured product. Reputable manufacturers have a 25-year warranty for 80-90% of the module's capacity, as well as 5 or more years for mechanical damage.

However, it should be borne in mind that the guarantee is valid as long as the manufacturer or importer exists. Here, "how the card will fall" - in recent years companies have left the solar business, which seemed to be in it for a very long time. But nevertheless, the general rule remains - buy from sellers and manufacturers who have been on the market for a long time and are steadily “floating” in the turbulent stream of the market. And this can only be done if there are professionals in the team (we are so modestly hinting at ourselves). Since few people buy modules directly from the manufacturer, it is important to choose the right vendor or installer to provide you with the right choices and modes of operation for your solar power system.

The cost of a module depends on its power in direct proportion. However, the higher the unit power of the module, the lower its cost per watt will be. Therefore, if you need a certain power, then it is better to collect it with large modules than with small ones - it will be both cheaper and more reliable, because you will have fewer connections. Also, the cost per watt of modules with a standard voltage of 12 / 24V (the number of cells in a module is 36 or 72) is usually higher than with a non-standard number of cells in a module 48, 54 or 60. For the latter, when charging the batteries, a more expensive MPPT controller is needed.

The type of solar cells used in a module also determines its size. Therefore, first calculate how much power you need to power your load, then see if you have enough space to accommodate so many modules. It may be necessary to select more expensive but more efficient modules in order to meet all your energy needs. By the way, do not forget that before designing a solar power supply system, you need to take all possible measures to save energy (this has already been written about on other pages of our site).

Peak power of all modules measured under standard test conditions:

Air mass AM = 1.5, radiation E = 1000 W / m2, and photovoltaic cell temperature Tc = 25 ° C. Such conditions do not exist during the actual operation of the modules - the modules usually heat up to 40-60 degrees, the illumination is almost always below 1000 W / m2 (with the exception of frosty clear days). Therefore, many manufacturers also give the characteristics of the module at NOCT (normal operation conditions) - usually for a module temperature of 45-47C and an illumination of 800 W / m2, while the output of the modules is about 25-30% lower than the peak. On a frosty clear day, the production of modules can reach up to 125% of the peak.

The type of solar cells is monocrystalline, polycrystalline, amorphous, etc.

The three main types of solar cells currently being marketed in large quantities (all silicon) are as follows:

monocrystalline. Have the highest efficiency and satisfactory temperature coefficients
polycrystalline. Currently, the most popular ones, as have a lower cost per watt with approximately the same characteristics as monocrystalline. Recent improvements in branded polycrystalline module technology have resulted in performance being even better than noname monocrystalline modules from panel manufacturers / assemblers.
amorphous (thin-film). Use least amount silicon. They have approximately 2 times lower efficiency compared to crystalline modules. The advantages include a low temperature coefficient (i.e., when heated, the power of such modules decreases slightly) and a high sensitivity at low illumination.

Which modules, from the ones listed above, work better? Lately, there have been many myths and unsubstantiated claims that some of these module types perform better than others. Some claim that polycrystalline cells work better in low light and cloudy weather. Others claim the same, but for monocrystalline elements. I even heard a version that polycrystalline elements convert scattered light better, because the crystals in them are “turned in different directions”.

Analysis of the results of testing hundreds of modules shows that the module is not good, which is mono or poly, but one that is made with high quality. PTC module testing results (which are closer to the actual operating conditions of the modules) show that some monocrystalline is better than some polycrystalline, and some polycrystalline is better than some monocrystalline. This fact is also confirmed by numerous comparison results of modules by end users - can be found as "proof" the advantages of mono over poly, and the advantages of poly over mono.

How to choose the right photovoltaic panels made in China and not regret it?

The general rule is to choose solar cells and modules from large, well-known companies. These modules are made from the highest quality elements.

Cells that have not passed the rigorous selection of a brand manufacturer are sold to photovoltaic panel assemblers, of which there are many in China. Moreover, all these assemblers sell their OEM modules, i.e. under the trade names of other companies. There are most of them on the Russian market now. Always pay attention to the manufacturer indicated on the module sticker. The risk of getting modules of unknown quality, which will not know how to work, is very high, and if you do not even know the manufacturer (the trade name of the seller will not help you in any way in obtaining a guarantee), then be prepared that you are buying solar modules without a guarantee.

Usually cheap Chinese modules have the following disadvantages:

Discrepancy between the declared power and the real
Strong degradation of modules in the very first years of operation (up to 20-30%)
Poor soldering and assembly quality
The use of low-quality materials in the manufacture of the module (fluxes, film, aluminum, solar cells, etc.)

You can also buy modules at the online auction. But will they work as stated? Most likely not, and we have facts confirming this.

There is one more point to consider when buying imported modules - guarantee issue... WITH Russian manufacturers there are no problems in this regard - they all produce quick replacement or repair of modules under warranty. Responsible Russian importers, who have been on the market for many years, also provide their guarantee for the solar modules they import. In other cases, you need to be very careful when choosing a solar panel supplier.

Modules with a sticker of trade brands without specifying the real manufacturer should make you wary - in most cases you will not be able to get warranty service for such modules, we have many examples of this.

Pay attention to how the modules are soldered. Small manufacturers solder the elements by hand, rather than by a robot, so the thickness of the solder changes when soldering the contact bars of the elements. Large firms solder with a robot, so the quality of soldering is much higher.

Be sure to find out how many years the module supplier has been on the market. Even if a Chinese manufacturer gives a guarantee for its products, think about how you will exchange the module - if your seller does not provide you with a guarantee, then practically you will not have it. If you directly contact a manufacturer in China, you will certainly incur the costs of transportation, customs clearance, etc. these costs are not covered by any foreign manufacturer. These costs can only be compensated for by a verified reliable seller who works in accordance with Russian law. If you buy modules from a well-known seller who has been working in this market for many years (for example, with us), you will also receive a guarantee for the modules from him. Beware of buying imported modules from installers or small sellers - they, in the vast majority of cases, cannot provide a warranty for the modules sold. Always ask them for a manufacturer's or importer's warranty card, do not be too lazy to call the phone number indicated in the warranty card and ask who and how provides warranty service.

Therefore, our recommendation is to choose only branded photovoltaic modules, or at least those on which their manufacturer is indicated. Among the Chinese, these are TrinaSolar, Yingli, Canadian Solar, JA Solar, Suntech, Motech, Linuo, Hanwha, ReneSola, Jinko, etc. - read more here. They will really have a guarantee for many years, and not as long as the seller and his trademark exist.

If there is no manufacturer data on the module, but only the name of the OEM seller, this should alert you. Usually such modules are made from elements Low quality(Grade B and C) and at a low price.

Solar modules are not cheap and are designed to last over 30 years. It would be very unwise to save 30-50% on the cost of the module and get a module that will not work in a few years, for which it is impossible to make claims to anyone. Remember that “cheap is never good”.

How to choose the right solar panels

General situation on the market of solar modules A few years ago there was no special choice of modules from a Ukrainian manufacturer for a buyer.

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 the power of the 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. 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 is currently comprised of crystalline silicon modules.

Other components in the system have different lifespans: the batteries have a lifespan of 2 to 15 years, and the power electronics have a lifespan of 5 to 20 years.

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 is reduced by no more than 10%. Mechanical damage is usually guaranteed for a period of 1 to 5 years.

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

The design life of crystal modules is usually 30 years. Manufacturers perform accelerated tests on the use of the module in order to assess its real life. The solar cells themselves used in solar modules have an almost unlimited lifespan 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; EVA is used) and destruction of the back surface of the module (usually polyvinyl phosphate film), as well as the gradual haze of the EVA film interlayer 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 trapped inside is discharged outside during the day when the module temperature rises. 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 a deterioration in the protection of the module from moisture. Moisture trapped inside the module leads to corrosion of electrical connections, an increase in resistance in the place of corrosion, overheating and destruction of the contact, or to a decrease in the output voltage of the module.

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

The maximum degradation is usually guaranteed by manufacturers to be no more than 20% over 25 years. However, measurements carried out on 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.