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Efficiency of solar panels. What determines the efficiency of solar panels and how to increase this indicator Modern solar panels with high efficiency

Solar batteries are a unique converter of the energy of light rays into electricity with an unlimited external source. The constantly growing demand for these products is due to the availability and environmental friendliness of energy supply without coolant consumption, as well as economic payback in 2 years with a minimum service life of the panels of 25 years.

The basis is semiconductors or film polymers; a plate of layers of different polarities converts light into the directional movement of electrons - this physical phenomenon is unchanged for all solar cells. At the same time, this design limits the efficiency of photoconverters; part of the photon energy is inevitably lost when passing p-n boundaries transition. In practice, the efficiency of batteries is influenced by many factors: material, area, location, intensity luminous flux, which is taken into account when purchasing and operating.

Dependence of efficiency on the type of photoconverters

This indicator is defined as the percentage of generated electrical energy to the power of incident sunlight. The value is affected by the purity of the plate and its structure: film, poly- or monocrystalline. The latter types are among the most expensive and take the longest to pay for themselves; affordable high-efficiency solar panels for the home are so far produced only from layers of silicon of different polarities. Less effective are panels made of cadmium terruride and CIGS, produced on the basis of film technology. The efficiency of cadmium batteries is only 11%, but they are cheap and quite reliable in operation. The indicator is slightly higher for films coated with particles of gallium, copper, indium and selenium; CIGS photocells are 15% efficient.

For comparison: the efficiency of monocrystalline silicon converters is 25%, and for thin-film or amorphous submodules made of the same material - a maximum of 10; devices based on organic polymers have a minimum value of 5%. Much depends on the area of the panel; single solar cells are limited in generating electricity.

The efficiency of small solar panels does not allow them to be used for full power supply, but they are enough to run some types of electronics. In any case, increasing the efficiency of devices and minimizing their cost is a priority task of modern energy.

Factors affecting the efficiency of solar panels

The efficiency depends not only on the material and technology used, but also on a whole range of external conditions:

1. Luminous flux intensity. In turn, this indicator is associated with the geographical coordinates of the located battery, in particular with latitude.

2. Angle of inclination of the structure. Ideally, solar panels should be installed that change it based on the gradient of the rays. Such a system is more expensive, but it allows you to accumulate an impressive amount of electricity (up to 40–60%) and is less dependent on the season and time of day.

3. Temperatures environment. Heating has a bad effect on the photoelectric effect; ventilated batteries have a very high efficiency. Paradoxically, in cold, clear weather they produce more energy than in hot weather (although the overall cumulative effect is reduced due to the short daylight hours).

4. Seasons. In practice, the efficiency of solar panels in winter decreases by 2–8 times, but this is not due to snowfall: it melts quickly on a dark surface, in addition, photoconverters perceive scattered light well.

5. Dustiness. The cleaner outer part solar panels large quantity photons will be converted, therefore, to increase efficiency, it is recommended to wipe the working surfaces at least once every two years.

6. Shadows. It is no secret that the efficiency of solar panels in cloudy weather is significantly reduced; there is no point in installing them in foggy and rainy areas; the same applies to shaded areas. It is not advisable to install the panels in the shade of tall trees or neighboring houses; when choosing a location, priority is given to the south side.

Solar panels are a unique system that allows you to convert solar rays into electrical and thermal energy. The growing demand for solar products today is determined by their quick payback, durability, and availability of coolant. But what voltage can solar panels produce? Read the article about how effective solar systems are and what their efficiency depends on.

High efficiency solar panels: types of converters

The efficiency of solar batteries is a value that is equal to the ratio of the power of electricity to the power incident on the panel of the device sun rays. Modern solar cells have an efficiency ranging from 10 to 45%. This large difference is due to differences between the materials used and the design of the battery plates.

So, solar panel plates can be:

Thin film;
Multi-junction.

The latter type of solar panels, today, are the most expensive, but also the most productive. This is due to the fact that each junction in the plate absorbs waves of a certain length. Thus, the device covers the entire spectrum of sunlight. The maximum efficiency of batteries with multijunction panels obtained in laboratory conditions is 43.5%.

Energy experts say with confidence that in a few years this figure will increase to 50%. The efficiency of thin-film plates depends, to a large extent, on the material they are made of.

Thus, thin-film solar batteries are divided into the following types:

Silicon;
Cadmium.

The most popular solar batteries that can be used for domestic purposes are those with silicon film wafers. The volume of such devices on the market is 80%. Their efficiency is quite low - only 10%, but they are affordable and reliable. The efficiency index is several percent higher for cadmium plates. Films with particles of selenide, copper, indium and gallium have a higher efficiency, which is equal to 15%.

What determines the efficiency of solar panels?

The efficiency of photoelectric converters is influenced by many factors. So, as noted above, the amount of energy generated depends on the structure of the converter panel and the material of their manufacture.

In addition, the efficiency of solar inverters depends on:

Forces of solar radiation. Thus, with a decrease in solar activity, the power of solar installations decreases. In order for the batteries to provide the consumer with energy at night, they are supplied with special batteries.
Air temperatures. Thus, solar panels with cooling devices are more productive: heating the panels negatively affects their ability to convert energy into current. So, in frosty, clear weather, the efficiency of solar batteries is higher than in sunny and hot weather.
The angle of inclination of the device and the incidence of sunlight. To ensure maximum efficiency, the solar panel should be aimed directly at the sun's radiation. The most effective models are those whose inclination level can be changed relative to the location of the Sun.
Weather conditions. In practice, it has been noted that in areas with cloudy, rainy weather, the efficiency of solar converters is much lower than in sunny regions.

In addition, the efficiency of solar converters is also affected by their level of cleanliness. In order for the device to work productively, its plates must consume as much solar radiation as possible. This can only be done if the devices are clean.

The accumulation of snow, dust and dirt on the screen can reduce the efficiency of the device by 7%.

It is recommended to wash screens 1-4 times a year, depending on the degree of contamination. In this case, you can use a hose with a nozzle for cleaning. Technical inspection of converter elements should be carried out every 3-4 months.

Solar power per square meter

As noted above, on average, one square meter of photovoltaic converters provides the generation of 13-18% of the power of the sun's rays falling on it. That is, under the most favorable conditions, with square meter solar panels can produce 130-180 watts.

The power of solar systems can be increased by increasing the panels and increasing the area of photovoltaic converters.

You can also get more power by installing panels with higher efficiency. However, the rather low (in comparison, for example, with induction converters) efficiency of available solar cells is the main obstacle to their widespread use. Increasing the power and efficiency of solar systems is the primary task of modern energy.

The most efficient solar panels: rating

The most efficient solar converters today are produced by Sharp. Three-layer, powerful, concentrating solar panels have an efficiency of 44.4%. Their cost is incredibly high, so they are used only in the aerospace industry.

The most affordable and effective are modern solar panels from the following companies:

Panasonic Eco Solutions;
First Solar;
MiaSole;
JinkoSolar;
Trina Solar;
Yingli Green;
ReneSola;
Canadian Solar.

Sun Power produces the most reliable solar inverters with an efficiency of 21.5%. The company's products are absolutely popular in commercial and industrial facilities, second only to devices from Q-Cells.

Efficiency of solar panels (video)

Modern solar panels, as environmentally friendly energy conversion devices with inexhaustible coolant, are gaining increasing popularity. Already today, devices with photoelectric converters are used for household purposes (charging phones, tablets). The efficiency of solar installations is still inferior to alternative methods of generating energy. But increasing the efficiency of converters is the primary task of modern energy.

Modern researchers who work on solar systems constantly debate among themselves about the efficiency of solar panels. This is one of the main criteria on the basis of which their effectiveness and level of productivity are assessed. Because the cost of converting solar energy into electricity for panels remains high, manufacturers are worrying about how to make them more efficient.

It is known that per 1 m² of cell area produces about 20% of the total solar radiation power that hits the battery. In this case, we are talking about the most favorable climate and weather conditions, which do not always happen. Therefore, to increase the rate, you need to install a lot of solar panels. This is not always convenient, and the cost is a pretty penny. Therefore, you need to understand how feasible it is to use these alternative energy sources and what prospects there are in the future.

So, the efficiency of a battery is the amount of potential it actually produces, expressed as a percentage. To calculate it, it is necessary to divide the power of electrical energy by the power of solar energy falling on the surface of the solar panels.

Now this figure ranges from 12 to 25%. Although in practice, taking into account weather and climatic conditions, it does not rise above 15. The reason for this is the materials from which they are made. solar batteries. Silicon, which is the main “raw material” for their manufacture, does not have the ability to absorb the UV spectrum and can only work with infrared radiation. Unfortunately, due to this deficiency, we waste the energy of the UV spectrum and do not use it beneficially.

Relationship between efficiency and materials and technologies

How do solar panels work? Based on the properties of semiconductors. The light that falls on them knocks out electrons located in the outer orbit of atoms with its particles. A large number of electrons creates the potential of an electric current - under closed circuit conditions.

To ensure a normal power indicator, one module will not be enough. The more panels, the more efficient the operation of the radiators, which supply electricity to the batteries, where it will accumulate. Exactly because of this reason The efficiency of solar panels also depends on the number of modules installed . The more of them there are, the more solar energy they absorb, and their power indicator becomes an order of magnitude higher.

Is it possible to improve battery efficiency? Such attempts were made by their creators, and more than once. A way out in the future may be the production of elements consisting of several materials and their layers. The materials are arranged in such a way that the modules can absorb different types energy.

For example, if one substance works with the UV spectrum, and another with the infrared, the efficiency of solar cells increases significantly. If we think at the theoretical level, then the highest efficiency could be about 90%.

Also, the type of silicon has a great influence on the efficiency of any solar system. Its atoms can be obtained in several ways, and all panels, based on this, are divided into three varieties:

polycrystals;
elements from .

Solar batteries are produced from monocrystals, the efficiency of which is about 20%. They are expensive because they have the highest efficiency. Polycrystals are much lower in cost, since in this case the quality of their work directly depends on the purity of the silicon used in their manufacture.

Elements based on amorphous silicon have become the basis for the production of thin films. The technology for their manufacture is much simpler, the cost is lower, but the efficiency is also lower - no more than 6%. They wear out quickly. Therefore, to improve their service life, selenium, gallium, and indium are added to them.

How to make your solar panel work as efficiently as possible

The performance of any solar system depends on:

temperature indicators;
angle of incidence of the sun's rays;
surface condition (it should always be clean);
weather conditions;
presence or absence of shadow.

The optimal angle of incidence of the sun's rays on the panel is 90°, that is, straight. There are already solar systems equipped with unique devices. They allow you to monitor the position of the luminary in space. When the position of the Sun relative to the Earth changes, the angle of inclination of the solar system also changes.

Constant heating of the elements also does not have the best effect on their performance. When energy is converted, serious losses occur. That's why You should always leave a small space between the solar system and the surface on which it is mounted . The air currents passing through it will serve as a natural way of cooling.

Cleanliness of solar panels - also an important factor influencing their efficiency. If they are very dirty, they collect less light, which means their effectiveness is reduced.

Correct installation also plays a big role. When installing the system, do not allow a shadow to fall on it. The best side on which it is recommended to install them is the south.

Moving on to weather conditions, we can at the same time answer the popular question of whether solar panels work in cloudy weather. Of course, their work continues, because electromagnetic radiation emanating from the Sun hits the Earth at all times of the year. Of course, the performance of the panels (efficiency) will be significantly lower, especially in regions with a lot of rainy and cloudy days a year. In other words, they will generate electricity, but in much smaller quantities than in regions with a sunny and hot climate.

A little about the efficiency champion batteries

German batteries are currently considered the record holder for efficiency in solar systems. They were created at the Institute of Solar Energy named after. Fraunhofer. They are based on photocells consisting of several layers. Company "Soytek" has been actively introducing them into widespread consumption since 2005.

The elements themselves are no more than 4 mm thick, and sunlight is focused on their surface using special lenses. Thanks to them, light particles are converted into electricity, and the efficiency is as much as 47%.

Second place is deservedly occupied by panels created by using photocells from three layers of the company "Sharp". These are also solar panels with high efficiency, although slightly less - 44%.

The three layers are represented by three substances: indium (gallium) phosphide, gallium arsenide and indium (gallium) arsenide. Between them there is a dielectric layer used to obtain a tunnel effect. As for the focusing of light, it is obtained by using the known Fresnel lens. The light concentration is reached to a level of 302 times, and then enters a three-layer semiconductor converter.

Of course, such an efficiency record can hardly be accessible to a wide range of consumers. By the way, Elon Musk, a famous American billionaire, is the owner of the company "Solar City". Not so long ago, in 2015, Musk’s company developed a “consumer” version of solar panels with an efficiency exceeding 22%.

Developments and numerous laboratory experiments are carried out to this day. You can be sure that such technologies have a great future - as an environmentally friendly alternative source of energy.

Billions of kilowatts are supplied to our planet every day. solar energy. People have long begun to use this energy for their needs. With the progress of progress, solar panels began to be used to convert the energy of sunlight. But are these devices effective? How much is the efficiency of solar panels, and what does it depend on? What is their payback period and how can you calculate the profitability of using solar panels? These questions concern everyone who is planning or has already decided to purchase solar panels, so this article is devoted to this pressing topic.

Let's briefly look at what the operating principle of solar panels is based on. It is based physical property semiconductors. Due to the knocking out of electrons from the outer orbit of atoms by light photons, enough a large number of free electrons. After the circuit is closed, it occurs electricity. But, as a rule, one or two solar cells are not enough to generate sufficient power, therefore, solar modules most often include several solar panels. The more solar cells are connected together, that is, the larger the area of the solar panels, the greater the power they produce. In addition to the area of the panels, the intensity of sunlight and the angle of incidence of the rays have a noticeable impact on the power produced.

Let's understand the concept of efficiency

The efficiency value of a panel is obtained by dividing the power of electrical energy by the power of sunlight falling on the panel. Today, the average value of this indicator in practice is 12-25%, but in theory this figure is close to 80-85%. What is the reason for such a big difference? First of all, it depends on the materials used to make solar panels. As is already known, the main element included in the panels is silicon. One of the main disadvantages of this substance is its ability to absorb only infrared radiation, that is, the energy of ultraviolet rays is wasted. Therefore, one of the main directions in which scientists are working, trying to increase the efficiency of solar panels, is the development of multilayer modules.

Multilayer batteries are a structure consisting of layers of different materials. They are selected based on quanta of different energies. That is, one layer absorbs green energy, the second - blue, the third - red. In theory, various combinations of these layers can give an efficiency value of 87%. But this, unfortunately, is just a theory. As practice shows, the manufacture of such structures on a production scale is a very labor-intensive task, and the cost of such modules is very high.

The efficiency of solar modules is also affected by the type of silicon used. Panels made from monocrystalline silicon have a higher efficiency than panels made from polycrystalline silicon. But the price of monocrystalline batteries is higher.

The basic rule: with a higher efficiency, to generate electricity of a given power, a module of a smaller area will be required, that is, a smaller number of photocells will be included in the solar panel.

How quickly will solar panels pay for themselves?

The cost of solar panels today is quite high. And taking into account the low efficiency of panels, the issue of their payback is very relevant. The service life of batteries powered by solar energy is about 25 years or more. We’ll talk about what causes such a long service life a little later, but for now let’s clarify the question raised above.

The payback period is affected by:

Type of equipment selected. Single-layer photocells have lower efficiency compared to multilayer ones, but also have a much lower price.
Geographical location, that is, the more sunlight in your area, the faster the installed module will pay for itself.
Cost of equipment. The more money you spent on purchasing and installing the elements included in the solar system energy savings, the longer the payback period.
The cost of energy resources in your region.

The average payback period for the countries of Southern Europe is 1.5-2 years, for the countries of Central Europe - 2.5-3.5 years, and in Russia the payback period is approximately 2-5 years. In the near future, the efficiency of solar panels will increase significantly, this is due to the development of more advanced technologies that will increase efficiency and reduce the cost of panels. And as a result, the period during which the solar energy saving system will pay for itself will also decrease.

How long will solar panels last?

Solar panels do not contain mechanical moving parts, so they are quite reliable and durable. As mentioned above, their service life is more than 25 years. With proper use, they can last 50 years. The big advantage is that such a long service life does not require major breakdowns; you just need to systematically clean the mirrors of the photocells from dust and other contaminants. This is necessary for better energy absorption, and, consequently, for a higher efficiency rate.

A long service life is one of the main criteria when deciding whether to purchase solar panels or not. After the batteries pay for themselves, the electrical energy you receive will be absolutely free. Even if the payback period is maximum (about 6 years), you will not pay for energy resources for at least 20-25 years.

Latest developments that increase efficiency

Almost every day, scientists around the world announce the development of a new method to increase the efficiency of solar modules. Let's get acquainted with the most interesting of them. Last year, Sharp introduced to the public a solar cell with an efficiency of 43.5%. They were able to achieve this figure by installing a lens to focus energy directly into the element.

German physicists are not far behind the Sharp company. In June 2013, they presented their photocell with an area of only 5.2 square meters. mm, consisting of 4 layers of semiconductor elements. This technology made it possible to achieve an efficiency of 44.7%. Maximum efficiency in this case is also achieved by placing a concave mirror at focus.

In October 2013, the results of the work of scientists from Stanford were published. They have developed a new heat-resistant composite that can increase the performance of solar cells. The theoretical efficiency value is about 80%. As we wrote above, semiconductors that contain silicon are capable of absorbing only IR radiation. So, the action of the new composite material is aimed at converting high-frequency radiation into infrared.

The next were English scientists. They have developed technology that can increase the efficiency of cells by 22%. They proposed placing aluminum nanospikes on the smooth surface of thin-film panels. This metal was chosen because sunlight is not absorbed by it, but, on the contrary, is scattered. Consequently, the amount of solar energy absorbed increases. Hence the increase in solar battery performance.

Here are only the main developments, but the matter is not limited to them. Scientists are fighting for every tenth of a percent, and so far they have succeeded. Let's hope that in the near future the efficiency of solar panels will be at the proper level. After all, then the benefits from using the panels will be maximum.

The article was prepared by Abdullina Regina

Moscow is already using new technologies for lighting streets and parks, I think the economic efficiency has been calculated there:

Date added: 04/30/2015

Nowadays, renewable energy, especially where solar energy is used, is developing very intensively. In this regard, an active search for methods and devices to increase productivity continues existing systems, allowing the most efficient conversion of solar energy into electricity. Two directions can be distinguished here - direct conversion solar radiation into electric current, and repeated conversion of solar energy - into heat, then into mechanical work, and then into electricity. So far, better results have been achieved in the second direction - industrial solar plants with concentrators, turbines or Stirling engines show excellent productivity in converting solar energy. Thus, at a solar station operating in New Mexico with solar concentrators and Stirling engines, an output efficiency of 31.25% was obtained, taking into account energy consumption for the orientation system, etc.

But such solar installations are extremely complex and expensive, are effective in conditions of very high solar insolation, and have not yet received sufficient development in the world. Therefore, direct converters of solar radiation - solar panels , occupy a leading position in the world of solar energy in terms of installations and range of applications. The productivity of serial industrial solar panels today, depending on the technology, ranges from 7 to 20%. Technologies do not stand still, they are developing and improving, new cells are already being developed and tested, at least twice as productive as the existing ones. Let's try to briefly consider the main directions of development of photovoltaic panels, technologies and their productivity.

The vast majority of solar converter cells of modern serial photomodules are made of monocrystalline (C-Si) or polycrystalline (MS-Si) silicon. Today, such silicon photovoltaic modules occupy about 90% of the photovoltaic converter market, of which approximately 2/3 is polycrystalline silicon and 1/3 is monocrystalline. Next come solar modules, the photocells of which are made using thin-film technology - the method of deposition, or sputtering of photosensitive substances onto various substrates. A significant advantage of modules made from these elements is more low cost products, because they require approximately 100 times less material compared to silicon wafers. And so far, the least represented are multijunction solar cells from the so-called tandem, or multijunction cells.

Market shares of photovoltaic panels of various technologies:

Silicon crystalline photomodules.

The efficiency of silicon module cells today is about 15 - 20% (polycrystals - single crystals). This figure as a whole may soon be increased by several percent. For example, SunTech Power, one of the world's largest manufacturers of crystalline silicon modules, has announced its intention to launch photovoltaic modules with an efficiency of 22% over the next couple of years. Existing laboratory samples of monocrystalline cells show a productivity of 25%, polycrystalline - 20.5%. The theoretical maximum efficiency of silicon unijunction (p-n) elements is 33.7%. While it has not been achieved, the main task of manufacturers, in addition to increasing the efficiency of cells, is to improve production technology and reduce the cost of photomodules.

Separately positioned are photo modules from Sanyo, produced using HIT (Heterojunction with Intrinsic Thin layer) technology using several layers of silicon, similar to tandem multilayer cells. The efficiency of such elements made of single-crystalline C-Si and several layers of nanocrystalline nc-Si is 23%. This is today’s highest efficiency indicator for cells of serial crystalline modules, a kind of nanosolar batteries.

Thin film solar cells efficiency.

This name refers to several different technologies, the performance of which will be briefly discussed. Currently, there are three main types of inorganic film solar cells - amorphous silicon (a-Si) films, cadmium telluride (CdTe) films, and copper indium gallium selenide (CuInGaSe2, or CIGS) films. The efficiency of modern thin-film solar cells based on amorphous silicon is about 10%, photomodules based on cadmium telluride - 10-11% (First Solar company), based on copper-indium-gallium selenide - 12-13% (Japanese solar modules SOLAR FRONTIER). Efficiency indicators of pre-series cells: CdTe have an efficiency of 15.7% (MiaSole modules), and CIGS cells have an efficiency of 18.7% (EMPA). The efficiency of individual thin-film solar cells is much higher, for example, data on the performance of laboratory samples of amorphous silicon cells is 12.2% (United Solar), CdTe cells - 17.3% (First Solar), CIGS cells - 20.5% ( ZSW). So far, solar converters based on thin films of amorphous silicon lead in production volumes among other thin-film technologies - the global market volume of thin-film Si cells is about 80%, solar cells based on cadmium telluride are about 18% of the market, and copper-indium-gallium selenide is 2% market. This is due, first of all, to the cost and availability of raw materials, as well as higher stability of characteristics than in multilayer structures. After all, silicon is one of the most common elements in the earth’s crust, while indium (CIGS elements) and tellurium (CdTe elements) are scattered and mined in small quantities. In addition, cadmium (CdTe cells) is toxic, although all manufacturers of such solar modules guarantee complete recycling of their products. Also, the degradation process in the elements of thin-film modules proceeds faster than crystalline cells. Further development of photoelectric converters based on inorganic thin films is associated with the improvement of production technology and stabilization of their parameters.

Thin-film solar cells also include organic/polymer thin-film photosensitive elements and sensitized dyes. In this direction, the commercial use of solar cells is still limited, everything is at the laboratory stage, as well as in improving the technology for future mass production. A number of sources have stated that the efficiency of elements based on organic converters has reached more than 10%: German company Heliatek -10.7%, University of California UCLA - 10.6%. A group of scientists from a laboratory at EPFL obtained an efficiency of 12.3% for cells made from sensitized dyes. In general, the direction of organic thin-film elements, as well as photosensitive dyes, is considered one of the most promising. Statements are regularly made about achieving another efficiency record, technology going beyond the walls of laboratories, and soon covering all available surfaces with highly efficient and cheap solar converters - companies Konarka, Dyesol, Solarmer Energy. Work is focused on increasing the stability of characteristics and reducing the cost of technology.

Multijunction (multilayer, tandem) solar panels characteristics.

Cells of such elements contain layers of various materials, forming several p-n junctions. An ideal solar cell would, in theory, have hundreds of different layers (pn junctions), each tuned to a small range of wavelengths of light across the entire spectrum, from ultraviolet to infrared. Each transition absorbs solar radiation at a specific wavelength, thus covering the entire spectrum. The main materials for such elements are gallium compounds (Ga) - gallium indium phosphide, gallium arsenide, etc.

One of the private solutions for converting the entire solar spectrum is the use of prisms that decompose sunlight into spectra, concentrating on single-junction elements with different ranges of radiation conversion. Despite the fact that research in the field of multijunction solar cells has been going on for two decades, and photomodules from such cells operate successfully in space (solar batteries of the Mir station, Mars Exploration Rover, etc.), their practical earthly use has begun relatively recently. The first commercial products based on such elements entered the market several years ago and showed excellent results, and research in this direction is constantly attracting attention. The fact is that the theoretical efficiency of two-layer cells can be 42% efficiency, three-layer cells 49%, and cells with an infinite number of layers - 68% of unfocused sunlight. The productivity limit of cells with an infinite number of layers is 86.8% when applying concentrated solar radiation. Today, practical efficiency results for multijunction cells are on the order of 30% in unfocused sunlight. This is not enough to offset the cost of producing such cells - the cost of a multijunction cell is approximately 100 times higher than that of a silicon cell of similar area, so multijunction cell module designs use concentrators to focus light 500 to 1000 times. A concentrator in the form of a Fresnel lens and a parabolic mirror collects sunlight from an area 1000 times larger than the cell area. The total cost of photomodules made from multijunction cells using concentrators (CPV) is significantly reduced in price due to inexpensive lenses and substrates, compensating for the high cost of production of the cell itself. At the same time, cell productivity increases up to 40%.

Solar batteries characteristics. For example, the efficiency of SolFocus cells measuring 5.5 mm x 5.5 mm is 40% when using concentrators; and the average cell sizes in CPV systems range from 5.5 mm x 5.5 mm to 1 cm x 1 cm. What does it have to do with the production of 1 cm? cells require 1/1000th of the raw material compared to a cell of similar productivity made from crystalline silicon. In order for multi-junction cells to operate with maximum efficiency, a constant high intensity of solar radiation is required; for this, two-axis orientation systems of CPV systems are used. The locations for deploying solar farms based on modules from multi-junction cells with concentrators are regions with high solar insolation.

The maximum efficiency of multijunction cells, obtained in laboratory conditions using concentrators, is currently 43.5% (Solar Junction), and is predicted to increase in the next couple of years to 50%.

As we can see, today there are solar cells with high productivity, manufactured using various technologies, and the main task of manufacturers is to reduce the cost of the final product and adapt laboratory research for mass production. Despite the low consumption of raw materials in thin-film solar cells, the cost of some components in different types quite high, just as the production technologies themselves are energy-intensive. The long-term stability of the parameters remains questionable. Multijunction solar cells are still very expensive, and for maximum efficient operation they also require an increased concentration of solar radiation. Therefore, crystalline silicon elements will in the near future hold a leading position in the photovoltaic converter market, decreasing in price. They will only be replaced by efficient and cheap thin-film modules, possibly made from polymer semiconductors or photosensitive dyes. But forecasting the development of this or that technology is not a rewarding task. Wait and see.