DIY solar cell production. Solar cell production: technology and equipment

Probably, there is no such person who would not like to become more independent. The ability to completely control your own time, travel without knowing borders and distances, not thinking about housing and financial problems - this is what gives a feeling of real freedom. Today we will tell you how, using solar radiation, to relieve yourself of the burden of energy dependence. As you may have guessed, we are talking about solar panels. To be more precise, about whether it is possible to build a real solar power plant with your own hands.

History of creation and prospects of use

The idea of ​​converting the energy of the Sun into electricity was hatched by humanity for a long time. The first to appear were solar thermal installations, in which steam superheated by concentrated solar rays rotated the turbines of a generator. Direct conversion became possible only in the middle of the 19th century, after the Frenchman Alexander Edmond Baccarel discovered the photoelectric effect. Attempts to create an operating solar cell on the basis of this phenomenon were crowned with success only half a century later, in the laboratory of the outstanding Russian scientist Alexander Stoletov. It was possible to fully describe the mechanism of the photoelectric effect even later - humanity owes this to Albert Einstein. By the way, it was for this work that he received the Nobel Prize.

Bakkarel, Stoletov and Einstein are the scientists who laid the foundation for modern solar energy

The creation of the first solar cell based on crystalline silicon was announced to the world by the employees of Bell Laboratories back in April 1954. This date, in fact, is the starting point of the technology, which will soon be able to become a full-fledged replacement for hydrocarbon fuel.

Since the current of one photovoltaic cell is milliamperes, they have to be connected in modular structures to generate sufficient power. Arrays of solar photovoltaic cells protected from external influences are a solar battery (due to their flat shape, the device is often called a solar panel).

Converting solar radiation into electricity has great prospects, because every square meter of the earth's surface accounts for an average of 4.2 kWh of energy per day, and this saves almost one barrel of oil per year. Originally used only for the space industry, the technology already in the 80s of the last century became so commonplace that solar cells began to be used for domestic purposes - as a power source for calculators, cameras, lamps, etc. At the same time, "serious" solar power plants were created. Attached to the rooftops of houses, they made it possible to completely abandon wired electricity. Today you can see the birth of power plants, which are many kilometers of fields of silicon panels. The power they generate allows them to power entire cities, so we can confidently say that the future belongs to solar energy.

Modern solar power plants are multi-kilometer fields of photovoltaic cells capable of supplying tens of thousands of homes with electricity.

Solar cell: how it works

After Einstein described the photoelectric effect, the whole simplicity of such a seemingly complex physical phenomenon was revealed to the world. It is based on a substance whose individual atoms are in an unstable state. When photons are bombarded with light, electrons are knocked out of their orbits - and so they are the sources of current.

For almost half a century, the photoelectric effect had no practical application for one simple reason - there was no technology for obtaining materials with an unstable atomic structure. Prospects for further research appeared only with the discovery of semiconductors. The atoms of these materials either have an excess of electrons (n-conductivity), or lack them (p-conductivity). When using a two-layer structure with an n-type layer (cathode) and p-type (anode), the "bombardment" with photons of light knocks out electrons from the atoms of the n-layer. Leaving their places, they rush to the free orbits of the p-layer atoms and then, through the connected load, return to their original positions. Probably each of you knows that the movement of electrons in a closed loop is an electric current. But it is possible to make electrons move not due to the magnetic field, as in electric generators, but due to the flow of particles of solar radiation.

The solar panel works thanks to the photovoltaic effect, which was discovered back in the early 19th century.

Since the power of a single photovoltaic module is insufficient to power electronic devices, multiple cells are connected in series to obtain the required voltage. As for the current strength, it is increased by parallel connection of a certain number of such assemblies.

The generation of electricity in semiconductors directly depends on the amount of solar energy, therefore, photocells are not only installed in the open air, but also try to orient their surface perpendicular to the incident rays. And to protect the cells from mechanical damage and weathering, they are mounted on a rigid base and protected from above with glass.

Classification and features of modern photocells

The first solar cell was made on the basis of selenium (Se), however, low efficiency (less than 1%), rapid aging and high chemical activity of selenium solar cells forced to look for other, cheaper and more efficient materials. And they were found in the face of crystalline silicon (Si). Since this element of the periodic table is a dielectric, its conductivity was ensured by inclusions of various rare earth metals. Depending on the manufacturing technology, there are several types of silicon solar cells:

• monocrystalline;
• polycrystalline;
• from amorphous Si.

The first ones are made by cutting the thinnest layers from silicon ingots of the highest purity. Externally, monocrystalline photocells look like monochromatic dark blue glass plates with a pronounced electrode grid. Their efficiency reaches 19%, and their service life is up to 50 years. And although the performance of panels made on the basis of monocrystals is gradually decreasing, there is evidence that batteries manufactured more than 40 years ago still remain operational today, giving out up to 80% of their original power.

Monocrystalline solar cells have a uniform dark color and cut corners - these features do not allow them to be confused with other solar cells

In the production of polycrystalline solar cells, not so pure, but cheaper, silicon is used. The simplification of the technology affects the appearance of the plates - they do not have a uniform shade, but a lighter pattern that forms the boundaries of many crystals. The efficiency of such solar cells is slightly lower than that of monocrystalline ones - no more than 15%, and the service life is up to 25 years. It must be said that the decrease in basic performance indicators has absolutely no effect on the popularity of polycrystalline solar cells. They benefit from a lower cost and less dependence on external pollution, low cloudiness and orientation to the Sun.

Polycrystalline solar cells have a lighter blue tint and a non-uniform pattern - a consequence of the fact that their structure consists of many crystals

For solar cells made of amorphous Si, not a crystal structure is used, but the thinnest layer of silicon, which is sprayed onto glass or polymer. Although this method of production is the cheapest, such panels have the shortest lifespan, the reason for which is the burnout and degradation of the amorphous layer in the sun. This type of photocells is not happy with its performance - their efficiency is no more than 9% and during operation it significantly decreases. The use of solar cells made of amorphous silicon is justified in deserts - high solar activity levels out the drop in productivity, and endless expanses make it possible to place solar power plants of any size.

The ability to spray silicon structure onto any surface allows for flexible solar panels

Further development of photovoltaic cell technology is driven by the need to reduce costs and improve performance. Film photocells have the maximum performance and durability today:

• based on cadmium telluride;
• from thin polymers;
• using indium and copper selenide.

It is still too early to talk about the possibility of using thin-film photocells in home-made devices. Today, only a few of the most "technologically advanced" companies are engaged in their production, so most often flexible photovoltaic cells can be seen as part of finished solar panels.

Which photovoltaic cells are best for a solar panel and where can you find them

Homemade solar panels will always be one step behind their factory counterparts, for several reasons. Firstly, renowned manufacturers carefully select photocells, screening out cells with unstable or reduced parameters. Secondly, in the manufacture of solar cells, special glass is used with increased light transmission and reduced reflectivity - it is almost impossible to find this on sale. And thirdly, before starting serial production, all parameters of industrial designs are tested using mathematical models. As a result, the effect of heating the cells on the efficiency of the battery is minimized, the heat removal system is improved, the optimal cross-section of connecting buses is found, ways to reduce the rate of degradation of photocells are being investigated, etc. It is impossible to solve such problems without an equipped laboratory and appropriate qualifications.

The low cost of self-made solar panels allows you to build an installation that allows you to completely abandon the services of energy companies

Nevertheless, self-made solar panels show good performance results and are not so far behind industrial counterparts. As for the price, here we have a gain of more than two times, that is, with the same costs, homemade products will give twice as much electricity.

Considering all of the above, a picture emerges of which photocells are suitable for our conditions. Film ones disappear due to lack of sale, and amorphous ones - due to a short service life and low efficiency. Cells of crystalline silicon remain. I must say that in the first home-made device it is better to use cheaper "polycrystals". And only after running in the technology and "having gotten a hand", one should switch to monocrystalline cells.

Cheap substandard photocells are suitable for testing technologies - like high-quality devices, they can be bought on foreign trading floors.

As for the question of where to get inexpensive solar cells, they can be found on foreign trading platforms such as Taobao, Ebay, Aliexpress, Amazon, etc. There they are sold both as individual photocells of various sizes and performance, and ready-made kits for assembling solar panels any power.

Sellers often offer so-called "B" class solar cells, which are damaged solar cells of a mono- or polycrystalline type. Small chips, cracks or the absence of corners have practically no effect on the performance of the cells, but allows them to be purchased at a much lower cost. It is for this reason that they are most profitable to use in homemade solar energy devices.

Is it possible to replace photovoltaic plates with something else

Rarely does a home craftsman not have a treasured box with old radio components. But diodes and transistors from old receivers and televisions are all the same semiconductors with p-n junctions that generate current when illuminated by sunlight. Taking advantage of these properties and connecting several semiconductor devices, you can make a real solar battery.

For the manufacture of a low-power solar battery, you can use the old element base of semiconductor devices

The attentive reader will immediately ask what the catch is. Why pay for factory-made mono- or polycrystalline cells when you can use what lies literally under your feet. As always, the devil is in the details. The fact is that the most powerful germanium transistors make it possible to obtain a voltage of no more than 0.2 V in the bright sun at a current strength measured in microamperes. In order to achieve the parameters that a flat silicon photocell produces, several tens, or even hundreds of semiconductors are required. A battery made from old radio components is only useful for charging a camping LED torch or a small mobile phone battery. For the implementation of larger-scale projects, purchased solar cells are indispensable.

What power of solar panels can you count on?

Thinking about building your own solar power plant, everyone dreams of completely abandoning wired electricity. In order to analyze the reality of this venture, let's make some small calculations.

It is not difficult to find out the daily consumption of electricity. To do this, it is enough to look at the invoice sent by the energy supply organization and divide the number of kilowatts indicated there by the number of days in a month. For example, if you are offered to pay 330 kWh, it means that the daily consumption is 330/30 = 11 kWh.

The graph of the dependence of the power of the solar battery depending on the illumination

In the calculations, it is necessary to take into account the fact that the solar panel will generate electricity only during daylight hours, and up to 70% of the generation is carried out from 9 to 16 hours. In addition, the efficiency of the device directly depends on the angle of incidence of sunlight and the state of the atmosphere.

A slight cloudiness or haze will reduce the efficiency of the solar unit's current output by 2–3 times, while a sky covered with solid clouds will provoke a drop in performance by 15–20 times. In ideal conditions, a solar battery with a capacity of 11/7 = 1.6 kW would be sufficient to generate 11 kWh of energy. Taking into account the influence of natural factors, this parameter should be increased by about 40-50%.

In addition, there is one more factor forcing to increase the area of ​​used photocells. Firstly, one should not forget that the battery will not work at night, which means that powerful batteries will be needed. Secondly, to power household appliances, you need a current of 220 V, so you need a powerful voltage converter (inverter). Experts say that losses for the accumulation and transformation of electricity take up to 20-30% of its total amount. Therefore, the real power of the solar battery should be increased by 60–80% of the calculated value. Assuming an inefficiency of 70%, we get the rated power of our solar panel equal to 1.6 + (1.6 × 0.7) = 2.7 kW.

The use of assemblies of high-current lithium batteries is one of the most elegant, but by no means the cheapest way to store solar energy.

To store electricity, you will need low-voltage batteries designed for voltages of 12, 24 or 48 V. Their capacity should be designed for daily energy consumption plus transformation and conversion losses. In our case, we need an array of batteries designed to store 11 + (11 × 0.3) = 14.3 kWh of energy. If you use ordinary 12-volt car batteries, then you need an assembly for 14300 W × h / 12 V = 1200 Ah, that is, six batteries, each rated for 200 Ah.

As you can see, even in order to provide electricity for the household needs of an average family, a serious solar power plant is needed. As for the use of self-made solar panels for heating, at this stage such an undertaking will not even reach the border of self-sufficiency, not to mention the fact that something could be saved.

Battery size calculation

The size of the battery depends on the required power and the size of the power sources. When choosing the latter, you will definitely pay attention to the offered variety of photocells. For use in DIY devices, it is most convenient to choose medium-sized solar cells. For example, polycrystalline panels with a size of 3 × 6 inches designed for an output voltage of 0.5 V and a current strength of up to 3 A.

In the manufacture of a solar battery, they will be connected in series in blocks of 30 pieces, which will make it possible to obtain the voltage required for charging a car battery of 13-14 V (taking into account losses). The maximum power of one such unit is 15 V × 3 A = 45 W. Based on this value, it will be easy to calculate how many elements are needed to build a solar panel of a given power and determine its dimensions. For example, to build a 180-watt solar electric collector, 120 photovoltaic cells with a total area of ​​2,160 sq. inches (1.4 sqm).

Building a homemade solar panel

Before proceeding with the manufacture of a solar panel, it is necessary to solve the problems of its placement, calculate the dimensions and prepare the necessary materials and tools.

Choosing the right installation location is important

Since the solar panel will be made by hand, the aspect ratio can be any. This is very convenient, since a home-made device can more successfully fit into the exterior of the roof or the design of a suburban area. For the same reason, you should choose a place for mounting the battery even before the start of design activities, not forgetting to take into account several factors:

• openness of the place for sunlight during daylight hours;
• lack of shading buildings and tall trees;
• the minimum distance to the room in which the storage capacities and converters are installed.

Of course, a roof-mounted battery looks more organic, but placing the unit on the ground has more benefits. In this case, the possibility of damage to the roofing materials during the installation of the supporting frame is excluded, the laboriousness of the installation of the device is reduced and it becomes possible to timely change the "angle of attack of the sun's rays". Best of all, bottom placement will make it much easier to keep the solar panel surface clean. And this is a guarantee that the installation will work at full capacity.

Mounting the solar panel on the roof is caused more by a lack of space than by necessity or ease of use

What is needed in the process of work

When starting to make a homemade solar panel, you should stock up on:

• photocells;
• stranded copper wire or special busbars for connecting solar cells;
• solder;
• Schottky diodes, designed for the current output of one photocell;
• high quality anti-reflective glass or plexiglass;
• slats and plywood for the manufacture of the frame;
• silicone sealant;
• hardware;
• paint and a protective compound for the treatment of wooden surfaces.

In work, you will need the simplest tool that the homely owner always has at hand - a soldering iron, glass cutter, saw, screwdriver, paint brush, etc.

Manufacturing instruction

For the manufacture of the first solar battery, it is best to use photocells with already soldered leads - in this case, the risk of damage to the cells during assembly is reduced. However, if you have the skills to handle a soldering iron, you can save some money by purchasing solar cells with unsoldered contacts. To build the panel, which we discussed in the above examples, 120 plates are required. Using an aspect ratio of approximately 1: 1, you will need to stack 15 rows of 8 photocells each. In this case, we will be able to connect every two "columns" in series, and connect four such units in parallel. In this way, cable tangle can be avoided and a smooth, beautiful installation can be achieved.

Electrical connection diagram of a home solar power plant

Frame

The assembly of a solar panel should always start with the fabrication of the case. To do this, we need aluminum corners or wooden slats no more than 25 mm high - in this case, they will not cast a shadow on the outer rows of photocells. Based on the dimensions of our 3x6 '' silicon cells (7.62x15.24 cm), the frame size must be at least 125x 125 cm.If you decide to use a different aspect ratio (for example, 1: 2), then the frame can be additionally reinforced with a slat cross member the same section.

The back side of the case should be sewn up with a plywood or OSB panel, and ventilation holes should be drilled at the bottom end of the frame. The connection of the inner cavity of the panel with the atmosphere will be needed to equalize the humidity - otherwise, fogging of the glasses cannot be avoided.

For the manufacture of the solar panel case, the simplest materials are suitable - wooden slats and plywood

A panel of plexiglass or high-quality glass with a high degree of transparency is cut to the outer dimension of the frame. As a last resort, you can use window glass up to 4 mm thick. For its fastening, corner brackets are prepared, in which drills are made for attachment to the frame. When using plexiglass, you can make holes directly in the transparent panel - this will simplify assembly.

To protect the wooden case of the solar battery from moisture and fungus, it is impregnated with an antibacterial compound and painted with oil paint.

For the convenience of assembling the electrical part, a substrate is cut out of fiberboard or other dielectric material according to the internal size of the frame. In the future, the installation of photocells will be carried out on it.

Brazing plates

Before you start soldering, you should "estimate" the installation of photocells. In our case, you will need 4 arrays of cells with 30 plates in each, and they will be located in the case in fifteen rows. Such a long chain will be inconvenient to work with, and moreover, the risk of damage to fragile glass plates increases. It will be rational to connect 5 parts each, and carry out the final assembly after the photocells are mounted on the substrate.

For convenience, photocells can be mounted on a non-conductive substrate made of textolite, plexiglass or fiberboard

After connecting each chain, you should check its performance. To do this, each assembly is placed under a table lamp. By writing down the values ​​of the current and voltage, you can not only monitor the performance of the modules, but also compare their parameters.

For soldering, we use a low-power soldering iron (maximum 40 W) and good, low-melting solder. We apply it in a small amount on the output parts of the plates, after which, observing the polarity of the connection, we connect the parts to each other.

When soldering photocells, you should exercise the utmost care, since these parts are highly fragile.

Having assembled the individual chains, we unfold them with their backs to the substrate and use silicone sealant to glue them to the surface. Each 15-volt photocell block is supplied with a Schottky diode. This device only allows current to flow in one direction, so it will not allow batteries to discharge when the solar panel voltage is low.

The final connection of the individual strings of photocells is carried out according to the above wiring diagram. For these purposes, you can use a special bus or stranded copper wire.

The hinged elements of the solar battery should be fixed with hot melt glue or self-tapping screws.

Panel assembly

The substrates with the photocells located on them are placed in the body and fixed with self-tapping screws. If the frame was reinforced with a cross member, then several drills are made in it for mounting wires. The cable, which is led out, is securely fixed to the frame and soldered to the terminals of the assembly. To avoid confusion with polarity, it is best to use two-color wires, connecting the red lead to the positive of the battery and the blue to the negative of the battery. A continuous layer of silicone sealant is applied along the upper contour of the frame, on top of which glass is laid. After the final fixation, the assembly of the solar cell is considered complete.

After the protective glass is installed on the sealant, the panel can be transported to the installation site

Installation and connection of the solar battery to consumers

For a number of reasons, a homemade solar panel is a rather fragile device, therefore, it requires the arrangement of a reliable supporting frame. The ideal option would be a design that will orient the source of free electricity in both planes, but the complexity of such a system is most often a weighty argument in favor of a simple tilted system. It is a movable frame that can be set at any angle to the luminary. One of the options for the frame, knocked down from a wooden bar, is presented below. You can use metal corners, pipes, tires, etc. to make it - everything that is at hand.

Solar cell frame drawing

To connect the solar panel to the batteries, you need a charge controller. This device will monitor the state of charge and discharge of the batteries, monitor the current flow and switch over to the mains supply in the event of a significant voltage drop. The device of the required power and the required functionality can be purchased at the same retail outlets where the photocells are sold. As for the power supply of household consumers, this will require transforming the low-voltage voltage to 220 V. Another device, an inverter, successfully copes with this. I must say that the domestic industry produces reliable devices with good performance characteristics, so the converter can be bought on the spot - in this case, a "real" guarantee will be a bonus.

One solar battery will not be enough for a full-fledged power supply at home - you will also need batteries, a charge controller and an inverter

On sale you can find inverters of the same power, differing in price at times. Such a spread is explained by the "purity" of the output voltage, which is a prerequisite for powering individual electrical devices. Converters with a so-called pure sine wave have a more complicated design, and as a result, a higher cost.

Video: DIY solar panel making

Building a home solar power plant is not a trivial task and requires both financial and time costs, and minimal knowledge of the basics of electrical engineering. When starting to assemble a solar panel, you should observe maximum attention and accuracy - only in this case you can count on a successful solution to the issue. Finally, I would like to remind you that glass contamination is one of the factors in the decline in performance. Remember to clean the solar panel surface in time, otherwise it will not be able to work at full power.

Currently, alternative energy sources are very fashionable and popular, especially among owners of country cottages or private houses. But often such a device costs a lot of money and not everyone can afford to buy solar panels for their home. Therefore, the manufacture of solar panels with your own hands has become very relevant. So how do you make solar panels yourself?

Solar Panel Feature

A solar cell is a semiconductor structure that is capable of converting solar radiation into electricity. This allows us to provide the house with an economical, reliable and, most importantly, uninterrupted power supply. Especially this is true for hard-to-reach areas of residence and also where there are frequent power outages from the main source.

Such an alternative source of energy is quite practical, because, unlike a traditional source of energy supply, it costs much less. Making solar panels with your own hands allows you not only to optimize energy consumption, but also saves finances.

Advantages

Solar panels have the following advantages:

• easy installation due to the fact that there is no need to lay a cable to the supports;
• the generation of electricity does not harm the environment at all;
• there are no moving parts;
• electricity is supplied independently of the distribution network;
• minimal time expenditures for system maintenance;
• low weight of batteries;
• silent work;
• long service life at minimum costs.

Flaws

Despite the rather significant advantages, solar panels have their disadvantages, such as:

• labor intensity of the manufacturing process;
• sensitivity to pollution;
• the efficient operation of solar panels is influenced by weather conditions (sunny or cloudy days);
• a lot of space is needed for such a design;
• the batteries do not work at night.

Requirements for a solar panel

Everyone can install solar panels in a private house. But in order for such a self-made design to bring benefits to the maximum, its features should be taken into account. The following requirements are imposed on the solar battery:

Materials required for making a solar panel with your own hands

If it is not possible to purchase solar panels, you can make them yourself. initially you need to decide on the material from which they will be made.

To create panels, high quality photocells will be needed. Manufacturers today offer the following types of devices:

• monocrystalline silicon elements have an efficiency of up to 13%, but in cloudy weather they are not efficient enough;
• photocells made of polycrystalline silicon have an efficiency of up to 9%, they can work both on sunny and cloudy days.

It is best to use polycrystals to power your home, which are available in kits.

It is important to know that all necessary for assembly cells are best purchased from one manufacturer, since the products of different brands have significant differences in the effectiveness of the products. This can create additional difficulties during assembly, entail costs as a result of operation, while the solar battery will have a low power.

To make a solar panel from improvised means, you will need special conductors designed to connect the photocells.

The case of the future design is best made of lightweight aluminum corners. You can also use a material such as wood. But due to the fact that the structure will be exposed to atmospheric influences all the time, its service life will decrease.

The dimensions of the panel body depend on the number of photocells.

The outer coating of the photocells can be made of plexiglass or transparent polycarbonate. Tempered glass is also used, which does not transmit infrared rays.

Thus, to make a solar battery with your own hands, you will need the following materials:

• photocells in the set;
• fastening hardware;
• high power copper electric wires;
• silicone vacuum coasters;
• soldering equipment;
• aluminum corners;
• Schottke diodes;
• transparent sheet of polycarbonate or plexiglass;
• set of screws for fasteners.

These materials are purchased from a building materials store or online store.

How to make solar panels with your own hands?

In order to make the panels with your own hands, you need to collect the required materials. A solar battery for the house is assembled in the following sequence.

To correctly make solar panels with your own hands, you need to adhere to the following recommendations:

Every person dreams of getting free electricity in their home and this dream is realizable. Having made solar panels with your own hands, you can enjoy an additional source of power supply. Wherein this design does not harm the environment and it is also very reliable and inexpensive.

Production of solar panels: business relevance + what are solar panels + advantages of installing solar panels + production technology + necessary raw materials and equipment + organizational aspects of starting a business + start-up capital and business profitability + an overview of creating a mini-production for the production of solar panels.

Solar cell production- this is undoubtedly an innovative type of business, especially in Russia. Although in other countries, for example, in Turkey, Spain and Germany, alternative methods of generating electricity are in demand, and therefore the production of such panels is no longer a novelty for them.

Of course, opening such a business in Russia is somewhat risky, since so far people are wary of such innovations. But, given the fact that this business niche is still free from competitors, and solar panels are indeed a very promising way to generate electricity, the launch of such an enterprise can be called a profitable investment.

In this review, we will tell you how to organize the production of such batteries, where it is best to do it, how much you need to invest in order to succeed in this area of ​​entrepreneurial activity.

Is it rational to establish the production of solar panels in Russia?

One can argue for a long time about whether such production will become in demand on the territory of the country. Indeed, on the one hand, this is indeed a very promising direction, which can eventually replace the usual production of electricity.

But, on the other hand, solar panels will be more in demand in solar regions, since the Sun is the main component of this alternative method of generating electricity.

If we consider the production of solar panels purely as a type of business, then, of course, this area of ​​entrepreneurial activity is very, very profitable.

Several factors contribute to this at once:

• The market for the production of solar panels in Russia remains among the most "empty", which indicates the absence of competitors on the way of building a business.
• In any case, oil and gas reserves are not infinite, and it is high time for people to think about alternative methods of generating electricity.
• Demand for solar panels is driven not only by the decline in natural resources. Also, people are stimulated by high prices for utilities, the costs of which can be significantly reduced by resorting to the use of solar energy.

In addition to these factors, solar panels also have a wide range of applications, so that they can be used in a wide variety of areas.

The most popular directions in this regard are used by the following:

• Battery charge for various equipment - portable electronics.
• Electric vehicle production.
• Providing residential buildings with electricity, which can be used for heating and lighting.

Of course, batteries for power supply of houses are in the greatest demand, therefore in this article we will consider exactly the organization of the production of batteries for these purposes.

In any case, the production of solar panels is a very popular niche that will become much more popular in Russia in a few years. And to try your hand at this business now is the most appropriate time due to the fact that until you meet too many competitors on your way.

What are solar panels and how are they produced?

In simple terms, a solar battery is an installation that is capable of converting solar energy into electric current, which is used to supply power to residential buildings.

To understand in general terms what a solar battery looks like and how its mechanism works, it will be enough to look at the figure:

Solar panels are alternative sources of electricity, similar to water and wind installations, which were used by our ancestors in order to obtain electricity.

Today, it is these batteries that are considered the most economical way to provide electricity to residential buildings, since their installation and installation are not as expensive as other devices, moreover, it is not possible to use the received electricity immediately.

Since the battery transforms the energy of the Sun "in excess", modern technologies allow it to be stored in special batteries and used at a time when solar activity is minimal, that is, in the evening or at night.

In order to install a solar panel and get energy, you don't even have to live in the sunniest place in the country. New developments make it possible to use installations even in those climatic zones where the sun is much smaller.

And by themselves, solar panels, as a source of electricity, have a lot of advantages, the main of which are the following:

1. Solar energy is the safest and cleanest energy available.
2. You can install a solar panel and. On average, the installation of a battery will cost up to 50 thousand rubles. Moreover, this includes not only the initial set itself, but also the installation of the battery.
3. In order to install the device, you do not need to change anything in the existing engineering networks, because such installations are easily mounted in existing networks.
4. Solar panels have a very long lifespan and do not need constant quality checks or repairs.
5. Batteries can be mounted on almost any building, which means that this method of generating energy is suitable for both large cities and small villages.

In a word, solar panels are a really working option that will help not only get clean energy, but also significantly reduce utility bills.

The only thing worth paying attention to is the direct scope of application of solar panels.

The fact is that many people confuse the concept of solar panels and collectors, the purpose of which is completely different. If solar panels are a device for generating electricity, then a collector is the receipt of thermal energy from the Sun, which is directed to other needs, such as, say, heating and heating water.

Collectors have a slightly different form and principle of operation, so these two terms should not be confused in any way.

Since we figured out the very concept of solar cells, we can go directly to the process of their production.

And here it is important to immediately note that for a future businessman there are two main ways in which he can develop this business:

• The first method consists in a full production cycle, that is, "from A to Z" - from the manufacture of components to their assembly into full-fledged batteries.
• The second method involves the purchase of ready-made materials and the installation of batteries from them.

Each of the methods has the right to exist, as well as its pros and cons.

For example, by making all batteries yourself, including their components, you can be sure of the quality of the final product. Also, due to this, you can significantly reduce the cost of each battery. But the organization of such a production will require significant investments, which is the main disadvantage of this method.

As for the second option, it will cost you less, but the cost of production due to purchased materials will be much higher.

In order to analyze in detail both the one and the other option, first we will consider the entire production cycle, as well as the way to organize it to start a business.

At the end, we will also give an example of organizing a mini-production, when all parts have already been purchased, and all you need to do is learn how to assemble, assemble and sell them.

Solar Cell Technology: A Step-by-Step Guide

In order for solar panels, first you need to figure out what the technology of their manufacture looks like, and what stages you will have to face.

So, in order to produce a ready-made solar battery from the purchased raw materials, you will need to carry out the following actions:

1. Cut the silicon wafers and clean them for further processing.
2. Etch the surface of the silicon wafers and structure it.
3. Apply phosphorus to the plate and then burn it out.
4. Metallize the surface.
5. Dry the silicon wafers.
6. Connect the electrical contacts on the front side of the plate.
7. Align the plates.
8. Frame the plates with aluminum frames.
9. Test the finished installation.

As a result, we get a solar panel that looks like this:

What is needed to organize production: what kind of raw materials and equipment to buy?

In view of the fact that we are analyzing the production of solar panels "from scratch", it is worth noting right away that to start a business you will need a lot of everything: both raw materials and equipment.

In addition, it is important to take into account that the production of such batteries is a very knowledge-intensive process, therefore it is better to look for and purchase the necessary components, having first consulted with an intelligent physicist or electromechanic, who will ultimately help to establish the production process.

By the way, it will not be so easy to find a suitable specialist, as well as all the necessary materials, since such production in Russia has not yet been established. It is better to search for all the necessary items and even specialists abroad.

On average, buying only raw materials will cost you about 100 thousand rubles, but buying only raw materials is, of course, not enough. Equipment is also needed to make the production of batteries possible.

Since we are talking about a large-scale enterprise with a full production cycle, it implies the purchase of an automated line for creating batteries, which will ensure the production of the highest quality products.

The entire production line will consist of a sufficiently large number of machines, which are much more rational to buy from one supplier.

And there are a number of reasons for this:

• Firstly, when buying a whole range of components, you can get some percentage of the discount.
• Secondly, often such equipment suppliers will not only sell it to you, but also help with installation and further operation.

And remember that the production of solar cells in Russia has not yet been established at all, so the equipment will most likely have to be bought abroad.

The cost of the production line will differ depending on the country of origin, and may range from 500 thousand rubles. up to 10 million rubles.

Equipment	Purpose	Cost, rub.)	Sample
Total:			1,348,000 rubles
Cutting Laser Machine	For cutting different mesh sizes with a fiber laser	From 190 thousand
Laminator	For lamination of solar modules with organic matter to protect against environmental influences	From 650 thousand
Framing Machine	For gluing tape edges and framing solar modules	From 315 thous.
Glass cleaning machine	For cleaning and drying glasses	From 126 thous.
Table for moving elements	For moving batteries using aluminum rails	From 12 thousand
High voltage test machine	To test a module for suitability	From 55 thousand

In the end, if we take the average prices for equipment as an example, the minimum set will cost you 1.3 million rubles.

But, in addition to the production line, you will also need to purchase hand tools and equipment (batteries, inverters) for installing batteries. As a result, the total cost of the equipment will be about 1.5 million rubles.

In addition to the costs of equipment and the purchase of raw materials, you will have other costs for various organizational issues, which we will discuss in more detail below.

Searching for premises, recruiting personnel and other subtleties of organizing a business for the production of solar panels

Any business in the field of production certainly begins not with the purchase of the necessary equipment, but with the preparation and legalization of its activities, in other words, registration.

You also need to find suitable premises and hire staff, which is also important, so we will consider each of the moments of the organization in as much detail as possible.

1. Registration of the company.

If you are planning to start a business in the field of production, at the same time, it is planned to produce solar panels "from scratch", then an LLC is more suitable for registering you as an entrepreneur.

To start the registration procedure, you will need to collect a certain list of documents and submit it to the Federal Tax Service Inspectorate at the place of business registration.

This list will include:

• Application form R11001.
• Founder's decision to establish an enterprise (if there is only one founder) or minutes of the meeting of participants (if there are several founders).
• LLC Charter.

Before you submit the documents, you will be required to pay the amount of the state fee, which today is 4 thousand rubles. The receipt for its payment is included in the liver of mandatory documents.

But not only the payment of the receipt will have to be spent when registering a business.

There are other expenses ahead of you:

• Opening a bank account - 2 thousand rubles.
• Production of a seal - 1 thousand rubles.
• Payment of the authorized capital - 10 thousand rubles.
• Payment for notary services - 1 thousand rubles.

In total, about 15-18 thousand rubles will need to be spent for the legal registration of entrepreneurial activity.

Also, do not forget about the mandatory receipt of permits from the fire and sanitary-epidemiological service after passing the registration procedure.

And one more important detail - when filling out the application, you will need to indicate the code of your activity according to OKVED. In this case, it is numbered 27.20.3.

2. Search and equipping premises for production.

Since a full cycle of battery production is planned, the selected room should be sufficient to accommodate all the necessary equipment, and also allocate two small warehouses: for storing components and for preparing ready-made batteries for installation.

On average, the area of ​​the premises should be at least 300 square meters, otherwise it will be impossible to manufacture solar panels due to lack of space.

Having chosen a suitable room, you need to take care of its repair, which in a situation of such production is very important, because we are talking about the creation of very precise and fragile parts.

The room must certainly contain:

• Ventilation system.
• Water supply.
• Heating.
• Power supply.
• Installed disinfection installations.

Without all this, neither the fire service nor the sanitary and epidemiological service will give you the necessary permits to start production.

3. Staff recruitment and organization of delivery and installation.

Due to the fact that almost the entire solar cell production process will be automated, you will need to hire a small staff.

The total number of employees will be about 6-8 people, of which you will need to hire:

• 1 specialist physicist-electromechanic.
• 2 shop workers.
• 2 workers for installation.
• 1 driver.
• 1 sales manager.
• 1 marketer.

At first, you can perform the duties of a director and an accountant on your own, this will allow you to control production more and understand the essence of your own business.

The most difficult thing in this situation will be to find a good specialist and shop workers, because due to the fact that the production of solar cells in Russia is not yet very developed, there are few such specialists in the country.

As for the transportation and installation of batteries, it is best to hire a driver for this work with his own car, or buy at least one truck.

4. Marketing and search for distribution channels for finished products.

At first, it is very important to have at least one marketer on your staff who will help with advertising and promoting solar panels in the region of production.

Since solar panels are a necessary, but still not very familiar product for people, you need to constantly tell and show that having solar panels on your roof is much more profitable than paying large sums for utilities.

• print flyers,
• let's announce,
• create a website that will be filled with useful information, and which will demonstrate examples of already made solar panels with their subsequent installation.

You can cooperate with both large enterprises and individuals. It all depends on how much your products are in demand in the region.

How much start-up capital will be required to start producing solar panels, and when will the business start to be profitable?

Expenditure item	Amount (RUB)
Total:	2,277,000 rubles
1. Registration of entrepreneurial activity.	17 thous.
2. Lease of premises (taking into account the lease for some time in advance).	350 thous.
3. Purchase of raw materials and components.	100 thous.
4. Purchase of equipment.	1,500 thous.
5. Remuneration of workers.	250 thous.
6. Financing the marketing plan.	45 thous.
7. Operating expenses.	15 thous.

It turns out that to launch an enterprise for the production of solar panels in Russia, an impressive amount will be required, which exceeds 2 million rubles.

But do not think that such an investment will pay off for too long. On average, such a production can start making a profit after 1.5 - 2 years.

It turns out that for each installed battery you will receive a net profit. about 10-15 thousand rubles... And taking into account the fact that you will produce and install from 5 to 10 such batteries per month, your net monthly profit will be from 75 thousand rubles.

The profitability of the business with the right organization will be at least 100%.

But, in any case, 2 million rubles. - this is a lot of money, which not everyone can invest in. Is it possible to open a similar production, but at a lower cost?

Solar cell production. How it works?

Installation diagram. Advantages and disadvantages.

Mini-production of solar panels: advantages, disadvantages and organization method

Mini-production for the manufacture of solar panels, first of all, involves such an organization of the enterprise, in which ready-made components for batteries will be purchased. Of these, you, as an entrepreneur, will only have to establish the assembly, transportation and installation process.

This method is much more economical than the option of manufacturing from scratch, since in this case you will not have to spend money on raw materials, equipment, numerous staff and registration of a legal entity.

But the cost of panels with this method will increase significantly, since buying ready-made components is more expensive than producing them yourself.

As a result, we can say that this method will be most appropriate in two cases:

1. When you don't have enough start-up capital to start a large production.
2. When there are absolutely no competitors in your area who are ready to offer batteries at a price much lower than yours.

Having decided on the advantages and disadvantages, we turn to the main question - how to organize a mini-production?

So, to start such a small business, you don't need to register an LLC first. In this case, registration of an individual entrepreneur will be enough.

Registration of an individual entrepreneur is much easier and costs much less, which will also allow you to save a lot.

To apply for registration with the Federal Tax Service Inspectorate, you will only need basic documents:

• Application for registration of individual entrepreneurs.
• Passport of a citizen of Russia.
• TIN code.
• Receipt for payment of state duty.
• Application for the transition to a simplified taxation system.

The cost of the state duty for such an operation is 800 rubles. But in addition to this amount, you will also have to pay for opening a bank account (2 thousand rubles) and making a seal (up to 1 thousand rubles).

In total, state registration will cost you only 3-4 thousand rubles.

Now let's talk about the premises, the purchase of components and equipment for mini-production.

You will not need a large premises to launch an enterprise - it is enough to rent an area of ​​100 sq. m., where you will allocate a room for the assembly of batteries, a warehouse for components, and also organize a small showroom for visitors.

In principle, with a small volume of orders, even your own spacious garage may be suitable for you. But do not forget that the requirements for the room will also be high, because you still have high-precision work.

It is better to order components for the production of batteries from direct suppliers abroad. Although you can search on the territory of Russia. The main thing is that the quality of the materials is at a high level, and at the same time they do not cost exorbitant money.

As for the equipment, then automated lines with this method of organizing production will not be needed. Actually, because of this, large areas will not be needed either.

As the main equipment, only simple tools are required:

Equipment	Quantity	Cost, rub.)	Sample
Total:			52,000 rubles
Drill	2	10 thous.
Screwdriver	2	6 thous.
Set of tools	2	10 thous.

Since there is less work to be done than with a full production cycle, and it is easier to manage such a mini-enterprise, only 3-5 people can be hired on a permanent staff.

Namely, we are talking about such personnel:

• 2 people will assemble the goods.
• 2 people will install the batteries.
• 1 person will be the driver (preferably with his own car).

At first, you can only hire three workers, and then get a couple more people.

With a small production, you can perform the functions of a manager, accountant and marketer yourself.

However, the marketing plan will remain the same. Your main consumer is an individual, so you need to constantly inform him about your product by creating a website and placing advertisements in newspapers, on TV and radio.

Now let's calculate how much cheaper this mini-production method will cost:

• Registration of individual entrepreneurs - 3 thousand rubles.
• Premises rental - 100 thousand rubles.
• Purchase of components - 50 thousand rubles.
• Purchase of equipment - 52 thousand rubles.
• Salary for employees - 75 thousand rubles.
• Website development and other marketing services - 55 thousand rubles.
• Running costs - 25 thousand rubles.

In total, the initial investment for launching a small enterprise will amount to 360 thousand rubles. , which is a much smaller amount compared to the organization of production facilities "from scratch".

Considering that the sale and production costs of batteries will slightly increase with this method, the net profit may be slightly lower. But at the expense of much smaller investments and with a constant flow of customers (at least 5 people per month), you will be able to recoup your business after a year of operation on the market.

So, we analyzed two main ways of organizing a business in the manufacture of installations for generating electricity from the energy of the Sun.

In conclusion, we recall that the production of solar panels in Russia is still a completely free niche, which, having occupied it now, you can get a good return in the future, since the demand for alternative methods of generating energy will increase every year.

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Life in the "Organic" style, such a popular idea in recent years, presupposes a harmonious "relationship" between a person and the environment. The stumbling block of any environmental approach is the use of minerals for energy.

Emissions of toxic substances and carbon dioxide into the atmosphere, released during the combustion of fossil fuels, are gradually killing the planet. Therefore, the concept of green energy, which does not harm the environment, is the basis for many new energy technologies. One of these areas for obtaining environmentally friendly energy is the technology of converting sunlight into electric current. Yes, that's right, we will talk about solar panels and the possibility of installing autonomous power supply systems in a country house.

At the moment, industrial power plants based on solar panels, used for complete energy and heat supply of a cottage, cost at least 15-20 thousand dollars with a guaranteed service life of about 25 years. The cost of any helium system in terms of the ratio of the guaranteed service life to the average annual cost of maintaining a country house is quite high: firstly, today the average cost of solar energy is commensurate with the purchase of energy resources from central power grids, and secondly, one-time capital investments are required to install the system ...

It is usually customary to separate solar systems intended for heat and power supply. In the first case, solar collector technology is used, in the second, the photovoltaic effect is used to generate electric current in solar panels. We want to talk about the possibility of self-manufacturing solar panels.

The technology for manually assembling a solar energy system is quite simple and affordable. Almost every Russian can assemble individual power systems with high efficiency at relatively low costs. It is profitable, affordable and even fashionable.

Choosing solar cells for a solar panel

When starting to manufacture a solar system, you need to pay attention that with individual assembly, there is no need for a one-time installation of a full-featured system, it can be built up gradually. If the first experiment was successful, then it makes sense to expand the functionality of the solar system.

At its core, a solar battery is a photovoltaic generator that converts solar energy into electrical energy. Light quanta hitting the silicon wafer knock out an electron from the last atomic orbit of silicon. This effect creates a sufficient number of free electrons to form a flow of electric current.

Before assembling the battery, you need to decide on the type of photoelectric converter, namely: monocrystalline, polycrystalline and amorphous. For self-assembly of a solar battery, select commercially available monocrystalline and polycrystalline solar modules.

Above: Monocrystalline modules without soldered contacts. Bottom: Polycrystalline modules with soldered contacts

Panels based on polycrystalline silicon have a rather low efficiency (7-9%), but this drawback is offset by the fact that polycrystals practically do not reduce power in cloudy and cloudy weather, the guaranteed durability of such elements is about 10 years. Panels based on monocrystalline silicon have an efficiency of about 13% with a service life of about 25 years, but these elements greatly reduce power in the absence of direct sunlight. The efficiency of silicon crystals from different manufacturers can vary significantly. According to the practice of solar power plants in field conditions, we can talk about the service life of monocrystalline modules for more than 30 years, and for polycrystalline ones - more than 20 years. Moreover, over the entire period of operation, the power loss for silicon mono- and polycrystalline cells is no more than 10%, while for thin-film amorphous batteries for the first two years, the power decreases by 10-40%.

Evergreen Solar Cells with contacts in a set of 300 pcs.

A Solar Cells kit for assembling a solar array from 36 and 72 solar cells can be purchased at Ebay. Such kits are available for sale in Russia as well. As a rule, B-type solar modules are used for self-assembly of solar panels, that is, modules rejected in industrial production. These modules do not lose their performance and are much cheaper. Some suppliers offer solar modules on a fiberglass board, which implies a high level of tightness of the elements, and, accordingly, reliability.

Name	Characteristics	Cost, $
Everbright Solar Cells (Ebay) without contacts	polycrystalline, set - 36 pcs., 81x150 mm, 1.75 W (0.5 V), 3A, efficiency (%) - 13 in a set with diodes and acid for soldering in a pencil	$46.00 $ 8.95 shipping
Solar Cells (US new)	monocrystalline, 156x156 mm, 81x150 mm, 4W (0.5 V), 8A, efficiency (%) - 16.7-17.9	$7.50
	monocrystalline, 153х138 mm, U cold. stroke - 21.6V, I short. deputy. - 94 mA, P - 1.53W, efficiency (%) - 13	$15.50
Solar Cells on fiberglass board	polycrystalline, 116x116 mm, U cold. stroke - 7.2V, I short. deputy. - 275 mA., P - 1.5W, efficiency (%) - 10	$14.50
		$87.12 $ 9.25 shipping
Solar Cells (Ebay) without contacts	polycrystalline, set - 72 pcs., 81x150 mm 1.8W	$56.11 $ 9.25 shipping
Solar Cells (Ebay) with contacts	monocrystalline, set - 40 pcs., 152x152 mm	$87.25 $ 14.99 shipping

Development of a project for a helium energy system

The design of the future solar system largely depends on the method of its installation and installation. Solar panels should be installed at an angle to ensure direct sunlight is at right angles. The performance of a solar panel is largely dependent on the intensity of light energy as well as the angle of incidence of the sun's rays. The location of the solar array in relation to the sun and the angle of inclination depend on the geographic location of the helium system and the time of year.

From top to bottom: Monocrystalline solar panels (80 watts each) in the country are installed almost vertically (winter). Monocrystalline solar panels in the country have a smaller angle (spring). Mechanical system for controlling the angle of inclination of the solar battery.

Industrial solar systems are often equipped with sensors that rotate the solar panel in the direction of the sun's rays, as well as with mirrors that concentrate the sun's light. In individual systems, such elements significantly complicate and increase the cost of the system, therefore they are not used. The simplest mechanical tilt control system can be applied. In winter, solar panels should be installed almost vertically, this also protects the panel from snow build-up and icing of the structure.

Scheme for calculating the angle of inclination of the solar panel depending on the season

Solar panels are installed on the sunny side of the building to provide the maximum amount of solar energy available during daylight hours. Based on geographic location and solstice level, the battery tilt angle is calculated to best suit your location.

When the design becomes more complex, it is possible to create a control system for the angle of inclination of the solar battery depending on the season and the angle of rotation of the panel depending on the time of day. The energy efficiency of such a system will be higher.

When designing a solar system that will be installed on the roof of a house, it is imperative to find out if the roof structure can support the required weight. The independent development of the project involves the calculation of the roof load taking into account the weight of the snow cover in winter.

Choosing the Optimal Static Tilt Angle for Monocrystalline Type Solar Roofing System

For the manufacture of solar panels, you can choose different materials for specific gravity and other characteristics. When choosing materials of construction, it is necessary to take into account the maximum permissible heating temperature of the solar cell, since the temperature of a solar module operating at full power should not exceed 250C. When the peak temperature is exceeded, the solar module abruptly loses its ability to convert sunlight into electrical current. Ready-made solar systems for individual use, as a rule, do not imply cooling of solar cells. Self-fabrication may involve cooling the solar system or controlling the angle of the solar panel to maintain the functional temperature of the module, as well as the selection of an appropriate transparent infrared absorbing material.

A competent design of the solar system allows you to provide the required power of the solar battery, which will approach the nominal. When calculating the structure, it is necessary to take into account that elements of the same type give the same stress, regardless of the size of the elements. Moreover, the current strength of large-sized cells will be higher, but the battery will also be much heavier. For the manufacture of a solar system, solar modules of the same size are always taken, since the maximum current will be limited by the maximum current of the small cell.

Calculations show that on average, on a clear sunny day, you can get no more than 120 W of power from 1 m of solar panel. Such power will not even provide a computer. A 10 m system gives more than 1 kW of energy and can provide electricity for the operation of basic household appliances: lamps, TV sets, computers. A family of 3-4 people needs about 200-300 kW per month, so a solar system installed on the south side with a size of 20 m can fully meet the family's energy needs.

If we consider the average statistical data on the power supply of an individual residential building, then: daily energy consumption is 3 kWh, solar radiation from spring to autumn is 4 kWh / m2 per day, peak consumption power is 3 kW (when the washing machine, refrigerator, iron and electric kettle are turned on) ). In order to optimize energy consumption for indoor lighting, it is important to use low energy consumption AC lamps - LED and fluorescent.

Solar cell frame fabrication

An aluminum corner is used as a frame for the solar battery. Ready-made frames for solar panels can be purchased at ebay. The transparent coating is selected at will, based on the characteristics that are required for a given structure.

Solar Panel Glass Frame Kit starting at $ 33

When choosing a transparent protective material, you can also focus on the following material characteristics:

Material	Refractive index	Light transmission,%	Specific gravity g / cm 3	Sheet size, mm	Thickness, mm	Cost, rub / m 2
Air	1,0002926	—	—	—	—	—
Glass	1,43-2,17	92-99	3,168	—	—	—
Plexiglass	1,51	92-93	1,19	3040x2040	3	960.00
Polycarbonate	1,59	up to 92	0,198	3050 x2050	2	600.00
Plexiglass	1,491	92	1,19	2050x1500	11	640.00
Mineral glass	1,52-1,9	98	1,40	—	—	—

If we consider the refractive index of light as a criterion for choosing a material. Plexiglass has the lowest refractive index, a cheaper version of a transparent material is domestic plexiglass, less suitable is polycarbonate. Polycarbonate is commercially available with an anti-condensation coating, and this material also provides a high level of thermal protection. When choosing transparent materials in terms of specific gravity and ability to absorb the infrared spectrum, polycarbonate will be the best. The best transparent materials for solar panels are those with high light transmittance.

When manufacturing a solar cell, it is important to choose transparent materials that do not transmit the infrared spectrum and, thus, reduce the heating of silicon cells that lose their power at temperatures above 250C. In industry, special glasses are used that have an oxide-metallic coating. The ideal glass for solar panels is considered to be the material that transmits the entire spectrum except for the infrared range.

Scheme of absorption of UV and IR radiation by various glasses.
a) ordinary glass, b) glass with IR absorption, c) duplex with heat-absorbing and ordinary glass.

The maximum absorption of the IR spectrum will be provided by a protective silicate glass with iron oxide (Fe 2 O 3), but it has a greenish tint. The IR spectrum is well absorbed by any mineral glass with the exception of quartz glass, plexiglass and plexiglass belong to the class of organic glasses. Mineral glass is more resistant to surface damage but is very expensive and unaffordable. For solar panels, special anti-reflective super-transparent glass is also used, transmitting up to 98% of the spectrum. Also, this glass assumes absorption of most of the infrared spectrum.

The optimal choice of optical and spectral characteristics of glass significantly increases the photoconversion efficiency of the solar panel.

Plexiglas solar panel

Many solar cell making workshops recommend using plexiglass for the front and back panels. This allows inspection of contacts. However, the plexiglass structure can hardly be called completely sealed, capable of ensuring uninterrupted operation of the panel for 20 years of operation.

Solar battery housing installation

The master class demonstrates the manufacture of a solar panel from 36 polycrystalline solar cells with a size of 81x150 mm. Based on these dimensions, you can calculate the dimensions of the future solar battery. When calculating the dimensions, it is important to make a small distance between the elements, which will take into account the change in the size of the base under atmospheric influence, that is, there should be 3-5 mm between the elements. The resulting size of the workpiece should be 835x690 mm with a corner width of 35 mm.

	A homemade solar panel made using an aluminum profile is most similar to a factory-made solar panel. This ensures a high degree of tightness and structural strength.
	For manufacturing, an aluminum corner is taken, and frame blanks of 835x690 mm are made. To be able to fasten the hardware, holes should be made in the frame.
	Silicone sealant is applied to the inside of the corner twice.
	Be sure to make sure that there are no empty places. The tightness and durability of the battery depends on the quality of the application of the sealant.
	Next, a transparent sheet of the selected material is placed in the frame: polycarbonate, plexiglass, plexiglass, anti-reflective glass. It is important to let the silicone dry in the open air, otherwise the fumes will create a film on the elements.
	The glass must be carefully pressed and fixed.
	For reliable fastening of the protective glass, you will need hardware. It is necessary to fix 4 corners of the frame and place two hardware on the long side of the frame and one hardware on the short side around the perimeter.
	The hardware is fixed with screws.
	The screws are tightly tightened with a screwdriver.
	The solar cell frame is ready. Before attaching solar cells, it is necessary to clean the glass from dust.

Selection and soldering of solar cells

At the moment, a huge range of products for self-made solar panels are presented at the ebay auction.

Solar Cells Kit Includes 36 Polycrystalline Silicon Cells, Cell Leads and Busbars, Schottke Diodes, and Acid Soldering Pen

Since a self-made solar battery is almost 4 times cheaper than a finished one, making it yourself is a significant cost saving. Defective solar cells can be purchased on Ebay, but they do not lose their functionality, so the cost of a solar cell can be significantly reduced if you can additionally sacrifice the appearance of the battery.

Damaged photocells do not lose their functionality

At the first experience, it is better to purchase kits for the manufacture of solar panels, solar cells with soldered conductors are available for sale. Soldering contacts is a rather complicated process, the complexity is exacerbated by the fragility of solar cells.

If you purchased silicon cells without conductors, then you must first solder the contacts.

	This is what a polycrystalline silicon cell looks like without conductors.
	The conductors are cut using a cardboard blank.
	Carefully place the conductor on the photocell.
	Apply soldering acid and solder to the soldering area. For convenience, the guide is fixed on one side with a heavy object.
	In this position, it is necessary to carefully solder the conductor to the photocell. During soldering, do not press on the crystal, because it is very fragile.

Soldering the elements is a rather painstaking work. If you cannot get a normal connection, then you need to repeat the work. According to the standards, silver sputtering on a conductor must withstand 3 soldering cycles at permissible thermal conditions; in practice, you are faced with the fact that the spraying is destroyed. The destruction of silver sputtering occurs due to the use of soldering irons with unregulated power (65W), this can be avoided by lowering the power as follows - you need to turn on the cartridge with a 100W light bulb in series with the soldering iron. The power rating of an unregulated soldering iron is too high for soldering silicon contacts.

Even if sellers of conductors assure that there is solder on the connector, it is better to apply it additionally. During soldering, try to carefully handle the elements, with minimal effort they burst; do not stack the elements in a bundle, the weight of the lower elements may crack.

Assembling and soldering a solar panel

When assembling a solar battery for the first time, it is better to use a marking substrate, which will help to arrange the elements evenly at some distance from each other (5 mm).

Layout substrate for solar cells

The base is made of a sheet of plywood with marking of the corners. After soldering, a piece of mounting tape is attached to each element from the back side, it is enough to press the back panel to the tape, and all the elements are transferred.

Mounting tape used for fixing on the back of the solar cell

With this type of fastening, the elements themselves are not additionally sealed, they can expand freely under the influence of temperature, this will not damage the solar battery and rupture of contacts and elements. Only the connecting parts of the structure can be sealed. This type of fastening is more suitable for prototypes, but can hardly guarantee long-term operation in the field.

A sequential battery assembly plan looks like this:

	We spread the elements on a glass surface. There must be a distance between the elements, which implies free resizing without damaging the structure. The elements must be pressed with weights.
	Soldering is performed according to the wiring diagram below. "Plus" live tracks are located on the front side of the elements, "minus" ones - on the back side. Before soldering, you need to apply flux and solder, then gently solder the silver contacts.
	All solar cells are connected according to this principle.
	The contacts of the extreme elements are output to the bus, respectively, to "plus" and "minus". The bus uses the wider silver conductor found in the Solar Cells kit. We also recommend drawing the "middle" point, with its help two additional shunt diodes are placed.
	The terminal is also installed on the outside of the frame.
	This is how the connection diagram of the elements looks without the derived midpoint.
	This is what the terminal strip looks like with the "midpoint" displayed. The "middle" point allows for a shunt diode to be placed on each half of the battery, which will prevent the battery from discharging when the lighting is reduced or one half is dimmed.
	The photo shows a bypass diode at the "positive" output, it resists the discharge of batteries through the battery at night and the discharge of other batteries during partial dimming. Most often, Schottke diodes are used as shunt diodes. They give less loss on the total power of the electrical circuit. A silicone-insulated acoustic cable can be used as current-carrying wires. For isolation, you can use dropper tubes. All wires must be firmly fixed with silicone.
	The elements can be connected in series (see photo), and not by means of a common bus, then the 2nd and 4th row must be rotated by 1800 relative to the 1st row.

The main problems of assembling a solar panel are associated with the quality of the soldering of the contacts, therefore, experts suggest testing it before sealing the panel.

Panel test before sealing, 14 volt mains voltage, 65 W peak power

Testing can be done after soldering each group of elements. If you pay attention to the photos in the master class, then part of the table under the solar cells is cut out. This is done intentionally to determine the health of the electrical network after soldering the contacts.

Solar Panel Sealing

Self-sealing solar panels is the most controversial issue among experts. On the one hand, panel sealing is necessary to increase durability and is always used in industrial production. For sealing, foreign experts recommend using the epoxy compound "Sylgard 184", which gives a transparent polymerized highly elastic surface. The cost of Sylgard 184 on Ebay is about $ 40.

Sylgard 184 High Elasticity Sealant

On the other hand, if you do not want to incur additional costs, it is perfectly possible to use a silicone sealant. However, in this case, you should not completely fill the elements in order to avoid their possible damage during operation. In this case, the elements can be attached to the back panel with silicone and only the edges of the structure can be sealed. It is difficult to say how effective such sealing is, but we do not recommend using non-recommended waterproofing mastics, the probability of breaking contacts and elements is very high.

	Sylgard 184 must be prepared before sealing.
	First, the joints of the elements are poured. The mixture must set in order to secure the elements to the glass.
	After fixing the elements, a continuous polymerizing layer of elastic sealant is made; it can be distributed with a brush.
	This is what the surface looks like after applying the sealant. The sealing layer must dry out. After complete drying, you can cover the solar panel with the back panel.
	This is what the front side of a homemade solar panel looks like after sealing.

House power supply diagram

Power supply systems for homes using solar panels are usually called photovoltaic systems, that is, systems that generate energy using the photoelectric effect. For individual residential buildings, three photovoltaic systems are considered: an autonomous power supply system, a hybrid battery-network photovoltaic system, and a batteryless photovoltaic system connected to a central power supply system.

Each of the systems has its own purpose and advantages, but most often photovoltaic systems with backup batteries and connection to a centralized power grid are used in residential buildings. The power grid is powered by solar panels, in the dark from batteries, and when they are discharged from the central power grid. In hard-to-reach areas where there is no central network, liquid-fueled generators are used as a backup source of energy.

A more cost-effective alternative to a hybrid battery-grid power system would be a battery-free solar system connected to a central grid. The power supply is carried out from solar panels, and in the dark, the network is powered from the central network. Such a network is more applicable for institutions, because in residential buildings most of the energy is consumed in the evening.

Schemes of three types of photovoltaic systems

Consider a typical installation of a battery-grid photovoltaic system. Solar panels act as a generator of electricity, which are connected through a junction box. Next, a solar charge controller is installed in the network to avoid short circuits during peak loads. Electricity is accumulated in backup batteries-accumulators, and is also supplied through an inverter to consumers: lighting, household appliances, an electric stove and, possibly, is used to heat water. To install a heating system, it is more efficient to use solar collectors, which belong to alternative solar technology.

AC hybrid battery-grid photovoltaic system

There are two types of power grids that are used in photovoltaic systems: DC and AC. The use of an alternating current network allows placing electrical consumers at a distance exceeding 10-15 m, as well as providing a conditionally unlimited load of the network.

For a private residential building, the following components of a photovoltaic system are usually used:

• the total power of solar panels should be 1000 W, they will provide an output of about 5 kWh;
• accumulators with a total capacity of 800 A / h at a voltage of 12 V;
• the inverter must have a rated power of 3 kW with a peak load of up to 6 kW, an input voltage of 24-48 V;
• solar discharge controller 40-50 A at a voltage of 24 V;
• uninterruptible power supply for short-term charging with current up to 150 A.

Thus, for a photovoltaic power supply system, you will need 15 panels for 36 elements, an example of the assembly of which is given in the master class. Each panel provides a total power of 65 watts. Monocrystal solar panels will be more powerful. For example, a solar panel of 40 monocrystals has a peak power of 160 watts, but such panels are sensitive to cloudy weather and clouds. In this case, solar panels based on polycrystalline modules are optimal for use in the northern part of Russia.

For a long time, the lot of solar cells were either bulky panels of satellites and space stations, or low-power solar cells in pocket calculators. This was due to the primitiveness of the first monocrystalline silicon photocells: they had not only low efficiency (no more than 25% in theory, in practice - about 7%), but also noticeably lost efficiency when the angle of incidence of light deviated from 90˚. Considering that in Europe in cloudy weather the specific power of solar radiation can fall below 100 W / m2, too large areas of solar panels were required to obtain any significant power. Therefore, the first solar power plants were built only under conditions of maximum luminous flux and clear weather, that is, in deserts near the equator.

A significant breakthrough in the creation of solar cells has returned interest in solar energy: for example, the cheapest and most affordable polycrystalline silicon cells, although they have a lower efficiency than monocrystalline ones, are less sensitive to operating conditions. A solar panel based on polycrystalline plates will give enough stable voltage in partly cloudy conditions... More modern photocells based on gallium arsenide have an efficiency of up to 40%, but are too expensive for making a solar battery with your own hands.

The video tells a story about the idea of ​​building a solar battery and its implementation.

Should I do it?

In many cases, the solar panel will be very useful: for example, the owner of a private house or summer cottage, located far from the mains, will be able to keep his phone charged even from a compact panel, connect low-power consumers like car refrigerators.

For this purpose, ready-made compact panels made in the form of quick-roll assemblies based on synthetic fabric are produced and sold. In central Russia, such a panel measuring about 30x40 cm will be able to provide power within 5 W at a voltage of 12 V.

A larger battery can provide up to 100 watts of electrical power. It would seem that this is not so much, but it is worth remembering the principle of operation of small ones: in them, the entire load is powered through a pulse converter from a battery of batteries that are charged from a low-power wind turbine. Thus, it becomes possible to use more powerful consumers.

Using a similar principle when building a home solar power plant makes it more profitable than a wind turbine: in summer, the sun shines for most of the day, as opposed to an intermittent and often absent wind. For this reason, the batteries will be able to charge up much faster during the day, and the solar panel itself is much easier to install than the one requiring a tall mast.

There is a sense in using a solar battery exclusively as an emergency power source. For example, if a gas heating boiler with circulation pumps is installed in a private house, when the power supply is cut off, it is possible to power them through a pulse converter (inverter) from batteries, which are kept charged from a solar battery, keeping the heating system operational.

TV story on this topic