We make a solar battery with our own hands. Prospects for the solar panel business

The world is experiencing a constant increase in electricity consumption, and the stocks of traditional energy sources are declining. Therefore, the demand for equipment that generates electricity using non-traditional sources of raw materials is gradually growing. One of the most common ways to generate electricity is solar panels powered by solar energy. They are composed of photovoltaic cells, the properties of which make it possible to convert solar radiation into electric current. For their manufacture, one of the most common chemical elements on Earth is used - silicon. In this article, we will talk about how silicon is converted into photovoltaic cells. Simply put, we will look at what solar cell production is and what equipment is required for this.

In the field of solar panels production, a fairly large market has already formed, in which large companies are present. Millions of dollars are already spinning here and there are brands that have earned a reputation for producing quality products. This refers to both the world market and the Russian one. The technologies underlying the production of solar panels are being improved as scientific research in this direction develops. Now solar panels are produced in various sizes and purposes. There are very small ones used in calculators and. And there are large panels used in solar systems and. One photocell has a small power and produces a very small current. Therefore, they are combined into . Now let's look at how photovoltaic cells are made.

First of all, it is worth saying that at the output, manufacturers receive three types of photocells:

• Monocrystalline;
• Polycrystalline;
• from amorphous silicon.

Monocrystalline solar cell wafers can be visually distinguished by uniformity in color. In their production from the feedstock (silicon), as a result of temperature melting, an ingot of single-crystal silicon is obtained. It has a high degree of purity and uniformity of the crystal lattice.

Polycrystalline cells are easier to manufacture. When creating them, there is no goal to grow an ingot from a single crystal and achieve a high uniformity of the structure. They have a lower cost, but pay for it with lower efficiency. Visually, they can be distinguished by heterogeneous colors.

And another type of solar cells are made of amorphous silicon. To obtain some characteristics, various microelements and nanoparticles are added to it. Production from this type of silicon is mainly focused on the production of flexible solar cells. This type of panel has the lowest efficiency.

As a result of the thermal treatment of silicon, cylindrical bars are obtained. Plates of small thickness are cut from it. As a result of this operation, damage appears on the surface of the plates, which are removed by etching and texturing. This is necessary in order to improve the absorption of light radiation. After such treatment, microscopic pyramids are formed on the surface of silicon wafers, arranged in a chaotic manner. When hit on them, light is reflected on the side surfaces of other such pyramids. Loosening the texture reduces reflectivity by about a quarter. The etching process itself is a series of successive treatments with alkalis and acids. As they say, experts, here you can not overdo it and pickle the excess. The layer is thin and the plate may not be suitable for further use.

The very technology for the production of photovoltaic cells is based on the use of a p-n junction. In the plate of the photocell, hole and electronic conductivity, p and n-type, respectively, are combined. This design has the properties of being a barrier and passing electric current in one direction. This is how solar panels work.

For laying on a silicon wafer of an n-type semiconductor, phosphorus diffusion is used in production. This layer is located near the surface of the plate, extending to a depth of about 0.5 µm. As a result, under the action of sunlight, charge carriers of the opposite sign penetrate to a shallow depth. This is done specifically to ensure that the path to the p-n junction zone is as fast as possible. Otherwise, they can extinguish each other when they meet. In this case, they do not generate electric current, which means they are wasted.

As a result of diffusion, a short circuit occurs between the front surface of the plate with a grating for current pickup and the reverse side, which is a solid contact. Various technologies are used to remove this short circuit. This can be plasma-chemical or chemical etching. And also it can be done by laser or mechanically. With the help of plasma-chemical etching, the short circuit is removed immediately for a stack of silicon wafers. The result of this procedure largely depends on the processing time, chemical composition, surface area of ​​the elements and many other factors.

A texture is then applied to the surface of the plate to reduce reflection. If this is not done, then 10% of the sun's rays will be reflected and will not take part in the generation of electric current. The coating is used for deep penetration of light, which prevents them from reflecting back.

When creating a metallized mesh on the front side of the plates is a difficult task. On the one hand, the minimum optical loss is achieved if the grid lines are thin and located at a significant distance from each other. If the grid is made larger, then part of the charges will not reach the contact and will be wasted. On the other hand, if the mesh strips are too thin, then there will be a lot of space for light absorption.

But thin lines cannot conduct much current. Therefore, the “golden mean” is being sought. There are standardized values ​​for line sizes and distances between them for various metals. Metallization technology is based on screen printing. The most commonly used material is a paste containing silver. Thanks to its use, the efficiency of the plates can be increased up to 15 percent.

Now, let's consider the production of solar panels at the stage of assembling them from the resulting photocells.

Solar battery production

The production of solar panels can be divided into the following main stages:

• Testing. At this stage, the electrical characteristics are measured. For this, flashes of powerful xenon lamps are used. Based on the test results, the photocells are sorted and sent to the next stage of production;
• At the second stage of production, the soldering of the elements in the section is performed. Sections are formed from them on a glass substrate. The assembled sections are transferred to the glass using vacuum grippers. This is a mandatory requirement to exclude mechanical or other effects on the surface of the plates. Blocks usually include 4-6 sections. Sections, in turn, consist of 9-10 photovoltaic panels;
• The next stage of production is lamination. The blocks of photocells connected by soldering are laminated with an ethylene vinyl acetate film. A special protective coating is also applied. All this is done on CNC equipment. The computer monitors such characteristics as pressure, temperature, etc. Depending on the material used, the lamination parameters can be changed;
• And the final stage is the manufacture of an aluminum profile frame and a special junction box. To ensure the reliability of the connection, glue-sealant is used. At the same stage of production, testing of solar panels is carried out. In this case, short-circuit currents, output voltage (working and no-load), current strength are measured.

Used equipment

Reputable manufacturers use modern software-controlled equipment in the production of solar panels. This approach ensures the minimum error and variation in the parameters of the assembled solar panels. In addition, computer equipment allows for more accurate and complete testing. The result is fewer scraps and longer battery life.

Let's list the equipment used for production.

• Tables for moving assemblies. On these tables, cutting, stacking elements, attaching a junction box, and so on. These tables have non-metal balls on the surface of the tabletop. This makes it easy to move the assemblies and not damage the elements;
• Laminator. This equipment is used for lamination and all parameters are configured in a special software for automatic operation. Although manual operation is also possible;
• Cell cutting tool. The cutting is done with a fiber laser. Parameters are also set programmatically;
• Equipment for cleaning glass substrates. The procedure takes place in several stages. Nylon brushes and detergent are used first. This is followed by a gradual rinse with deionized water. This is followed by drying with hot and cold air.

Major manufacturers of solar panels

The production of solar panels and finished solar systems is a profitable and promising business. The number of purchased batteries is growing from year to year. As a result, there is a constant sales market, which many large manufacturers pay attention to.

First of all, this market is being developed by companies from China. With low cost, they squeeze out all other companies from the market. So, due to Chinese expansion, four medium-sized German companies, as well as one American manufacturer, were forced to curtail production. Work in this direction was closed by Siemens and Bosch. The result is natural, since solar panels made in China cost twice as much as European and American products.

Among the global manufacturers, the following large companies producing solar panels can be named:

• Yingli Green Energy. The company annually produces solar panels with a total capacity of 2 gigawatts. They produce batteries from monocrystalline and polycrystalline cells;
• First Solar. They were forced to close the plant in Germany, but they are still one of the largest in the world. They produce panels per year with a total capacity of 3.5 gigawatts;
• Suntech Power Co. This is a Chinese giant producing 1.8 gigawatts of products. Their production facilities are located in eighty countries around the world.

Solar batteries of Russian production are produced by the following companies:

• Hevel LLC (Novocheboksarsk);
• Telecom-STV (Zelenograd);
• ZAO "Termotron-Zavod";
• OJSC "Ryazan Plant of Metal-Ceramic Instruments" (Ryazan).

In the countries of the former USSR, you can also find many industries. For example, in Astana. Moreover, local silicon is used for production. During the construction, modern equipment was installed at the enterprise. A similar enterprise is going to be built in Uzbekistan. Moreover, the construction is also carried out by Chinese manufacturers.
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The benefits of solar energy are obvious, a lot has already been said about this and there is no doubt about it. It is for this reason that many people have already installed panels on their homes today, while others only dream about it. Solar panels are certainly profitable, but such devices are quite expensive, which is why not everyone can afford such a luxury. Thanks to this, many are wondering - how to make a solar battery with your own hands, is it possible, and what is needed for this?

The answer is, of course, it is quite real. And today there are several ways that will help you make solar panels with your own hands. The choice of method depends on what kind of performance you need.

1. Preparation of starting materials

• Elements made of polycrystalline silicon;
• Monocrystalline solar cells.

The first option has a lower level of efficiency (COP), which is about 7-9%. However, panels consisting of such elements do not lose their effectiveness, even in cloudy weather. They are almost equally productive both on sunny days and in rainy weather.

Monocrystalline panels, in turn, have a higher level of efficiency, which is about 13%. However, they are more effective only in sunny weather, and in the case of cloudiness or darkening, their productivity is significantly reduced. Due to these features, most often in order to get a sufficiently powerful home-made solar battery that will be equally effective in all weather conditions, it is polycrystalline photovoltaic cells that are used.

It is highly recommended to purchase solar cells from one manufacturer. This is because devices from different brands may well have differences in efficiency, which in turn creates additional difficulties at the time of determining the total battery power. In addition, the estimated period of operation of the elements may also differ.

The simplest and most common method of acquiring the necessary items today is eBay auctions. Here you can buy ready-made sets of photocells, while they will have a very reasonable cost. In order to assemble solar panels for the home with your own hands from the materials at hand, you will need special conductors that connect the photocells to each other. In addition, you will need a soldering iron and soldering tools.

It is quite possible to purchase slightly damaged photocells, as they do not lose any performance at all, but at the same time they have a much lower cost. Of course, such elements have a less aesthetic appearance.

For the manufacture of the battery case, the most suitable material is aluminum corners, which have a small height. Of course, it is quite possible to make solar panels with your own hands from improvised means, without buying corners, but using, for example, wooden bars. However, it should be understood that homemade solar panels will be constantly used, which means they will be subjected to various weather conditions. In this case, the tree can deteriorate extremely quickly, due to which the case will have to be redone.

The dimensions of the solar array depend on the number of solar cells to be used. The outer protective coating of the panel must be transparent and at the same time sufficiently strong and durable. As such a coating, it is best to use plexiglass or polycarbonate. You can, of course, use durable tempered glass, but you should be more careful with such panels. Also, it will be better if this protection does not transmit infrared rays, since due to such protection, the heating of the panel during use is reduced.

2. Soldering conductors

After you have purchased all the necessary materials, you can proceed to the assembly of a homemade solar battery. First of all, you need to solder the conductors to the photocells. This process is very time consuming and will require some patience and accuracy from you. During the soldering process, some difficulties may arise due to the fragility of the photocell structure. It will be much easier to buy elements that already have soldered conductors, however, even with self-soldering, you will soon “stuff” your hand and easily cope with this task. In addition, already soldered photocells may have a higher cost.

In the event that you plan to solder the conductors yourself, you need to know the following procedure:

• The first step is to cut the existing conductors to the required length (it is more convenient to do this using a cardboard template);
• Next, you need to carefully place the cut conductor on the photocell;
• After that, soldering acid should be applied, as well as solder to the place where the soldering will be performed;
• Carefully and carefully solder the conductor. In this case, in no case should you press the crystal. Soldering is easy and fast. This will come with experience.

This process is not fast, which is why making homemade solar panels for the home, you will need some amount of time, as well as patience.

3. Assembly of the body and installation of photocells

As already mentioned, for the manufacture of a frame that has the required size, aluminum corners are needed, as well as fastening materials (hardware). It is best to take corners with a low height, otherwise they will cover the Sun and create a shadow on the photocells. In addition, using corners that are too high will result in an unnecessarily wide body for the panel.

Silicone sealant must be applied to the inner edges of the bonded profiles. This is necessary in order for the homemade solar battery to be airtight. A sheet of plexiglass cut to size should be laid on the applied sealant, pressing it tightly and fixing it. After the sealant dries, the plexiglass can be additionally fixed with hardware.

After performing the above steps, it is necessary to place photocells with soldered conductors on the inner plane of the transparent sheet. In this case, a small distance (about 5 mm) must be maintained between the cells. This is due to the fact that the elements in the process of use can expand under the influence of temperature. In addition, thanks to these indents, the possibility of breaking contacts is excluded. In order for the solar battery for the house to be assembled correctly with your own hands, this process must be approached with all care. In addition, to facilitate the work, you can pre-mark the substrate.

4. Combining photocells into a single system

It is necessary to solder all photocells into one system following the electrical circuit. To date, several schemes are known:

• serial connection;
• Connection to a common bus;
• A connection with an inferred midpoint.

There are also other schemes, therefore, it is best to pre-select the most suitable option. In this case, the main thing is that shunt diodes are present in the circuit, which must be installed on a common “+” conductor. These diodes are required in order to prevent the device from discharging at night or with partial blackout. For these purposes, it is best to use Schottky diodes. As current-carrying wires, you can use ordinary cables with silicone insulation. Of course, they must be securely and firmly fixed.

After combining the photocells according to the selected scheme, the resulting solar battery must be tested for current and voltage. To do this, you need a conventional ammeter and voltmeter, or a multimeter that has both of these functions. If the check is successful, it means that the elements are connected correctly and all contacts are intact.

After checking, fix all photocells and seal the panel. The easiest way is to apply mounting silicone to each element, after which the device must be closed with a panel, which can be made of durable plastic. Moreover, if you use transparent plastic, then you will have the opportunity to monitor the possible appearance of defects or cracks in the elements. After the silicone has dried, the back panel needs to be fixed into the prefabricated aluminum frame. All seams of the structure must also be sealed with silicone. You can also use double-sided adhesive tape to fix the photocells. The main rule is that the thickness of this tape (or layer of silicone) exceeds the soldering height. This will help prevent damage to the contacts.

5. Do-it-yourself solar battery from transistors

Today, it is possible to make a solar battery with your own hands, without using purchased solar cells. For example, it can be made from transistors or diodes. Of course, it is impossible to make a solar battery from these materials that can power an entire house, but such a device is quite capable of powering small and compact electrical appliances.

So, how to make a homemade solar panel? Quite simply. To make a homemade panel, you will need old transistors, it is best to take devices of the “P” or “KT” types. First of all, it is necessary to cut down the upper part of the body very carefully so that sunlight can reach the p-n transitions. In the case of using “P” transistors, it will additionally be necessary to pour powder out of it and blow through the inside.

Further, the resulting photocells must be combined into blocks. The connection is carried out in series - to increase the voltage, and in parallel - to increase the current. By connecting transistors in this way, it is quite possible to create a solar battery with your own hands, which will have the necessary parameters. It is convenient to fix such elements on a textolite substrate by hanging installation.

In addition, it is possible to assemble a solar battery from diodes, for example, D223B. At the same time, they do not even need to be disassembled, it is quite enough to simply wipe off the paint with acetone. Under the paint, you will find a glass case. Due to the small size of such diodes, a high density of elements is achieved. It is necessary to solder the diodes into the substrate vertically, as this will allow to achieve the maximum illumination of the crystal, and, consequently, the maximum performance.

6. DIY solar battery: Video

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 their own hands has become very relevant. So how do you make solar panels yourself?

Solar panel feature

A solar battery is a semiconductor structure that is capable of converting solar radiation into electricity. This allows you 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, as well as 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 not only to optimize energy consumption, but also saves finances.

Advantages

Solar panels have the following advantages:

• simple installation due to the fact that there is no need to lay a cable to the supports;
• electricity generation does not harm the environment at all;
• no moving parts;
• electricity is supplied independently of the distribution network;
• minimal time spent on system maintenance;
• small weight of batteries;
• silent operation;
• long service life at minimum cost.

disadvantages

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

• the complexity of the manufacturing process;
• sensitivity to pollution;
• the effective operation of solar panels is affected by weather conditions (sunny or cloudy days);
• for such a design, a lot of space is needed;
• Batteries don't work at night.

Requirements for a solar battery

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

Materials needed for making a solar battery with your own hands

If it is not possible to purchase solar panels, you can make them yourself. at first 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:

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

For the energy supply of the house, it is best to use polycrystals, which are available in sets.

It is important to know that everything needed for assembly cells are best purchased from one manufacturer, since products of different brands have significant differences in the effectiveness of products. This can create additional difficulties during assembly, incur 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 photocells.

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

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

The outer coating of photocells can be made of plexiglass or transparent polycarbonate. Also used tempered glass that 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;
• fasteners;
• copper electrical wires of high power;
• silicone vacuum stands;
• soldering equipment;
• aluminum corners;
• Schottke diodes;
• transparent sheet of polycarbonate or plexiglass;
• set of fixing screws.

Such materials are purchased at a building materials store or in an online store.

How to make solar panels with your own hands?

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

To properly 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 feasible. By making solar panels with your own hands, you can enjoy an additional source of electricity. Wherein this design does not cause any harm to the environment besides it is very reliable and inexpensive.

If you pay attention to the roofs of many private houses or small companies, you can see solar panels there. The rise in the price of energy carriers leads to the fact that people begin to look for alternative sources. Under these conditions, the demand for solar panels is growing day by day.

Potential Opportunities

In the context of the growing popularity of alternative energy sources, it is advisable to occupy a niche in the market in time. To do this, you first need to purchase equipment for the production of solar panels. It can be bought both in Europe, the USA and the CIS, and in China.

Depending on the demand for these products in your region or in places where you can supply the manufactured goods, you need to decide what your production will be focused on. Currently on the market you can find panels designed for various areas of use.

These can be as light portable options that you take with you on camping trips, stationary modules suitable for installation on the roofs of buildings and residential buildings, or powerful panels that are used as small power plants.

Working lines

If you have a manufacturing facility, then you can think about buying equipment for the production of solar panels. Also, do not forget that when making them, you should always have the necessary consumables in sufficient quantities.

So, the list of necessary equipment includes machines that laser cut the material for panels into squares, sort them, laminate them, insert them into frames and join them together. In addition, production requires machines that knead special glue, cut the film under the panel and their edges. In the manufacture of tables, on which it will be necessary to correct the angles, insert wires into the panels and form them, and trolleys designed to move and press them, one cannot do without tables.

Each solar cell production machine is an indispensable component of the solar cell production line. Therefore, before you start ordering materials for production, calculate the total cost of equipment and analyze whether you can afford such expenses. True, it is worth considering that if there are distribution channels, they quickly pay off.

Manufacturing process

If you have seen solar panels before only in pictures and have a poor idea of ​​​​how their creation is going on, then it is better to find a person who knows the technology for the production of solar panels. If we talk about it in general terms, then you need to know that it consists of a number of stages.

Production begins with the verification and preparation for work of the materials received by the workshop. After cutting and sorting of photovoltaic converters (PVCs), they go to the equipment, where the process of soldering to the contacts of the panels of special tinned copper bars takes place. Only after this, the process of connecting all solar cells into chains of the required length begins.

The next step is to create a sandwich, which consists of transducers assembled into a matrix, glass, two layers of sealing film and the back side of the panel. It is at this stage that the equipment for the production of solar panels forms the circuit of the module, and its operating voltage is immediately determined.

The assembled structure is checked and sent for lamination - sealing, which takes place under pressure at high temperature. Only after that, a frame is attached to the prepared semi-finished product and a special junction box is mounted.

Product testing

It is almost impossible to meet a marriage among similar products on the market, because after assembly each panel goes to a special testing workshop.

It is there that they are checked for the possibility of voltage breakdown. After that, they are sorted, packed and sent for sale; in stores you can find both small portable options and solar panels for the home.

The production of these species is practically no different.

Of course, only a large manufacturer with large production volumes and a sufficient number of employees can afford to strictly observe all the stages. It is difficult for new small manufacturers to compete with the giants, because the one-time creation of large batches makes it possible to reduce the cost of production.

Quartz sand with a high mass content of silicon dioxide (SiO 2) is used as a raw material. It undergoes multi-stage purification to get rid of oxygen. Occurs by high-temperature melting and synthesis with the addition of chemicals.