Do-it-yourself modules for a solar battery. Do-it-yourself solar battery from improvised means and materials at home - how to assemble and make a solar battery from diodes, transistors and foil? The principle of operation of solar panels

Organic living, such a popular idea in recent years, involves a harmonious "relationship" of man with the environment. The stumbling block of any ecological 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 basic basis for many new energy technologies. One of such 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 full 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 energy networks, and secondly, one-time capital investments are required to install the system .

It is usually customary to separate solar systems designed 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 of manual assembly of a solar energy system is quite simple and affordable. Almost every Russian can assemble individual energy systems with high efficiency at relatively low cost. It is profitable, affordable and even fashionable.

Choosing solar cells for 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 fully functional system, it can be built up gradually. If the first experience turned out to be successful, then it makes sense to expand the functionality of the solar system.

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

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

Top: 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 disadvantage is offset by the fact that polycrystalline silicon practically does not reduce power in cloudy and cloudy weather, the warranty life 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 the field, we can talk about the service life of single-crystal modules for more than 30 years, and for polycrystalline modules - more than 20 years. Moreover, over the entire period of operation, the power loss in silicon mono- and polycrystalline cells is no more than 10%, while in thin-film amorphous batteries, the power decreases by 10-40% in the first two years.

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

On the eBay auction, you can purchase a Solar Cells kit for assembling a solar array of 36 and 72 solar cells. Such sets are available for sale in Russia. As a rule, for self-assembly of solar panels, B-type solar modules are used, 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.

Development of a project for a helium energy system

The design of a 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 hits at right angles. The performance of a solar panel largely depends on the intensity of light energy, as well as the angle of incidence of the sun's rays. The placement of the solar battery relative to the sun and the angle of inclination depends 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 house are installed almost vertically (winter). Monocrystalline solar panels in the country have a smaller angle (spring) Mechanical system for controlling the angle of the solar battery.

Industrial solar systems are often equipped with sensors that ensure the rotational movement of the solar panel in the direction of the movement of the sun's rays, as well as mirrors concentrating sunlight. In individual systems, such elements significantly complicate and increase the cost of the system, and therefore are not used. The simplest mechanical tilt angle control system can be used. In winter, solar panels should be installed almost vertically, this also protects the panel from snow and icing on the structure.

Scheme for calculating the angle of inclination of the solar panel depending on the time of year

Solar panels are installed on the sunny side of the building to provide the maximum amount of solar energy available during daylight hours. Depending on the geographic location and the level of the solstice, the angle of the battery is calculated, which is most suitable for your location.

With the complexity of the design, it is possible to create a system for controlling 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 whether the roof structure can withstand the required mass. Self-development of the project involves the calculation of the roof load, taking into account the weight of the snow cover in winter.

Selecting the optimal static tilt angle for a rooftop solar system of a single crystal type

For the manufacture of solar panels, you can choose different materials according to specific gravity and other characteristics. When choosing construction materials, it is necessary to take into account the maximum allowable heating temperature of the solar cell, since the temperature of the solar module operating at full capacity should not exceed 250C. When the peak temperature is exceeded, the solar module dramatically loses its ability to convert sunlight into electrical current. Ready-made solar systems for individual use, as a rule, do not require cooling of solar cells. Do-it-yourself manufacturing may involve cooling the solar system or controlling the angle of the solar panel to ensure the module's functional temperature, as well as the selection of an appropriate transparent material that absorbs IR radiation.

Competent design of the solar system allows you to provide the required power of the solar battery, which will be close to the nominal. When calculating the structure, it must be taken 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 greater, 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 element.

Calculations show that on average, on a clear sunny day, no more than 120 W of power can be obtained from 1 m of a solar panel. Such power will not even ensure the operation of a computer. A 10 m system gives more than 1 kW of energy and can provide electricity to the main household appliances: lamps, TV, computer. For a family of 3-4 people, about 200-300 kW per month is needed, 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 - 4 kWh / m per day, peak power consumption - 3 kW (when the washing machine, refrigerator, iron and electric kettle are turned on ). In order to optimize energy consumption for lighting inside the home, it is important to use low-energy AC lamps - LED and fluorescent.

Making a solar battery frame

An aluminum corner is used as the frame of the solar battery. On ebay, you can buy ready-made frames for solar panels. The transparent coating is selected as desired, based on the characteristics that are required for this design.

Solar glass frame kit starting at $33

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

If we consider the refractive index of light as a criterion for choosing a material. Plexiglas has the lowest refractive index, domestic plexiglass is a cheaper option for a transparent material, and polycarbonate is less suitable. Polycarbonate with an anti-condensation coating is available for sale, 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 IR spectrum, polycarbonate will be the best. The best transparent materials for solar panels are materials with high light transmission.

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

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

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

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

Solar panel in plexiglass housing

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

Mounting the solar panel housing

The master class shows the manufacture of a solar panel from 36 polycrystalline solar cells measuring 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 dimensions 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 835x690 mm are made. In order to be able to fasten the hardware, holes should be made in the frame.
	Silicone sealant is applied twice to the inside of the corner.
	Make sure there are no empty spaces. The tightness and durability of the battery depends on the quality of the sealant application.
	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.
	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 along the perimeter.
	Hardware is fixed with screws.
	The screws are tightened tightly with a screwdriver.
	The frame of the solar battery is ready. Before fixing the solar cells, it is necessary to clean the glass from dust.

Selection and soldering of solar cells

At the moment, the Ebay auction presents a huge range of products for self-manufacturing solar panels.

Solar Cells kit includes a set of 36 polysilicon cells, cell conductors and busbars, Schottke diodes, and a soldering acid stick

Since a do-it-yourself solar battery is almost 4 times cheaper than a finished one, self-manufacturing is a significant cost savings. You can buy defective solar cells on eBay, but they do not lose their functionality, so the cost of a solar panel can be significantly reduced if you can further 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 commercially available. 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 element looks like without conductors.
	The conductors are cut using a cardboard blank.
	It is necessary to carefully place the conductor on the photocell.
	Apply soldering acid and solder to the place of soldering. For convenience, the conductor is fixed on one side with a heavy object.
	In this position, carefully solder the conductor to the photocell. During soldering, do not press on the crystal, because it is very fragile.

Soldering elements is quite painstaking work. If you cannot get a normal connection, then you need to repeat the work. According to the standards, the silver coating on the conductor must withstand 3 soldering cycles under permissible thermal conditions; in practice, you encounter the fact that the coating is destroyed. The destruction of silver plating 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 a non-adjustable soldering iron is too high for soldering silicon contacts.

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

Assembly and soldering of the solar battery

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

Marking substrate for solar cells

The base is made of plywood with corner markings. After soldering, a piece of mounting tape is attached to each element on the reverse side, it is enough to press the back panel against the adhesive tape, and all elements are transferred.

Mounting tape used for mounting, on the back of the solar cell

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

A sequential battery assembly plan looks like this:

	We lay out the elements on the glass surface. There must be a distance between the elements, which implies a free change in size without compromising the structure. Elements need to be pressed with weights.
	We solder according to the wiring diagram below. "Plus" current-carrying tracks are located on the front side of the elements, "minus" - on the reverse side. Before soldering, you need to apply flux and solder, then carefully 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 the "plus" and "minus". The bus uses a wider silver conductor, which is available in the Solar Cells kit. We also recommend that you bring out 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 elements without a derived midpoint looks like.
	This is what the terminal strip looks like with the “middle” point drawn out. The “middle” point allows you to put a shunt diode on each half of the battery, which will prevent the battery from discharging when the lighting decreases or one half is darkened.
	The photo shows a shunt diode on the "positive" output, it resists the discharge of batteries through the battery at night and the discharge of other batteries during partial blackout. More often, Schottke diodes are used as shunt diodes. They give less loss on the total power of the electrical circuit. An acoustic cable in silicone insulation can be used as current-carrying wires. For isolation, you can use tubes from under the dropper. All wires must be firmly fixed with silicone.
	The elements can be connected in series (see photo), and not through a common bus, then the 2nd and 4th row must be rotated 1800 relative to the 1st row.

The main problems of assembling a solar panel are related to the quality of soldering contacts, so experts suggest testing it before sealing the panel.

Panel testing before sealing, mains voltage 14 volts, peak power 65 W

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

Solar Panel Sealing

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

Sealant with a high degree of elasticity "Sylgard 184"

On the other hand, if you do not want to incur additional costs, it is quite possible to use silicone sealant. However, in this case, it is not necessary to 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.

	Before starting sealing, it is necessary to prepare a mixture of "Sylgard 184".
	First, the joints of the elements are poured. The mixture should set 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. After complete drying, you can close 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 scheme

Power supply systems for houses using solar panels are commonly called photovoltaic systems, that is, systems that provide energy generation using the photovoltaic effect. Three photovoltaic systems are considered for individual residential buildings: an autonomous power supply system, a hybrid battery-grid photovoltaic system, a batteryless photovoltaic system connected to a central power supply system.

Each of the systems has its own purpose and advantages, but most often in residential buildings, photovoltaic systems are used with backup batteries and connection to a centralized power grid. 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 fuel generators are used as a backup source of power supply.

A more economical alternative to a hybrid battery-grid power system would be a batteryless solar system connected to a central power grid. Electricity is supplied from solar panels, and at night the network is powered by the central network. Such a network is more applicable for institutions, because in residential buildings most of the energy is consumed in the evening.

Diagrams of three types of photovoltaic systems

Let's consider a typical installation of a battery-grid photovoltaic system. The 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 at peak load. Electricity is stored in backup batteries, 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.

Hybrid battery-grid photovoltaic system with alternating current

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

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 the production of about 5 kWh;
• batteries 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, input voltage 24-48 V;
• solar discharge controller 40-50 A at 24 V;
• uninterruptible power supply to provide a short-term charge with a current of up to 150 A.

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

Although the use of solar energy has become widespread today, the price of photovoltaic batteries remains at a high level. But they can be made by hand. In most cases, owners of private houses are interested in this. But some manage to supply even their apartment with self-made photo panels.

Solar battery device

Before you create a solar battery with your own hands, you should understand how it works. Batteries store electrical energy. The operation of the battery itself is based on the photoelectric effect. It occurs in solar cells, which "collect" the energy of the sun's rays. Such plates just act as the main part of the photobatteries. How is energy converted from solar to electrical?

1. The rays of the sun fall on one of the sides of the plate, which has a thin layer of boron or phosphorus.
2. Under their influence, many electrons are released. The phosphor film holds them, preventing them from flying apart.
3. The movement of electrons is ordered by the metal "tracks" that each plate is equipped with.
4. This is how an electric current is generated. It can be obtained the more, the more silicon cells are taken.

The first in the list of necessary materials are, of course, solar photovoltaic cells. Since it does not stand still, many different solar plates have already been developed.

• Film. Today they are produced only by technologically "advanced" companies, so they can only be "hunted". Such elements are found in ready-made photobatteries.
• Amorphous. These are photographic plates capable of collecting the sun's rays in any weather conditions: at sunset, in dusty air, in rain, etc. Amorphous elements are based on the thinnest layer of silicon deposited on a glass or polymer surface. To create a homemade solar battery with your own hands, such elements are rarely used due to the short service life and insufficient efficiency.
• From crystalline silicon. There are two types of photographic plates:
  • Monocrystalline. Consist of a single silicon crystal. The efficiency of such panels is higher due to the one-way direction. Such elements are more often used in regions with high solar activity. Such cells can be recognized by a uniform dark color and cut corners. Their efficiency is about 19%, and the service life reaches 50 years.
  • Polycrystalline. Many small crystals are combined into one element. The efficiency of this is reduced, but the panels can be used where the sun is not too active. The structure of a large number of crystals can be detected by a lighter shade of blue and an inhomogeneous pattern. Polycrystals are inferior to single crystals in service life (up to 25 years) and efficiency (up to 15%).

For the first time, it is better to make a solar battery with your own hands from cheaper polycrystalline plates. It is worth switching to single-crystals after the technology has been run-in. Inexpensive photographic plates are sold in foreign online stores. The most famous among them are EBay, Aliexpress and Amazon.

Today, some vendors offer discounted "B" grade photographic plates. They are cheaper due to the existing damage: various chips, missing corners, microcracks, etc. The performance of the cells does not suffer from this, but the price is significantly reduced. For "stuffing the hand" such elements are quite suitable.

Having decided to make a solar battery with your own hands from improvised means, you can replace photographic plates with semiconductors with p-n junctions. They often remain from old receivers and televisions. Semiconductors are also capable of generating current when exposed to solar radiation. For the manufacture of the panel, it remains only to connect several similar parts.

The catch here is the insufficient power of the devices received. With the most powerful transistors, it is possible to obtain a voltage of no more than 0.2 V from each. The current strength in them will be measured in microamps, and this is in the brightest sun. To achieve the same parameters that give silicon solar cells, you will need to find hundreds of semiconductors. But even in the best case, you can only charge an LED flashlight or a mobile phone.

An important step in the instructions on how to make a solar battery with your own hands is the calculation of its size. The voltage and current of the photocells are important here. For medium cells, these parameters are 0.5 V and 3 A, respectively. If 30 cells are connected to create a battery, then its power will be 30 0.5 V 3 A = 45 watts.

What else is needed to create a photo battery

Before starting work, check if everything from the list is at your fingertips:

• slats and plywood for the frame;
• silicone sealant;
• solder;
• antiseptic and paint for wood;
• stranded copper wire for connecting photocells;
• aluminum corners;
• anti-reflective glass, polycarbonate or plexiglass;
• Schottky diodes, designed for the return of one photographic plate.

You will also need a simple tool: a soldering iron, a saw, a glass cutter, a screwdriver, a paint brush - everything that any household owner has.

Instructions for creating a solar panel

When connecting solar cells, it is worth adhering to an aspect ratio of 1: 1. For example, if according to your calculations it turns out that you need to lay 120 plates, then you can arrange them in 12 rows of 10 pieces. Connect every two "columns" in parallel, and 5 received blocks - in series. So the wires will be laid neatly. Having decided on the location of the cells, you can begin to follow the instructions on how to assemble a solar battery with your own hands. It includes several main steps.

The body is made of wooden slats. Their height should not be more than 25 mm, otherwise the extreme rows of cells will be shaded. Aluminum corners are used to connect the rails. The dimensions of the body are determined by the dimensions of the photographic plates. For cells 3x6 inches (7.62x15.24 cm) when arranged in 12 rows of 10 pcs. a frame of at least 160x100 cm is required.

The reverse side is sewn up with plywood, and ventilation holes are drilled at the bottom of the frame. To protect the wood, it is coated with an antiseptic and then painted. Already on the finished frame of glass or plexiglass, a panel is cut out, which is fixed with the help of corner brackets.

To complete this task, you need a soldering iron with a power of up to 40 W and low-melting solder. A small amount of it is applied to the output parts of the plates. Be sure to observe the polarity of the connection. The distance between the photocells must be at least 5 mm to account for possible expansion. To increase the voltage, the elements are connected in series, and to increase the current - in parallel.

When the individual chains are assembled, they are placed with their back to the substrate and glued with a sealant. Each block of solar plates must be equipped with a Schottky diode, which prevents the batteries from discharging at night. According to the scheme presented above, all chains are connected using a copper wire or a special bus.

final assembly

Already finished substrates are placed in the body. Self-tapping screws are used for fastening. If there is a cross member in the frame, holes for the wires are drilled in it. The cable brought out is fixed and soldered to the terminals of the assembly. The glass is placed in the frame, having previously applied a layer of sealant to the upper contour of the frame.

Having studied how do-it-yourself solar panels are made at home, we can conclude that this requires at least minimal knowledge of electrical engineering. But having done everything as carefully as possible, you can hope for a successful completion of the task. You also need to be prepared, which requires financial and time costs. After practicing on the first panel, you can make more than one solar battery, thereby providing your home with free electricity.

In the modern world it is difficult to imagine existence without electrical energy. Lighting, heating, communications and other joys of a comfortable life directly depend on it. This forces us to look for alternative and independent sources, one of which is the sun. This area of ​​energy is not yet too developed, and industrial installations are not cheap. The output will be the manufacture of solar panels with their own hands.

What is a solar battery

The solar battery is a panel consisting of interconnected photocells. It directly converts solar energy into electrical current. Depending on the design of the system, electrical energy is accumulated or immediately goes to the energy supply of buildings, mechanisms and devices.

A solar battery is made up of interconnected photovoltaic cells.

Almost everyone used the simplest photocells. They are built into calculators, flashlights, batteries for recharging electronic gadgets, garden lanterns. But the use is not limited to this. There are solar-powered electric vehicles; in space, this is one of the main sources of energy.

In countries with a lot of sunny days, batteries are installed on rooftops and used for heating and hot water. This type is called collectors, they convert the energy of the sun into heat.

Often, the power supply of entire cities and towns occurs only due to this type of energy. Solar power plants are being built. They are especially popular in the USA, Japan and Germany.

Device

The device of the solar battery is based on the phenomenon of the photoelectric effect, discovered in the twentieth century by A. Einstein. It turned out that in some substances, under the action of sunlight or other substances, charged particles are detached. This discovery led in 1953 to the creation of the first solar module.

The material for the manufacture of elements are semiconductors - combined plates of two materials with different conductivity. Most often, polycrystalline or monocrystalline silicon with various additives is used for their manufacture.

Under the action of sunlight, an excess of electrons appears in one layer, and their deficiency in the other. "Extra" electrons go into the area with their lack, this process is called p-n transition.

The solar cell consists of two semiconductor layers with different conductivity

Between the materials that form an excess and a shortage of electrons, a barrier layer is placed that prevents the transition. This is necessary so that the current occurs only when there is a source of energy consumption.

Light photons hitting the surface knock out electrons and supply them with the necessary energy to overcome the barrier layer. Negative electrons pass from the p-conductor to the n-conductor, and positive electrons make the opposite path.

Due to the different conductivity of semiconductor materials, it is possible to create a directed movement of electrons. Thus, an electric current is generated.

The elements are connected in series with each other, forming a panel of a larger or smaller area, which is called a battery. Such batteries can be directly connected to the source of consumption. But since solar activity changes during the day, and stops altogether at night, batteries are used that accumulate energy during the absence of sunlight.

A necessary component in this case is the controller. It serves to control the charging of the battery and turns off the battery when fully charged.

The current generated by the solar battery is constant, to use it must be converted to alternating current. This is what an inverter is for.

Since all electrical devices that consume energy are designed for a certain voltage, a stabilizer is needed in the system to provide the desired values.

Additional devices are installed between the solar module and the consumer

Only if all these components are present, it is possible to obtain a functional system that supplies energy to consumers and does not threaten to disable them.

Types of elements for modules

There are three main types of solar panels: polycrystalline, monocrystalline and thin film. Most often, all three types are made from silicon with various additives. Cadmium telluride and copper-cadmium selenide are also used, especially for the production of film panels. These additives contribute to an increase in cell efficiency by 5-10%.

crystalline

The most popular are monocrystalline. They are made of single crystals, have a uniform structure. Such plates have the shape of a polygon or a rectangle with cut corners.

The single-crystal cell has the shape of a rectangle with beveled corners.

The battery, assembled from single-crystal elements, has a higher productivity compared to other types, its efficiency is 13%. It is light and compact, not afraid of slight bending, can be installed on uneven ground, service life of 30 years.

The disadvantages include a significant decrease in power during cloudiness, up to a complete cessation of energy generation. The same happens when it gets dark, the battery will not work at night.

The polycrystalline cell has a rectangular shape, which allows you to assemble the panel without gaps

Polycrystalline are produced by casting, have a rectangular or square shape and a heterogeneous structure. Their efficiency is lower than single-crystal ones, the efficiency is only 7-9%, but the drop in output in cloudy, dusty or at dusk is not significant.

Therefore, they are used in the construction of street lighting, but they are more often used by homemade ones. The cost of such plates is lower than single crystals, the service life is 20 years.

Film

Thin-film or flexible elements are made from an amorphous form of silicon. The flexibility of the panels makes them mobile, rolled up, you can take them with you on trips and have an independent power source anywhere. The same property allows you to mount them on curved surfaces.

The film battery is made of amorphous silicon

In terms of efficiency, film panels are twice as inferior to crystalline ones; to produce the same amount, a double battery area is required. And the film does not differ in durability - in the first 2 years, their efficiency drops by 20-40%.

But when cloudy or dark, energy production is reduced by only 10-15%. Their relative cheapness can be considered an undoubted advantage.

What can you make a solar panel at home

Despite all the advantages of commercially produced batteries, their main disadvantage is their high price. This trouble can be avoided by making the simplest panel with your own hands from improvised materials.

From diodes

A diode is a crystal in a plastic case that acts as a lens. It concentrates the sun's rays on the conductor, resulting in an electric current. By connecting a large number of diodes together, we get a solar battery. Cardboard can be used as a board.

The problem is that the power of the received energy is small, to generate a sufficient amount, a huge number of diodes will be needed. In terms of financial and labor costs, such a battery is much superior to the factory one, and in terms of power it is much inferior to it.

In addition, production drops sharply with a decrease in illumination. Yes, and the diodes themselves behave incorrectly - spontaneous glow often occurs. That is, the diodes themselves consume the generated energy. The conclusion suggests itself: inefficient.

From transistors

As in diodes, the main element of the transistor is a crystal. But it is enclosed in a metal case that does not let in sunlight. To make a battery, the case cover is sawn off with a hacksaw.

A low power battery can be assembled from transistors

Then the elements are attached to a plate of textolite or other material suitable for the role of the board, and connected to each other. In this way, you can assemble a battery, the energy of which is enough to operate a flashlight or radio, but you should not expect much power from such a device.

But as a camping source of energy of small power it is quite suitable. Especially if you are fascinated by the process of creation itself and the practical benefits of the result are not very important.

Craftsmen suggest using CDs and even copper plates as photocells. Portable phone charger is easy to make from photocells from garden lanterns.

The best solution would be to buy ready-made plates. Some online sites sell modules with a small manufacturing defect at an affordable price, they are quite suitable for use.

Rational placement of batteries

The placement of the modules largely determines how much power the system will produce. The more rays hit the photocells, the more energy they will produce. For an optimal location, the following conditions must be met:

Important! The current strength of a battery is determined by the performance of the weakest cell. Even a small shadow on one module can reduce system performance by 10 to 50%.

How to calculate the required power

Before proceeding with the assembly of the battery, it is necessary to determine the required power. The number of purchased cells and the total area of ​​​​finished batteries depend on this.

The system can be either autonomous (providing electricity to the house on its own) or combined, combining the energy of the sun and a traditional source.

The calculation consists of three steps:

1. Find out the total power consumption.
2. Determine the sufficient battery capacity and inverter capacity.
3. Calculate the required number of cells based on the insolation data in your area.

Power consumption

For an autonomous system, you can determine it by your electric meter. Divide the total amount of energy consumed per month by the number of days to get the average daily consumption.

If only a part of the devices will be powered from the battery, find out their power according to the passport or marking on the device. Multiply the resulting values ​​by the number of hours of work per day. Adding the obtained values ​​​​for all devices, get the average consumption per day.

AB (battery) capacity and inverter power

AB for solar systems must withstand a large number of discharge and discharge cycles, have low self-discharge, withstand high charging current, operate at high and low temperatures, while requiring minimal maintenance. These parameters are optimal for lead-acid batteries.

Another important indicator is capacity, the maximum charge that a battery can accept and store. Insufficient capacity is increased by connecting batteries in parallel, in series, or by combining both connections.

Calculation will help to find out the required number of ABs. Consider it for the concentration of energy reserves for 1 day in a battery with a capacity of 200 Ah and a voltage of 12 V.

Assume daily demand is 4800Vh, system output voltage is 24V. Assuming inverter loss is 20%, enter a correction factor of 1.2.

4800:24х1.2=240 Ah

The depth of discharge of AB should not exceed 30-40%, we will take this into account.

240х0.4= 600 Ah

The resulting value is three times the capacity of the battery, so 3 batteries connected in parallel will be required to supply the required amount. But at the same time, the battery voltage is 12 V, in order to double it, you will need 3 more batteries connected in series.

To obtain a voltage of 48 V, connect in parallel two parallel chains of 4 ABs

The inverter is used to convert direct current into alternating current. Choose it by peak, maximum load. On some consumer devices, the starting current is much higher than the nominal one. It is this indicator that is taken into account. In other cases, nominal values ​​are taken into account.

The form of tension also matters. The best option is a pure sine wave. For devices that are insensitive to voltage drops, a square shape is suitable. You should also consider the possibility of switching the device from AB directly to solar panels.

Required number of cells

Insolation indicators in different areas are very different. For a correct calculation, you need to know these numbers for your area, the data is easy to find on the Internet or at a weather station.

Monthly insolation table for different regions

Insolation depends not only on the time of year, but also on the angle of the battery

When calculating, be guided by the indicators of the least insolation during the year, otherwise the battery will not produce enough energy during this period.

Let's assume that the minimum indicators - in January, 0.69, the maximum - in July, 5.09.

Correction coefficient for winter time - 0.7, for summer time - 0.5.

Required amount of energy - 4800 Wh.

One panel has a power of 260 W and a voltage of 24 V.

Losses on AB and inverter are 20%.

We calculate consumption taking into account losses: 4800 × 1.2 = 5760 Wh = 5.76 kWh.

We determine the performance of one panel.

Summer: 0.5×260×5.09= 661.7 Wh.

Winter: 0.7×260×0.69=125.5 Wh.

We calculate the required number of batteries by dividing the energy consumed by the performance of the panels.

Summer: 5760/661.7=8.7 pcs.

In winter: 5760/125.5=45.8 pcs.

It turns out that for full provision, five times more modules will be needed in winter than in summer. Therefore, it is worth immediately installing more batteries or providing for a hybrid power supply system for the winter period.

How to assemble a solar battery with your own hands

The assembly consists of several stages: the manufacture of the case, the soldering of the elements, the assembly of the system and its installation. Before you get started, stock up on everything you need.

The battery is made up of several layers.

Materials and tools

• photocells;
• flat conductors;
• alcohol-rosin flux;
• soldering iron;
• aluminum profile;
• aluminum corners;
• hardware;
• silicone sealant;
• hacksaw for metal;
• screwdriver;
• glass, plexiglass or plexiglass;
• diodes;
• measuring instruments.

It is better to order photocells complete with conductors, they are specially designed for this purpose. Other conductors are more brittle, which can be a problem when soldering and assembling. There are cells with already soldered conductors. They cost more, but save a lot of time and labor.

Purchase plates with conductors, this will reduce the operating time

The body frame is usually made of an aluminum angle, but it is possible to use wooden slats or 2x2 square bars. This option is less preferred as it does not provide sufficient weather protection.

For a transparent panel, choose a material with a minimum refractive index of light. Any obstacle in the path of the rays increases the energy loss. It is desirable that the material transmits as little infrared radiation as possible.

Important! The more the panel heats up, the less power it generates.

Frame calculation

The dimensions of the frame are calculated based on the size of the cells. It is important to provide a small distance of 3-5 mm between adjacent elements and take into account the width of the frame so that it does not overlap the edges of the elements.

The cells are produced in various sizes, consider the option of 36 plates, 81x150 mm in size. We arrange the elements in 4 rows, 9 pieces in one. Based on these data, the dimensions of the frame are 835x690 mm.

Box manufacturing

Soldering elements and assembling modules

If the elements are purchased without contacts, they must first be soldered to each plate. To do this, cut the conductor into equal segments.

1. Cut out a rectangle of the desired size from cardboard and wind the conductor around it, then cut it on both sides.
2. Apply flux to each conductor, attach a strip to the element.
3. Carefully solder the conductor along the entire length of the cell.

   Solder the conductors to each plate

4. Lay the cells in a row one after another with a gap of 3-5 mm and sequentially solder together.

   During installation, periodically check the functionality of the modules

5. Transfer the finished rows of 9 cells into the body and align with each other and the outline of the frame.
6. Solder in parallel, using wider tires and observing the polarity.

   Lay rows of elements on a transparent substrate and solder together

7. Bring out the contacts "+" and "-".
8. Apply 4 drops of sealant to each element and lay the second glass on top.
9. Let the glue dry.
10. Fill around the perimeter with sealant so that moisture does not get inside.
11. Fasten the panel to the housing using the corners, screwing them into the sides of the aluminum profile.
12. Install a Schottke blocking diode with sealant to prevent battery discharge through the module.
13. Provide the output wire with a two-pin connector, then connect the controller to it.
14. Screw the corners to the frame to secure the battery to the support.

Video: soldering and assembling the solar module

The battery is ready, it remains to install it. For more efficient work, you can make a tracker.

Production of a rotary mechanism

The simplest rotary mechanism is easy to make yourself. The principle of its operation is based on a system of counterweights.

1. From wooden blocks or an aluminum profile, assemble a support for the battery in the form of a stepladder.
2. Using two bearings and a metal rod or pipe, mount the battery on top so that it is fixed in the center of the larger side.
3. Orient the structure from east to west and wait until the sun is at its zenith.
4. Rotate the panel so that the rays hit it vertically.
5. Fix a container of water at one end, balance it at the other end with a load.
6. Make a hole in the container so that the water flows out little by little.

As the water flows out, the weight of the vessel will decrease and the edge of the panel will rise up, turning the battery towards the sun. The size of the hole will have to be determined empirically.

The simplest solar tracker is made on the principle of a water clock

All you need is to pour water into a container in the morning. You can’t install such a structure on the roof, but for a garden plot or lawn in front of the house, it is quite suitable. There are other, more complex tracker designs, but they will cost more.

Video: how to make your own electronic solar tracker

Battery Installation

Now you can test and enjoy free electricity.

Module maintenance

Solar panels do not require special maintenance, because they have no moving parts. For their normal functioning, it is enough from time to time to clean the surface from dirt, dust and bird droppings.

Wash the batteries with a garden hose, with good water pressure, you don’t even need to climb onto the roof for this. Check the condition of the additional equipment.

How soon will the costs pay off

You should not expect momentary benefits from the solar power supply system. Its average payback is approximately 10 years for an autonomous system at home.

The more energy you consume, the faster your costs will pay off. After all, for both small and large consumption, the purchase of additional equipment is required: a battery, an inverter, a controller, and they leave a small part of the costs.

Consider also the life of the equipment, and the life of the panels themselves, so that you do not have to change them before they pay off.

Despite all the costs and disadvantages, solar energy is the future. The sun is a renewable energy source and will last at least another 5,000 years. Yes, and science does not stand still, new materials for photocells appear, with a much higher efficiency. So, soon they will be more affordable. But you can use the energy of the sun already now.

Solar energy is just great, but here's the problem: even one battery costs a lot of money, and for a good effect, you need more than one, or even two. That's why the idea comes - to collect everything yourself. If you have a little soldering skill, this is easy to do. The whole assembly consists in sequentially connecting the elements into tracks, and fixing the tracks on the body. Let's talk about the price right away. A set for one panel (36 pieces) costs around $70-80. And completely with all the materials, do-it-yourself solar panels will cost you about $ 120-150. Much smaller than factory ones. But I must say that in terms of power they will also be less. On average, each photoconverter produces 0.5 V, if you connect 36 pieces in series, it will be about 18 V.

A bit of theory: types of photovoltaic cells for solar panels

The biggest problem is to acquire photovoltaic converters. These are the same silicon wafers that convert sunlight into electricity. Here you need to understand a little about the types of photocells. They are produced in two types: polycrystalline and monocrystalline. Monocrystalline ones are more expensive, but have a higher efficiency - 20-25%, polycrystalline ones are cheaper, but they also have less productivity - 17-20%. How to distinguish them externally? Polycrystalline have a bright blue color. Monocrystalline ones are a little darker and they have a polyhedral rather than a square shape - a square with cut edges.

About the release form. There are photocells for solar panels with already soldered conductors, and there are kits where the conductors are attached and everything needs to be soldered by yourself. Everyone decides what to buy, but I must say that without the skill you will damage at least one plate, but rather not one. And if you don’t know how to solder very well ... then it’s better to pay a little more, but get the parts almost ready for use.

It is unrealistic to make photocells for solar panels with your own hands. To do this, you need to be able to grow silicon crystals, and then process it further. That's why you need to know where to buy. More on this later.

Where and how to buy solar cells

Now about quality. On all Chinese sites like Ebay or Alibaba, rejection is sold. Those parts that have not passed the tests at the factory. Because you will not get the perfect battery. But the price they have is not the highest, so you can put up with it. In any case, at first. Assemble a couple of test solar panels with your own hands, fill your hand, and then you can take it from the factory.

Some sell solar cells sealed in wax. This prevents them from spoiling during transit, but getting rid of the wax without damaging the plates is quite difficult. It is necessary to dip them all together in hot, but not boiling water. Wait until the wax melts, then carefully separate. Then alternately bathe each plate in a hot soapy solution, then dipping in clean hot water. Such “ablutions” may need several, water and soap solution will have to be changed, and more than once. After removing the wax, lay the clean plates on a terry towel to dry. This is a very troublesome business. So better buy without wax. So much easier.

Now about shopping on Chinese sites. Specifically about Ebay and Alibaba. They are checked, thousands of people buy something there every day. The system is no different. After registration, as usual, type the name of the element in the search bar. Then choose the offer you like for some reason. Be sure to choose from those options where there is free shipping (in English free shipping). If there is no such mark, then the delivery will have to be paid separately. And it is often more than the cost of the goods and certainly more than the difference that you gain on the price.

You need to focus not only on the price, but also on the seller's rating and reviews. Carefully read the composition of the product, its parameters and reviews. You can communicate with the seller, only you need to write messages in English.

About payment. It is transferred to the seller on these sites only after you unsubscribe in receiving the goods. In the meantime, the delivery is in progress, your money is on the account of the trading platform. You can pay with a card. If you are afraid to show card data, use intermediate services. They are different, but the essence is the same - your card will not light up. There are also return of goods on these sites, but this is a long song, so it’s better to take it from trusted sellers (with good ratings and reviews).

Yes. Shipping varies by region. And the point is not so much how long it will take to go from China, but how soon the mail will deliver it. At best, three weeks, but maybe a month and a half.

How to assemble

Assembling a solar battery with your own hands consists of three stages:

1. Frame manufacturing.
2. Soldering solar cells.
3. Framing and sealing.

The frame can be made from aluminum corners or from wooden slats. But the shape of the frame, materials, manufacturing sequence depend on the installation method.

Method one: window installation

The battery is hung on the window, on the frame from inside the room or outside, but also on the window. Then you need to make a frame from an aluminum corner, and glue glass or polycarbonate to it. In this case, at least small gaps remain between the photocells, through which a little light enters the room. Choose the size of the frame based on the size of your photocells and how you are going to arrange them. The dimensions of the window can also play a role. Please note that the plane must be flat - photovoltaic converters are very fragile, and will crack at the slightest misalignment.

Turning the finished frame with glued glass face down, apply a layer of sealant to the glass surface. On the sealant, again face down, lay out the rulers assembled from the photocells.

From thick elastic foam rubber (thickness not less than 4 cm) and a piece of polyethylene film (200 microns) make a mat: cover the foam rubber with a film and fasten it well. It is better to solder polyethylene, but you can also use tape, only all joints should be on one side. The second should be even and smooth. In terms of size, the mat should fit well into the frame (without bends and effort).

They laid the mat on photocells recessed in the sealant. On it is a board, which is slightly smaller in size than the frame, and on the board is a solid load. This simple device will help expel air bubbles that are under the photocells. Air reduces productivity, and very much. Because the fewer bubbles, the better. Leave the entire structure for 12 hours.

Now it's time to remove the load and peel off the mat. Do it slowly and slowly. It is important not to damage the soldering and conductors. Therefore, pull smoothly, without jerking. After the mat has been removed, the panel must be left to dry for a while. When the sealant stops sticking, you can hang the panel and use it.

Instead of a lengthy sealant procedure, you can take a special sealing film. It's called EVA. Just spread the film on top of the battery assembled and laid on the glass and heat it with a building hair dryer until it is completely sealed. The time is much less.

Method two: installation on the wall, roof, etc.

In this case, everything is different. The back wall must be dense and non-conductive. Perhaps - wooden, plywood, etc. Therefore, it makes sense to make a frame from wooden bars. Only the height of the body should be small so that the shadow from the sides does not interfere.

In the photo, the body consists of two halves, but this is not at all necessary. It's just easier to assemble and stack short rulers, but in this case there will be more connections. Yes. A few nuances: you need to provide several holes in the case. In the lower part, several pieces are needed to exit the condensate, as well as two holes for the output of conductors from the battery.

Then paint the battery case with white paint - silicon wafers have a fairly wide operating temperature range, but it is not unlimited: from -40 o C to +50 o C. And in the summer in a closed box +50 o C runs easily. Therefore, white is needed so that the photoconverters do not overheat. Overheating, like undercooling, leads to a decrease in efficiency. This, by the way, can be an explanation for an incomprehensible phenomenon: noon, the sun is hot, and the battery began to produce less electricity. And she just overheated. For the southern regions, you probably need to lay the foil. It will be more efficient. Moreover, the productivity is likely to increase: the radiation reflected by the foil will also be captured.

After the paint has dried, you can lay the assembled tracks. But this time face up. How to fasten them? On a drop of heat-resistant sealant in the middle of each plate. Why not apply over the entire surface? Due to thermal expansion, the plate will change dimensions. If you stick it only in the middle, nothing will happen to it. If there are at least two points, it will burst sooner or later. Therefore, carefully apply a drop in the middle, gently press the plate. Do not crush - it is very easy to crush.

In some cases, the plates were first attached to the base - a fiberboard sheet painted in the same white color. And then, on the basis, they were fixed to the body with screws.

After all the lines are laid, connect them in series. To prevent the conductors from hanging out, they can be fixed with a few drops of sealant. You can bring the wires from the elements through the bottom or through the side - whichever is more convenient. Pull them through the hole, and then fill the hole with the same sealant. Now you need to let all the joints dry. Covering the lid too early will cause deposits on the glass and photocells, which will greatly reduce battery efficiency. Therefore, we wait at least a day (or as much as indicated on the packaging of the sealant).

Now it's up to the small thing - to cover everything with glass or transparent plastic. How to attach is up to you. But at first, do not seal. At least until the test. There might be a problem somewhere.

And one more nuance. If you plan to connect batteries to the system, you will need to install a diode that will prevent the battery from discharging through the battery at night or in bad weather. It is best to put a Schottky diode. I connect it to the battery in series. It is better to install it inside the structure - at high temperatures, its voltage drop decreases, i.e. in working condition, it will “sit down” voltage less.

How to solder elements for a solar battery

A little about handling silicon wafers. They are very, very brittle and easily crack and break. Therefore, they must be handled with extreme caution, stored in a rigid container away from children.

You need to work on a flat hard surface. If the table is covered with oilcloth, put a sheet of something hard. The plate should not bend, but the entire surface should be rigidly supported by the base. Moreover, the base must be smooth. As experience shows, the ideal option is a piece of laminate. It is hard, smooth, smooth. Solder on the back side, not on the front.

For soldering, you can use flux or rosin, any of the compositions in the soldering marker. Here everyone has their own preferences. But it is desirable that the composition does not leave marks on the matrix.

Lay the silicon wafer face up (the face is the blue side). It has two or three tracks. You coat them with a flux or marker, an alcohol (not water-alcohol) solution of rosin. Photoconverters are usually supplied with a thin contact tape. Sometimes it is cut into pieces, sometimes it comes in a spool. If the tape is wound on a reel, you need to cut off a piece equal to twice the width of the solar cell, plus 1 cm.

Solder the cut piece onto the flux-treated strip. The tape turns out to be much longer than the plate, the entire remainder remains on one side. Try to lead the soldering iron without tearing it off. As much as possible. For better soldering, you should have a drop of solder or tin on the tip of the tip. Then the soldering will be of high quality. There should be no unsoldered places, warm everything up well. But don't push! Especially around the edges. These are very fragile items. Alternately solder the tapes to all tracks. Photoconverters are obtained "tailed".

Now, in fact, about how to assemble a solar battery with your own hands. Let's start assembling the line. There are also tracks on the back of the record. Now we solder the “tail” from the top plate to the bottom. The technology is the same: we coat the track with flux, then solder it. So in series we connect the required number of photoelectric converters.

In some variants, there are not tracks on the back side, but platforms. Then there are fewer solderings, but there may be more claims for quality. In this case, we coat only the sites with flux. And we also solder only on them. That's all. Assembled tracks can be transferred to the base or body. But there are many more tricks.

So, for example, a certain distance (4-5 mm) must be maintained between the photocells, which is not so easy without clamps. The slightest distortion, and it is possible to break the conductor, or break the plate. Therefore, to set a certain step, construction crosses are glued to a piece of laminate (used when laying tiles), or markings are made.

All the problems that arise in the manufacture of solar panels with their own hands are associated with soldering. Therefore, before sealing, and even better before transferring the ruler to the case, check the assembly with an ammeter. If everything is fine, you can continue to work.

Results

Now you know how to make a solar battery at home. It is not the most difficult task, but it requires hard work.

Mankind, in order to care for the environment and save money, began to use alternative energy sources, which, in particular, include solar panels. Buying such a pleasure will be quite expensive, but it is not difficult to make this device with your own hands. Therefore, it does not hurt you to learn how to make a solar battery yourself. This will be discussed in our article.

Solar panels are devices that generate electricity using photovoltaic cells.

Before talking about how to make a solar battery with your own hands, you need to understand the device and the principles of its operation. The solar battery includes photocells connected in series and in parallel, a battery that stores electricity, an inverter that converts direct current into alternating current, and a controller that monitors the charging and discharging of the battery.

As a rule, photocells are made of silicon, but its purification is expensive, so elements such as indium, copper, and selenium have recently begun to be used.

Each photocell is a separate cell that generates electricity. The cells are linked to each other and form a single field, the area of ​​which determines the power of the battery. That is, the more solar cells, the more electricity is generated.

In order to make a solar panel with your own hands at home, you need to understand the essence of such a phenomenon as the photoelectric effect. A photocell is a silicon plate, when light hits it, an electron is knocked out from the last energy level of silicon atoms. The movement of the flow of such electrons generates a direct current, which is subsequently converted into alternating current. This is the phenomenon of the photoelectric effect.

Advantages

Solar panels have the following advantages:

• harmlessness to the environment;
• durability;
• silent operation;
• ease of manufacture and installation;
• independence of electricity supply from the distribution network;
• immobility of parts of the device;
• insignificant financial costs;
• light weight;
• operation without mechanical transducers.

Varieties

Solar panels are divided into the following types.

Silicon

Silicon is the most popular battery material.

Silicon batteries are also divided into:

1. Monocrystalline: These batteries use very pure silicon.
2. Polycrystalline (cheaper than monocrystalline): Polycrystals are obtained by gradual cooling of silicon.

Film

Such batteries are divided into the following types:

1. Based on cadmium telluride (efficiency 10%): cadmium has a high light absorption coefficient, which makes it possible to use it in the production of batteries.
2. Based on copper selenide - indium: the efficiency is higher than that of the previous ones.
3. Polymer.

Solar batteries from polymers have begun to be manufactured relatively recently, usually furellenes, polyphenylene, etc. are used for this. Polymer films are very thin, about 100 nm. Despite the efficiency of 5%, polymer batteries have their advantages: cheap material, environmental friendliness, elasticity.

amorphous

The efficiency of amorphous batteries is 5%. Such panels are made of silane (silicon hydrogen) on the principle of film batteries, so they can be attributed to both silicon and film batteries. Amorphous batteries are elastic, generate electricity even in bad weather, absorb light better than other panels.

materials

To make a solar battery, you will need the following materials:

• photocells;
• aluminum corners;
• Schottky diodes;
• silicone sealants;
• conductors;
• fixing screws and hardware;
• polycarbonate sheet/plexiglass;
• soldering equipment.

These materials are required in order to make a solar battery with your own hands.

Choice of photocells

To make a solar battery for your home with your own hands, you should choose the right solar cells. The latter are subdivided into monocrystalline, polycrystalline and amorphous.

The efficiency of the first is 13%, but such photocells are ineffective in bad weather, outwardly they are bright blue squares. Polycrystalline solar cells are capable of generating electricity even in bad weather, although their efficiency is only 9%, they are darker in appearance than monocrystalline ones and cut off at the edges. Amorphous photocells are made of flexible silicon, their efficiency is 10%, their performance does not depend on weather conditions, but the production of such cells is too expensive, so they are rarely used.

If you plan to use the electricity generated by photovoltaic cells in the country, then we advise you to assemble a solar battery with your own hands from polycrystalline cells, since their efficiency is sufficient for your purposes.

You should buy photocells of the same brand, since photocells of several brands can vary greatly - this can cause problems with battery assembly and its functioning. It should be remembered that the amount of energy produced by a cell is directly proportional to its size, that is, the larger the photocell, the more electricity it produces; cell voltage depends on its type, and not on size.

The amount of current produced is determined by the dimensions of the smallest photocell, so you should buy photocells of the same size. Of course, you should not buy cheap products, because this means that they have not passed the test. Also, you should not buy photocells coated with wax (many manufacturers cover photocells with wax to preserve products during transportation): removing it can damage the photocell.

Calculations and project

Building a solar panel with your own hands is a simple task, the main thing is to approach its implementation responsibly. To make a solar panel with your own hands, you should calculate the daily electricity consumption, then find out the average daily solar time in your area and calculate the required power. Thus, it will become clear how many cells and what size you need to purchase. After all, as mentioned above, the current generated by the cell depends on its dimensions.

Knowing the required size of the cells and their number, it is necessary to calculate the dimensions and weight of the panel, after which it is necessary to find out whether the roof or other place where the solar battery is planned to be installed will withstand the intended design.

When installing the panel, you should not only choose the sunniest place, but also try to fix it at a right angle to the sun's rays.

Stages of work

Frame

Before you start making a solar panel with your own hands, you need to build a frame for it. It protects the battery from damage, moisture and dust.

The body is assembled from a moisture-resistant material: plywood coated with a moisture-repellent agent, or aluminum corners, to which plexiglass or polycarbonate is glued with silicone sealant.

In this case, it is necessary to observe the indents between the elements (3-4 mm), since it is necessary to take into account the expansion of the material with increasing temperature.

Soldering elements

The photocells are laid out on the front side of the transparent surface, so that the distance between them on all sides is 5 mm: in this way, the possible expansion of the photocells with increasing temperature is taken into account.

Converters having two poles are fixed: positive and negative. If you want to increase the voltage, connect the elements in series, if the current - in parallel.

To avoid discharging the battery at night, a Schottky diode is included in a single circuit consisting of all the necessary parts, connecting it to the positive conductor. Then all the elements are soldered together.

Assembly

Soldered transducers are placed in the finished frame, silicone is applied to the photocells - all this is covered with a layer of fiberboard, closed with a lid, and the joints of the parts are treated with sealant.

Even a city dweller can make and place a solar battery on the balcony with their own hands. It is desirable that the balcony be glazed and insulated.
So we figured out how to make a solar battery at home, it turned out that it was not difficult at all.

Ideas from improvised materials

You can make a solar battery with your own hands from improvised materials. Consider the most popular options.

Many will be surprised to learn that foil can be used to make a solar battery with your own hands. In fact, this is not surprising, because the foil increases the reflectivity of materials. For example, to reduce overheating of the panels, they are placed on foil.

How to make a foil solar panel?

We will need:

• 2 "crocodiles";
• copper foil;
• multimeter;
• salt;
• empty plastic bottle without a neck;
• electric oven;
• drill.

After cleaning the copper sheet and washing our hands, we cut off a piece of foil, put it on a hot electric stove, heat it for half an hour, observing blackening, then remove the foil from the stove, let it cool and see how the pieces peel off from the sheet. After heating, the oxide film disappears, so the black oxide can be gently removed with water.

Then a second piece of foil is cut out the same size as the first, the two parts are bent, lowered into the bottle so that they do not have the opportunity to touch.

Foil can also be used for heating. To do this, it must be pulled onto the frame, to which you then need to connect hoses connected, for example, to a watering can.

So we learned how to make a solar panel for the home from foil.

Many houses have old transistors lying around, but not everyone knows that they are quite suitable for making a solar battery for a summer cottage with their own hands. In this case, the photocell is a semiconductor wafer located inside the transistor. How to make a solar battery from transistors with your own hands? First you need to open the transistor, for which it is enough to cut off the cover, so we can see the plate: it is small in size, which explains the low efficiency of solar panels from transistors.

Next, you need to check the transistor. To do this, we use a multimeter: we connect the device to a transistor with a well-lit p-n junction and measure the current, the multimeter should record the current from a few fractions of a milliamp to 1 or a little more; then we switch the device to the voltage measurement mode, the multimeter should give out tenths of a volt.

We place the tested transistors inside the case, for example, sheet plastic and solder it. You can make such a solar battery with your own hands at home and use it to charge batteries and low power radios.

Old diodes are also suitable for assembling batteries. Making a solar battery with your own hands from diodes is not difficult at all. It is necessary to open the diode, exposing the crystal, which is a photocell, then heat the diode for 20 seconds on a gas stove, and when the solder melts, remove the crystal. It remains to solder the pulled out crystals to the case.

The power of such batteries is small, but it is enough to power small LEDs.

This option of making a solar battery with your own hands from improvised means will seem very strange to most, but making a solar battery with your own hands from beer cans is simple and cheap.

We will make the case from plywood, on which we will place polycarbonate or plexiglass, on the back surface of the plywood we will fix foam or glass wool for insulation. Aluminum cans will serve as photocells. It is important to choose exactly aluminum cans, since aluminum is less susceptible to corrosion than, for example, iron and has better heat transfer.

Further, holes are made in the bottom of the cans, the lid is cut off, and unnecessary elements are bent to ensure better air circulation. Then it is necessary to clean the jars of grease and dirt with the help of special products that do not contain acids. Next, you need to hermetically fasten the cans together: with silicone gel that can withstand high temperatures, or with a soldering iron. Be sure to dry the glued cans very well in a stationary position.

Having attached the cans to the body, we paint them black and close the structure with plexiglass or polycarbonate. Such a battery is capable of heating water or air with subsequent supply to the room.

We looked at options for how to make a solar panel with your own hands. We hope that now you will not have a question about how to make a solar battery.

Video

How to make solar panels with your own hands - video tutorial.