How to assemble a solar power plant. Do-it-yourself solar power plant. Homemade solar power plant with hands, roof installation feature

Every year, solar energy is becoming more and more popular, which is explained by the decreasing cost of the panels used, as well as the increasing efficiency of this technology. A solar station installed on a dacha or the roof of a private house will have an affordable price, and the generated electricity will be enough to meet all the energy needs of the homeowner.

Description of technology

Solar cells are semiconductor devices capable of converting radiation from the sun into electrical energy. The main task of such a station is an uninterrupted, economical and reliable power supply to the home. Such devices can be installed not only in areas where there are problems with the power supply, but also simply to reduce the homeowner’s utility bills.

If in the past the efficiency of solar panels left much to be desired, and it was possible to provide electricity to a house only by allocating an area of ​​several hundred square meters for the installation of batteries, today, with the development of technology, even several receiver units will be enough to generate the required amount of electricity.

Advantages of solar panels:

By choosing the right system, it will be possible to provide the house with electricity, and heating in winter will be powered by an electric boiler, which completely eliminates the need to connect to gas or install solid fuel equipment.

However, this technology still has disadvantages. These include the following:

• At night, electricity production stops.
• The devices are sensitive to surface contamination.
• Occupy part or all of the roof.
• High cost of battery and battery.
• Efficiency depends on climatic conditions.

In recent years, the latest generation of solar panels, which combine affordable cost and efficiency, have become popular. They are able to generate electricity even under snow and on a cloudy day. Every year, the cost of such stations for domestic use invariably decreases, their efficiency increases, which affects the popularity of solar energy among ordinary homeowners.

How the device works

The principle of operation of the station is extremely simple. The photovoltaic converters used, which consist of several silicon wafers, are distinguished by their conductivity and can generate electricity due to the influence of light on them. Sunlight hits the negatively charged panels, a potential difference appears between the two outer plates, which are coated with boron and phosphorus, which leads to the generation of voltage, which is transmitted to the converters and then sent to the home's electrical network.

The latest generation batteries are characterized by an increased size of the photoconverter, which allows them to generate the maximum possible amount of electricity with a small area of ​​the receiver itself. The insolation level of such systems will be consistently high, which guarantees the longest possible service life and excellent efficiency even in low light conditions.

Types of batteries

All performance characteristics, including installation method, power, efficiency and ability to generate electricity under snow and on cloudy days, will directly depend on the type of batteries. Today, three main types of solar stations have become widespread:

• Amorphous.
• Monocrystalline.
• Polycrystalline.

Solar systems built on polycrystalline batteries have a low efficiency of 18%, but such panels are capable of generating electricity even in cloudy weather. The batteries have a characteristic dark blue color and a heterogeneous structure of silicon crystals. Polycrystalline solar cells are very popular in regions with rainy and cloudy climates.

Monocrystalline converters are distinguished by the characteristic black color of the panels, which is explained by the use of pure silicon for their production. Such batteries have the highest efficiency rate to date, which is 25%. The disadvantage of this technology is that electricity generation is only possible when the panels are facing the sun. But in cloudy weather, the efficiency of electricity generation decreases significantly.

Amorphous batteries were popular in the past, but the technology is largely unused today. This is explained by the fact that the efficiency of such batteries is 15-20%, and literally a year and a half later there is a significant deterioration in electricity generation. The maximum service life of amorphous stations is 2 years. Despite the affordable cost, it is recommended to refrain from purchasing amorphous solar panels, which will soon require new financial investments and significant costs for the homeowner.

All solar panels used today are equipped with controllers, the main purpose of which is to redistribute the received energy and direct it to the source of use. Advanced installations can be additionally equipped with a battery that stores the generated electricity. Subsequently, in the dark, when generation tends to zero, the battery is responsible for uninterrupted power supply to the house.

Solar energy for private homes

Just a few years ago, the possibility of a completely autonomous power supply to a home using solar panels seemed like something out of science fiction to us. However, today technology does not stand still, the efficiency of electricity generation is constantly increasing, the cost of equipment is decreasing, which allows many homeowners to completely solve problems with the energy supply of private homes with the help of such batteries.

Solar stations are very popular in Western European countries, where the cost of a kilowatt-hour of energy consumed is extremely high. Therefore, many homeowners, in order to save money, install solar panels on the roof of their private house, which completely cover their electricity needs.

Many of us find it difficult to understand how much power a solar power plant needs to use and how much it will cost to install such equipment. When performing calculations, it is necessary to proceed primarily from the general indicators of electricity consumption in a private home. So, for a country house where only a few electrical appliances are used, a small refrigerator and a TV are running, a solar battery with a power of 250 W will be sufficient. But to create a full-fledged station, a panel power of 1000 W or more is required.

The cost of the equipment used will directly depend on the number of panels, their total capacity, the controller used and the presence or absence of a battery. It is the battery that is the most expensive element of the entire solar station, while such devices often fail, have a short service life and require replacement every 3-4 years.

In Western countries, where the ability of a homeowner to sell electricity to the state is enshrined at the legislative level, the homeowner can discharge electricity into the general network, and subsequently take it back at the same preferential price from the general network; accordingly, the use of batteries is not required. This allows you to significantly reduce the overall cost of installing a completely autonomous power generation station in a private home, which covers all the energy needs of the homeowner.

In Russia, it is also theoretically possible to sell electricity generated by a solar panel to the public grid, but the cost at which the state purchases electricity is not too high. In the future, we will be forced to take the voltage we need from the general power grid at a price several times higher than the cost at which the state buys it from us. Accordingly, to solve this problem it is still necessary to install batteries that will store the generated energy.

The simplest installations of solar stations, which have batteries and a controller intended for power supply to country houses, will cost about 60-80 thousand rubles. But to provide electricity to a private house with an area of ​​200-300 square meters, where people live all year round, a station power of a thousand watts or more will be required. Such a system is necessarily equipped with a battery, which leads to a significant increase in the cost of the equipment. On average, purchasing a high-quality solar station built on reliable components will cost 400-600 thousand rubles or more.

Does the investment pay off?

Many of us wonder whether the costs of installing a solar station in a country house or private home are worth it. Modern installations, which are built on the latest generation batteries, make it possible to generate electricity at minimal cost, while they are durable and can pay for themselves in 5-6 years of active use.

If it is necessary to use solar stations with a battery, the cost of such equipment increases significantly; accordingly, the payback period for investments can reach 12-15 years. During the operation of the equipment, it will invariably be necessary to replace batteries and maintain panels, which will be the key to trouble-free and long-lasting operation of the equipment.

Today you can find solar panels and all the necessary equipment for them on sale from Western European and Chinese manufacturers. In recent years, Chinese companies have significantly improved their quality, while traditionally the cost of such stations is at an affordable level. By purchasing batteries from Chinese manufacturers, you can not only reduce your costs, but also subsequently solve problems with the energy supply of your home, ensuring complete autonomy and no need to connect your home to various utilities.

Solar power plant for home is a promising technology, which is already very popular among summer residents and owners of private houses. By installing a solar station on the roof of your house, you can completely solve energy supply problems, and the cost of such equipment will not be too high. You just need to choose the right power of the panels, install them correctly, connecting them to the network via a controller and an appropriate battery.

I decided to present to your attention an article about how to do solar power plant with your own hands.

The design differs from similar power plants improved electronic filling:

• batteries have a large capacity;
• efficient charge controller;
• improved electrical safety;
• more exits;
• Digital displays show the amount of electricity consumed and generated.

If you want to make a power plant or are simply interested in the structure of this device, then this article will be of interest to you.

Step 1: What is needed to build such a system

The first thing you need to do when starting to plan a project is decide, which power you want to receive from the system. It would be great to provide electricity to the entire house, but then this system would be expensive and lose its mobility. My power plant can only power a small LCD TV, a couple of 12W energy saving light bulbs, a digital receiver, a CD player and a radio. It is also possible to charge mobile phones and other low-power devices.

It is very important to determine the prices of the components that will be used in the project. I wanted to do everything the best, so I chose the PS-30M 30 Amp Morningstar Charge controller.

This charge controller uses a pulse width modulator to smoothly charge the battery once the system is fully charged.

For the battery pack was purchased two Trojan T-105, in one 6 V, and the total voltage 12 V And 225 Ah. The battery capacity is huge and sufficient to power a large number of electrical appliances.

The importance of choosing the main elements of the system lies in the fact that their parameters are necessary to calculate the amount of generated energy. The LCD TV and receiver consume 2.2A DC at 12V, the energy efficient lighting consumes only 1A for a 12W bulb. While the phone/GPS consumes much less energy during charging.

Using the TV for 3 hours a day, it will consume 6.6 Ah. Lighting for 4-5 hours consumes up to 4 Ah, while charging portable devices will consume 2 Ah. The total value will be 12.6 Ah. The deep cycle battery charge should not drop below 50% from full capacity. To extend battery life, operation should use a shorter discharge cycle. Therefore, a 30Ah battery will be sufficient.

In my region, sunlight falls on the earth during 6 hours. Therefore, to restore the battery charge, 50 W from solar panels and approximately 5 hours of solar activity will be required.

Using the power formula W = V*A, let's calculate the average current from the solar panel at a maximum power of 50 W/17 V = 2.94 A

In order to charge the batteries when using solar panels, you need to spend 13 Ah / 2.94 A = 4.76 hours of direct sunlight.

In the real world things will be different:

• The panels are covered with protective coatings;
• Overcast weather;
• Battery temperature;
• Wire cross-section;
• Wiring length;
• Other losses.

Therefore, it is more efficient to use a battery with a high capacitive charge. In this case, such a system can be used several times, without consequences for its elements, if the weather conditions the next day are not suitable for efficient charging using solar panels. 225 Ah is more than enough, but it’s better to have more than you need.

Step 2: Planning the project

The next step is to plan what the project will look like. By experimenting with installation design options, various designs were developed. Microsoft Word was used for design. This will help you understand the placement of components and will highlight aspects of the design that will not be functional.

Two were purchased Turnigy wattmeter, which are most often used in aircraft modeling. These intelligent meters show voltage, current, watt-hours, amp-hours, minimum voltage, and maximum current draw, ideal for use in a solar panel system. Using one device it will be possible to control how many watts of energy and how many ampere-hours per day the solar panels produce, and the other - how many watts are used and how much capacitive charge is left in the batteries.

After various options for the layout of elements that are mounted in separate compartments, external and internal batteries, wide and narrow installations, an option was adopted with an inclined dashboard, a vertically mounted charge controller and a separate battery pack for ease of transportation.

Step 3: Making the battery case

The first step is to create an external battery pack. Used for construction 12 mm chipboard, the total weight of the structure including batteries was 56 kg. Rollers and handles are installed to move the unit.

Having the dimensions of the installation, we will draw out a large sheet of chipboard. Then we cut out the elements of the cabinets and assemble them, as shown in the images.

Step 4: Main Unit

Once the battery pack was assembled, it was time to build the main part. We repeat the procedure: mark a large sheet of chipboard by size. Cut everything out using wood saw.

This is the easiest way to cut long straight lines. This breaks a large piece of chipboard into smaller pieces that are easy to manage. After using a wood saw, you must use sandpaper for removing burrs.

Instead of a saw, you can use jigsaw, the work will go faster and easier with it, but the lines from the jigsaw may not be as smooth.

After all panel elements are cut out, it is necessary to check the compliance of the sizes and shapes with the developed plan model. We use bars for the frame of the device 20*20 mm, to connect them we will use 30 mm screws.

After completing the main structure, we proceed to the installation of electronic components. First we install the connectors on the front panel, as they are easier to install. The connection includes two sockets for plugs and three for car charging, which are most suitable for powering devices directly from 12 V.

The following is what we connect:

• Switches;
• Radio;
• Charge controllers;
• Counters.

The meters supplied by Turnigy are housed in a plastic housing that is easily removed by removing four small screws. LCD meter displays are soldered directly to the board, which means there is no need to fuss with soldering a cable from the display to the pads on the chip.

For protective displays of meters we will use 3 mm plexiglass. To cut it you can use knife or saw By metal. The safety glass frames are mounted on the front panel and secured using hot hot melt glue.

The project uses chrome-plated metal switches with two operating positions. Colorful LED rings illuminate the 12V charging sockets.

The charge controller is simply bolted to the back panel. The most expensive element of the project are the batteries, so they require special care.

The rear of the unit provides a host of ports, eight radio inputs/outputs including four speaker outputs, two preamp outputs, one microphone input and one subwoofer output.

In this article I want to tell you how you can independently assemble a small autonomous power plant using solar panels, what you will need for this, and why you chose certain components of the power plant. Let’s say we need to install electricity in (a country house, a security trailer, a garage, etc.), but the budget is limited, and we want to get at least something for a minimum of money. And at a minimum, we need light, power and charging for small electronics, and sometimes we also want, for example, to use power tools.

Solar power plant

Photo of solar panels on the roof of the house, two panels of 100 watts each

For this, at a minimum, we will need solar panels of 200-300 watts, of course, 100 watts in total, and even less if you need very little energy. But it’s better to take it with a reserve, and you can immediately decide what voltage to build the system for. For example, if you want to power everything from a voltage of 12 volts, then it is better to buy 12 volt panels, and if everything is powered through an inverter, then the system can cost 24/48 volts. For example, two panels of 100 watts each, which can provide 700-800 watts of energy per daylight hours. When there is sun here and there is a lot of energy from one panel, but it is better to take 2-3 pieces at once so that in cloudy weather and in winter there will also be energy, since in cloudy weather the production drops 5-20 times and the more panels the more better.

There are a lot of electronics and various chargers for 12 volts, most of our cars have a 12v on-board network and for this voltage there is almost everything, and it is available. For example, LED strips operate from 12v, which are well suited for lighting; there are 12v LED bulbs in any store. Also, for charging phones and tablets, there are car adapters that turn 12/24v into 5v. Such adapters have either one or two or more USB outputs, or with a wire for a specific phone or tablet model; in general, there are no problems charging electronics from 12 volts.

If you need to power a laptop from 12 volts, then for this there are also car charging adapters that turn 12v into 19v. In general, almost everything can be powered by twelve volts, even boilers, refrigerators and electric kettles. There are also 12-volt TVs, which are 15-19 inches diagonal and are usually placed in the kitchen. But of course, if the power of solar panels is small and the capacity of the batteries is also small, then you can’t count on constantly using powerful consumers, except perhaps in the summer. photo consumers for 12v

12v devices and adapters

For example, some types of converters operating on 12 volts, and some devices operating on 12 volts, such as a kettle, boiler, refrigerator. 12 volt lighting

If you do everything at 12v, then there is an advantage in saving electricity, since a 12/220 volt inverter also has an efficiency of about 85-90%, and cheap inverters consume 0.2-0.5 A at idle, which is 3 -6 watt/hour, or 70-150 watts per day. Agree that you don’t want to waste 70-150 watts of energy per day just like that, for example, this is enough for an LED light bulb to shine for an additional few hours, the TV to work for 5-7 hours, you can charge your phone twenty times with this energy. Plus, when working on an inverter, 10-15% of energy is lost, and as a result, the total amount of energy lost on the inverter is significant. And this is especially not rational when we turn 12 volts into 220 volts, and then plug in a 12 volt or 5 volt power supply into the outlet. In this case, the efficiency of the entire system is very low because a lot of energy is spent on the converters.

The only inconvenience is that there are few power tools with 12 volts, and it is not widespread; it is also difficult to find refrigerators, pumps, etc. on sale. Therefore, if you need to power something else from your battery besides any small electronics, then without an inverter 12/220 volts is not enough. And here you need to take into account that the inverter itself has efficiency, and some devices are not particularly economical. All this entails the need to increase the capacity of batteries and the power of solar panels in proportion to consumption.

There seem to be two options: either optimize everything to a low voltage of 12 volts, or then immediately transfer everything to 220 volts. Well, you can also just install an inverter and use it when needed, and power everything that works constantly (lights, TV, chargers) from 12 volts. In this case, even a cheap inverter with a modified sine wave may be suitable.

Pumps and refrigerators often refuse to work through inverters with a modified sine wave, since the frequency and voltage form are not suitable for demanding equipment. But any 220-volt light bulbs, power tools (drills, grinders, etc.), and electronics with switching power supplies (modern TVs and other electronics) work normally through such inverters. In general, to ensure that there are no problems, it is better to immediately take an inverter with a pure sine wave at the output, otherwise if something fails due to the inverter, then the loss will be greater than the savings.

Battery charge controller, inverters

Despite the fact that, for example, we have a small power of solar panels, it is better to take a controller with a double power reserve, especially if you buy a cheap controller. Failure of the controller can lead to many more problems; it can damage the batteries, or charge them incorrectly, causing them to quickly lose capacity. Also, if the controller supplies all the voltage from the joint venture to the network, then the electronics powered by 12V may deteriorate, since the joint venture supplies up to 20 volts at idle. More about controllers - Controllers for solar panels

By the way, if you power everything through an inverter, then the system can be built not only at 12 volts, but also, for example, at 24 or 48 volts. The main difference is that the thickness of the wires required is much less since the current through the wires will be less. For example, if we have a 12-volt system, then the charging current through the wires will reach up to 12 Amps, and if through an MPPT controller, then up to 18A. And so that the wires do not heat up and there are no losses, the cross-section of the wire should be thick, and the further the solar panels are from the batteries, the thicker the wire should be.

So, for example, for a current of 6 Amps, the wire cross-section should be 4-6 kV. and if we have a current of 12A, then we already need a 10-12 kW wire. And if we have 50 Amperes, then the wires must be thicker than welding wires (50 sq.) so that they do not heat up and there are no losses. So, in order to save on thickness and not waste energy, the system is built on 24v 48v. In the case of 48 volts, the thickness of the wire can be reduced by four times and this will save a lot. And there are inverters for both 24v and 48v. There are also controllers, I think you understand, the main point is savings in wires and less loss in transmitting electricity from solar panels to batteries.

There are two types of controllers, MPPT and PWM controllers. The first type can squeeze up to 98% of power from solar panels, but is more expensive. But PWM controllers are simple and charge with the current that is available, that is, with them the power from solar panels is only 60-70%. The MPPT controller works better in bright sunshine and makes a lower 14V and more current from the high voltage of the SP. And ordinary PWM cannot convert, but in cloudy weather, when the current from the panels is very small, such controllers provide a little more energy to the batteries.

I don’t think it’s possible to clearly define which controller to buy here, some people need to take all the energy from the sun, while others, when the sun is shining, already have plenty of energy, but in cloudy weather they want at least a little more, but more. In principle, if you buy another solar panel instead of the expensive MPPT, then the advantage of the MPPT will be compensated, and plus there will be more benefit in cloudy weather. I personally am more inclined towards conventional controllers, since when there is sun there is nowhere to put the energy, and when there is no sun, then an extra solar panel will help a lot. For example, three panels of 100 watts each will give 18A with a conventional controller, and with MPPT they will give 27A. But when the weather is cloudy, then three panels via MPPT will give, for example, 3A, and with a conventional controller it will already be about 3.6A, and if you buy a fourth panel instead of MPPT, then 4.8A.

I’m giving all this as an example, the difference of course for a sunny day is 18 and 27 A is big, but if even at 18 A the batteries are still charged during the day, then why more power, anyway, when the controller is charged, it will turn off the panels and they will just be illuminated the sun. But when there is no sun, you are happy with the extra ampere, which is why more panels are better than an expensive controller.

About batteries for autonomous systems

Batteries are probably the most expensive and important part of the system, they are very capricious and quickly deteriorate, there are many types of them and they need to be treated with care, otherwise they quickly lose capacity and deteriorate. That’s why you need to buy a smart controller so that it can be configured for different types, or it should already have pre-installed settings for working with different types of batteries.

For example, car starter batteries lose capacity very quickly in autonomous systems, just 1-2 years and they already lose 90% of capacity. This is due to deep discharges, since cheap controllers turn off consumers at 10 volts, and car batteries are not designed for this, so if you use them, do not discharge them more than 110.8-12.0 volts.

Alkaline batteries are very durable, but also very expensive. And if lead batteries have an efficiency of 85-90%, then alkaline batteries are a little inferior here, and if they are operated by charging and discharging with high currents, then their efficiency noticeably deteriorates. Such batteries are not profitable, especially in winter, since there is already little energy coming in, and even the batteries give out 30% less energy than they receive from solar panels. Although now it seems that alkaline batteries with improved efficiency have appeared, the overall picture is the same.

Lithium iron phosphate batteries are the most promising for autonomous systems; they have a high efficiency of 95-98%, and at the same time are not at all afraid of undercharging, deep discharges, and high discharge-charge currents. But they are also expensive and require an additional BMS cell condition monitoring system. If such a battery is charged or discharged below the required level, it irreversibly loses capacity or the cell stops working altogether. But the condition of the battery is monitored by the BMS and it also balances the battery charge, so if something goes wrong, it will protect the battery and turn everything off, and it will not deteriorate.

You can’t describe everything in one article, but I tried to mention and describe the main things so that it would be clear to those who are not at all familiar with this. You can read more in other articles from the section. But in general, at the moment, judging by my experience, it is more profitable to build a small power plant without an inverter and power all electronics from 12 volts, and if everything is transferred to 220 volts, then build a system at 48 volts. Especially in winter, even a little extra energy is very necessary. Also, this winter I have lithium iron phosphate (lifepo4) batteries, and obviously the energy in general is noticeably greater than when using car batteries, plus lifepo4 have not deteriorated at all and there is no loss of capacity, although they have not been charged for a whole month before end and were constantly discharged until shutdown.

For decades now, humanity has been searching for alternative energy sources that can at least partially replace existing ones. And the most promising of all today seem to be two: wind and solar energy.

True, neither one nor the other can provide continuous production. This is due to the variability of the wind rose and daily-weather-seasonal fluctuations in the intensity of the solar flux.

Today's energy industry offers three main methods of generating electrical energy, but all of them are harmful to the environment in one way or another:

• Fuel electric power industry- the most environmentally polluting, accompanied by significant emissions of carbon dioxide, soot and useless heat into the atmosphere, causing a reduction in the ozone layer. The extraction of fuel resources for it also causes significant harm to the environment.
• Hydropower is associated with very significant landscape changes, flooding of useful lands, and causes damage to fisheries resources.
• Nuclear power- the most environmentally friendly of the three, but requires very significant costs to maintain safety. Any accident may be associated with causing irreparable, long-term harm to nature. In addition, it requires special measures for the disposal of used fuel waste.

Strictly speaking, there are several ways to obtain electricity from solar radiation, but most of them use its intermediate conversion into mechanical power, rotating the generator shaft, and only then into electrical power.

Such power plants exist, they use Stirling external combustion engines, they have good efficiency, but they also have a significant drawback: in order to collect as much solar radiation energy as possible, it is necessary to manufacture huge parabolic mirrors with systems for tracking the position of the sun.

It must be said that there are solutions to improve the situation, but they are all quite expensive.

There are methods that make it possible to directly convert light energy into electric current. And although the phenomenon of the photoelectric effect in the semiconductor selenium was discovered already in 1876, it was only in 1953, with the invention of the silicon photocell, that the real possibility of creating solar cells for generating electricity arose.

At this time, a theory was already emerging that made it possible to explain the properties of semiconductors and create a practical technology for their industrial production. To date, this has resulted in a real semiconductor revolution.

The operation of a solar battery is based on the photoelectric effect of a semiconductor p-n junction, which is essentially an ordinary silicon diode. When illuminated, a photovoltage of 0.5~0.55 V appears at its terminals.

When using electric generators and batteries, it is necessary to take into account the differences that exist between. By connecting a three-phase electric motor to the appropriate network, you can triple its output power.

By following certain recommendations, with minimal costs in terms of resources and time, you can manufacture the power part of a high-frequency pulse converter for domestic needs. You can study the structural and circuit diagrams of such power supplies.

Structurally, each element of a solar battery is made in the form of a silicon wafer with an area of ​​several cm2, on which many such photodiodes connected into a single circuit are formed. Each such plate is a separate module that produces a certain voltage and current when exposed to sunlight.

By connecting such modules into a battery and combining their parallel-serial connection, you can obtain a wide range of output power values.

The main disadvantages of solar panels:

• Great unevenness and irregularity of energy output depending on the weather and seasonal height of the sun.
• Limits the power of the entire battery if at least one part of it is shaded.
• Dependence on the direction of the sun at different times of the day. To use the battery as efficiently as possible, you need to ensure that it is always aimed at the sun.
• In connection with the above, the need for energy storage. The greatest energy consumption occurs at a time when its production is minimal.
• Large area required for a structure of sufficient power.
• The fragility of the battery design, the need to constantly clean its surface from dirt, snow, etc.
• Solar modules operate most efficiently at 25°C. During operation, they are heated by the sun to a much higher temperature, which greatly reduces their efficiency. To maintain optimal efficiency, the battery must be kept cool.

It should be noted that developments of solar cells using the latest materials and technologies are constantly appearing. This allows you to gradually eliminate the disadvantages inherent in solar panels or reduce their impact. Thus, the efficiency of the newest cells using organic and polymer modules has already reached 35% and there are expectations of reaching 90%, and this makes it possible to obtain much more power with the same battery dimensions, or, while maintaining energy efficiency, to significantly reduce the dimensions of the battery.

By the way, the average efficiency of a car engine does not exceed 35%, which suggests that solar panels are quite effective.

There are developments of elements based on nanotechnology that work equally effectively at different angles of incident light, which eliminates the need for their positioning.

Thus, today we can talk about the advantages of solar panels compared to other energy sources:

• No mechanical energy conversions or moving parts.
• Minimal operating costs.
• Durability 30~50 years.
• Quiet operation, no harmful emissions. Environmental friendliness.
• Mobility. The battery for powering a laptop and charging the battery for an LED flashlight will fit in a small backpack.
• Independence from the presence of constant current sources. The ability to recharge the batteries of modern gadgets in the field.
• Undemanding to external factors. Solar cells can be placed anywhere, on any landscape, as long as they receive enough sunlight.

In the equatorial regions of the Earth, the average solar energy flux is on average 1.9 kW/m 2. In central Russia it is in the range of 0.7~1.0 kW/m2. The efficiency of a classic silicon photocell does not exceed 13%.

As experimental data show, if a rectangular plate is directed with its plane to the south, to the point of solar maximum, then over a 12-hour sunny day it will receive no more than 42% of the total luminous flux due to a change in its angle of incidence.

This means that with an average solar flux of 1 kW/m2, 13% battery efficiency and its total efficiency of 42% can be obtained in 12 hours no more than 1000 x 12 x 0.13 x 0.42 = 622.2 Wh, or 0 .6 kWh per day from 1 m 2. This is assuming a full sunny day, in cloudy weather it is much less, and in the winter months this value must be divided by another 3.

Taking into account voltage conversion losses, an automation circuit that provides optimal charging current for batteries and protects them from overcharging, and other elements, the figure of 0.5 kWh/m 2 can be taken as a basis. With this energy, you can maintain a battery charge current of 3 A at a voltage of 13.8 V for 12 hours.

That is, to charge a completely discharged car battery with a capacity of 60 Ah, a solar panel of 2 m2 will be required, and for 50 Ah - approximately 1.5 m2.

In order to obtain such power, you can purchase ready-made panels produced in the electrical power range of 10~300 W. For example, one 100 W panel for a 12-hour daylight hours, taking into account the coefficient of 42%, will provide 0.5 kWh.

Such a Chinese-made panel made of monocrystalline silicon with very good characteristics now costs about 6,400 rubles on the market. Less effective in open sun, but having better performance in cloudy weather, polycrystalline - 5,000 rubles.

If you have certain skills in installing and soldering electronic equipment, you can try to assemble such a solar battery yourself. At the same time, you should not count on a very large gain in price; in addition, the finished panels are of factory quality, both the elements themselves and their assembly.

But the sale of such panels is not organized everywhere, and their transportation requires very strict conditions and will be quite expensive. In addition, with self-production, it becomes possible, starting small, to gradually add modules and increase the output power.

Selection of materials for creating a panel

Chinese online stores, as well as the eBay auction, offer the widest selection of elements for self-manufacturing solar panels with any parameters.

Even in the recent past, home-made workers purchased plates that were rejected during production, had chips or other defects, but were significantly cheaper. They are quite efficient, but have a slightly reduced power output. Given the constant decline in prices, this is now hardly advisable. After all, losing on average 10% of power, we also lose in the effective panel area. And the appearance of the battery, consisting of plates with broken pieces, looks quite artisanal.

You can also purchase such modules in Russian online stores, for example, molotok.ru offers polycrystalline elements with operating parameters at a luminous flux of 1.0 kW/m2:

• Voltage: idling - 0.55 V, operating - 0.5 V.
• Current: short circuit - 1.5 A, working - 1.2 A.
• Operating power - 0.62 W.
• Dimensions - 52x77 mm.
• Price 29 rub.

Advice: It is necessary to take into account that the elements are very fragile and some of them may be damaged during transportation, so when ordering you should provide some reserve for their quantity.

Making a solar battery for your home with your own hands

To make a solar panel, we need a suitable frame, which you can make yourself or pick up a ready-made one. The best material to use for it is duralumin; it is not subject to corrosion, is not afraid of dampness, and is durable. With appropriate processing and painting, both steel and even wood are suitable for protection from precipitation.

Advice: You should not make the panel very large: it will be inconvenient to assemble the elements, install and maintain. In addition, small panels have low windage and can be more conveniently placed at the required angles.

We calculate components

Let's decide on the dimensions of our frame. To charge a 12-volt acid battery, an operating voltage of at least 13.8 V is required. Let’s take 15 V as a basis. To do this, we will have to connect 15 V / 0.5 V = 30 elements in series.

Tip: The output of the solar panel should be connected to the battery through a protective diode to prevent it from self-discharging through solar cells at night. So the output of our panel will be: 15 V – 0.7 V = 14.3 V.

To obtain a charging current of 3.6 A, we need to connect three such chains in parallel, or 30 x 3 = 90 elements. It will cost us 90 x 29 rubles. = 2610 rub.

Tip: Solar panel elements are connected in parallel and in series. It is necessary to maintain equality in the number of elements in each sequential chain.

With this current we can provide a standard charge mode for a completely discharged battery with a capacity of 3.6 x 10 = 36 Ah.

In reality, this figure will be less due to uneven sunlight throughout the day. Thus, to charge a standard 60 Ah car battery, we will need to connect two such panels in parallel.

This panel can provide us with an electrical power of 90 x 0.62 W ≈ 56 W.

Or during a 12-hour sunny day, taking into account the correction factor of 42% 56 x 12 x 0.42 ≈ 0.28 kWh.

Let's place our elements in 6 rows of 15 pieces. To install all the elements we need a surface:

• Length - 15 x 52 = 780 mm.
• Width - 77 x 6 = 462 mm.

To freely accommodate all the plates, we will take the dimensions of our frame: 900×500 mm.

Tip: If there are ready-made frames with other dimensions, you can recalculate the number of elements in accordance with the outlines given above, select elements of other standard sizes, and try to place them by combining the length and width of the rows.

We will also need:

• Electric soldering iron 40 W.
• Solder, rosin.
• Installation wire.
• Silicone sealant.
• Double sided tape.

Manufacturing stages

To install the panel, it is necessary to prepare a level workplace of sufficient area with convenient access from all sides. It is better to place the element plates themselves separately to the side, where they will be protected from accidental impacts and falls. They should be taken carefully, one at a time.

Residual current devices improve the safety of your home electrical system by reducing the likelihood of electrical shock and fires. A detailed acquaintance with the characteristic features of different types of differential current switches will tell you for apartments and houses.

When using an electric meter, situations arise when it needs to be replaced and reconnected - you can read about this.

Typically, to produce a panel, they use the method of gluing plates of elements pre-soldered into a single circuit onto a flat base-substrate. We offer another option:

1. We insert it into the frame, fasten it well and seal the edges with glass or a piece of plexiglass.
2. We lay out the element plates on it in the appropriate order, gluing them with double-sided tape: the working side to the glass, the soldering leads to the back side of the frame.
3. By placing the frame on the table with the glass down, we can conveniently solder the terminals of the elements. We carry out electrical installation in accordance with the selected circuit diagram.
4. We finally glue the plates on the back side with tape.
5. We put some kind of damping pad: sheet rubber, cardboard, fiberboard, etc.
6. We insert the back wall into the frame and seal it.

If desired, instead of the back wall, you can fill the frame at the back with some kind of compound, for example, epoxy. True, this will eliminate the possibility of disassembling and repairing the panel.

Of course, one 50 W battery is not enough to power even a small house. But with its help it is already possible to implement lighting in it using modern LED lamps.

For a comfortable existence of a city dweller, at least 4 kWh of electricity is now required per day. For a family - according to the number of its members.

Therefore, the solar panel of a private house for a family of three should provide 12 kWh. If the home is supposed to be supplied with electricity only from solar energy, we will need a solar battery with an area of ​​at least 12 kWh / 0.6 kWh/m2 = 20 m2.

This energy must be stored in batteries with a capacity of 12 kWh / 12 V = 1000 Ah, or approximately 16 batteries of 60 Ah each.

For normal operation of a battery with a solar panel and its protection, a charge controller is required.

To convert 12 VDC to 220 VAC, you will need an inverter. Although now there is already a sufficient quantity of electrical equipment on the market for voltages of 12 or 24 V.

Tip: In low-voltage power supply networks, currents operate at significantly higher values, so when wiring to powerful equipment, you should select a wire of the appropriate cross-section. Wiring for networks with an inverter is carried out according to the usual 220 V circuit.

Drawing conclusions

Subject to the accumulation and rational use of energy, today non-traditional types of electric power are beginning to create a significant increase in the total volume of its production. One could even argue that they are gradually becoming traditional.

Taking into account the recently significantly reduced level of energy consumption of modern household appliances, the use of energy-saving lighting devices and the significantly increased efficiency of solar panels of new technologies, we can say that they are already capable of providing electricity to a small private house in southern countries with a large number of sunny days a year.

In Russia, they may well be used as backup or additional energy sources in combined power supply systems, and if their efficiency can be increased to at least 70%, then it will be quite possible to use them as the main suppliers of electricity.

Video on how to make a device for collecting solar energy yourself

The article examines the practical application of solar panels, describes in detail the components necessary for uninterrupted power supply, independent connection and configuration of solar panels.

Power supply system equipment: range, characteristics

In the previous article we looked at the types of solar panels. But in solar energy generation systems, these elements are only primary converters. To create a full-fledged home power plant, we will need the following set of equipment:

• battery charge controller
• rechargeable battery
• voltage inverter

Battery charge controllers There are two types: PWM controllers (PWM controllers) and OTMM controllers (MPPT controllers).

A PWM controller is a simpler and cheaper device that controls battery charging. The efficiency of a PWM controller is usually higher than that of an OTMM controller due to the fact that at the initial charging stage it connects the battery almost directly to the solar panel without converting the generated voltage. OTMM controllers are recommended for use with modules with a non-standard output voltage of 28 V and higher.

The use of OTMM controllers will be economically justified in generation systems with a rated power of more than 400 W. Another reason for using such a controller is designing a solar station for year-round electricity generation. On cloudy winter days, when charging batteries, the OTMM controller will show its best side.

Battery in a solar power supply system it plays the role of a buffer that accumulates electrical energy.

Unlike all other solar station equipment, the battery is a consumable item. Therefore, the longer it works without replacement, the shorter the payback period for the components you purchase will be. In order for the battery to serve for a long time, you need to take a responsible approach to its choice. The main parameters of the battery that are of interest to the potential owner are:

• voltage (Volt, V) - there are batteries for sale for solar panels with voltages of 12, 24 and 48 V. For small home stations with a power of 200-300 W, 12 V batteries are quite suitable;
• electrical capacity (Ampere⋅hour, A⋅h) - characterizes the amount of electricity that can be accumulated. Accordingly, the larger this parameter, the more the electrical system can work in autonomous mode (in cloudy weather or at night);
• self-discharge level (% of the nominal capacity) - the lower this parameter, the better the battery.

Voltage inverter designed to convert DC battery voltage into AC voltage of 220 V, supplying household loads.

There is a wide range of inverters available in the market with a variety of features. Among the most important parameters, the following should be noted:

• inverter power;
• primary circuit voltage (voltage of the connected battery);
• the presence of built-in protections (from overload, from battery reverse polarity, from short circuit in the load, from excessive battery discharge);
• sinusoidality of the output voltage (essentially, if the connected load contains motors, for example, washing machines, refrigerators, circulation pumps, fans, etc.).

It should also be noted that an excessive number of functions only increases the cost of the device and complicates its setup and operation.

Solar station equipment connection diagram

Assembling the solar power plant circuit is quite simple. Below is a sequence of connections, illustrated with photographs. To assemble a simple system, a solar panel with polycrystalline cells, a charge controller and a battery are used. We begin the assembly by connecting the cable to the solar battery.

Batteries that come with the cable do not require this step. We connect the battery to the output terminals of the controller. Next, the wires coming from the panel must be connected to the input terminals of the charge controller.

All connections are made according to the principle “+” to “+”, and “-” to “-”. We supply power from the battery to the input terminals of the inverter. After turning on the charge controller and inverter, we see that the electricity generated by the solar panel begins to charge the battery.

In order to determine the polarity of the solar battery terminals, it is enough to measure the voltage at the terminals using a multimeter. If there is a minus sign next to the voltage readings, then the position of the black probe corresponds to the positive terminal (check that the probes are connected correctly before measuring). If there is no minus sign, then the position of the black probe corresponds to the negative terminal of the battery.

Installation of solar panels and auxiliary electrical equipment

The electrical equipment of the solar station is installed using copper wire. The cross-section of the copper wire for one panel should be chosen at least 2.5 mm 2. This is due to the fact that the normal current density in a copper conductor is 5 amperes per 1 mm 2. That is, with a cross section of 2.5 mm 2, the permissible current will be 12.5 A.

At the same time, the short-circuit current of the RZMP-130-T panel with a power of 145 W is only 8.5 A. When combining several panels with parallel connection, the cross-section of the common output cable should be selected based on the maximum total current of all panels according to the concept described above (5 A per 1 mm 2).

There are a variety of cables available for connecting solar panels. Their distinctive feature is that the external insulation of the cable has undergone special treatment and has increased resistance to ultraviolet radiation. It is not necessary to purchase such cables. Solar panels can be connected with a cable with regular PVC insulation, but it should be laid in a corrugated sleeve, which is designed for laying external wiring. This option will cost 30-40% less.

The battery charge controller and inverter must be placed in a dry room at room temperature, for example, in a closet or hallway. It is not advisable to place this equipment outdoors, since the electronic components of the equipment should not be subject to significant fluctuations in temperature and humidity. The battery itself can be placed together with the electronics.

If you decide to use acid or alkaline batteries, you should place them in a well-ventilated non-residential area, since during their operation harmful electrolyte fumes are released. In addition, in the room with batteries there should be no sources of spark and fire hazards, since the released oxygen and hydrogen in poorly ventilated areas can form an explosive mixture.

The solar panel can be installed in two ways:

• fixed installation involves permanently placing the panels on the roof of the house or on a bracket attached to a wall or foundation. In this case, the panels should be directed to the south, the horizontal inclination of the panels should be an angle equal to the latitude of the area plus 15°. The latitude of your location can be determined, for example, from the readings of a GPS navigator or in the Google Maps service;
• movable installation of the panels is carried out on a traverse, which is capable of rotating azimuthally (in the direction of the sun's movement along the horizon) and zenithally, tilting the panels so that the sun's rays fall on them perpendicularly. This installation system makes it possible to increase the efficiency of the solar panels used, but requires additional tangible financial costs for the design of the traverse, drive motors and the system for their control.

Ways to increase the efficiency of autonomous power supply

To increase the efficiency of a solar power plant, you can go in two ways: increase the amount of generated electricity on the one hand and reduce its consumption on the other. Ways to increase the generated electricity can be the following:

• installation of solar panels on a movable traverse or on a zenithal tilt control mechanism (a half-measure, but also quite effective, mainly for monocrystalline panels);
• use of high-quality batteries with a low percentage of self-discharge and a long service life without a significant reduction in capacity;
• regular maintenance of the system: cleaning panels from dust and snow, servicing detachable and terminal connections in order to reduce contact resistance and, as a result, power losses.

On the load side, energy efficiency can be increased as follows:

• separating a low-voltage power supply circuit directly from the battery, for example, to connect LED lighting. This will avoid double conversion of energy in the inverter;
• turning off the inverter when the load at its output is disconnected, since an inverter running idle still consumes a small amount of energy;
• installation together with motion sensor lighting with a timer to eliminate the annoying waste of electricity due to the fact that you simply forgot to turn off the lamp in the hallway.

Vlad Taranenko, rmnt.ru