The controller used a simple cheap PWM at 24 volts 20A. The entire solar power plant produced up to 230 watt*h. Now I have installed 6 panels of 50 watt*h and 2 panels of 100 watt*h. The total power of these panels was 500 watt*h. By the way, the panels are made in Germany. I connected the panels at 24 volts, two in parallel and then in series. Operating voltage 39V.
Today at one o'clock in the afternoon I carried out the first test results, and received almost the calculated power, despite the slight haze in the sky. In the photo of the panel in the top row, there are 2 German panels on the left, 100 watt*h each, and on the right, Krasnodar ones, 75 watt*h each, but they are not connected, since they have an operating point voltage lower than the others by 2 volts.
The controller readings show a recorded power of 490 watt*h.
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The controller charges six 120Ah AGM batteries; I used them in my electric car before. I connected two in series at 24 volts and in parallel. Energy is taken from the batteries using two inverters using a pure sine wave. One only powers lighting throughout the house and adjacent buildings, its power is 500 watt*h. The second one is more powerful, it is used to power powerful consumers, it is 1.5 aWh with a short-term load of up to 3 kWh for 10 seconds.
DIY portable solar battery.
Also, here are some more photos of a solar portable power station made for one of my friends. The power of the panels is 100 watts, and can be switched to charge 12/24 volt batteries as long as the corresponding controller is installed. But the controller is ordinary, so the maximum current is 6A. Well, in general it turned out well, although it was very simple.
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Let's return to the main power plant. I just finished installing 1kW solar panels. An inverter with 3.5 kW continuous power, pure sine wave, was also purchased in China. The MPPT controller TS-MPPT-45 is busy charging the batteries. The total battery capacity is 7 kW*h.
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The first data and readings were recorded sometime during the day, despite the high temperature outside and a slight haze in the sky, the power plant produced 900 watts, the result met all expectations. In winter, I think there will be more power since our skies are clearer in winter and the low temperature will not allow the solar panels to overheat.
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In general, the power plant is still working fine, although the house is connected to the central power grid, but the lighting in the house is now completely powered by solar energy. Just recently, the electricity was cut off for a day, some kind of repair work was going on, there wasn’t a light around, one of my windows had lights on all evening. By the way, the output from the panels is not only full for 1-2 hours a day, but almost all daylight hours, even with indirect sunlight, the panels provide power more than 50% of the possible one. The article was written based on materials >>source
Autonomous power supply systems for suburban properties allow you to live in comfort even far from centralized communications. Often, along with traditional schemes, alternative ones are used, based on the use of solar energy.
In order for the solar system to function correctly, a well-designed solar panel connection diagram is required. You will need a set of high-quality equipment capable of coping with the assigned responsibilities.
We will tell you how to correctly plan the placement of mini-power plant components. You will learn how to select technical devices for assembling the system and how to connect them correctly. Taking into account our advice, you can build an efficient installation.
Let's look at how a solar system for a country house is designed and works. Its main purpose is to convert solar energy into 220 V electricity, which is the main power source for household electrical appliances.
The main parts that make up the SES:
- Batteries (panels) that convert solar radiation into direct voltage current.
- A controller that regulates the battery charge.
- Battery pack.
- An inverter that converts battery voltage to 220 V.
The design of the battery is designed in such a way that it allows the equipment to operate in various weather conditions, at temperatures from -35ºС to +80ºС.
It turns out that correctly installed ones will work with the same performance in both winter and summer, but under one condition - in clear weather, when the sun gives off the maximum amount of heat. In cloudy conditions, work efficiency decreases sharply.
The efficiency of solar power plants in mid-latitudes is high, but not enough to fully supply large houses with electricity. More often, a solar system is considered as an additional or backup source of electricity
The weight of one 300 W battery is 20 kg. Most often, the panels are mounted on the roof, facade, or special racks installed next to the house. Necessary conditions: turning the plane towards the sun and an optimal tilt (on average 45° to the surface of the earth), ensuring a perpendicular incidence of the sun's rays.
If possible, install a tracker that tracks the movement of the sun and regulates the position of the panels.
The top plane of the batteries is protected by tempered shockproof glass, which can easily withstand hail impacts or heavy snow drifts. However, it is necessary to monitor the integrity of the coating, otherwise damaged silicon wafers (photocells) will stop working
The controller performs several functions. In addition to the main one - automatic regulation of the battery charge, it regulates the supply of energy from solar panels, thereby protecting the battery from complete discharge.
When fully charged, the controller automatically disconnects the battery from the system. Modern devices are equipped with a control panel with a display showing battery voltage.
For homemade solar systems, the best choice is gel batteries, which have an uninterrupted service life of 10-12 years. After 10 years of operation, their capacity decreases by approximately 15-25%. These are maintenance-free and absolutely safe devices that do not emit harmful substances.
In winter or cloudy weather, the panels also continue to work (if they are regularly cleared of snow), but energy production is reduced by 5-10 times
It is worth knowing that household power plants are capable of servicing a constantly running refrigerator, a periodically running submersible pump, a TV, and a lighting system. To provide energy for the functioning of a boiler or even a microwave oven, more powerful and very expensive equipment will be required.
The simplest diagram of a solar power plant, including the main components. Each of them performs its own function, without which the operation of the SES is impossible
There are other, more complex ones, but this solution is universal and the most popular in everyday life.
Steps for connecting batteries to solar power plant equipment
The connection occurs in stages, usually in the following order: first, the controller is connected to the battery, then the controller is connected to the solar panels, then the battery is connected to the inverter, and lastly, the wiring is done to consumers.
Step #1: Connecting to Battery
Batteries occupy a clearly defined place in the network. They are not connected to the solar panels directly, but through a controller that regulates their loading/unloading. On the other hand, the battery pack is connected to an inverter that converts the current.
Thus, the connection diagram to the battery looks like this:
- We connect the battery/controller (then the controller/solar panels);
- connect the battery and inverter.
Other connection options are possible, but this one is optimal, as it saves unspent energy and, if necessary, transfers it to consumers.
There are two options for purchasing batteries: as part of a solar power plant that is completely ready for installation or separately, according to specified parameters. An inexpensive Chinese kit costs no more than 2000 rubles
If one battery is not enough, purchase several batteries with the same characteristics. They are installed in one place and connected in series.
For ease of use and maintenance, the blocks are installed on a metal rack with a polymer coating.
Let's look at how the battery is connected to the controller and inverter.
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The next step is to connect the controller to the solar panels and the battery pack to the inverter.
Step #2: connecting to the controller
Let's consider an option that is often used in practice by owners of country houses. They order inexpensive equipment made in China on one of the Internet sites.
A budget controller with a minimum number of settings, equipped with three pairs of terminals, capable of servicing a 150 W solar battery pack. Cost – 1300 rubles
Connection occurs in the following order:
- First, a battery pack is connected to the controller. This is done intentionally to check how the device will detect the rated mains voltage (standard values - 12 V, 24 V). When connecting to the battery, use the first pair of terminals.
- Then the solar panels are directly connected, using the wires supplied with them, and the controller has a second pair of terminals.
- Lastly, night lighting equipment is installed. I – this is exactly what the third pair of terminals is for. Apart from low-voltage lighting, which operates only after dark and is powered by a battery, other equipment cannot be used.
For any type of connection, you must ensure polarity.
Failure to observe the polarity leads to instant failure of the controller, as well as failure of solar panel parts.
After connecting the controller to the battery and panels, we connect the inverter and, if necessary, low-voltage lighting devices.
The installation location of the inverter in the solar power plant system is between the battery unit and energy consumers, that is, home appliances, lighting devices, etc. (+)
The device is purchased in the same way as the rest of the solar system: as part of the SES kit or separately.
Procedure for connecting the inverter to the battery:
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We take the device out of the box, check it for integrity, and remove the protective films. We study the instructions so as not to make mistakes when connecting
Along with the device, the kit necessarily contains 2 wires with special terminals and “crocodiles” for connecting it to the battery.
The special cable that comes with the inverter is very easy to install: the terminals are placed on the contacts of the device and secured with plastic screw caps
Connecting to the battery is also very simple: we fix two special clamps on the battery contacts, observing the polarity - plus to plus, minus to minus
If you have not previously installed solar power plants, we recommend purchasing not individual devices, but a complete system.
The advantage of a ready-to-install system is that it matches the equipment parameters (batteries correctly selected for power, the required number of solar panels, a set of wires for quick connection).
It is logical that devices compatible in capacity, voltage and power will be much more efficient at converting solar energy and providing the house with electricity. In fact, free “green energy” can be used with heating systems
Video #3. Overview of one of the home installation options:
The use of alternative energy for the needs of humanity is truly a big technological leap. Today, every homeowner can independently assemble and connect a solar power plant that supplies the house with electricity. Taking into account the cost-effectiveness and environmental friendliness, this is a practical and effective solution.
Would you like to tell us about how you assembled a small solar power station with your own hands? Are there any interesting facts or useful information on the topic of the article? Please write comments in the block below, share your impressions, opinions and thematic photographs.
Scientific and technological progress does not stand still. People have learned to use the power of nature and its resources, which are completely free and do not impoverish nature. The use of wind, water and solar energy is absolutely harmless to nature, which makes this fact especially valuable. Solar panels are a great option for saving on utility bills. Solar panels work using the energy of the sun, absorbing sunlight, they produce energy.
DIY solar power plant assembly
Buying a solar installation to generate electricity for your home is not difficult; you can find many different offers on the market, but the cost of such equipment is quite high. Not everyone can afford to buy a system. There is an alternative - making a solar installation yourself.
The current strength that a photocell can create will depend on the number of solar cells that fall on the surface. The number of these elements directly depends on a number of factors:
- battery size;
- strength and intensity of sunlight;
- duration of use;
- efficiency of the structure;
- temperature indicators.
The size of the battery determines the amount of energy generated. The larger the structure area, the more energy is generated and the higher the cost of the equipment.
Depending on the cost and power of the equipment, solar panels for converting solar energy into electricity are divided into:
- Low power designs - the power of this equipment can provide charging for a tablet and other electronic devices. But with a high cost and such low power, this equipment is not very popular
- Universal designs - most often purchased for use in hiking and camping. This is a more powerful design that can power several electrical appliances simultaneously.
- Solar batteries are flat photographic plates mounted on a special base. They are installed on the roofs of houses and, thanks to a complex device, allow you to completely cover all electrical energy needs.
Do-it-yourself solar power plant
Solar power plants in everyday life are no longer a rarity or a curiosity. This design increases the comfort of living and ensures independence from the work of public utilities. If you have basic knowledge in electrical engineering, you can make a solar power plant yourself and at the same time save significant money. There are three types of solar power plants:
- autonomous;
- network;
- combined.
To provide a home with electricity, an autonomous solar power plant is considered the most optimal option.
Any solar power plant that produces alternating current consists of four main components:
- Photomodules - the number and area of photocells is determined depending on the needs of the house and solar activity in a specific geographic area. You can install the modules on your own; you will only have to buy silicon photocells or buy solar blocks, provided that the dimensions of the blocks match all the requirements.
- Rechargeable batteries are needed to prevent power outages. In bad weather and cloudy days, batteries will be able to maintain the supply of electricity on days without sun.
- Controllers are a kind of “sentinel” that monitors batteries from overcharging. When the battery is fully charged, they will reduce the current produced by the solar cell to the amount necessary to maintain self-discharge. In a homemade installation, this equipment is necessary to extend the service life.
- Inverters are special devices that convert direct current into alternating current, which powers all equipment in the house. In a private solar power plant we are talking about sine wave batteries. This option is cheaper and suitable for home use. When there is an excess of electricity, inverters act as a link between the home and municipal energy systems. They redirect excess electricity to the general network.
- Cables - they play an important role. All outdoor cables must be of high quality and resistant to bad weather and temperature changes. To reduce energy losses, a short path and a special cross-section of at least four millimeters are recommended.
Solar power plant assembly diagram
Solar modules should be installed on the roof of the house. The structure is located in accordance with the instructions: positioned at right angles to the incident light, the angle of deflection should not be more than fifteen degrees. Provided that year-round use of the solar installation is planned, the batteries are located at an angle of +15 degrees to the geographic latitude. If the battery is used only in the summer, it is required to adhere to the angle of inclination - minus fifteen degrees to latitude. You can ask someone who is competent in this matter to help you position the solar panels correctly. The batteries are installed one above the other, taking into account how the shadow will fall, so as not to block the access of the sun.
When arranging panels in several rows, a certain distance should be maintained between the devices. In this case there will be no shading. The panels are secured in four, or better yet, six places. The batteries are secured only with “original” fasteners, otherwise there will be no guarantee of reliable fastening.
Assemble a solar power station by hand
To save on installing equipment that a team of specialists will produce for a certain cost, you must follow the rules and listen to the recommendations of experienced people. Otherwise, the photo panels will not be able to operate with the maximum possible power and the material costs for manufacturing or purchasing will be in vain.
A self-made solar power station is assembled taking into account the following rules:
- Illumination - the panels must be installed in the most illuminated place without the slightest shading. As a rule, this is the roof of the room or the facade.
- Direction - installation of photo batteries is carried out on the south side of the roof, taking into account the correct angle of inclination. The south side receives maximum solar energy.
- Angle of inclination - for the effectiveness and maximum efficiency of the panels, it is necessary to take into account the correct angle of inclination in relation to the horizon. The rule for choosing an angle was described above, but if this option is not available for use, a constant angle equal to geographic latitude is selected.
- Maintenance - If solar panel surfaces are allowed to become dirty, there will be a noticeable loss in panel surface performance. It is necessary to regularly clean the surface: in summer from dust and leaves, in winter from snow and dirt.
- If the batteries are installed on the ground surface, then it is necessary to raise the structure above the ground by about half a meter.
But besides these nuances, the type of roof plays a big role during battery installation.
Homemade solar power plant with hands, roof installation feature
The location of the battery depends on the roof option. Even the color of the roof plays a significant role. For example, a dark roof gets hotter in the sun and causes the solar panel to overheat. If the roof covering is dark in color, a light insert must be provided at the location of the battery. If the photopanel is installed on a flat roof on your own, this process should not cause difficulties. A flat roof is considered the best option for placing a solar panel. For installation, support frames are purchased to conveniently position the panel at the correct angle. It is much more convenient to care for panels and clean their surface on flat roofs.
Pitched roofs require a slightly different installation option. Batteries are installed on special mounts, taking into account the material from which the roof is made. Each option uses its own fastening material. Also, installation technologies differ in each specific case. For natural cooling of the solar battery, it is recommended to create a gap between the roof and the equipment, this ensures the circulation of air masses.
Homemade solar power station
Before you start making your own solar power plant, you need to decide on the material. Most often, the photopanel is based on polycrystalline silicon or monocrystalline material. Polycrystalline material has a low efficiency, but a panel made of such material is effective at any solar strength. As for monocrystalline substances, they have higher performance, but noticeably reduce efficiency in the absence of sun in cloudy weather. Because of this, home craftsmen prefer polycrystals.
This fact should be taken into account: all photocells are purchased from the same manufacturer in order to eliminate situations where difficulties arise in determining the total power or the elements have different shelf life. Some enterprising craftsmen buy sets at online auctions, which means a good deal. In addition to the above, you need to buy conductors that serve as connecting elements for solar cells, and soldering equipment.
Light materials, such as aluminum corners, are used for the panel body. Wood can also serve as a base for batteries, but given the fact that it will be subject to endless negative influences, it is not recommended to use this material. It should be remembered that many installation elements are sold at auctions, including the finished housing. For the external transparent coating, polycarbonate or plexiglass is used. Ideally, any transparent material that does not transmit infrared rays, which degrade the quality of the system, will do.
How to assemble a solar power plant for your home
After preparing all the materials, you can begin directly assembling the solar power plant. First, the conductors with solar cells are soldered. Since this procedure is quite labor-intensive and is accompanied by damage to the elements due to their fragility, it is recommended to purchase cells with soldered conductors. But if the product was purchased separately and needs to be connected, there is the following algorithm of action:
- prepare conductors of the required length;
- extremely carefully move the conductors into the cell;
- Apply a special agent - soldering acid and solder - to the joint;
- Without putting pressure on the crystal, you should solder the conductor.
The soldering process is painstaking and time-consuming.
You can connect elements according to different schemes: in series, in parallel, in series, with a midpoint. This is not important, the main thing is that there are shunt diodes, thanks to which discharge will not occur at night. Before installation, tests are carried out for current, voltage, fixation of elements and sealing. You can seal each cell with a special agent and seal it with plastic.
Step-by-step instructions in the video will help you cope with such a task as installing a solar power plant with your own hands. Solar batteries are profitable, accessible and inexpensive. As a result of installing an innovative system, you can not depend on weather conditions when electricity is lost due to strong wind or rain as a result of a short circuit or equipment failure. Solar power plants are convenient.
The article examines the practical use 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 220 V alternating voltage 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 the 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 their operation produces harmful electrolyte fumes. 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;
- The 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);
- the 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
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 pn 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/m2. 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:
- We insert it into the frame, fasten it well and seal the edges with glass or a piece of plexiglass.
- 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.
- 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.
- We finally glue the plates on the back side with tape.
- We put some kind of damping pad: sheet rubber, cardboard, fiberboard, etc.
- 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