How to make a solar battery with your own hands: instructions for self-assembly. Instructions for self-assembly of a solar battery from inexpensive Chinese panels How to assemble solar panels
For more than a decade, humanity has been looking for alternative energy sources that can at least partially replace the existing ones. And the most promising of all today are two: wind and solar energy.
True, neither one nor the other can provide continuous production. This is due to the inconsistency of the wind rose and daily-weather-seasonal fluctuations in the intensity of the solar flux.
Today's energy industry offers three main methods for generating electrical energy, but all of them are harmful to the environment in one way or another:
- Fuel power industry- the most environmentally polluted, 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 nature.
- hydropower is associated with very significant landscape changes, flooding of useful lands, causing damage to fish resources.
- Nuclear power- the most environmentally friendly of the three, but requires a very significant cost to maintain security. Any accident can be associated with irreparable long-term damage to nature. In addition, it requires special measures for the disposal of used fuel waste.
Strictly speaking, there are several ways to get electricity from solar radiation, but most of them use its intermediate conversion into mechanical, rotating the generator shaft, and only then into electricity.
Such power plants exist, they use Stirling external combustion engines, they have a good efficiency, but they also have a significant drawback: in order to collect as much solar energy as possible, it is necessary to manufacture huge parabolic mirrors with systems for tracking the position of the sun.
I must say 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 electricity. And although the phenomenon of the photoelectric effect in the semiconductor selenium was discovered already in 1876, but only in 1953, with the invention of the silicon photocell, did it become possible to create solar panels to generate electricity.
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.
Job solar battery based on the photoelectric effect semiconductor p-n junction, which is essentially a conventional silicon diode. At its conclusions, when illuminated, a photo-emf of 0.5 ~ 0.55 V appears.
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 guidelines, minimal cost according to resources and time, it is possible to manufacture the power part of a high-frequency pulse converter for household needs. You can study the structural and schematic diagrams of such power supplies.
Structurally, each element of the solar battery is made in the form of a silicon wafer with an area of several cm 2, on which a plurality of such photodiodes connected in a single circuit is formed. Each such plate is a separate module, which gives a certain voltage and current under sunlight.
By connecting such modules in a battery and combining them in series-parallel connection, a wide range of output power values can be obtained.
The main disadvantages of solar panels:
- Great unevenness and irregularity of energy output, depending on the weather, and the seasonal height of the sun.
- Limiting 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. For the most efficient use of the battery, you need to ensure its constant orientation to 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 sufficient capacity construction.
- The fragility of the battery design, the need for constant cleaning of its surface from dirt, snow, etc.
- Solar modules work most efficiently at 25°C. During operation, they are heated by the sun to much more high temperature, greatly reducing their effectiveness. To keep the efficiency at an optimal level, it is necessary to provide cooling of the battery.
It should be noted that the development of solar cells using latest materials and technology. This allows you to gradually eliminate the disadvantages inherent in solar panels or reduce their impact. So, the efficiency of the latest cells using organic and polymer modules already reaches 35% and there are expectations of reaching 90%, and this makes it possible to obtain much more power with the same battery size, or, while maintaining energy efficiency, significantly reduce the size of the battery.
By the way, the average efficiency of a car engine does not exceed 35%, which allows us to talk about a fairly serious efficiency of solar panels.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, already today we can talk about the advantages of solar panels compared to other energy sources:
- No mechanical energy conversions and no moving parts.
- Minimum operating costs.
- Durability 30~50 years.
- Quiet operation, no harmful emissions. Environmental friendliness.
- Mobility. The battery for powering the laptop and charging the battery for the 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 are sufficiently illuminated by sunlight.
In the equatorial regions of the Earth, the average solar energy flux is 1.9 kW / m 2 on average. IN middle lane In Russia, it is in the range of 0.7 ~ 1.0 kW / m 2. 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 in 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 / m 2, 13% of the 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 under the condition of a full sunny day, in cloudy weather - much less, and in winter months This value must be divided by 3.
Taking into account the voltage conversion losses, the automation circuit that provides the optimal charging current of the batteries and protects them from overcharging, and other elements, can be taken as a basis for the figure of 0.5 kWh / m 2. With this energy, it is possible to 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 m 2 is required, and for 50 Ah - about 1.5 m 2.In order to get such power, you can purchase ready-made panels that are produced in the range of electrical powers of 10~300W. For example, one 100 W panel for a 12-hour daylight hours, taking into account a coefficient of 42%, will just provide 0.5 kWh.
Such a Chinese-made panel made of monocrystalline silicon with very good characteristics is now on the market for about 6400 rubles. Less effective in the open sun, but having a better return in cloudy weather, polycrystalline - 5000 r.
If you have certain skills in the installation and soldering of electronic equipment, you can try to assemble a similar solar battery yourself. At the same time, you should not count on a very large gain in price, in addition, the finished panels have factory quality of both the elements themselves and their assembly.
But the sale of such panels is far from being organized everywhere, and their transportation requires very harsh conditions and will be quite expensive. In addition, with self-manufacturing, it becomes possible, starting small, to gradually add modules and increase output power.
Selection of materials for creating a panel
In Chinese online stores, as well as on eBay, the widest selection of elements for self-manufacturing solar panels with any parameters is offered.
Even in the recent past, do-it-yourselfers purchased plates that were rejected during production, having chips or other defects, but much cheaper. They are fully functional, but have a slightly reduced return on power. Given the constant decline in prices, now it is hardly advisable. After all, losing an average of 10% of power, we lose in the effective area of the panel. Yes and appearance a battery consisting of plates with chipped pieces looks rather 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: idle - 0.55 V, working - 0.5 V.
- Current: short circuit - 1.5 A, working - 1.2 A.
- Working power - 0.62 W.
- Dimensions - 52x77 mm.
- Price 29 p.
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. Of the materials for it, it is best to use 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 atmospheric precipitation.
Tip: Do not make the panel very large sizes A: it will be inconvenient in the assembly of elements, installation and maintenance. In addition, small panels have low windage, they can be more conveniently placed at the required angles.We calculate components
Decide on the size 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 cells in series.
Tip: The output of the solar panel should be connected to the battery through a protective diode to avoid its self-discharge at night through the solar cells. So the output of our panel will be: 15 V - 0.7 V = 14.3 V.To get 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 rubles.
Tip: Solar panel elements are connected in parallel-series. It is necessary to observe the equality of the number of elements in each consecutive chain.With this current, we can provide a standard charge mode for a fully discharged battery with a capacity of 3.6 x 10 = 36 Ah.
In reality, this figure will be less due to uneven sunlight during 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 with a 42% correction factor 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.
For the free placement of all 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 above, select elements of other sizes, try to place them by combining the length and width of the rows.We will also need:
- Soldering iron electric 40 W.
- Solder, rosin.
- Mounting wire.
- Silicone sealant.
- Double sided tape.
Manufacturing steps
For mounting the panel, it is necessary to prepare an even workplace sufficient area with a convenient approach from all sides. It is better to place the element plates themselves separately to the side, where they will be protected from accidental bumps and falls. Take them carefully, one at a time.
Residual current devices increase the safety of your home electrical circuit by reducing the risk of electric shock and fire. Detailed introduction to characteristic features different types differential current switches will tell you for an apartment and a house.
During the operation of the electric meter, situations arise when it needs to be replaced and reconnected - you can read about this.
Usually, for the manufacture of a panel, the method of gluing elements pre-soldered into a single chain of plates onto a flat base substrate is used. We offer another option:
- We insert it into the frame, fix it well and seal the glass or a piece of plexiglass around the edges.
- We lay it out on it in the appropriate order, gluing them double sided tape, element plates: working side to the glass, soldering leads to the rear side of the frame.
- Putting the frame on the table with the glass down, we can conveniently solder the leads of the elements. We carry out electrical installation according to the chosen circuit diagram inclusions.
- We finally glue the plates on the back side with adhesive 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 already exclude the possibility of disassembling and repairing the panel.
Of course, one 50 W battery is not enough to provide energy even 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 it is supposed to supply the home only from solar energy, we will need a solar battery with an area of at least 12 kWh / 0.6 kWh / m 2 \u003d 20 m 2.
This energy must be stored in batteries with a capacity of 12 kWh / 12 V = 1000 Ah, or approximately 16 batteries of 60 Ah.
A charge controller is required for normal operation of the battery with a solar panel and its protection.
To convert 12V direct current at 220 V AC, you will need an inverter. Although now the market already has a sufficient number of electrical equipment for voltages of 12 or 24 V.
Tip: In low-voltage power networks, currents are much higher, so for wiring to powerful equipment, you should choose a wire of the appropriate size. Wiring for networks with an inverter is carried out according to the usual 220 V scheme.Drawing conclusions
Under the condition of accumulation and rational use energy, already today non-traditional types of electric power industry are beginning to create a solid increase in the total volume of its generation. It can even be argued that they are gradually becoming traditional.
Considering the level of energy consumption of modern household appliances that has significantly decreased in recent years, the use of energy-saving lighting fixtures and significantly increased efficiency of solar batteries of new technologies, we can say that even now they are able to provide electricity to a small a private house in southern countries with a large number sunny days in a year.
In Russia, they may well be used as a backup or additional sources energy in combined power supply systems, and if their efficiency can be increased to at least 70%, then it will be quite realistic to use them as the main suppliers of electricity.
Video on how to make a device for collecting solar energy yourself
If you decide to assemble a solar panel on your own, then you will most likely come across such a thing as soldering conductors to photovoltaic cells. By itself, the process of soldering tires to solar cells is very painstaking, therefore difficult. So that your desire for the use of alternative energy sources does not encounter such an obstacle, you can familiarize yourself with the basic aspects of the correct soldering of conductors to solar panel elements.
Materials needed for soldering elements:
1) solar cells
2) thin flat conductors
3) soldering iron
4) wide flat conductors
5) flux
6) solder
Let us consider in more detail all the nuances of the process of soldering solar panel elements.
The most important thing in this process is not to rush. The solar cells themselves are very thin and fragile, their thickness is only 0.2 mm, so any excessive force or sudden movement can break them.
On average, it takes about two days to solder one solar panel consisting of 36 elements. Therefore, if you decide to assemble entire systems consisting of many solar panels, then seriously think about the amount of time spent on soldering conductors, it may be more profitable for you to purchase solar cells with ready-made conductors.
The main mistake of those who first decided to assemble a solar panel is that they consider it sufficient to purchase only the solar cells themselves in the store, and the rest can be replaced with analogues sold on the local radio components market. However, this vision is not entirely correct, flat conductors are used in solar panels, which are not recommended to be replaced with ordinary wires, since rather thick wires are required, which means a lot of time spent on soldering, an unaesthetic appearance of the structure, and, moreover, excessive wire rigidity can cause damage to the element itself.
That is why the author recommends ordering a set of solar cells already with diodes, tires, thin flat conductors for soldering elements and wider ones for connecting sections to each other. This approach will save both your time and money on shipping.
We also need a soldering iron with a power of 60-80 watts. If the soldering iron is less powerful, then most likely it will cool faster due to the fact that the large surface of the solar cell will take away heat, therefore, you will have to press down on the soldering iron and hold it longer on the solar cell. This, in turn, can cause the element to break or overheat. As a solder, the author recommends using wire tin, you can even use rosin. Any acid-free flux for soldering electronics is suitable as a flux, but it is advisable to use one that does not require rinsing and leaves less greasy marks.
After everything necessary tools and components have been assembled, you can begin to prepare for soldering solar cells. First you need to cut flat conductors. The length of the conductors must be calculated so that it is slightly shorter than the width of the solar cell. Thus, when using solar cells measuring 78 by 156 mm, the length of the conductor should be 146 mm, taking into account the gap of 5 mm between the cells. The distribution of the conductor over the element is as follows: 78 mm is soldered to the front of the element, 5 mm is left for the gap between them, and 63 mm is soldered to three contacts located on the back of the element.
It is quite convenient to cut conductors using thick cardboard. Two sheets of cardboard 63 mm wide and 5 mm thick are taken, they are put together, and then the conductor is wound around them. Then the cardboard is moved apart and on one side the conductor is cut with scissors.
It should also be noted that when soldering elements 6 by 6, in order to save money, it is permissible to solder the tire not along the entire length, but simply tin the remaining part.
However, remember how well the conductors are soldered will greatly depend on the efficiency of the entire solar battery.
After cutting the conductor, you can begin to prepare the elements for soldering. Usually the front side of the elements is a minus, and the back side is a plus. therefore, along the entire length of the contact pad of the front side, it is smeared with flux.
Then the flat conductor is applied and fixed with a soldering iron. It is not necessary to tin the contact, since the contacts are silver-plated on the front side, and there is a thin layer of tin on the bus itself. The main thing is that the tire is firmly soldered to the contacts and held well, otherwise you should still tinker.
After that, the conductor is soldered on the reverse side of the element with a smooth movement, the main thing is to ensure that the element itself does not overheat during the process.
These actions must be done with each element, and then start soldering them into a common circuit. As a standard, it is customary to connect the elements in series from plus to minus in one chain, so the voltage of all elements is summed up, and the current remains the same.
Below is a diagram of soldering elements into a common circuit:
After you have decided on the final shape of the solar panel, you should place the elements in several rows on the work surface with the back side up.
There are several points that will help you fix the elements during soldering, so that in the end the panel has a nice and neat look. The edges of the solar cells can be grabbed with adhesive tape, which is later simply cut off with a clerical knife. In order for the distance between the elements to be the same, you can use construction crosses, which are usually used for laying tiles, these crosses will provide a gap of 2-5 mm.
It is best to make a whole layout from plywood, on which crosses are glued.
For a long time, solar panels were either bulky panels of satellites and space stations, or low-power photocells in pocket calculators. This was due to the primitiveness of the first single-crystal silicon photocells: they not only had a low efficiency (no more than 25% in theory, in practice - about 7%), but also noticeably lost efficiency when the angle of incidence of light deviated from 90˚. Taking into account that in Europe in cloudy weather the specific power of solar radiation can fall below 100 W/m 2 , too large areas of solar panels were required to obtain any significant power. Therefore, the first solar power plants were built only in conditions of maximum luminous flux and clear weather, that is, in deserts near the equator.
A significant breakthrough in the creation of solar cells has returned interest in solar energy: for example, the cheapest and most accessible polycrystalline silicon cells, although they have a lower efficiency than monocrystalline ones, are less sensitive to operating conditions. A solar panel based on polycrystalline wafers will give enough stable voltage under partly cloudy conditions. More modern photovoltaic cells based on gallium arsenide have an efficiency of up to 40%, but are too expensive to make a solar battery with your own hands.
The video is a story about the idea of building a solar battery and its implementation
Is it worth doing?
In many cases solar will be very useful: for example, the owner of a private house or cottage, located far from the mains, can even support his phone charged from a compact panel, connect low-power consumers like car refrigerators.For this purpose, ready-made compact panels are produced and sold, made in the form of quickly folded assemblies based on synthetic fabric. In central Russia, such a panel measuring about 30x40 cm can provide power within 5 W at a voltage of 12 V.
A larger battery can provide up to 100 watts of electrical power. It would seem that this is not so much, but it is worth remembering the principle of operation of small ones: in them, the entire load is powered through a pulse converter from a battery of batteries that are charged from a low-power windmill. Thus, it becomes possible to use more powerful consumers.
Using a similar principle when building a home solar power plant makes it more profitable than a windmill: in summer, the sun shines most of the day, in contrast to the fickle and often absent wind. For this reason, the batteries will be able to gain charge during the day much faster, and the solar panel itself is much easier to install than requiring a high mast.
It also makes sense to use a solar battery solely as an emergency power source. For example, if a gas heating boiler with circulation pumps is installed in a private house, when the power is turned off, it is possible to power them through a pulse converter (inverter) from batteries that are maintained charged by a solar battery, keeping the heating system operational.
TV story on the subject
Own power supply will help out both in the absence of a centralized network (in remote and hard-to-reach regions, in the country, on a hike), and when building a more environmentally friendly approach to the consumption of natural resources.
It is not difficult to assemble your own solar station, it contains only four components:
- solar panels;
- battery charge;
- controller;
- inverter.
All of them are easy to find and order through online stores. But how to make a solar power plant with your own hands in order to create a full-fledged autonomous power supply system at home? First you need to collect information about your needs, the possibilities of the area where the solar station will operate, and make all the necessary calculations for the selection of components.
How to calculate the number of solar panels
Choosing a solar station begins with finding information on insolation in your area - the amount of solar energy that hits the earth's surface (measured in watts per square meter). These data can be found in special weather reference books or the Internet. Usually insolation is indicated separately for each month, because the level is highly dependent on the season. If you plan to use a solar station all year round, then you need to navigate by the months with the lowest rates.
Next, you need to calculate your electricity needs for each month. Remember that for an autonomous power supply system, not only the efficiency of energy storage, but also its economical use plays a role. Smaller needs will significantly save when buying solar panels and creating a budget version of a solar power plant with your own hands.
Compare your electricity needs with the insolation level in your area and you will find out the area of solar panels that is needed for your solar station. Please note that the efficiency of the panels is only 12-14%. Always go for the lowest score.
Thus, if the level of insolation in the most unfavorable month in your area is 20 kWh / m², then with an efficiency of 12%, one panel of 0.7 m² will generate 1.68 kWh. Your energy demand, for example, is 80 kWh/month. This means that in the most non-solar month, 48 panels (80/1.68) will be able to satisfy this need. You can read more about how to choose solar panels in our previous one.
How to install a solar panel
For best efficiency, install the solar panel so that the sun's rays fall on it at an angle of 90 degrees. Since the sun is constantly moving across the sky, there are two solutions here:
- Dynamic setup. Use a servo to turn the solar panel as the sun moves across the sky. The servo drive will allow you to collect 50% more energy than a static installation.
- Stationary installation. To extract maximum benefit From the fixed position of the solar panel, it is necessary to find the installation angle at which the panel will collect the maximum possible amount of sun rays. For year-round operation, this angle is calculated using the formula +15 degrees to the latitude of the area. For the summer months, this is -15 degrees to the latitude of the area.
How to choose a charge controller
Another way to assemble a solar power plant yourself in order to make it work efficiently is to use it, which allows you to track maximum power points (eng. MPPT). Such a controller can accumulate energy even during low light conditions and continues to supply it to the battery in an optimal way.
So, from the solar panels, energy is supplied to the battery. This allows energy to be stored so that it can be used even in the absence of sunlight. In addition, batteries smooth out uneven energy supply, for example, when strong wind or clouds.
To choose and install a battery for a home solar power station with your own hands, you need to consider two parameters:
- It is very important that the charging current (from the panels) does not exceed 10% of the rated capacity level for acid batteries and 30% for alkaline devices.
- Inverter design with voltage on the low side.
Consider battery self-discharge indicators (not always indicated by manufacturers). For example, acid devices are recharged every six months to avoid breakage.
How to choose an inverter
Description of the parameters and mandatory functions of the ideal inverter:
- sinusoidal signal with distortion not higher than three percent;
- when the load is connected, the voltage amplitude changes by no more than ten percent;
- double current conversion - direct and alternating;
- analog AC conversion part with good transformer;
- short circuit protection;
- overload reserve.
When modeling your home's electrical system, group the loads so that different types of loads are powered by different inverters.
Heliostations are a working alternative way of supplying the house with energy. But not in all regions, insolation is sufficient for the payback of solar equipment and for the full supply of electricity. Sometimes you should pay attention to hybrid solar power plants, which can also be built with your own hands, but where, in addition to solar panels, there can be windmills, as well as diesel or even gasoline generators.
If you just want to try to “tame” solar energy, but are not ready to completely change the power supply of your home, make a mini solar power station with your own hands. It will consist of several solar panels, a battery and a controller. All this will fit in a suitcase, but will provide you with energy in case of a sudden power outage, a trip to the country or to nature. Calculations and selection of components are carried out according to the same principle as for a full-fledged home station.
Why pay a lot of money (or any money at all) for a program that shows you how to make a solar panel when you can get the same thing for free?
I will tell you how to make a solar panel, the cost of which will be half that of the purchased counterpart. Such systems are made from materials sold in local hardware stores and electronics stores. You can also buy materials online. Time to collect sunlight and make electricity free!
Step 1: How it all started
I have watched my electricity bills go up year after year, simply because modern Appliances always on in standby mode. And this is not only harming the environment, but also harming my bank account, because I am actually paying for “nothing”. I could not constantly turn off devices from the network, as this complicated their use and took extra time for permanent settings. Gradually, I began to look for renewable energy sources to offset my unnecessary expenses. was not an option, I live in a very quiet area with no winds. Hydroelectric power is also not suitable, since I live in a flat area with practically no rivers. That's why solar energy seemed like the best choice to me.
The cost of ready-made solar systems is simply enormous, such an installation will not pay for itself even in 20 years of continuous operation. I tried to win one of the government grants for such a system, but there are very few of them, and I did not get mine. But this did not make me give up the goal, although I did not want to pay so much money for the system. The logical decision was to make it yourself. Yes, you read that right, I wanted to make my own solar system. Now I can say for sure that this is quite possible, all materials are available in local stores or on the Internet. I am not a technical genius and do not have much experience in working with electricity, I just studied the design of solar panels, what they are made of, how you can assemble a solar system with your own hands. The result is this master class.
Step 2: Start
For one panel you will need:
28 solar cells with a peak power of 3.1 W
- 2 sheets of glass
- 6A blocking diode
- 24 m of ribbon wire 2 mm wide
- 2 m ribbon wire 5 mm wide
- flux
- junction box
- terminal block
- solder
- 1 m heat shrink tubing
- 100% silicone sealant
- crosses for tiles
- 2 aluminum corners
In addition, you will need mounting materials. The total cost of one panel was 211.36 euros. I made a list the right materials for one panel, and the design provides for two, one inverter and a device for measuring production. In total, the cost of materials is 441.72 euros or 20,778 rubles.
Shortly after planning the right materials, I found solar panels online. After collecting information from various sources, I made a wiring diagram and purchased ordinary glass from a local store. Tools were also purchased locally.
Mounting materials, such as wires, mounting box, screws, mounting brackets, I did not buy, because all this was already gathering dust in the shed.
Step 3: Production process
I soldered the solar cells according to the wiring diagram in groups. This summed the voltage of all cells to achieve the desired output (the maximum possible). I made a panel of 28 cells (4 rows of 7 elements). In this arrangement and size, the panel fit perfectly into place in my garden. As a result, I received 28x0.5V = 14V (in theory). I still did not know the current strength, because I bought inexpensive class B elements for this experiment (I just saved it).
When I finished soldering the cells, they were all upside down (since I soldered them from the back). I dripped silicone onto each panel and glued them to a 4mm sheet of glass (this sheet will be the back of the panel).
I let it dry to allow the silicone to evaporate enough (it's really important that any excess fumes are gone as they react with the solder on the batteries).
Then I turned the glass sheet over and inserted small tile crosses between the sections (usually used when laying tiles on the walls to maintain the same gap on all sides). I did this so that, together with the second sheet of glass, the whole structure would be more dense and durable. After placing the crosses, I applied a layer of silicone around the edges of the glass sheet at a distance of about 3 cm from the edge (we need this edge for embedding in the next steps).
I then placed another sheet of glass on top of the elements so that the solar cells are now sandwiched between two sheets of 4mm thick glass (you could say I glazed the elements, that was my simple plan).
Step 4: Evaporation
I left the whole structure to dry for at least a day. The longer the better. Between two sheets of glass left empty place along the edges. I filled this space with sealant. I sealed the cells with two layers of silicone, and if one of them depressurizes, then the second one will reliably protect the batteries inside. After applying the second layer, I left the structure to dry for another 3 days. When the silicone was completely dry, I made an aluminum profile frame to protect the glass body of the panel.
Step 5: Back Box
On the back side of the panel, I made a mounting box with a terminal block. On one side of the block there is a +, and on the other side there will be a wire to the inverter. There is also a diode in the back box between the + from the panel to the + going to the inverter, this prevents electricity from flowing to the panel when the panel is not producing any electricity (e.g. at night).
Step 6: Inverter
I contacted a solar panel vendor to order a suitable inverter. I need a small inverter (I'm going to produce a small amount of electricity with my system). I took an OK-4 inverter rated for 24 - 50V, 100W max. It was the smallest inverter. It turns out that one panel will not be enough, because it gives out a maximum of 14V. I needed a second panel, and in total I will get 28V, which will be enough for the inverter. Given that this is not a strong current, then two panels could not be enough. And I made the third panel, which achieved consistently high performance.
I know this inverter is maxed out at 100 watts and my three panels will do more (135 watts), but that maximum from the panels will be canceled out by the inverter. Anything that goes beyond the allowable power will be released in the form of heat. Yes, I know what you're thinking: I'm wasting electricity. This is true, but such a bust will only be in the brightest hours, just a few hours a day. For most of the day, the panels don't get enough light to generate more than 100 watts. But with this design, I constantly extract electricity in sufficient quantities - from sunrise to sunset, simply because the inverter is able to operate at low voltage. I get a lot more electricity powering the panels all day than I lose mowing maximum power during the zenith hours.
Step 7: Figures and Facts
My OK-4 inverter did not have a built-in output display, so I needed a separate meter.
Well, again, I did not want to lay out a lot of money for this device. In a local store, I bought just such a model - ELRO M12 Power Calculator, which is designed to calculate the electricity consumption of household appliances, but it works well for calculating the generation of solar electricity (this calculator works in both ways, it can both take and give electricity to the network) .
And this calculator plugs directly into the outlet without super complicated wiring (just what you need).
Each solar cell puts out 0.5V x 6A = 3W, but that's the maximum output under ideal conditions. For the entire panel, this maximum power is 28 cells x 3W = 84W.
But I know from experience that these are very optimistic figures, which in reality are usually 20% less. So in real life I expect a performance of about 67W.
My panel isn't exactly positioned perfectly to the sun, but it's not that important right now. The panels are at a 10 degree angle (instead of 35) and not exactly south.
But this is a temporary setup, I just want to see how they perform in real conditions in cold air temperatures, a lot of rain and a foggy sun.
In the near future I will fix the installation.
Considering all factors, the panels produce 15V x 3A = 45W each, provided that the cell voltage is used to the maximum.
The amperage can be increased by tilting the panels more towards the sun, but this is currently not possible where I placed them.
Step 8: Performance
