Do-it-yourself solar generator: instructions for making an alternative energy source
Alternative energy sources, allowing to provide living space with heat and electricity in the required amount - an expensive “pleasure”, requiring significant financial costs for the purchase, installation and installation.
Make the solar generator with your own hands much cheaper and quite capable of many home craftsmen. Consider the instructions available to describe all the nuances of the manufacturing process.
How does a solar power generator work?
A solar generator is a complex of photoelectric semiconductor elements that directly convert solar energy into electrical energy.
The quanta of light produced by rays when they hit the photographic plate knock out an electron from the final atomic orbit of the work item.This effect creates a multitude of free electrons, which form a continuous stream of electric current.
Silicon is used as the active material. It is characterized by high efficiency and provides the photoelectric conversion coefficient in the normal mode at the level of 20%, and under favorable conditions - up to 25%.
On one side of the silicon wafer is applied a thin coating of passive chemical elements - boron or phosphorus. It is on this surface as a result of intense exposure to sunlight that the active release of electrons occurs. Phosphoric film securely holds them in one place and does not allow to scatter.
Metal “tracks” are located on the working plate itself. Free electrons are built on them, thus creating an orderly movement, that is, an electric current.
The disadvantages of the plates include only the complexity and costly process of cleaning the silicon itself, and to avoid these problems, they actively master the use of alternatives in the form of gallium, cadmium, indium and various copper compounds. However, so far there are no real competitors for silicon elements.
What you need to work?
For the manufacture of the generator in the home requires tools and materials such as:
- modules to convert sunlight into energy;
- aluminum corners;
- wooden slats;
- chipboard sheets;
- a transparent element (glass, plexiglass, plexiglas, polycarbonate) to create protection for silicon wafers;
- screws and screws of different sizes;
- dense foam with a thickness of 1.5-2.5 mm;
- high-quality sealant;
- diodes, terminals and wires;
- screwdriver or a set of screwdrivers;
- soldering iron;
- hacksaw for wood and metal (or Bulgarian).
The amount of materials needed will directly depend on the planned size of the generator.Large-scale work will entail additional costs, but in any case will cost less than the purchase module.
For the final testing of the assembled unit using an ammeter. It allows you to fix the real efficiency of the installation and helps determine the actual return.
How to choose the type of photoconverter?
The actions to create a solar generator with your own hands begin with the choice of the type of photoelectric silicon converter. These components are of three types:
- single crystal;
Each option has its own advantages and disadvantages, and the choice in favor of any of them is made based on the amount of funds allocated for the purchase of all system components.
Amorphous modules consist not of crystalline silicon, but of its derivatives (silane or silicon-hydrogen).By vacuum deposition, they are applied with a thin layer on high-quality metal foil, glass or plastic.
Finished products have a faded, blurry gray tint. Visible silicon crystals on the surface are not observed. The main advantage of the elements is an affordable price, however, their efficiency is very small and varies in the range of 6-10%.
Polycrystalline solar cells are produced with the gradual very slow cooling of the silicon melt. The resulting products are distinguished by a rich blue color, have a surface with a clearly defined pattern resembling a frosty pattern, and are effective in the region of 14-18%.
The areas inside the material, separated from the general structure by granular boundaries, interfere with higher efficiency-productivity.
Single crystal converters
Single-crystal modules are characterized by a dense dark color and consist of whole crystals of silicon. Their effectiveness exceeds the performance of other elements and is 18-22% (under favorable conditions - up to 25%).
Another advantage is considered an impressive service life - according to the manufacturers over 25 years. However, with prolonged use, the efficiency of single crystals falls and after 10–12 years, the photo output already amounts to no more than 13–17%.
To create a solar generator at home, they mainly take poly-and single-crystal plates of various dimensions. They are purchased in popular online stores, including on eBay or Aliexpress.
Due to the fact that photovoltaic cells are valued quite highly, many suppliers offer customers products of group B, that is, fully serviceable fragments with a small defect.Their cost differs from the standard price by 40-60%, due to which the collection of the generator costs a reasonable price, which is not too expensive to afford.
How to make a frame for the plates?
For the manufacture of the frame of the future generator using durable wooden slats or aluminum corners. The wooden version is considered less practical, since the material requires additional processing in order to avoid subsequent decay and delamination.
Aluminum has much more attractive physical characteristics and, due to its lightness, does not exert an unnecessary load on the roof or other supporting structure, where it is planned to install the unit.
In addition, due to the anti-corrosion coating, the metal does not rust, does not rot, does not absorb moisture and easily tolerates the effects of any aggressive atmospheric manifestations.
To create a frame construction of aluminum corners, first determine the size of the future panel.In the standard version, one photocell uses 36 photocells with a size of 81 mm x 150 mm.
For the correctness of the subsequent operation between the fragments leave a small gap (about 3-5 mm). This space allows to take into account the change in the basic parameters of the base, exposed to atmospheric manifestations. As a result, the total size of the workpiece is 83 mm x 690 mm with a frame angle of 35 mm.
After determining the size of the corners cut out the necessary fragments and using fasteners assemble them into frame frames. A layer of silicone sealant is applied to the inner surface of the structure, very carefully observing that there are no gaps or voids. On this depends the integrity, strength and durability of the mounted structure.
A protective transparent material is placed on top (glass with anti-reflective coating, plexiglas or polycarbonate with special parameters) and securely fasten it with metal hardware (1 each with a short and 2 each with a long frame part and 4 corners).For work use a screwdriver and screws of suitable diameter. At the end of a transparent surface gently cleaned of dust and small debris.
Selection of a transparent element
The main criteria for selecting a transparent element to create a generator:
- the ability to absorb infrared radiation;
- the level of refraction of sunlight.
The lower the refractive index, the higher the efficiency of the silicon wafers.
Plexiglas and plexiglas have the lowest light reflectance. Polycarbonate also has far from the best performance. To create frame structures for home-made heliosystems, it is recommended, if possible, to use anti-reflective transparent glass or a special type of polycarbonate with an anti-condensation coating that provides the necessary level of thermal protection.
The best characteristics in terms of absorption of infrared radiation have a strong heat-absorbing plexiglass and glass with the option of infrared absorption. In plain glass, these figures are much lower. It depends on the efficiency of IR absorption, whether silicon wafers will be heated during operation or not.
If the heat is minimal, photovoltaic cells will last a long time and provide a stable return. Overheating of the plates will lead to interruptions in the operation and rapid failure of individual fragments of the system or the entire complex.
Installation of silicon photocells
Immediately before installation, protective glass, laid in aluminum frames, is well cleaned of dust and degreased with an alcohol-containing composition.
The purchased photocells are placed exactly on a marking substrate at a distance of 3-5 millimeters from each other and mark the corners of the overall structure. Then proceed to the soldering of elements - the most important and time-consuming part of the work on assembling the generator.
The propelling of the active elements of the generator is carried out according to the scheme in which the “+” tracks are on the outside, and the “-” channels are located on the inside of the plate. For correct connection of the contacts, flux (soldering acid) and solder are first applied, and then they are processed in strict sequence from top to bottom. In the end, all rows are interconnected.
The next step is to make the sizing of photocells.To do this, a little sealant is squeezed out into the center of each silicon plate, the resulting chains of elements are turned upside down and placed in strict accordance with the markings previously applied. Gently press the plates with your hands, locking them in place. Act very carefully, trying not to damage or bend the material.
The contacts of photocells located at the edges lead to a separate tire (wide silver conductor), as “+” and “-”. Additionally, the complex is equipped with a blocking diode. Connecting to the contacts, it prevents the batteries from discharging through the frame structure at night.
At the bottom of the frame, drill holes through which the wires lead to the outside. That they do not sag, use in work silicone sealant.
How to test the mounted unit?
Before finally sealing the assembled generator, it must be tested to identify potential faults during the soldering process. The most sensible option is to check each soldered row separately. So immediately it becomes clear where the contacts are connected poorly and re-processing is required.
For the test using a household ammeter.The measurement is carried out in a cloudless sunny day at lunchtime (period from 13 to 15 hours). The design is placed in the courtyard and set at an appropriate angle of inclination.
An ammeter is connected to the output contacts of the solar battery and the short-circuit current is measured. If the device shows results above 4.5 A, the system is completely correct and all connections are soldered clearly and correctly. Lower data appearing on the tester’s display indicate violations that need to be traced and re-soldered.
Traditionally, solar generators, self-designed from photovoltaic cells with a small defect (group B), on the test, show figures from 5 to 10 Amps. Factory production units show data 10-20% higher. This results from the fact that in production silicon plates of group A are used, which do not have any defect in the structure.
The final stage of work
If the test showed that the battery is fully functional, it is sealed with a special silicone sealant or a more expensive and durable epoxy compound. The work provides two ways to conduct.
- Full fill - when the entire surface is covered with a hermetic composition.
- Partial treatment - when the sealant is applied only on the extreme elements and the empty space between the elements.
The first option is considered more reliable and provides the system with full protection from external factors. Photo cells are clearly fixed in their places and work correctly with maximum efficiency.
When the filling is done, the sealant is allowed to “grab”. Then cover with a transparent element and tightly pressed to the plates.
Then a load is placed on the surface, which acts on the layers and squeezes air bubbles out of them. The finished generator is tested again and finally mounted on a previously prepared place.
Where and how to place the generator?
The installation site of the solar generator is chosen very carefully and without haste. Plates that receive light must be placed at an inclination so that the rays do not “fall” onto the surface perpendicularly, but rather “flow” along it. Ideally, the design is positioned so that it remains possible, if necessary, to adjust the angle of inclination, in such a way as to “catch” the maximum amount of sun.
It is quite permissible to put a solar system on the ground, but most often for placement they choose the roof of a house or utility room, namely, that part of it that goes to the most consecrated, mainly southern side of the site. It is very important that there are no high buildings and powerful, spreading trees nearby. Being in close proximity, they create a shadow and interfere with the full operation of the unit.
The average optimum for the installation of a solar generator is considered the level of the angle of inclination of the roof at 45⁰. With this arrangement, photovoltaic cells absorb the solar flux very efficiently and deliver the necessary amount of energy to ensure the proper functioning of the house.
For the European part of the CIS states, there are several other indicators. Professionals recommend taking a stationary angle of 50-60⁰ as a basis, and in moving structures during the winter season, position the batteries at an angle of 70⁰ to the horizon.
In the summer, to change the position and tilt the photocells at an angle of 30⁰.
Immediately before installation, the roof is additionally strengthened and equipped with special strong opornikami, since not every design has the ability to withstand the full weight of equipment for the conversion of solar energy.
In some cases, reinforced rafters are placed under the roof, protecting the roof from collapsing, potentially due to the increased load, which significantly increases in the winter season when snow accumulates on the roofing surface.
Conclusions and useful video on the topic
Features and nuances of photocell propayka for making their own home in an effective solar generator. Tips and tricks for masters, curious ideas and personal insights.
How to correctly test the photocell and measure its basic parameters. This information is useful in the subsequent calculations of the exact number of plates required for the full operation of the system.
A complete step-by-step description of the process of collecting a solar battery for a generator at home. Rules of work, ranging from the acquisition of the necessary elements and ending with the general test of the manufactured device.
Knowing about the device of solar generators, assemble them at home is not a big deal. Of course, the work will require attention, accuracy and thoroughness, but the result will justify all financial and labor costs. The finished unit in full will provide the building with heat and electricity, creating for the residents the necessary level of comfort.
Immediately threaten a large project is not worth it. For a start, it makes sense to try your hand at assembling a small unit, and then, having fully mastered all the nuances of the process, begin building a more powerful and large-scale installation.