Ecology of consumption. Science and technology: The successful use of solar ovens (cookers) was noted in Europe and India already in the 18th century. Solar cookers and ovens absorb solar energy, converting it into heat, which is stored inside an enclosed space.
The successful use of solar ovens (cookers) was noted in Europe and India as early as the 18th century. Solar cookers and ovens absorb solar energy, converting it into heat, which is stored inside an enclosed space. The absorbed heat is used for cooking, frying and baking. The temperature in the solar oven can reach 200 degrees Celsius.
Box solar ovens
Box solar ovens consist of a well-insulated box, painted black on the inside, in which black pots of food are placed. The box is covered with a two-layer "window" that lets solar radiation into the box and keeps the heat inside. In addition, a lid with a mirror is attached to it. inside, which, being folded back, amplifies the incident radiation, and when closed, improves the thermal insulation of the furnace.
The main advantages of box solar ovens:
- Use both direct and diffuse solar radiation.
- They can heat several pans at the same time.
- They are lightweight, portable and easy to handle.
- They don't need to follow the Sun.
- Moderate temperatures make stirring unnecessary.
- Food stays warm all day long.
- They are easy to manufacture and repair using local materials.
- They are relatively inexpensive (compared to other types of solar ovens).
Of course, they also have some drawbacks:
- With their help, you can only cook during the daytime.
- Due to moderate temperatures, cooking takes a long time.
- The glass lid leads to significant heat loss.
- Such ovens "do not know how" to fry.
Due to their advantages, box solar ovens are the most common type of solar ovens. They are different types: industrial production, artisanal and homemade; the shape can resemble a flat suitcase or a wide low box. There are also stationary stoves made of clay, with a horizontal lid (in tropical and subtropical regions) or inclined (in temperate climates). For a family of five, standard models with an aperture area (entrance area) of about 0.25 m2 are recommended. On sale there are also larger versions of furnaces - 1 m2 or more.
Since the heat absorbed inner surface boxes should be transferred to pots, the best material for the box is aluminum, which has high thermal conductivity. In addition, aluminum does not corrode. For example, a steel box, even with a galvanized coating, cannot withstand the hot and humid environment inside the oven for a long time during the cooking process. Sheet copper is too expensive.
Do not attach metal parts to the outside of the box that could create thermal bridges. thermal insulation material can serve as glass, synthetic wool or some natural material(hulls of peanuts, coconuts, rice, corn, etc.). Whatever material is used, it must remain dry.
The furnace cover can consist of one or two glasses with an air layer. The distance between two layers of glass is usually 10-20 mm. Studies have shown that the use of a transparent honeycomb material that divides the interior into small vertical cells can significantly reduce the heat loss of the oven, thus increasing its efficiency. The inner glass is subjected to thermal stress, so it is often used strained glass; or both layers may consist of ordinary glass with a thickness of about 3 mm.
The outer cover of the solar oven is a reflector that amplifies the incident radiation. The reflective surface can be an ordinary glass mirror, a plastic sheet with a reflective coating, or an unbreakable metal mirror. IN last resort, you can use foil from cigarette packs.
The outer box of a solar oven can be made of wood, fiberglass or metal. Fiberglass is lightweight, inexpensive, and water resistant, but not very durable in continuous use. Wood is stronger, but heavier and more susceptible to deterioration due to moisture. Aluminum sheets in combination with wooden fasteners form the highest quality surface, resistant to mechanical stress, temperature changes and humidity. An aluminum-reinforced wooden box is the most durable, but it is more expensive and quite heavy, and it takes time to make.
The performance of a standard solar oven with an aperture area of 0.25 m2 reaches about 4 kg of food per day, i.e. Enough for a family of five.
Peak temperatures inside a solar oven can reach over 150°C on a sunny day in the tropics; this is approximately 120°C higher than the ambient temperature. Since the water contained in food does not heat up above 100°C, the temperature inside the filled oven will always be correspondingly lower.
The temperature in the solar oven drops sharply when dishes with food are placed in it. It is also important that the temperature remains well below 100°C. most cooking time. But a boiling point of 100°C is not necessary for cooking most vegetables and cereals.
The average cooking time in a solar oven is 1-3 hours in good sunny conditions and a moderate load. The use of thin-walled aluminum pans significantly reduces the cooking time compared to pans made of of stainless steel. In addition, the following factors also influence:
- Cooking time is reduced in high light conditions, and vice versa.
- High ambient temperatures shorten the cooking time and vice versa.
- A small amount of food in one preparation reduces the cooking time - and vice versa.
Mirror ovens (with reflector)
The simplest mirror oven is a parabolic reflector and a pan stand located at the focus of the oven. If the stove is exposed to the sun, then sunlight is reflected from all reflectors to the central point (focus), heating the pan. The reflector may be a paraboloid made of, for example, sheet steel or reflective foil. The reflecting surface is usually made of polished aluminium, mirror metal, or plastic, but may also consist of many small flat mirrors attached to the inner surface of the paraboloid. Depending on the desired focal length, the reflector can be in the form of a deep bowl into which the pan with food is completely immersed (short focal length, the dishes are protected from the wind) or a shallow plate if the pan is installed at the focal point at a certain distance from the reflector.
All reflector ovens use only direct solar radiation, and therefore must constantly turn towards the sun. This complicates their operation, as it makes the user dependent on the weather and the control device.
Advantages of mirror ovens:
- The ability to reach high temperatures and, accordingly, fast cooking food.
- Relatively inexpensive models.
- Some of them can also be used for baking.
The listed advantages are accompanied by some disadvantages:
- Depending on the focal length, the oven should rotate behind the Sun approximately every 15 minutes.
- Only direct radiation is used, and scattered sunlight is lost.
- Even with a little cloud cover, large heat losses are possible.
- Handling such a furnace requires a certain skill and understanding of the principles of its operation.
- The radiation reflected by the reflector is very bright, dazzles the eyes, and can cause burns if it comes into contact with the focal spot.
- Cooking is limited to daytime hours.
- The cook has to work in the hot sun (with the exception of fixed focus ovens).
- The efficiency of the stove depends to a large extent on the changing strength and direction of the wind.
- A dish cooked during the day cools down in the evening.
The difficulty of handling these ovens, combined with the fact that the cook has to stand in the sun, is the main reason for their lack of popularity. But in China, where cooking traditionally requires high temperature and power, they are widespread.
Thermal power
The heat output of a solar oven is determined by the amount of solar radiation, the working absorbing surface of the oven (typically between 0.25 m2 and 2 m2) and its thermal efficiency (typically 20-50%). The table compares typical values for area, efficiency and power for a box oven and a reverberatory oven.
Standard values for area, efficiency and output of box oven and reverberatory oven
As a rule, reflector ovens have a much larger work surface than box ones. Consequently, they are much more powerful, able to boil more water, cook more food, or process comparable quantities in less time. On the other hand, their thermal efficiency is lower because the dishes cool down under the influence of the atmosphere.
In tropical and subtropical countries, you can expect clear weather and normal daily light almost all year round. Around noon, when the total solar irradiance reaches 1000 W / m2, it is quite realistic to count on a thermal output of 50-350 W, depending on the type and size of the stove. The amount of radiation in the morning and in the daytime is naturally lower and cannot be fully compensated by the solar tracking system.
For comparison, burning 1 kg of dry wood produces approximately 5000 watts times the thermal efficiency of the stove (15% for a primitive hearth and 25-30% for an improved stove used in developing countries). The heat output actually reaching the dishes is therefore 750-1500 watts.
The amount of solar radiation is sharply reduced when cloudy and during the rainy season. In conditions of lack of direct radiation, a solar oven is unsuitable for anything other than keeping cooked food warm. The weak point of solar ovens (regardless of their type) is that on cloudy and rainy days (2-4 months per year for most developing countries) food has to be cooked using conventional means: wood, gas or kerosene burner.
Solar radiation and stoves
The main prerequisite for the successful use of a solar oven is adequate illumination with a small number of cloudy days throughout the year. The duration and intensity of solar radiation must allow the use of the solar oven for extended periods. While in Central Europe cooking using solar energy maybe on a sunny summer day, preferably for a solar oven minimal amount solar energy 1500 kWh/m2 per year (corresponding to an average daily insolation of 4 kWh/m2). But annual averages can sometimes be misleading. An essential condition for the suitability of a solar oven is stable summer weather, i.e. regular, predictable periods of cloudless days.
Resources of solar energy in different countries differ significantly even within the tropical belt in third world countries. For example, solar radiation in most regions of India is considered very good in terms of solar energy utilization. The average amount of solar energy is between 5 and 7 kWh/m2 per day, depending on the region. In much of the country, illumination is at its lowest during the rainy season and almost as low during December and January.
The climate and solar potential of Kenya are favorable for the use of solar ovens. Kenya is located close to the equator and therefore has a tropical climate. In the capital, Nairobi, the amount of solar energy ranges from 3.5 kWh/m2 per day in July to 6.5 kWh/m2 per day in February, while in other areas it remains almost unchanged (6.0 - 6.5 kWh/m2 per day in Lodwar). Solar radiation in Nairobi allows cooking with solar energy nine months of the year (except June-August). On the other hand, on cloudy or foggy days, one has to rely on traditional views fuel. However, in the province of Lodwar, solar ovens can be used all year round.
Solar ovens for developing countries
The purpose of using solar ovens is undoubtedly to save energy in the face of a double energy crisis: a crisis of the poor, consisting in a growing shortage of firewood, and a national energy crisis, increasing pressure on its balance of payments.
Compared to other countries, developing countries consume very little energy. For example, the rate of energy consumption per capita in India in 1982 - 7325 GJ - was one of the lowest in the world. But the country's energy consumption is growing almost twice as fast as its gross national product. The same is happening in other developing countries.
Most people in developing countries get the bulk of their energy from non-commercial sources: from traditional local energy resources, through their physical labor. They simply cannot afford to buy the right amount of commercially produced energy.
The logical consequence of this is the relative lack of fuel for the poor, whose standard of living is further degraded as a result. Solar ovens are a step towards improving their living conditions.
Of all the "poor majority" of the inhabitants of the third world countries, solar ovens should be used primarily by the rural population.
How much energy do you need to cook food
The daily need for fuel depends on what kind of food is cooked and on its quantity. A resident of a developing country burns, on average, 1 ton of firewood per year. A typical Indian family needs 3-7 kg of firewood per day; in cooler regions, the daily amount of firewood for one family is almost 20 kg in winter and 14 kg in summer. In the south of Mali, the average family (of 15 people) burns about 15 kg of firewood per day. A study conducted at an Afghan refugee camp in Pakistan showed that the daily need for firewood there is up to 19 kg per family. More than half of the firewood in a typical household goes to baking bread, the rest - to cooking other food. In winter, of course, more firewood is required.
Even though the amount of energy needed for cooking varies, solar cookers offer significant energy savings. The primary goal of solar ovens is to reduce the need for firewood, which is still the most important fuel for cooking. The problem is that wood is inexpensive compared to kerosene, bottled gas and electricity. Increasing uncontrolled cutting of trees for own use and for sale is the main cause of deforestation, desert expansion, soil erosion, lowering of groundwater levels, and has a long-term adverse impact on the ecological balance. The scarce remnants of forests in Pakistan and rampant deforestation in Kenya are proof that fears about this are not exaggerated.
In general, solar ovens are unlikely to make a big contribution to the national energy. However, they can significantly improve the living conditions of the poor, help them overcome their personal energy crisis.
Solar ovens come in many shapes and sizes. Here are some examples: oven, concentrator oven, reflector, solar steamer, etc. With all the variety of models, all ovens capture heat and keep it in a heat-insulated chamber. In most models, sunlight directly affects food.
A solar oven is a self-contained oven that operates without the use of combustible fuels and electricity, but only with solar energy, which is an environmentally friendly free renewable natural resource with a large capacity.
Description:
A solar oven is a self-contained oven that works without the use of fuel. fuel and electricity, but only through solar energy, which is an environmentally friendly free renewable natural resource of large capacity.
For maximum efficiency solar bake should be used in places with high light, with the most days of clear weather and warm temperatures environment. The lower the illumination and the colder the ambient temperature, the lower the efficiency of the furnace.
The general principle of operation of solar ovens:
The design of the solar furnace can be any, but the principle of their operation is the same.
The direct and reflected sun rays from the mirror surface are directed and concentrated, raising the temperature in a certain area, in which the cooking utensils are placed, painted in a dark color for better heating.
Advantages:
- autonomy. The solar oven does not depend on the connection to the power supply network, storage and fuel, as it uses only thermal energy from the sun,
– environmental friendliness. The operation of the furnace does not harm the environment,
- mobility. The ability to move the oven to the right place without much effort,
– fire safety. The use of combustible fuel and electricity is excluded.
Application:
The solar oven is used for:
– water heating;
- cooking;
Under changing environmental conditions, the solar stove can be used in conjunction with other types of stoves to save fuel resources.
The most common types of solar ovens are:
box look:
A solar oven is a box that is closed on top with glass that lets the sun's rays in, but does not release thermal energy. To increase heating, reflective panels are installed on the sides of the structure, which, at a set angle of inclination, direct the sun's rays into the oven. In this type of ovens, it is provided that the panels are closed after use for more convenient and safe transportation and storage.
For heating, the stove uses direct and reflected diffused sunlight.
Parabolic reflector:
The solar oven is a concave mirror disk, in the focus of which there are platforms for a container where food is cooked. This type of solar ovens requires adjustment to the sun, which is carried out by a manual or automatic drive, which allows you to direct the structure along the movement of the sun and receive maximum thermal energy.
Use the potential solar heat It is possible not only to generate electricity at large power plants or to heat housing and utility complexes, but also in the ordinary household sphere of human activity, for example, for cooking. The very idea of \u200b\u200bcreating a stove that runs exclusively on solar energy is so relevant that craftsmen have long been able to put it into practice. This article will help you make a DIY solar oven with little effort so that you can provide yourself and your friends with a delicious hot lunch. The very forces of nature will assist you in this. It is clear that the cooking time in a solar oven will be much longer,than in a conventional oven or on an electric stove. However, such a design can be placed next to a barbecue or barbecue, thereby giving newness to your site.
For the manufacture of a solar furnace, inexpensive and commonly available materials are used:
bars;
- plywood 6-10 mm;
- roofing iron 0.5mm (galvanized);
- glass 3-4 mm;
- insulation (mineral wool).
- mirror.
First of all, we make the frame of the solar furnace from 40x40 bars and plywood. The thicker the plywood, the stronger the structure will be.
We make a glass frame that is attached to the body with hinges.
From roofing iron 0.5 mm. cut out the inside of the furnace (casing). At the same time, we cut the sheet according to the drawing.
After the casing is ready, with the help of nails we nail it inside the casing. Then we process the edges with sandpaper so that there are no burrs.
We install the glass in the frame on a transparent silicone sealant and fix it with glazing beads.
We mount the reflective panel on the hinges.
Do not forget to attach handles for carrying the solar oven and for opening the glass door.
We carefully insulate with mineral wool on the sides, between the metal casing and the body, and the bottom of the furnace. Then we sew the bottom with plywood.
We paint the metal casing with heat-resistant, black matte paint.
Glue a mirror onto the reflective panel ( mirror tiles)
The solar oven is ready to go. The first use of the solar oven, it is necessary to produce without food. Since the paint, in the early days, may give off an unpleasant odor.
Do not forget to treat the oven body with paint, antiseptic, to prevent atmospheric exposure.
The oven must be placed in direct sunlight. If the sun is low, use a reflector for maximum efficiency.
For faster cooking, use black cookware, preferably thin aluminum.
Second production method. Unfortunately, no photos.
So, to build a solar oven, we need the following materials:
- wooden or metal box
- a piece of dark cardboard, preferably black
- several pieces of small, black-colored stones
- glass according to the size of the box
- four pieces of tin as reflectors.
Let's start with the construction of the main frame. It can be welded from metal corners, and it is best to knock it down from bars and boards. Choose the size and shape of the box to your taste, depending on the type and amount of food being cooked. It does not have to be a strictly square or rectangular stove. You can give the design any shape, such as hexagonal, round, and even elliptical. Here, perhaps, everything depends on your imagination and desire to do something unusual and original.
When the box is done, it is necessary to cover the bottom and inner walls with black cardboard or thick paper. The color of the skin must be black, as it absorbs the sun's rays more efficiently. It is necessary to fasten the paper to the box with carnations with a large hat or self-tapping screws with a washer.
Now cut the reflectors out of tin to fit the box, sand all sides with sandpaper or a file to remove burrs, and attach four reflectors to the top of the box. This can be done using metal or plastic corners, or simply screw the sheet with screws and bend it at the required angle to the Sun. It would be more correct to install reflectors on window hinges, which can be bought on the market or in any hardware store. With the help of loops, you can easily adjust the reflectors depending on the position of the Sun in the sky.
Tin reflectors concentrate and redirect the sun's rays into wooden box, thus ensuring high-quality and fast cooking.
The last step in making a solar cooker is cutting and installing the glass, which will perform the main function of absorbing sunlight, which will be converted into heat energy to heat food. In addition, the glass is a cover for your solar oven.
Now it remains only to find on your site or elsewhere a few dark stones of medium size and lay them on the bottom of the box. If you come across stones that are too light, try repainting them black and letting them dry completely. What are the stones for? They will be a kind of storage of solar heat. With their help, you can adjust the temperature in the stove, removing or, conversely, placing new stones. Hot stones will allow you to cook dinner even at a time when the Sun is not so bright and warm.
If you want to know exactly what the temperature is inside your "solar oven", don't be too lazy to install a small food thermometer, which can be purchased at any grocery store.
The heating time of the solar stove is about 20-30 minutes, depending on the time of day and the amount of solar activity.
That's it, your oven is ready. Enjoy only clean and healthy food!
The simplest design of solar ovens made from cardboard boxes
And now a master class on how to make the solar battery itself.
So what is solar battery, panel (sat)? Essentially, it is a container containing an array of solar cells. Solar cells are the ones that actually do all the work of converting solar energy into electricity. Unfortunately, to obtain power sufficient for practical use, solar cells need a lot. Also, solar cells are VERY fragile. Therefore, they are united in the SB. The battery contains enough cells to produce high power and protects the cells from damage. Doesn't sound too difficult. I'm sure I can do it myself.
I started my project, as usual, by searching the net for information on homemade SBs and was shocked at how little there was. The fact that few people have made their own solar panels made me think that it must be very difficult. The idea was shelved, but I never stopped thinking about it.
After some time, I came to the following conclusions:
- the main obstacle in the construction of the SB is the acquisition of solar cells at a reasonable price
- new solar cells are very expensive and difficult to find in normal quantities for any money
- defective and damaged solar cells are available on eBay and other places much cheaper
- solar cells of the "second grade" can possibly be used to make a solar battery
When it dawned on me that I could use defective items to make my SB, I set to work. Started by buying items on eBay.
Bought several blocks of monocrystalline solar cells measuring 3x6 inches. To make a SB, it is necessary to connect 36 such elements in series. Each element generates about 0.5V. 36 cells connected in series will give us about 18V, which will be enough to charge 12V batteries. (Yes, such a high voltage is indeed necessary for efficient charging of 12V batteries). Solar cells of this type are thin as paper, fragile and brittle like glass. They are very easy to damage.
The seller of these items dipped sets of 18 pcs. in wax for stabilization and delivery without damage. Wax is headache when it is removed. If you have the opportunity, look for items that are not covered with wax. But remember that they can get more damage in transit. Note that my elements already have wires soldered on. Look for elements with already soldered conductors. Even with such elements, you need to be prepared to do a lot of work with a soldering iron. If you buy elements without conductors, get ready to work with a soldering iron 2-3 times more. In short, it is better to overpay for already soldered wires.
I also bought a couple of sets of elements without wax filling from another seller. These items came packaged in a plastic box. They dangled in the box and chipped a little on the sides and corners. Minor chips don't really matter. They will not be able to reduce the power of the element enough to worry about it. The items I bought should be enough to assemble two SBs. I know I might break a couple while reassembling, so I bought a little more.
Solar cells are sold in a wide range of shapes and sizes. You can use larger ones or smaller ones than my 3" x 6". Just remember:
- Cells of the same type produce the same voltage regardless of their size. Therefore, to obtain a given voltage, the same number of elements will always be required.
- Larger elements can generate more current, and smaller ones, respectively, less current.
- The total power of your battery is defined as its voltage multiplied by the generated current.
Using larger cells will allow you to get more power at the same voltage, but the battery will be larger and heavier. Using smaller cells will make the battery smaller and lighter, but will not deliver the same amount of power. It is also worth noting that the use of cells in one battery different sizes - bad idea. The reason is that the maximum current generated by your battery will be limited by the current of the smallest cell, and larger cells will not work at full capacity.
The solar cells I chose are 3x6 inches and are capable of generating about 3 amps of current. I plan to connect 36 of these elements in series to get a voltage of just over 18 volts. The result should be a battery capable of delivering about 60 watts of power in bright sunlight. Doesn't sound very impressive, but it's still better than nothing. Moreover, this is 60W every day when the sun is shining. This energy will be used to charge the battery, which will be used to power lamps and small equipment just a few hours after dark. It's just that when I go to sleep, my energy needs are reduced to zero. In short, 60 watts is quite enough, especially considering that I have a wind generator that also produces energy when the wind blows.
After you buy your solar cells, store them in a safe place where they won't break, play with, or be eaten by your dog until you're ready to install them in your solar panel. The elements are very fragile. Rough handling will turn your expensive solar cells into little blue shiny and useless shards.
So, the solar battery is just a shallow box. I started by building such a box. I made it shallow so the sides don't obscure the solar cells when the sun is at an angle. Made from 3/8" plywood with 3/4" battens. The sides are glued and screwed into place. The battery will contain 36 3x6 inch cells. I decided to divide them into two groups of 18 pieces. just to make it easier to solder them in the future. Hence the central bar in the middle of the box.
Here is a small sketch showing the dimensions of my SB. All measurements are in inches (sorry, metric fans). The 3/4" thick beading goes around the entire plywood sheet. The same side goes in the center and divides the battery into two parts. In general, I decided to do so. But in principle, the dimensions and overall design are not critical. You can freely vary everything in your sketch. I give the dimensions here for those people who constantly whine so that I include them in my sketches. I always encourage people to experiment and invent their own ideas rather than blindly follow instructions written by me (or anyone else). Perhaps you can do better.
View of one of the halves of my future battery. This half will house the first group of 18 elements. Notice the small holes in the sides. This will be the bottom of the battery (the top is at the bottom in the photo). These are ventilation openings designed to equalize the air pressure inside and outside the SB and serve to remove moisture. These holes should only be at the bottom of the battery, otherwise rain and dew will get inside. The same ventilation holes must be made in the central dividing bar.
Next, I cut out two pieces of fiberboard that fit the size. They will serve as substrates on which solar cells will be assembled. They should fit freely between the sides. It is not necessary to use perforated fiberboard sheets I just happen to have these on hand. Any thin, rigid, and non-conductive material will do.
To protect the battery from weather troubles, front side cover with plexiglass. These two pieces of plexiglass were cut out to cover the entire battery. I didn't have one large enough piece. Glass can also be used, but glass breaks. Hail, rocks, and flying debris can shatter glass or bounce off plexiglass. As you can see, a picture is starting to emerge of how the solar battery will look like in the end.
Oops! In the photo, two sheets of plexiglass are connected on the central partition. I drilled holes around the edge to seat the plexiglass on the screws. Be careful when drilling holes near the plexiglass edge. You will press hard - it will break, which happened to me. In the end, I just glued the broken off piece and drilled a new hole nearby.
After that, I painted all the wooden parts of the solar panel with several coats of paint to protect them from moisture and environmental influences. I painted the box inside and out. When choosing the type of paint and its color, a scientific approach was used. I churned out all the leftover paint I had in the garage and chose one that had enough paint to do the job.
The substrates were also painted in several layers on both sides. Make sure you paint everything well, otherwise the wood may warp from moisture. And this can damage the solar cells that will be glued to the substrates.
Now that I have the base for the SB, it's time to prepare the solar cells.
As I said before, removing wax from solar cells is a real headache. After some trial and error, I finally found a good way. But I still recommend buying items from someone who doesn't wax them.
The first step is to "dip" in hot water to melt the wax and separate the elements from each other. Do not let the water boil, otherwise the steam bubbles will strongly hit the elements one against the other. Boiling water may also be too hot, the elements may be broken electrical contacts. I also recommend dipping elements in cold water and then heat them slowly to avoid uneven heating. Plastic tongs and a spatula will help separate the elements once the wax has melted. Try not to pull hard on the metal conductors - they can break. I discovered this when I was trying to separate my elements. It's good that I bought them with a margin.
Here is the final version of the "installation" that I used. My friend asked what I was cooking. Imagine her surprise when I answered, "Solar cells." The first "hot bath" for melting the wax is in the background on the right. In the foreground on the left is hot soapy water and on the right is clean hot water. Temperatures in all pots are below the boiling point of water. First, melt the wax in a distant pan, transfer the elements one by one to soapy water to remove wax residues, and then rinse in clean water. Lay items out on a towel to dry. You can change the soapy water and rinse water more often. Just do not drain the used water into the sewer, because. the wax will harden and clog the drain. This process removed virtually all of the wax from the solar cells. Only a few left thin films, but this will not interfere with the soldering and operation of the elements. Washing with solvent will probably remove the wax residue, but it can be dangerous and smelly.
Several separated and cleaned solar cells are dried on a towel. Once separated and the protective wax removed, they became surprisingly difficult to handle and store due to their brittleness. I recommend leaving them in the wax until you are ready to install them in your Sat. This will keep you from breaking them before you can use them. Therefore, build the base for the battery first. It's time for me to install them.
I started by drawing a grid on each base to make it easier to set up each element. Then I laid out the elements on this grid with the reverse side up, so they can be soldered together. All 18 cells for each half of the battery must be connected in series, after which both halves must also be connected in series to obtain the required voltage.
Soldering the elements together is difficult at first, but I quickly got used to it. Start with just two items. Place the connecting wires of one of them so that they cross the solder points on the back of the other. You also need to make sure that the spacing between the elements matches the markup.
I used a low power soldering iron and rosin core solder rod. Also, before soldering, I smeared the solder points on the elements with flux using a special pencil. Do not put pressure on the soldering iron! The elements are thin and fragile, press hard and break. I was sloppy a couple of times - I had to throw out a few elements.
I had to repeat soldering until a chain of 6 elements was obtained. I soldered the connecting busbars from the broken elements to the back of the last element of the chain. I made three such chains, repeating the procedure twice more. There are 18 cells in total for the first half of the battery.
Three chains of elements must be connected in series. Therefore, we rotate the middle chain by 180 degrees with respect to the other two. The orientation of the chains turned out to be correct (the elements are still lying upside down on the substrate). The next step is to glue the elements into place.
Gluing the elements will require some skill. We apply a small drop of silicone sealant in the center of each of the six elements of one chain. After that, turn the chain face up and place the elements according to the markup that was applied earlier. Lightly press down on the elements, pressing in the center to stick them to the base. Difficulties arise mainly when flipping a flexible chain of elements. A second pair of hands won't hurt.
Do not apply too much glue and do not glue the elements anywhere but the center. The elements and the substrate on which they are mounted will expand, contract, bend and deform with changes in temperature and humidity. If you glue the element over the entire area, it will break over time. Gluing only in the center allows the elements to freely deform separately from the base. The elements and the base can be deformed in different ways and the elements will not break.
Here is the fully assembled half of the battery. I used a copper braid from a cable to connect the first and second chain of elements.
You can use special tires or even ordinary wires. I just had a copper braid from the cable at hand. We make the same connection on the reverse side between the second and third chain of elements. With a drop of sealant, I attached the wire to the base so that it would not “walk” or bend.
Test the first half of the solar battery in the sun. With a weak sun in a haze, this half generates 9.31V. Hooray! Works! Now I need to make another half of the same battery.
After both bases with elements are ready, I can place them in place in the prepared box and connect.
Each of the halves is placed in its place. I used 4 small screws to secure the base with the cells inside the battery.
I passed the wire for connecting the halves of the battery through one of the ventilation holes in the central side. Here, too, a couple of drops of sealant will help secure the wire in one place and prevent it from dangling inside the battery.
Each a solar panel in the system must be provided with a blocking diode connected in series with the battery. The diode is needed to prevent the discharge of batteries through the battery at night and in cloudy weather. I used a 3.3A Schottky diode. Schottky diodes have a much lower voltage drop than conventional diodes. Accordingly, there will be less power loss on the diode. I bought a set of 25 31DQ03 diodes on eBay for just a couple of bucks. I will still have a lot of diodes for my future SBs.
At first I planned to attach a diode outside the battery. But after looking specifications diodes, I decided to put them inside the battery. For these diodes, the voltage drop decreases with increasing temperature. There will be a high temperature inside my battery, the diode will work more efficiently. We use some more silicone sealant to secure the diode.
I drilled a hole in the bottom of the battery near the top to get the wires out. The wires are tied into a knot to prevent them from being pulled out of the battery, and secured with the same sealant.
It is important to let the sealant dry before we put the plexiglass in place. I recommend based on previous experience. Vapors from silicone can form a film on the inside surfaces of plexiglass and elements if you do not allow the silicone to air dry.
And a little more sealant to seal the outlet.
I screwed a two-pin connector onto the output wire. The socket of this connector will be connected to the battery charge controller that I use for my wind turbine. Thus, the solar battery will be able to work with it in parallel.
This is what the finished SB looks like with the Plexiglas screen screwed on. Plexiglas is not sealed yet. At first I did not seal the joints. Did a little testing first. According to the results of the tests, I needed access to the insides of the battery, a problem was discovered there. I lost contact on one of the elements. Maybe this happened due to a temperature difference or due to careless handling of the battery. Who knows? I disassembled the battery and replaced this damaged element. Since then there have been no problems. In the future, I may seal the joints under the plexiglass with sealant or cover them with an aluminum frame.
Here are the voltage test results of the completed battery in the bright winter sun. The voltmeter shows 18.88V with no load. This is exactly as I expected.
And here is the current test under the same conditions (bright winter sun). The ammeter shows 3.05A - short circuit current. This is just close to the calculated current of the elements. Solar battery works great!
Solar battery at work. I move it around a couple of times a day to keep it aligned with the sun, but it's not that big of a deal. Perhaps someday I will build an automatic system for tracking the sun.
The solar oven is made according to different technologies, so its device is different from each other. Industrially produced, such products are characterized by a high price. Many models can be made by yourself with a minimum of funds and a maximum of effort. Before starting the analysis of homemade models, we will consider one industrial furnace for general development - GoSun.
This solution is based on two technologies: a vacuum tube takes on concentrated energy from a mirror stand - a concentrator. Thus, the temperature inside the tube reaches 280 ° C in a few minutes, which makes it possible to cook, steam, fry any dish. There are a number of sites with recipes adapted for such an oven. This cooking method is in no way inferior to the usual existing ones, it only adds environmental friendliness to the process.
Operation and types
operate such devices better in summer in open unshaded areas. All types of concentrators of such energy use reflective surfaces, so you should protect your eyes from the rays by wearing sunglasses when working with the stove.
First view from satellite dish
An oven based on an old satellite dish. To prevent the pot from blocking the sun, you should choose an offset type of antenna, the principle of operation is shown in the figure below.
The antenna mirror should be pasted over with a reflective film. In the place where the satellite converter stood, a cooking place should be equipped where dishes for cooking or heating food are installed or hung. To ensure the maximum temperature, it is necessary to move the antenna every half hour, thereby maintaining the maximum thermal focus on the heated object. The second view is from the Fresnel lens. With it, distilled or fresh water is obtained. Used in areas where there is a shortage fresh water or on the coast. At the epicenter of the beam, the temperature can reach 1000°C, which is a risk for thermal burns. Therefore, it must be used with extreme caution.
The basis of the design is the Fresnel lens. Previously used in the manufacture of televisions, you can get it from there or just buy it. It is in the lens that the price of the issue of manufacturing the furnace will consist. Manufacturing consists in building a frame for an existing lens, as shown in the illustration below.
Third view from cardboard. Similar to the first one considered, only the antenna is made of cardboard. The base is cut out, folded into a parabolic plate. A reflective layer of aluminum foil is glued onto the inner cup.
As an example, consider a reflector with a focal length of 130 mm and a diameter of 800 mm. The size is scaled if necessary. You will need a sheet measuring: meter by meter. It can be solid or composite of two or four pieces. Draw four concentric circles with the radii shown in the table. We divide them into 8 evenly spaced diameters (by 22.5 °). Each consists of 16 identical sectors.
On each, an arc is symmetrically marked, the length of which is shown in the table below. These values are the total length of the arc, including both sides of the division. Each arc runs at a very small angle (less than 5°) and is virtually indistinguishable from the corresponding cord.
Connect, approximately along the radial direction, the endpoints of the arcs just marked. You want to cut off the area outside the largest circle. The wedges indicated by the connections in the figure below will not collect beams. These will either be removed or used as fields to connect adjacent oars. There is no need to rush to cut the radial joints, instructions will be given later.
The oars are bent over the circles drawn earlier to create the edges. The circles are shown as dotted lines in the figure above. It is not easy to make a bend in an arc if the sheet material is not very thin and elastic.
Assembly
The sheet consists of parts connected in a circle. The best way- duplicate it on one part. You need to attach each part of the reflector on top of the duplicate.
After bending, the blades overlap so that one is above or below both neighbors. It is important that the paddle has two fields, one on each side. Shoulder blades with and without fields alternate in a circle: figure below. Paddles with brim will be lower than oars without brim.
Since the blades are flat, there is a transition between them and the overlapping areas. To avoid interference in the transition zone, provide some clearance between adjacent blades. The extra width can be cut with or without brim blades, see picture above.
Drill a hole with a diameter of about 5 mm at the tip of each wedge. These holes are too small to be shown in the picture above. They make cutting easier.
Attach the oars together by various means: staples, nails, glue, sewing or otherwise. The optimal solution depends on the sheet material and the affordability of the fastener.
In the rare case where the flat sheet is very thick, the blades may abut each other. In this case, there are no guarantees. It is necessary to provide some clearance for the glue. In addition, gap-applied adhesive tapes can also be applied to the inner and outer surfaces to hold the blades together. The tapes applied to the surface need to be very thin so as not to distort the reflective surface.
Sunlight energy. Attach one blade at a time, clockwise or counterclockwise. First by attaching each blade from the outer section. Similarly, continuing to move inward. All sections of the oar must be attached before starting work on another oar.
The reflective film is applied after the parabolic reflector has taken shape. Aluminum foil for general use is ideal in the kitchen. A thicker (heavier) film will be more durable. Aluminum plastic film, used in food and drink bags or gift wrapping, is acceptable but slightly less effective and noticeably less durable than aluminum foil.
Usually the foil is glued to the reflector. Glue must be used on water based. This includes glue made from flour, rice or starch. To avoid wrinkles on the film, use a thin, non-flowing adhesive.
It is easier to glue foil on a flat sheet than on a parabolic dish. However, if the sheet is very thin, the bending process of the sheet will create wrinkles in the coating. Therefore, it is best to stick it after making a cardboard plate. Sheet material that expands and contracts significantly with humidity and temperature also tends to create wrinkles in the film. Therefore, cardboard is not an ideal sheet material. Wrinkles reduce effectiveness. They also shorten the life of the reflective coating.
First, the foil must be cut into trapeziums. Two identical trapeziums can be cut from a rectangle with very little waste (picture below). Try using newspaper first to determine the optimal width, length, and slant, as this will depend on the shape and size of your foil. Short slots can be cut along the edges of the trapezoid so that it can be applied without wrinkles. The trapezoids completely cover all the faces, except that the circle will be covered with foil at the end.
The figures show: a) cutting out two trapezoidal parts from a rectangular one; b) cutting short slots along the edges of each wedge
Carefully cover the surface of the oar with glue. However, you should not abuse it if the sheet material (for example, cardboard) can swell when wet. In order to avoid the appearance of bubbles, first you need to attach a small piece of foil to the paddle. Keep most of the film in the air, no glue. Slowly stretching the captured area, click on it. The foil is attached near its center line (along its length). It will be obvious how much it bends and overlaps near its edges. Normally, if excess glue comes out on a reflective surface, it will be erased later.
When the reflective surface is coated with the reflector, wipe it gently with a damp, clean cloth. Wiping removes excess adhesive, evens out the glued film. The adhesive must be allowed to dry, this may take several days if the sheet material is permeable to water. Then you need to wipe again with a damp clean cloth to remove the remaining adhesive and smear.
We install the finished product on a swivel support, above the focus of solar energy we make a holder for cooking utensils.
In fact, there are several such structures in the world. Let's start with Solar Furnace in France, i.e. from France.
The Solar Furnace in France is designed to generate and concentrate the high temperatures needed for various processes.
This is done by capturing the sun's rays and concentrating their energy in one place. The structure is covered with curved mirrors, their radiance is so great that it is impossible to look at them, to the point of pain in the eyes. In 1970, this structure was erected, as the most suitable place Eastern Pyrenees were chosen. And up today The furnace remains the largest in the world.
Photo 2. 
The array of mirrors is entrusted with the functions of a parabolic reflector, and a high temperature regime in the focus can reach up to 3500 degrees. Moreover, you can regulate the temperature by changing the angles of the mirrors.
The Solar Furnace, using the natural resource of sunlight, is considered an indispensable way to obtain high temperatures. And they, in turn, are used for various processes. So, the production of hydrogen requires a temperature of 1400 degrees. Test modes of materials, carried out in high-temperature conditions, provide for a temperature of 2500 degrees. This is how spacecraft are tested and nuclear reactors.
Photo 3. 
So the Solar Furnace is not just an amazing building, but also a vital and efficient one, while it is considered an environmentally friendly and relatively cheap way to get high temperatures.
The array of mirrors acts as a parabolic reflector. The light is focused in one center. And the temperature there can reach temperatures at which steel can be melted.
But the temperature can be adjusted by setting the mirrors at different angles.
For example, temperatures around 1400 degrees are used to produce hydrogen. Temperature of 2500 degrees - for testing materials in extreme conditions. For example, this is how nuclear reactors and spacecraft are tested. But temperatures up to 3500 degrees are used for the manufacture of nanomaterials.
The Solar Furnace is an inexpensive, efficient and environmentally friendly way to produce high temperatures.
Photo 5. 
In the south-west of France, grapes take root wonderfully and all kinds of fruits ripen - it's hot! Among other things, the sun shines here almost 300 days a year, and in terms of the number of clear days, these places are perhaps second only to the Côte d'Azur. If we characterize the valley near Odeio from the point of view of physics, then the power of light radiation here is 800 watts per 1 square meter. Eight powerful incandescent bulbs. A little? It is enough for a piece of basalt to spread into a puddle!
Photo 6. 
- The solar oven in Odeyo has a capacity of 1 megawatt, and this requires almost 3 thousand meters of mirror surface, says Serge Chauvin, curator of the local solar museum. - Moreover, you need to collect light from such a large surface at a focal point with a diameter of a dinner plate.
Photo 7. 
Against parabolic mirror installed heliostats - special mirror plates. There are 63 of them with 180 sections. Each heliostat has its own "point of responsibility" - the sector of the parabola, on which the collected light is reflected. Already on a concave mirror, the rays of the sun are going to a focal point - that same stove. Depending on the intensity of the radiation (read - the clarity of the sky, time of day and season), temperatures can be very different. In theory - up to 3800 degrees Celsius, in reality it went up to 3600.
Photo 8. 
- Along with the movement of the sun, heliostats also move across the sky,- Serge Chauvin begins his tour. - Each has an engine installed at the back, and all together they are centrally controlled. It is not necessary to set them in an ideal position - depending on the tasks of the laboratory, the degree at the focal point can vary.
Photo 9. 
The solar oven in Odeyo began to be built in the early 60s, and was put into operation in the 70s. For a long time it remained the only one of its kind on the planet, but in 1987 a copy was erected near Tashkent. Serge Chauvin smiles: "Yes, yes, exactly a copy."
The Soviet stove, by the way, also remains operational. True, not only experiments are carried out on it, but also some practical tasks are performed. True, the location of the furnace does not allow reaching the same high temperatures as in France - at the focal point, Uzbek scientists manage to get less than 3000 degrees.
The parabolic mirror consists of 9000 plates - facets. Each of them is polished, has an aluminum coating and is slightly concave for better focusing. After the kiln building was built, all bevels were installed and manually calibrated - it took three years!
Serge Chauvin leads us to a site near the kiln building. Together with us - a group of tourists who arrived in Odeyo by bus - the flow of lovers of scientific exoticism does not dry out. The museum curator was about to demonstrate the hidden potential of solar energy.
- Madame and Monsieur, your attention!- Although Serge looks more like a scientist, he looks more like an actor. - The light emitted by our star makes it possible to instantly heat materials, ignite and melt them.
Photo 10. 
Photo 4. 
A solar oven worker picks up an ordinary branch and places it in a large vat with a mirrored interior. It takes Serge Chauvin a few seconds to find a focus point, and the stick instantly flares up. Miracles!
While the French grandparents are gasping and groaning, the museum worker moves to a free-standing heliostat and moves it exactly so that the reflected rays hit a small copy of the parabolic mirror installed right there. This is another illustrative experiment showing the possibilities of the sun.
- Madame and Monsieur, now we will melt the metal!
Serge Chauvin sets a piece of iron in the holder, moves the vise in search of a focus point and, having found it, moves away a short distance.
The sun is doing its job.
A piece of iron instantly heats up, begins to smoke and even spark, succumbing to hot rays. Literally in 10-15 seconds, a hole the size of a coin of 10 euro cents is burned in it.
- Voila! Serge rejoices.
While we are returning to the museum building, and the French tourists are seated in the cinema hall to watch a scientific film about the work of the solar furnace and laboratory, the caretaker tells us some interesting things.
- Most often people ask why all this is necessary,- throws up his hands Serge Chauvin. - From the point of view of science, the possibilities of solar energy have been studied, applied where possible in everyday life. But there are tasks that, due to their scale and complexity of execution, require installations like this one. For example, how do we model the effect of the sun on the skin of a spaceship? Or the heating of the descent capsule returning from orbit to Earth?
In a special refractory container, installed at the focal point of the solar furnace, it is possible to recreate such, without exaggeration, unearthly conditions. It has been calculated, for example, that a skin element must withstand temperatures of 2500 degrees Celsius - and this can be tested empirically here in Odeyo.
The caretaker leads us through the museum, where various exhibits are installed - participants in numerous experiments carried out in the oven. Our attention is drawn to the carbon brake disc…
- Oh, this thing is from the wheel of a Formula 1 car, Serge nods. - Its heating under certain conditions is comparable to what we can reproduce in the laboratory.
As mentioned above, the temperature at the focal point can be controlled using heliostats. Depending on the experiments carried out, it varies from 1400 to 3500 degrees. The lower limit is necessary for the production of hydrogen in the laboratory, the range from 2200 to 3000 is for testing various materials under extreme heating conditions. Finally, above 3000 - the area of work with nanomaterials, ceramics and the creation of new materials.
- The oven in Odeyo does not perform practical tasks,- continues Serge Chauvin. - Unlike our Uzbek colleagues, we do not depend on our own economic activity and are engaged exclusively in science. Among our customers are not only scientists, but also a variety of departments, such as defense.
We are just stopping at a ceramic capsule, which turns out to be the hull of a drone ship.
- The War Department built a smaller diameter solar oven for their own practical needs here, in the valley near Odeyo, Serge says. - It can be seen from some sections of the mountain road. But they still turn to us for scientific experiments.
The caretaker explains the advantage of solar energy over any other in the course of scientific tasks.
- First, the sun shines for free, he curls his fingers. - Secondly, mountain air contributes to conducting experiments in a "pure" form - without impurities. Thirdly, sunlight makes it possible to heat materials much faster than any other apparatus, which is extremely important for some experiments.
It is curious that the furnace can work almost all year round. According to Serge Chauvin, the best month for experiments is April.
- But if necessary, the sun will melt a piece of metal for tourists even in January, the caretaker smiles. - The main thing is that the sky is clear and cloudless.
One of the undeniable advantages of the very existence of this unique laboratory is its complete openness to tourists. Up to 80 thousand people come here every year, and this does much more to popularize science among adults and children than a school or university.
Font-Romeu-Odeillo is a typical French pastoral town. Its main difference from thousands of the same is the coexistence of the sacrament of everyday life and science. Against the background of a 54-meter mirror parabola - mountain dairy cows. And constant hot sun.
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Now let's move on to another building.
Forty-five kilometers from Tashkent, in the Parkent district, in the foothills of the Tien Shan, at an altitude of 1050 meters above sea level, there is a unique structure - the so-called Big Solar Furnace (BSP) with a capacity of a thousand kilowatts. It is located on the territory of the Institute of Materials Science NPO "Physics-Sun" of the Academy of Sciences of the Republic of Uzbekistan. There are only two such furnaces in the world, the second is in France.
The BSP was put into operation back in the Soviet Union in 1987,” says the scientific secretary of the Institute of Materials Science of the NPO “Physics-Sun”, Candidate of Technical Sciences Mirzasultan Mamatkasymov. “Sufficient funds are allocated from the state budget to preserve this unique object. Two laboratories of the institute are located here, four - in Tashkent, where the main scientific base is located, on which the study of chemical and physical properties new materials. We are in the process of synthesizing them. We experiment with these materials by observing the melting process at different temperatures.
BSP is a complex optical-mechanical complex with automatic control systems. The complex consists of a heliostat field located on a mountainside and directing the sun's rays into a paraboloid concentrator, which is a giant concave mirror. At the focus of this mirror, the highest temperature is created - 3000 degrees Celsius!
Photo 15. 
The heliostat field consists of sixty-two heliostats arranged in a checkerboard pattern. They provide mirror surface concentrator with a luminous flux in the mode of continuous tracking of the Sun throughout the day. Each heliostat, measuring seven and a half by six and a half meters, consists of 195 flat mirror elements called "facets". The reflecting area of the heliostat field is 3022 square meters.
The concentrator, on which the heliostats direct the sun's rays, is a cyclopean structure forty-five meters high and fifty-four meters wide.
Photo 16. 
It should be noted that the advantage of solar furnaces, in comparison with other types of furnaces, is the instantaneous achievement of a high temperature, which makes it possible to obtain pure materials without impurities (due to the purity of mountain air as well). They are used for oil and gas, textile and a number of other industries.
Mirrors have a certain service life and sooner or later fail. In our workshops, we manufacture new mirrors that we install to replace the old ones. There are 10700 of them only in the concentrator, and 12090 in heliostats. The process of manufacturing mirrors takes place in vacuum installations, where aluminum is deposited on the surface of used mirrors.
Photo 17. 
Ferghana.Ru:- How do you solve the problem of finding specialists, because after the collapse of the Union, there was an outflow of them abroad?
Mirzasultan Mamatkasymov:- At the time of the launch of the installation in 1987, specialists from Russia and Ukraine worked here, who trained ours. Thanks to our experience, we now have the opportunity to train specialists in this field on our own. Young people come to us from the Faculty of Physics National University Uzbekistan. I myself have been working here since 1991 after graduating from university.
Ferghana.Ru:- When you look at this grandiose structure, at the openwork metal structures, as if floating in the air and at the same time supporting the "armor" of the concentrator, frames of science fiction films pop up in your memory ...
Mirzasultan Mamatkasymov:- Well, in my lifetime no one has tried to shoot science fiction using these unique "settings". True, Uzbek pop stars came to shoot their videos.
Photo 18. 
Mirzasultan Mamatkasymov:- Today we will melt briquettes pressed from powdered aluminum oxide, the melting point of which is 2500 degrees Celsius. During the melting process, the material flows down an inclined plane and drips into a special pan, where granules are formed. They are sent to a ceramic workshop located near the BSP, where they are crushed and used to make various ceramic products, ranging from small thread guides for the textile industry to hollow ceramic balls that look like billiard balls. Balls are used in the oil and gas industry as floats. At the same time, evaporation from the surface of oil products stored in large containers at oil depots is reduced by 15-20 percent. In recent years, we have produced about six hundred thousand of these floats.
Photo 19. 
We manufacture insulators and other products for the electrical industry. They are characterized by increased wear resistance and strength. In addition to aluminum oxide, we also use more refractory material- zirconium oxide with a melting point of 2700 degrees Celsius.
The melting process is controlled by the so-called "vision system", which is equipped with two special television cameras. One of them directly transmits the image to a separate monitor, the other - to a computer. The system allows both to observe the melting process and to carry out various measurements.
Photo 20. 
It should be added that the BSP is also used as a universal astrophysical instrument that opens up the possibility of conducting studies of the starry sky at night.
In addition to the above works, the institute pays great attention to the manufacture medical equipment based on functional ceramics (sterilizers), abrasive tools, dryers and much more. Such equipment has been successfully implemented in medical institutions of our republic, as well as in similar institutions in Malaysia, Germany, Georgia and Russia.
In parallel, solar installations were developed at the Institute low power. So, for example, scientists of the institute created solar furnaces with a capacity of one and a half kilowatts, which were installed on the territory of the Tabbe Institute of Metallurgy (Egypt) and at the International Metallurgical Center in Hyderabad (India).
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sources
http://englishrussia.com/2012/01/25/the-solar-furnace-of-uzbekistan/3/
http://www.epochtimes.ru/content/view/77005/69/
http://victorprofessor.livejournal.com/profile
http://loveopium.ru/rekordy-i-rejtingi/solnechnaya-pech.html
http://tech.onliner.by/2012/07/09/reportage
http://www.fergananews.com/article.php?id=4570
And here's more on this topic . Of course, let's also remember about . Oh yes, but you know The original article is on the website InfoGlaz.rf Link to the article from which this copy is made -
