Batteries and solar panels, solar panels, alternative energy, solar energy

On the first Earth satellites, the equipment consumed relatively little current power and its operating time was very short. Therefore, ordinary space energy sources were successfully used as the first space energy sources. batteries.

As you know, on an airplane or car, the battery is an auxiliary current source and works in conjunction with an electric machine generator, from which it is periodically recharged.

The main advantages of batteries are their high reliability and excellent performance. A significant disadvantage of rechargeable batteries is their high weight and low energy consumption. For example, a silver-zinc battery with a capacity of 300 Ah weighs about 100 kg. This means that with a current power of 260 watts (normal consumption on the manned Mercury satellite), such a battery will operate for less than two days. The specific gravity of the battery, which characterizes the weight perfection of the current source, will be about 450 kg/kW.

Therefore, the battery as an autonomous current source has so far been used in space only with low power consumption (up to 100 watts) and a service life of several tens of hours.

For large automatic satellites of the Earth, saturated with a variety of equipment, more powerful and lighter current sources with a very long service life were required - up to several weeks and even months.

Such current sources were purely space generators - semiconductor photovoltaic elements operating on the principle of converting the light energy of solar radiation directly into electricity. These generators are called solar panels .

We have already talked about the power of thermal radiation from the Sun. Let us recall that outside the earth's atmosphere the intensity of solar radiation is quite significant: the energy flow incident on the surface perpendicular to the sun's rays is 1340 watts per 1 m2. This energy, or rather, the ability of solar radiation to create photoelectric effects, is used in solar batteries. The operating principle of a silicon solar cell is shown in Fig. thirty.

A thin wafer consists of two layers of silicon with different physical properties. The inner layer is pure monocrystalline silicon. On the outside, it is coated with a very thin layer of “contaminated” silicon, for example mixed with phosphorus. After irradiating such a “wafer” with sunlight, a flow of electrons arises between the layers and a potential difference is formed, and an electric current appears in the external circuit connecting the layers.

The thickness of the silicon layer required is insignificant, but due to imperfect technology it is usually from 0.5 to 1 mm, although only about 2% of the thickness of this layer takes part in creating the current. For technological reasons, the surface of one element of a solar battery is very small, which requires a series connection of a large number of elements in a circuit.

A silicon solar battery produces current only when the sun's rays fall on its surface, and the maximum current collection will be when the plane of the battery is perpendicular to the sun's rays. This means that when a spacecraft or spacecraft moves in orbit, the batteries must be constantly oriented towards the Sun. Batteries will not provide current in the shade, so they must be used in combination with another current source, such as a battery. The latter will serve not only as a storage device, but also as a damper for possible fluctuations in the amount of energy required.

Efficiency solar panels are small, it does not yet exceed 11-13%. This means that from 1 m 2 of modern solar panels, the power is about 100-130 watts. True, there are possibilities to increase efficiency. solar batteries (theoretically up to 25%) by improving their design and improving the quality of the semiconductor layer. It is proposed, for example, to stack two or more batteries one on top of the other so that the lower surface uses that part of the solar energy spectrum that the upper layer transmits without absorbing.

Efficiency battery depends on the surface temperature of the semiconductor layer. The maximum efficiency is achieved at 25°C, and when the temperature increases to 300C the efficiency is decreases by almost half. Solar batteries are advantageous to use, just like batteries, for low current consumption due to their large surface area and high specific gravity. To obtain, for example, a power of 3 kW, a battery consisting of 100,000 cells with a total weight of about 300 kg is required, i.e. with a specific gravity of 100 kg/kW. Such batteries will occupy an area of ​​more than 30 m2.

Nevertheless, solar panels have proven themselves well in space as a fairly reliable and stable source of energy, capable of operating for a very long time.

The main danger to solar cells in space is cosmic radiation and meteor dust, which cause erosion of the surface of silicon elements and limit the life of the batteries.

For small inhabited stations, this current source will apparently remain the only acceptable and quite effective one, but large NCS will require other energy sources, more powerful and with a lower specific gravity. At the same time, it is necessary to take into account the difficulties of obtaining alternating current using solar panels, which will be required for large scientific space laboratories.

These are photovoltaic converters - semiconductor devices that convert solar energy into direct electric current. Simply put, these are the basic elements of the device we call “solar panels.” With the help of such batteries, artificial Earth satellites operate in space orbits. Such batteries are made here in Krasnodar - at the Saturn plant. The plant management invited the author of this blog to look at the production process and write about it in his diary.

1. The enterprise in Krasnodar is part of the Federal Space Agency, but Saturn is owned by the Ochakovo company, which literally saved this production in the 90s. The owners of Ochakovo bought a controlling stake, which almost went to the Americans. Ochakovo invested heavily here, purchased modern equipment, managed to retain specialists, and now Saturn is one of the two leaders in the Russian market for the production of solar and rechargeable batteries for the needs of the space industry - civil and military. All profits that Saturn receives remain here in Krasnodar and go towards the development of the production base.

2. So, it all starts here - at the so-called site. gas phase epitaxy. In this room there is a gas reactor, in which a crystalline layer is grown on a germanium substrate for three hours, which will serve as the basis for a future solar cell. The cost of such an installation is about three million euros.

3. After this, the substrate still has a long way to go: electrical contacts will be applied to both sides of the photocell (moreover, on the working side the contact will have a “comb pattern”, the dimensions of which are carefully calculated to ensure maximum passage of sunlight), an anti-reflective coating will appear on the substrate coating, etc. - a total of more than two dozen technological operations at various installations before the photocell becomes the basis of the solar battery.

4. Here, for example, is a photolithography installation. Here, “patterns” of electrical contacts are formed on photocells. The machine performs all operations automatically, according to a given program. Here the light is appropriate, which does not harm the photosensitive layer of the photocell - as before, in the era of analogue photography, we used “red” lamps.

5. In the vacuum of the sputtering installation, electrical contacts and dielectrics are deposited using an electron beam, and antireflective coatings are also applied (they increase the current generated by the photocell by 30%).

6. Well, the photocell is ready and you can start assembling the solar battery. Busbars are soldered to the surface of the photocell in order to then connect them to each other, and protective glass is glued onto them, without which in space, under radiation conditions, the photocell may not withstand the loads. And, although the glass thickness is only 0.12 mm, a battery with such photocells will work for a long time in orbit (in high orbits for more than fifteen years).

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7. The electrical connection of photocells to each other is carried out with silver contacts (they are called bars) with a thickness of only 0.02 mm.

8. To obtain the required network voltage generated by the solar battery, photocells are connected in series. This is what a section of series-connected photocells (photoelectric converters - that's correct) looks like.

9. Finally, the solar battery is assembled. Only part of the battery is shown here - the panel in mockup format. There can be up to eight such panels on a satellite, depending on how much power is needed. On modern communications satellites it reaches 10 kW. Such panels will be mounted on a satellite, in space they will open like wings and with their help we will watch satellite television, use satellite Internet, navigation systems (GLONASS satellites use Krasnodar solar panels).

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10. When a spacecraft is illuminated by the Sun, the electricity generated by the solar battery powers the spacecraft's systems, and excess energy is stored in the battery. When the spacecraft is in the shadow of the Earth, the device uses electricity stored in the battery. The nickel-hydrogen battery, having a high energy capacity (60 W h/kg) and an almost inexhaustible resource, is widely used on spacecraft. The production of such batteries is another part of the work of the Saturn plant.

In this photo, the assembly of a nickel-hydrogen battery is carried out by Anatoly Dmitrievich Panin, holder of the medal of the Order of Merit for the Fatherland, II degree.

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11. Assembly area for nickel-hydrogen batteries. The battery contents are prepared for placement in the housing. The filling is positive and negative electrodes separated by separator paper - it is in them that the transformation and accumulation of energy occurs.

12. Installation for electron beam welding in a vacuum, with the help of which the battery case is made from thin metal.

13. Section of the workshop where battery housings and parts are tested for high pressure.
Due to the fact that the accumulation of energy in the battery is accompanied by the formation of hydrogen, and the pressure inside the battery increases, leak testing is an integral part of the battery manufacturing process.

14. The housing of a nickel-hydrogen battery is a very important part of the entire device operating in space. The housing is designed for a pressure of 60 kg s/cm 2; during testing, rupture occurred at a pressure of 148 kg s/cm 2.

15. Tested batteries are charged with electrolyte and hydrogen, after which they are ready for use.

16. The body of a nickel-hydrogen battery is made of a special metal alloy and must be mechanically strong, lightweight and have high thermal conductivity. The batteries are installed in cells and do not touch each other.

17. Rechargeable batteries and batteries assembled from them are subjected to electrical tests on installations of our own production. In space it will no longer be possible to correct or replace anything, so every product is carefully tested here.

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18. All space technology is subjected to mechanical testing using vibration stands that simulate the loads when launching a spacecraft into orbit.

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19. In general, the Saturn plant made the most favorable impression. The production is well organized, the workshops are clean and bright, the people working are qualified, communicating with such specialists is a pleasure and very interesting for a person who is at least to some extent interested in our space. I left Saturn in a great mood - it’s always nice to see a place here where they don’t engage in idle chatter and shuffle papers, but do real, serious work, successfully compete with similar manufacturers in other countries. There would be more of this in Russia.

Photos: © drugoi

P.S. Blog of the Vice President of Marketing at Ochakovo

The invention relates to energy systems for space objects based on the direct conversion of radiant energy from the Sun into electricity, and can be used to create economical large-area solar panels. Essence: in a space solar battery containing a supporting frame, photocells placed on it, including two conducting electrodes separated by a gap, one of which is made translucent, on the inner surface there is a coating made of materials with a work function less than the work function of the electrode material, and the size of the gap does not exceed the free path of photoelectrons. 5 ill.

The invention relates to energy systems of space objects based on the direct conversion of radiant energy from the Sun into electricity, and can be used to create large-area space solar panels (SB). Solar batteries are known that contain a frame, photocells placed on it, including two conductive electrodes separated by a gap, one of which is made transparent. Solar batteries based on semiconductor structures of various types have a fairly high efficiency of solar energy conversion. The disadvantages of known SBs based on the internal photoelectric effect are the complexity of the PV structure with the use of scarce materials, such as gallium arsenide; the fundamental limitation from below of the PV thickness due to the multilayer, especially graded-gap, structure of the converter using substrates, various optical and protective coatings and, as a result, the relatively large mass of the PV, exceeding the mass of the SB frame made of high-strength materials; sensitivity to the effects of the space environment, in particular to corpuscular radiation, which causes rapid degradation of performance characteristics, reducing service life. As a result, these shortcomings lead to the high cost of electricity generated by such SBs. The closest to the proposed technical solution is a space solar battery selected as a prototype, containing a supporting frame, photocells placed on it, including two conducting electrodes separated by a gap, one of which is made translucent. As a current-generating area formed between the surfaces of the solar cell, in such a solar cell A homo- or heterostructural layer(s) is used, onto which electrodes (for example, optical and barrier) and the necessary coatings are applied. Current-collecting elements can be made in the form of thin conductive meshes formed on the surfaces of the electrodes. The supporting frame is a truss structure made of high-strength, for example carbon fiber, rod elements, onto which FEP is stretched in the form of flexible panels on a mesh substrate, fixed to the frame along the periphery. The known SB has a fairly high efficiency (almost up to 15-20%) and a small thickness of flexible SB panels (up to 100-200 microns), facilitating storage, transportation and deployment of the SB into working condition, for example, from a roll. The disadvantages of the known SB are those already noted above, which are typical for semiconductor solar cells. These shortcomings, ultimately, are expressed in insufficiently high specific energy characteristics (power does not exceed 0.2 kW/kg or 0.16 kW/m2) and operational and technological characteristics (significant specific gravity of solar panels due to PV, manufacturing complexity, sensitivity to cosmic influences, etc. ), which leads to an increased cost of generating electricity from a solar system of this type. The purpose of the invention is to increase the specific electrical power per unit mass while simultaneously increasing resistance to external influences in outer space conditions. This goal is achieved by the fact that in a space solar battery containing a supporting frame, photocells placed on it, including two conducting electrodes separated by a gap, one of which is made translucent, on the inner surface of one of the electrodes there is a coating made of a material with a work function of less than the work function yield of its material, and the gap size does not exceed the free path of photoelectrons. The essence of the invention is to use in the design of the proposed SB, in contrast to the traditional principle of the external photoelectric effect, while one of the conducting electrodes serves as a photocathode, from which photoelectrons can be ejected predominantly either in the direction of the incident light from the shadow surface of the film, or in the opposite direction from the illuminated surface films. The photoelectrons are captured by another film with a conducting electrode, which acts as an anode. Since the cathode and anode films are made of materials with different electron work functions, when the SB is exposed to a light flux between the films, a certain equilibrium potential difference is established (EMF of the order of 0.6-0.8 V) provided that the gap between the films is less than the free length the path of photoelectrons in the gap medium (this condition is satisfied for the cosmic vacuum with a weak external magnetic field). The most significant thing is that conductive (including metal) films can be made much thinner than SB semiconductor panels of the order of 0.5 microns or less, so that the specific characteristics of the proposed SB are much higher than those of traditional SB. In addition, the sensitivity of the electrophysical characteristics of the proposed SB to the effects of factors in the space environment (micrometeorites, corpuscular radiation) is much weaker. The production of films and the assembly of solar panels from them on a supporting frame are technologically simple, and the conditions of low gravity (weightlessness) make it possible to create lightweight solar panels of a very large area, and therefore, power. The preferred embodiment of the proposed SB is a design where each of the films with a conductive electrode is made in the form of strips isolated from each other, and the strips of different films in pairs form sections of a photoelectric converter, combined into a series circuit in which each rear strip of one of the sections of the converter is electrically connected with the solar-oriented strip of the adjacent section of the converter, and the current-collecting elements are electrically connected to the rear strip at one end of the circuit and to the solar-oriented strip at the opposite end of the circuit. This design has increased manufacturability when constructing a large area SB. At the same time, this design of the SB makes it possible to reduce the amount of current flowing through the PV sections per unit of generated power and thereby reduce the thickness of the films, i.e., further reduce the mass of the SB. In the proposed SB, a coating is applied to the surface of the film with a conducting electrode (photocathode), which reduces the work function of electrons from this film. This can be done, for example, by oxidizing a corresponding metal (eg aluminum) film. When the anode is located above the photocathode, the first must be translucent, therefore, in this version of the proposed SB, the conductive film oriented towards the Sun can be made of a perforated or mesh structure with the minimum possible shading of the cathode film. The essence of the invention is illustrated by drawings, where Fig. 1 shows a diagram of a solar system with a film photocathode oriented towards the Sun; Fig. 2 shows a diagram of a SB with a photocathode on the rear surface; Fig. 3 shows a schematic diagram of a SB with partitioning; Figure 4 shows the equivalent electrical circuit of the SB; Figure 5 shows a design option for the SB. As shown in Fig. 1, the SB contains conductive films placed on a supporting dielectric frame 1, one of which serves as a photoemission cathode 2, and the other as an anode 3. Film 2 is located along the surface oriented to the solar light flux 4. Through current collecting elements 5, conductive films can be connected to load 6. According to another embodiment of the SB, shown in Fig. 2, the photocathode 2 can be located along the rear surface, and the anode film 3 is made transparent, in particular perforated or made in the form of a fine wire mesh. Electrode materials can include metals such as aluminum, silver, gold, platinum, some alloys, alkali metal oxides and other compounds. Different electron work functions were obtained for films of the same metal due to oxidation of one of them or other surface treatment. As shown in Fig. 3, the cathode and anode films can be made in the form of strips 7 and 8 isolated from each other, with strips of one type (anodic) electrically connected to strips of another type (cathode) along contact joints (seams) 9 so, that here a large-area solar cell is a system (chain) of series-connected power-generating sections of 10 smaller sizes. Each section increases the voltage supplied to the load 6 in accordance with the equivalent circuit diagram shown in FIG. 4. As shown in Fig. 5, structurally the SB with the diagram according to Fig. 3 may contain a folding or prefabricated frame with longitudinal 11 and transverse 12 load-bearing elements. Fragments of FEP 13 in the form of joined strips of different types are stretched onto the frame, passing them through transverse elements 12 and fastening along the edges to the same elements 12, for example, using dielectric elastic fabrics (mesh, braces, etc.) 14. Rigidity of SB in in the deployed state, it is ensured by braces 15, tightening the ends of the longitudinal rod elements 11, articulated in their central parts. The functioning and operation of the SB according to the invention is carried out as follows. Either the entire solar system in folded form or its fragments, which are then assembled into a single system, are launched into outer space. When deployed into working condition, the SB is oriented towards the Sun with one of its film surfaces, depending on the type of photocathode (see Figs. 1 and 2). Due to the resulting electron emission, an electric field appears in the gap between the films, creating a potential difference between the anode and cathode films equal to the difference in the work functions of these films. When a certain load 6 is connected to the SB through current-collecting elements 5, an electric current arises in the PV circuit, supplying the load with the necessary electricity. The primary area of ​​application of the proposed SBs is high, in particular geostationary, orbits, where the influence of the atmosphere, the planet’s magnetic field and its gravitational gradient is minimal, which makes it possible to create SBs of a very large area and, therefore, high power. The technical and economic efficiency of the proposed invention can be confirmed by the following estimates. It is known that the efficiency of energy conversion with the external photoelectric effect is 2-10%. Considering that the power of the solar light flux near the Earth is approximately 1.4 kW/m2, the electrical power generated per unit surface of the solar panel will be about 0.051400 70 W/m2 , if we assume an efficiency of 5%, this figure is noticeably worse than that of serial silicon SBs, where 110 W/m2 is achieved. However, the thickness of the films can be increased to 0.5 microns. Then the mass of 1 m 2 of film, for example, made of aluminum will be 110.510 -6 2.710 3 1.3510 -3 kg 1.35 g for a thickness of 0.5 microns. Hence, the specific electrical power (based on the mass of the PV), taking into account the use of two films, will be For a PV with a specific mass of 25 10 g/m2 and a frame with the same average specific mass, i.e. e. if the specific mass of the solar battery is approximately 20 g/m2, the specific electrical power of the solar panel will be This main indicator of the proposed SB is almost 20 times higher than the same indicator for promising semiconductor SBs, reaching 200 W/kg, and the implementation of the proposed SB does not require scarce materials and complex technologies, since the production of very thin conductive films is a practically mastered process. The cost of creating the proposed SB should be expected at the level of the cost of putting them into orbit, and since the latter is proportional to the mass of the SB, the gain in the cost of generating electricity using the proposed SB becomes quite obvious. In addition, the proposed SBs are characterized by a longer service life and less stringent operational requirements. The proposed SBs allow for the possibility of their effective use as control (solar-sail) organs for orientation and correction of the orbit of space objects. Prospects for improving the proposed SBs are mainly related to the creation of especially thin conductive films (less than 0.1 microns) and ultra-light load-bearing frames. Relevant research is being conducted in the field of solar sail devices. Sources of information 1. Koltun M.M. Solar cells. M. Science, 1987, pp. 136-154. 2. Grilikhes V.A. and others. Solar energy and space flights. M. Science, 1984 p.144 (prototype).

More than sixty years ago, the era of practical solar power began. In 1954, three American scientists introduced the world to the first silicon-based solar cells. The prospect of obtaining free electricity was realized very quickly, and leading scientific centers around the world began to work on the creation of solar power plants. The first “consumer” of solar panels was the space industry. It was here, like nowhere else, that renewable energy sources were needed, since the on-board batteries on satellites were quickly exhausting their resources.

And just four years later, solar panels in space began their indefinite duty. In March 1958, the United States launched a satellite with solar panels on board. Less than two months later, on May 15, 1958, the Soviet Union launched Sputnik 3 into an elliptical orbit around the Earth with solar panels on board.

The first domestic solar power plant in space

Silicon solar panels were installed on the bottom and nose of Sputnik 3. This arrangement made it possible to receive additional electricity almost continuously, regardless of the satellite’s position in orbit relative to the sun.

The third artificial satellite. The solar panel is clearly visible

The onboard batteries exhausted their service life within 20 days, and on June 3, 1958, most of the instruments installed on the satellite were de-energized. However, the device for studying the radiation of the Sun, the radio transmitter that sent the received information to the ground, and the radio beacon continued to work. After the on-board batteries were depleted, these devices were completely powered by solar panels. The radio beacon operated almost until the satellite burned up in the Earth's atmosphere in 1960.

Development of domestic space photoenergy

Designers thought about power supply for spacecraft even at the design stage of the very first launch vehicles. After all, batteries cannot be replaced in space, which means that the active service life of a spacecraft is determined only by the capacity of the onboard batteries. The first and second artificial earth satellites were equipped only with on-board batteries, which were depleted after a few weeks of operation. Starting with the third satellite, all subsequent spacecraft were equipped with solar panels.

The main developer and manufacturer of space solar power plants was the Kvant research and production enterprise. Kvant solar panels are installed on almost all domestic spacecraft. In the beginning it was silicon solar cells. Their power was limited by both given dimensions and weight. But then Kvant scientists developed and manufactured the world's first solar cells based on a completely new semiconductor - gallium arsenide (GaAs).

In addition, completely new helium panels were put into production, which had no analogues in the world. This new product is highly efficient helium panels on a substrate with a mesh or string structure.

Helium panels with mesh and string backing

Silicon helium panels with bidirectional sensitivity were designed and manufactured specifically for installation on low-orbit spacecraft. For example, for the Russian segment of the international space station (the Zvezda spacecraft), silicon-based panels with bidirectional sensitivity were manufactured, and the area of ​​​​one panel was 72 m².

Solar battery of the Zvezda spacecraft

Flexible solar cells with excellent specific gravity characteristics were also developed on the basis of amorphous silicon and put into production: with a weight of only 400 g/m², these batteries generated electricity with an indicator of 220 W/kg.

Flexible gel battery based on amorphous silicon

To improve the efficiency of solar cells, extensive ground-based research and testing has been carried out to reveal the negative effects of the Big Space on helium panels. This made it possible to move on to the production of solar batteries for various types of spacecraft with an active life of up to 15 years.

Venus mission spacecraft

In November 1965, with an interval of four days, two spacecraft, Venera 2 and Venera 3, launched to our closest neighbor, Venus. These were two absolutely identical space probes, the main task of which was to land on Venus. Both spacecraft were equipped with solar panels based on gallium arsenide, which had proven themselves on previous near-Earth spacecraft. During the flight, all equipment of both probes worked uninterruptedly. 26 communication sessions were carried out with the Venera-2 station, and 63 with the Venera-3 station. Thus, the highest reliability of solar batteries of this type was confirmed.

Due to failures in the control equipment, communication with Venera 2 was lost, but the Venera 3 station continued on its way. At the end of December 1965, following a command from Earth, the trajectory was corrected, and on March 1, 1966, the station reached Venus.

The data obtained as a result of the flight of these two stations was taken into account in the preparation of the new mission, and in June 1967 a new automatic station, Venera-4, was launched towards Venus. Just like its two predecessors, it was equipped with gallium arsenide solar panels with a total area of ​​2.4 m². These batteries supported the operation of almost all equipment.

Station "Venera-4". Below is the descent module

On October 18, 1967, after the descent module separated and entered the atmosphere of Venus, the station continued its work in orbit, including serving as a relay of signals from the radio transmitter of the descent vehicle to Earth.

Spacecraft of the Luna mission

Solar batteries based on gallium arsenide were Lunokhod-1 and Lunokhod-2. The solar panels of both devices were mounted on hinged covers and served faithfully throughout the entire operating period. Moreover, on Lunokhod-1, the program and resource of which were designed for a month of operation, the batteries lasted three months, three times longer than planned.

Lunokhod-2 worked on the surface of the Moon for just over four months, covering a distance of 37 kilometers. It could still work if the equipment had not overheated. The device fell into a fresh crater with loose soil. I skidded for a long time, but in the end I was able to get out in reverse gear. When he climbed out of the hole, a small amount of soil fell on the cover with solar panels. To maintain a given thermal regime, the folded solar panels were lowered onto the top cover of the hardware compartment at night. After leaving the crater and closing the lid, soil from it fell onto the hardware compartment, becoming a kind of heat insulator. During the day the temperature rose above a hundred degrees, the equipment could not stand it and failed.

Modern solar panels, manufactured using the latest nanotechnology, using new semiconductor materials, have made it possible to achieve efficiency of up to 35% with a significant reduction in weight. And these new helium panels serve faithfully on all devices sent both to near-Earth orbits and into deep space.

These semiconductor devices convert solar energy into direct electrical current. Simply put, these are the basic elements of the device we call “solar panels.” With the help of such batteries, artificial Earth satellites operate in space orbits. Such batteries are made here in Krasnodar - at the Saturn plant. Let's go there on an excursion.

The enterprise in Krasnodar is part of the Federal Space Agency, but Saturn is owned by the Ochakovo company, which literally saved this production in the 90s. The owners of Ochakovo bought a controlling stake, which almost went to the Americans.

Large amounts of money were invested here and modern equipment was purchased, and now Saturn is one of the two leaders in the Russian market for the production of solar and rechargeable batteries for the needs of the space industry - civil and military. All profits that Saturn receives remain here in Krasnodar and go towards the development of the production base.

So, it all starts here - at the so-called site. gas phase epitaxy. In this room there is a gas reactor, in which a crystalline layer is grown on a germanium substrate for 3 hours, which will serve as the basis for a future solar cell. The cost of such an installation is about 3 million euros:

After this, the substrate still has a long way to go: electrical contacts will be applied to both sides of the photocell (moreover, on the working side the contact will have a “comb pattern”, the dimensions of which are carefully calculated to ensure maximum passage of sunlight), an anti-reflective coating will appear on the substrate and etc. - a total of more than two dozen technological operations at various installations before the photocell becomes the basis of the solar battery.

For example, photolithography installation. Here, “patterns” of electrical contacts are formed on photocells. The machine performs all operations automatically, according to a given program. Here the light is appropriate, which does not harm the photosensitive layer of the photocell - as before, in the era of analogue photography, we used “red” lamps^

In the vacuum of the sputtering installation, electrical contacts and dielectrics are deposited using an electron beam, and antireflective coatings are also applied (they increase the current generated by the photocell by 30%):

Well, the photocell is ready and you can start assembling the solar battery. Busbars are soldered to the surface of the photocell in order to then connect them to each other, and protective glass is glued onto them, without which in space, under radiation conditions, the photocell may not withstand the loads. And, although the glass thickness is only 0.12 mm, a battery with such photocells will work for a long time in orbit (in high orbits for more than 15 years).

The electrical connection of photocells to each other is carried out by silver contacts (they are called bars) with a thickness of only 0.02 mm.

To obtain the required network voltage generated by the solar battery, photocells are connected in series. This is what a section of series-connected photocells (photoelectric converters - that's correct) looks like:

Finally, the solar panel is assembled. Only part of the battery is shown here - the panel in mockup format. There can be up to eight such panels on a satellite, depending on how much power is needed. On modern communications satellites it reaches 10 kW. The panels will be mounted on the satellite, in space they will open like wings and with their help we will watch satellite television, use satellite Internet, navigation systems (GLONASS satellites use Krasnodar solar panels):

When the spacecraft is illuminated by the Sun, the electricity generated by the solar battery powers the spacecraft's systems, and excess energy is stored in the battery. When the spacecraft is in the shadow of the Earth, the device uses electricity stored in the battery. Nickel-hydrogen battery, having high energy intensity (60 W h/kg) and a practically inexhaustible resource, is widely used on spacecraft. The production of such batteries is another part of the work of the Saturn plant.

In this photo, the assembly of a nickel-hydrogen battery is carried out by Anatoly Dmitrievich Panin, holder of the medal of the Order of Merit for the Fatherland, II degree:

Nickel-hydrogen battery assembly area. The battery contents are prepared for placement in the housing. The filling is positive and negative electrodes separated by separator paper - it is in them that the transformation and accumulation of energy occurs:

Installation for electron beam welding in a vacuum, with the help of which the battery case is made of thin metal:

The area of ​​the workshop where battery housings and parts are tested for high pressure. Due to the fact that the accumulation of energy in the battery is accompanied by the formation of hydrogen, and the pressure inside the battery increases, leak testing is an integral part of the battery manufacturing process:

The housing of a nickel-hydrogen battery is a very important part of the entire device operating in space. The housing is designed for a pressure of 60 kg s/cm 2; during testing, rupture occurred at a pressure of 148 kg s/cm 2:

Strength-tested batteries are charged with electrolyte and hydrogen, after which they are ready for use:

The body of a nickel-hydrogen battery is made of a special metal alloy and must be mechanically strong, lightweight and have high thermal conductivity. The batteries are installed in cells and do not touch each other:

Rechargeable batteries and batteries assembled from them are subjected to electrical tests on our own production facilities. In space it will no longer be possible to correct or replace anything, so every product is carefully tested here.

All space technology is subjected to testing for mechanical stress using vibration stands that simulate the loads when launching a spacecraft into orbit.

In general, the Saturn plant made the most favorable impression. The production is well organized, the workshops are clean and bright, the people working are qualified, communicating with such specialists is a pleasure and very interesting for a person who is at least to some extent interested in our space. I left Saturn in a great mood - it’s always nice to see a place here where they don’t engage in idle chatter and shuffle papers, but do real, serious work, successfully compete with similar manufacturers in other countries. There would be more of this in Russia.