The principle of operation of the solar battery: how the solar panel is arranged and works

water clock

This method of controlling the rotary device was invented by an enterprising Canadian student and is responsible for turning only one axis, the horizontal one.

The principle of operation is also simple and is as follows:

1. The solar battery is installed in its original position when the sun's rays hit the photocell perpendicularly.
2. After that, a container with water is attached to one of the sides, and some object of the same weight as the container with water is attached to the other side. The bottom of the container should have a small hole.
3. Through it, water will gradually flow out of the tank, due to which the weight will decrease, and the panel will slowly tilt towards the counterweight. It will be necessary to determine the dimensions of the hole for the container experimentally.

This method is the simplest.In addition, it saves material resources that would be spent on the purchase of an engine, as in the case of a clockwork. In addition, you can install the rotary mechanism in the form of a water clock yourself, without even having any special knowledge.

The benefits of solar panels

Solar energy is a promising area that is constantly developing. They have several main advantages. Ease of use, long life, safety and affordability.

The positive aspects of the use of this type of battery:

• Renewable - this source of energy has practically no restrictions, moreover, it is free. At least for the next 6.5 billion years. It is necessary to select the equipment, install it and use it for its intended purpose (in a private house or cottage plot).
• Abundance - The surface of the earth receives on average about 120,000 terawatts of energy, which is 20 times the current energy consumption. Solar panels for cottages or private houses have a huge potential for use.
• Constancy - solar energy is constant, so humanity is not threatened with overexpenditure in the process of its use.
• Availability - solar energy can be generated in any area, as long as there is natural light. In this case, most often it is used for home heating.
• Ecological cleanliness - solar energy is a promising industry that will replace power plants operating on non-renewable resources: gas, peat, coal and oil in the future. Safe for the health of people and pets.

• During the production of panels and the installation of solar power plants, significant emissions of harmful or toxic substances do not occur into the atmosphere.
• Quiet – Electricity generation is almost silent, and therefore this type of power plant is better than wind farms. Their work is accompanied by a constant hum, because of which the equipment quickly fails, and employees must take frequent breaks for rest.
• Economical – when using solar panels, property owners experience a significant reduction in utility bills for electricity. The panels have a long service life - the manufacturer gives a guarantee on the panels from 20 to 25 years. At the same time, the maintenance of the entire power plant is reduced to periodic (every 5-6 months) cleaning of the panel surfaces from dirt and dust.

The principle of operation of the solar battery

As a result of the charge flow at the boundary of the p- and n-layers, a zone of uncompensated positive charge is formed in the n-layer, and a negative charge is formed in the p-layer, i.e. known to everyone from the school course of physics p-n-junction. The potential difference that occurs at the transition, the contact potential difference (potential barrier) prevents the passage of electrons from the p-layer, but freely passes minor carriers in the opposite direction, which makes it possible to obtain photo-EMF when sunlight hits the solar cell.

When exposed to sunlight, the absorbed photons begin to generate non-equilibrium electron-hole pairs. The electrons generated near the transition pass from the p-layer to the n-region.

Similarly, excess holes and layer n get into the p-layer (figure a). It turns out that a positive charge accumulates in the p-layer, and a negative charge accumulates in the n-layer, causing a voltage in the external circuit (Figure b). The current source has two poles: positive - p-layer and negative - n-layer.

This is the basic principle of how solar cells work. The electrons thus seem to be running in a circle, i.e. leave the p-layer and return to the n-layer, passing through the load (accumulator).

Photoelectric outflow in a single-junction element is provided only by those electrons that have an energy higher than the width of a certain band gap. Those that have less energy do not participate in this process. This limitation can be removed by multilayer structures consisting of more than one SC, in which bandgap different. They are called cascade, multi-junction or tandem. Their photoelectric conversion is higher due to the fact that such solar cells operate with a wider solar spectrum. In them, photocells are located as the band gap decreases. The sun's rays first fall on the photocell with the widest zone, while the absorption of photons with the highest energy occurs.

Then, the photons passed by the upper layer fall on the next element, and so on. In the field of cascade elements, the main direction of research is the use of gallium arsenide as one component or several. Such elements have a conversion efficiency of 35%. The elements are connected into a battery, since technical capabilities do not allow manufacturing a separate element of a large size (hence, power).

Solar cells can work for a long time.They have proven themselves as a stable and reliable source of energy, having been tested in space, where the main danger for them is meteoric dust and radiation, which lead to the erosion of silicon elements. But, since, on Earth, these factors do not have such a negative effect on them, it can be assumed that the service life of the elements will be even longer.

Solar panels are already at the service of man, being a power source for various devices, ranging from mobile phones to electric vehicles.

And this is already the second attempt of man to curb the boundless solar energy, forcing it to work for his own good. The first attempt was to create solar collectors, in which electricity was generated by heating water to a boiling point with the concentrated rays of the sun.

The advantage of solar batteries is that they directly produce electricity, losing much less energy than solar multi-stage collectors, in which the process of obtaining it is associated with the concentration of the sun's rays, heating water, generating steam that rotates a steam turbine, and only after that generating electricity by a generator. The main parameters of solar panels - first of all, power

Then it is important how much energy they have

This parameter depends on the capacity of the batteries and their number. The third parameter is the peak power consumption, which means the number of devices that can be connected at the same time. Another important parameter is the rated voltage, which determines the choice of additional equipment: inverter, solar panel, controller, battery.

Advantages and disadvantages

Solar panels, like other devices, have their own advantages and disadvantages. The undoubted advantages of these systems include the following:

• The possibility of autonomous operation allows you to organize the power supply of objects, electronic devices and lighting, remote at a considerable distance from stationary electrical networks.
• Significant cost savings during operation. Sunlight that turns into electricity costs nothing and does not require additional costs. You have to pay only for inverters and batteries that require periodic replacement. And even in this case, solar panels will pay off in about 10 years with an average warranty period of 25-30 years. If you follow all the rules of operation, the batteries can last even longer.
• Compared with conventional power plants that consume fuel and pollute the environment, the solar panel operation scheme is environmentally friendly and noise-free.

However, these devices also have serious drawbacks, which should be taken into account in advance in preliminary calculations:

• The high cost of not only panels, but also additional components - inverters, controllers, batteries.
• Payback takes too long. Money is withdrawn from circulation for a long time.
• Solar systems with photovoltaic cells require a lot of space. Quite often, for these purposes, it is necessary to use not only the entire roof, but also the walls of the building, seriously violating design design decisions. Additional space is needed for batteries with a large capacity, which in some cases can take up an entire room.
• The process of generating electricity occurs unevenly, depending on the time of day. This disadvantage is compensated by rechargeable batteries, which accumulate electricity during the day and give it to consumers at night.

Transistors as the basis of light elements

Transistors are suitable for our purpose, since inside they have a fairly large silicon semiconductor element, which will be used to produce electricity. It is best to opt for transistors such as KT or P.

We start work. First of all, we cut off the metal cover from the required number of radio components. This is easier to do if you clamp the transistor in a vise and carefully cut it with a hacksaw. Inside you will see a plate. This is the main part of our future device. It will serve as a photocell for us.

The part will have three contacts: base, emitter and collector. During assembly, choose the collector junction due to the highest potential difference.

Do-it-yourself assembly is best done on a flat surface from any dielectric material.

Those transistors that you are going to use when creating solar panels should be checked before work. For these purposes, we take a simple multimeter. It is necessary to switch the device to the current measurement mode, turn it on between the base and the collector or emitter of the transistor. We remove the indicator - usually the device demonstrates a small current - fractions of a milliamp, less often a little more than 1 mA.Next, we switch the device to the voltage measurement mode (limit 1-3 V), and we get the value of the output voltage (it will be about a few tenths of a volt). It is desirable to group transistors with close values ​​of output voltages.

Mounting

Solar panels are mounted on a special structure, the connection with which determines the ability of the photocells to withstand any adverse weather conditions, such as strong wind, rain or snow, and also contributes to the formation of the correct angle of inclination.

This design is available for sale in the following versions:

• inclined - such systems are optimal for installation on a pitched roof;
• horizontal - this design is attached to flat roofs;
• free-standing - batteries of this type can be installed on roofs of various types and sizes.

The actual process of installing batteries is carried out according to the following scheme:

for fastening the frame of the panel, metal squares of 50x50 mm in size are required, and in addition, squares of 25x25 mm are required, which are used for spacer beams

The presence of these parts makes it possible to achieve the required strength and reliable stability of the supporting structure, and also gives the required degree of inclination;
you need to assemble the frame, for this you need bolts of 6 and 8 m in size;
the structure is fastened under the roofing with 12 mm studs;
small holes are formed in the prepared squares, panels are fixed in them, and screws should be used for stronger adhesion;
during installation work, special attention should be paid to the frame - there should not be any distortions in it.Otherwise, overvoltage of the system may occur, which will lead to cracking of the glass.

The installation of solar heat and light sources on the loggia or on the balcony takes place according to a similar scheme. The only exception is that the frame is mounted on an inclined plane. It is mounted between the main bearing wall of the building and the end of the building, always on the sunny side. Self-assembly and installation of solar panels of all types does not require experience in construction work, however, some installation skills will still be required. If you wish, you can safely do the installation yourself, however, before that it would be nice to read special literature about the features of installing pales and study the master classes that are available on the Internet, and, of course, stock up on the necessary tools.

The advantages of working with your own hands are obvious - this is saving a lot of money on the services of specialists, as well as tremendous experience that you may need in the future. At the same time, if personal abilities are not enough, then you can not only lose time, but also cause the panels to break or their low efficiency.

Peculiarities

Today, batteries based on photovoltaic polycrystals are the most widely used. Such models are distinguished by an optimal combination of cost and the amount of energy released, they are characterized by a rich blue color and a crystalline structure of the main elements. They are very easy to install, because even a master without much work experience can cope with their installation in his private house and at their summer cottage. Monocrystalline photovoltaic panels are the second most popular.

Solar cells, which are made using amorphous silicon, are characterized by rather low efficiency. However, their prices are somewhat lower than the cost of analogues, so the model is in demand among the owners of country houses. At the moment, such products account for 85% of the market. They cannot boast of high power and cadmium telluride modifications; their production is based on a high-tech film technique: several hundred micrometers of a substance is applied in a thin layer on a durable surface. It is noteworthy that at a very low level of efficiency of the product, its power is quite high.

Another option for solar-powered batteries are the CIGS semiconductor-based varieties. Like the previous version, they are produced using film technology, however, their efficiency is much higher. Separately, it is worth dwelling on the mechanism of operation of solar heat and light sources. The main thing is to clearly realize that the total amount of energy generated cannot in any way depend on the degree of efficiency of the device itself, since usually all types of such devices provide approximately identical power. The main difference is that panels that have maximum efficiency require less space for their installation.

Solar panels have the following advantages:

• environmental friendliness of the installation;
• long period of use, during which the operational features of the panels remain consistently high;
• technologies rarely break down, therefore they do not need service and maintenance, as well as expensive repairs;
• the use of batteries based on solar energy allows you to reduce the cost of electricity and gas in the house;
• solar panels are exceptionally easy to use.

However, it was also not without drawbacks, among the most significant are the following:

• high stage panels;
• the need to install a variety of additional equipment to effectively synchronize the energy received from the battery and that obtained from traditional sources;
• the panels cannot be used in contact with such appliances that require high powers.

9. Features of solar cells with quantum dots

The last promising type of batteries of the near future is built on the properties of physical quantum dots - microscopic inclusions of semiconductors in a particular material. Geometrically, these "dots" are a few nanometers in size and are distributed in the material so as to cover the absorption of radiation from the entire solar spectrum - IR, visible light and UV.

A huge advantage of such panels is the ability to work even at night, generating about 40% of the maximum daytime power.

Physical and technical characteristics, certification and labeling

Regardless of what solar panels are made of, each of them has a number of the following important characteristics:

• mechanical – geometric parameters, total weight, type of frame, protective glass, number of cells, type and width of connectors;
• electric or volt-ampere - power, open-circuit voltage, current strength at maximum load, efficiency of the panel as a whole and individual cells in particular;
• temperature - change in efficiency with an increase in temperature by a certain unit of magnitude (usually - 1 degree);
• quality – service life, cell degradation rate, presence in the Bloomberg rating lists;
• functional - the need and ease of care, ease of installation / dismantling.

Industrial solar panels, no matter what materials they are made of, must be certified. The minimum requirements are quality certificates ISO, CE, TUV (international) and / or the Customs Union (when sold within it).

International labeling rules are also mandatory. For example, abbreviation CHN-350M-72 contains the following information:

• CHN - identifier of the manufacturer (in this case, the Chinese ChinaLand);
• 350 – panel power in watts;
• M – designation of single-crystal silicon;
• 72 is the number of photovoltaic cells in the module.

What can you make solar panels with your own hands at home

This requires the following:

Pre-drawn scheme and calculations.
A certain number of prefabricated solar cells - they are the cheapest to buy online, for example, on the Aliexpress website or in other online stores

Pay attention to the fact that all elements have the same electrical characteristics. Homemade frame made of timber and plywood - the rules for its assembly can be viewed on numerous videos on the net

Plexiglas or plexiglass for surface protective coating.
Paint and heat-resistant glue for processing wooden surfaces.
Contact strips and wires for connecting cells. Diagrams of various connection methods can also be studied on the Internet.
Soldering iron and solder. Soldering work should be carried out very carefully so as not to spoil the future product.
Silicone glue and self-tapping screws for fixing the prefabricated battery in the frame.

A small battery will require about $30-50 investment, while a factory version of the same capacity will cost only 10-20% more.

Of course, such a home-made design will not last 25 years, will not have the power of a full-fledged solar power plant, and will not be able to boast of significant efficiency. However, its cost will be as minimal as possible.

Solar battery device

In order for the solar battery to be able to convert the light of the sun into current, the following elements are necessary:

1. A photovoltaic layer that plays the role of a semiconductor. It is represented by two layers of materials of different conductivity. Here, electrons are able to move from the p (+) region to the n (-) region. This is called a p-n junction;
2. An element is placed between two layers of semiconductors, which is essentially a barrier to the transition of electrons;
3. Source of power. It is necessary to connect to an element that prevents the transfer of electrons. It transforms the movement of charged electrons, i.e. creates an electric current. Accumulator battery. Accumulates and stores energy;
4. charge controller. Its main function is to connect and disconnect the solar battery based on the level of charge. More sophisticated devices are able to control the maximum power level;
5. DC to AC converter (inverter);
6. Voltage stabilizer.Provides protection for the solar battery system from power surges.