Solar panels working principle – One of the advantages of a country cottage and a country house is the possibility of their subsequent modification, including full or partial modernization of the centralized power supply network.
For this, autonomous systems operating on alternative energy sources are widely used. And solar energy attracts people most of all. The technology, which was originally developed for the needs of the space industry, is available today in civil engineering.
Experts in the field of world energy agree that the use of stationary power plants operating on solar batteries in everyday life is the most “painless” way for the environment to extract natural resources.
The only problem faced by the owners of private houses is the choice of the optimal design and model of the solar system, taking into account the economic benefits and the increase in efficiency indicators.
In this article, we will touch upon the principle of operation of solar panels, consider the popular methods of installing solar plants and talk about the important aspects of the operation of equipment that will help determine the choice of a power plant configuration for domestic use.
The principle of operation of the “home” solar system
The working elements of a solar battery for a private house are photovoltaic plates. They absorb infrared radiation from the sun and generate free natural eco-resources in direct electric current.
In order for the photo panels to work properly and provide the necessary power, they are connected to each other, alternating parallel and serial connection methods.
Direct electric current, depending on the design, is fed to the inverter, where it is converted into alternating current 220 V, or temporarily “settles” in the storage tanks.
The second option is more practical, since the accumulation of electricity “in reserve” allows:
- eliminate sudden voltage drops in the home network;
- rationally use the resources received;
- automatically or manually adjust the intensity of the power plant.
With proper installation, the efficiency of modern solar systems is kept at the level of 35–40%. Modular solar panels for the home demonstrate the highest efficiency rates in the southern regions of Russia, where good weather lasts more than 200 days a year.
When installing solar panels for a private house, it is extremely important to take into account not only the area, but also the geographical latitude, since the sun’s radiation is less intense closer to the poles. But even in the northern and eastern regions, the use of alternative energy will allow you to save on the consumption of traditionally “home” resources.
As mentioned earlier, the generation of electric current occurs at the moment the sun’s rays come into contact with the surface of the photocells. Infrared radiation displaces electrons from their “native” orbits, resulting in a directional movement of charged ions.
With proper installation, one solar panel with an area of 10 sq. m is capable of generating about 1 kW of energy. The power of household solar systems is influenced by the characteristics of the photocell.
1) Monocrystalline silicon
Such solar panels for the home are quite lightweight, compact in size, and also have a long service life. They are very convenient to mount, only monocrystalline photocells are demanding on the intensity of solar radiation and the direction of the rays. Even a slight cloudiness is critical for a solar battery, since it almost always leads to a cessation of the generation of electricity from the sun.
The thickness of the panels ranges from 200-300 microns, and the efficiency in good weather and the correct location of the structure is kept at the level of 17-19%. The disadvantage is the high cost for private houses.
2) Polycrystalline silicon
On average, the service life is 15-20 years, the efficiency is 14%. In terms of electrical characteristics, polycrystalline solar cells are inferior to single crystals.
But due to the fact that the silicon crystals are directed in different directions, the plates on solar batteries catch scattered light beams well, and therefore “suffer” much less in the absence of the sun.
3) Thin film panels
In this case, a light-absorbing film is used, which “absorbs” the energy of the sun even in cloudy weather. That’s just their efficiency is kept at the level of 8-10%, but this disadvantage is more than compensated for by the low cost.
Thin-film photocells can be installed in any convenient place on the roof or wall of the building. They do not attract dust and even work under unfavorable environmental conditions, but at low solar radiation intensity, the efficiency decreases by 15%. The disadvantage is that a large installation area is required.
There are also photocells made of amorphous silicon, which are an economical option for country houses (efficiency 7–8%), and cadmium telluide panels made using film technology, with an efficiency in the region of 9–11%.
Solar panel wiring diagrams
There are several main categories of photovoltaic power supply systems for a private house (PSE), which differ in technical parameters and functional characteristics.
The first group includes completely autonomous (closed) systems that are not integrated into the centralized power supply network. Solar generators operate in their own circuit, and household appliances are directly connected. Efficiency indicators increase after installing batteries and a charge controller.
The second group is an open-type solar array system. By default, storage tanks are not provided in it. FSE are connected to a centralized power supply network through an inverter. At the permissible value of the power consumption, only photo panels work, which generate current directly.
If the load increases, electricity is consumed from conventional sources. Such solar systems are inexpensive, but also not highly efficient.
The third category includes combined PSEs, which have the characteristics of open and closed solar systems. Such designs are distinguished by their high cost, since their operation is associated with the use of high-capacity rechargeable batteries and network multifunctional converters.
Heating your home with solar panels
For autonomous heating of a private house, standard solar systems are used mainly in the south of Russia, where thermal energy is the primary source of electricity. It is more expedient for owners of country houses and small cottages to purchase a household collector for heating water.
The choice of a specific connection scheme directly depends on the operating conditions of the equipment and personal needs. As practice shows, the use of solar panels in winter makes it possible to save up to 25% of all costs on traditional energy sources, depending on the ambient temperature.
Standard set of equipment
To provide a private home with electricity at “green” tariffs, solar panels alone are not enough. The basic equipment, in addition to photocells, necessarily implies the use of auxiliary equipment:
- storage tanks;
- grid inverter;
- battery charge controller.
If you decide to make your own power plant powered by solar panels, do not choose car batteries for accumulating electricity – their service life under heavy load is only 2-3 years, so such “batteries” will have to be regularly replaced.
Solar systems based on a vacuum collector or solar module for heating water are additionally equipped with a pump for constant circulation of the heat carrier, a water boiler with a capacity of up to 1000 liters and electric heating elements.
Thus, solar energy resources can be used for power supply, hot water supply or heating, including the “warm floor” system. To choose the most suitable option for an autonomous home, you must first calculate the total power consumption of household appliances, and also be sure to take into account the level of insolation, the location and angle of inclination of the photo panels, the average number of sunny days per year.
Methods for installing household solar plants
There is nothing difficult in installing solar panels. The most important thing is to correctly place the modules. When installing, it is important to adhere to a certain angle of inclination, which should correspond to the geographical latitude of the area. During the installation process, you must also observe the azimuth. For the northeast, it is 180 degrees.
In winter, the efficiency of a power plant with solar panels can drop to minimum values, since heavy snowfalls will prevent the sun’s rays from reaching the outer surface of the photovoltaic cells.
Therefore, during installation, it is important to take into account that free space will be required on the roof to clean the structure from adhered snow and dirt.
However, this hassle can be avoided by fixing the solar panels on the surface of the southern wall at an angle of 60-80 degrees. In practice, different options for the location of photovoltaic modules are used for cottages:
- roof – you will additionally need to install a reliable supporting structure made of metal profiles or guide rails;
- walls – in this case, a frame system is mounted on the facade of the building to hold the photo panels “suspended”;
- backyard territory – an alternative option for the location of the batteries, when the roof of the house is heavily shaded or is not designed for additional load.
Free placement has many advantages, but it requires sufficient space in the backyard. To automate the process of tilting and moving photovoltaic panels in the direction of the sun, it is additionally recommended to use special hinged structures with an electric drive.
Payback and service life
The use of solar panels will save on lighting and heating, regardless of the season. The highest energy efficiency indicators of the solar system are shown in southern latitudes, where the number of sunny days prevails.
This is not surprising, since a prerequisite for a highly productive operation of a power plant is a stable supply of infrared radiation and visible light to the surface of photovoltaic cells.
According to statistics, solar panels for a private house with a capacity of 4-5 kW, with constant use, pay for themselves in 8-10 years, after which they work for the future. At the same time, the service life is on average 20-25 years, but the batteries will have to be replaced every 5-6 years.
To many, such payback periods will seem long, but in reality it is worth it, given that soon there will be practically no fossil resources on the planet, and the cost of one kilowatt of electricity will increase significantly.