How to choose solar panels. Buyer Tips

How to choose solar panels. Buyer Tips


A solar battery is a device that converts solar radiation into electrical energy. For the first time, the method of operating a solar battery was developed in 1839 by physicist Alexander Becquerel. The method received practical application in 1873 after the invention of the first semiconductor. The technology of using solar energy for the purpose of supplying resources is gaining popularity around the world. Best Solar Panel Company in Pakistan The resulting type of energy is renewable, the financial costs of operating solar panels are very low – funds are required only for the purchase and installation of equipment. The energy generated by this source is cheap and available and is therefore widely used throughout the world. And if you decide to join the society of “green energy”, then you need to start from the fact

How are solar panels arranged?
A standard solar cell consists of an aluminum frame, solar cells, special glass, backing, conductors and a junction box.
The choice of solar panel parameters
When choosing a solar battery, the buyer is faced with the question “How to choose a suitable solar battery?” There are several types of photocells with their own advantages and disadvantages:

Polycrystalline cells, in which a semiconductor is produced by a polycrystalline method, this method reduces the cost of a solar battery, but reduces its efficiency. The efficiency of the elements is 17-19%.
Monocrystalline. If the cells are grown in a monocrystalline way, the efficiency of photocells is 20-21%. The cost of batteries with this method of silicon production increases, but the area of ​​photocells for producing energy of the same amount is reduced. Ready-made solar cells manufactured by the polycrystalline method have an efficiency of 13-17%, and with solar cells made by a single-crystal method – an efficiency of 15-18.5%,
Amorphous. The lowest efficiency (4-6%) is possessed by solar cells, in which solar cells are made of amorphous silicon.
Gallium arsenide. For the manufacture of highly efficient converters, GaAs – gallium arsenide, which has a heterostructure and a wider band gap, is currently widely used, this allows increasing the efficiency of solar cells to 35-40%, although this type of element has a very high price and is used only in the space industry.
What to look for when choosing solar panels?
When choosing solar panels for a private house or summer cottage, it is necessary to pay attention not only to the battery efficiency, which in modern designs based on silicon cells is limited to 20-21%, but also to the total capacity of the purchased solar power plant . It must provide enough electricity to be consumed by the electrical system at home in any weather.

In winter, the length of daylight hours is greatly reduced, therefore, in regions where this is observed, it is necessary to make a reserve of power so that the batteries are enough for a time when the sun is less active. Why is the output in winter less? Solar Panel in Pakistan Do not think that the cold will make the battery work worse. Precipitation in the form of snow, which must be removed, and shorter daylight hours with high clouds have a negative effect on the efficiency of work – this is what negatively affects the generation of electricity in winter. In summer, the solar panel generates less voltage than in winter. In hot weather, the temperature on the surface of the solar panel can reach 50–55 ° С, which reduces the efficiency of photovoltaic cells.

Another important point in drawing up a plan “How to choose solar panels for a home power plant” is the effectiveness of financial investments. With the right choice, many batteries pay off quickly enough, since the electricity generated using the energy of the sun is free. The output rated voltage of solar panels is a multiple of 12V and 24V, but there are also 20V – these are panels with 60 cells. The actual voltage at the output of the solar panels is usually higher than the nominal one. So a solar panel with a nominal output voltage equal to 12V, at the point of maximum power gives out 17V, and at idle it gives out 23V. Batteries with a rated output voltage of 20V and 24V work in a similar way. The 20-volt battery provides a voltage at the output of 30V at the maximum power point and 39V at idle,

Typical mistakes when choosing solar panels for home
When assembling a solar power plant on your own, mistakes are most often made associated with the selection of equipment, we note the main ones:

Incorrectly selected voltage of batteries and solar panels used in the same system;
Using a PWM controller with a 60 cell solar panel;
Not taken into account the temperature coefficient associated with voltage changes with temperature changes;
Using different batteries when connected in series;
Incorrectly selected cross-section of jumpers between the inverter and the battery;
Disregard for protective devices.
After the selection of equipment, the mistakes of amateurs do not end, since installation is ahead. When installing a solar power plant with your own hands, mistakes are often made like this:

Incorrect spatial installation of the solar panels themselves;
Falling shadows on cells from trees and neighboring buildings;
Incorrect hardware connection. If there are even only two batteries in the system, the serial connection may be confused with the parallel one. Not to mention several batteries when you need to make a series-parallel connection. This also applies to connecting solar panels;
Poor contact in electrical connections. With regards to the manufacture of jumpers by handicraft, without the use of special tools. Application of twisting, soldering MC4 connectors and other unreliable connections.
These are only the most common mistakes, but in practice there are many more. If you decide to assemble a solar power plant yourself, consult with specialists, this will help to avoid mistakes, save money, and yes, you can get advice from us for free.

Expert opinions on products
The choice of the type of solar station depends on the problem that needs to be solved using alternative energy sources.

Currently, three types of solar power plants are most widely used:

Autonomous . In places where there is no connection to the central grid, in gardens, in summer cottages, autonomous solar power plants are most in demand, well suited for lighting and other vital electrical appliances. The use of autonomous solar stations can significantly save money on liquid fuel for generators, especially in areas with a large number of sunny days.
Combined with a network . If there is a central network, then there is no need to abandon it; it is better to make a system compatible with the network. The automatic operation of the inverter, which is part of such a station, will independently select the power source for electrical appliances. And the batteries included in the composition will be a source of backup power supply in case of network outages.
Networked on-grid… On-grid solar power plants are the most profitable and quickly pay off, since they do not have batteries in their composition and energy conversion occurs with high efficiency. Moreover, they allow to transfer (sell) surplus generated electricity to the network, thereby accelerating the payback process. In many countries, with such generation from renewable sources, the sale of electricity is subject to a “green tariff”. In 2019, the Russian Federation adopted in the first reading Federal Law No. 581324-7 “On Amendments to the Federal Law” On Electric Power Industry “in terms of the development of microgeneration”, which will allow selling electricity generated by alternative sources at a special tariff. The purchase by the guaranteed electricity supplier from micro-generation facilities will be mandatory. The purchase and sale price will be equal to the weighted average unregulated price of electricity on the wholesale electricity market. The income of individuals arising from the sale of excess electricity produced for the needs of their households will not be taxed.
Regardless of the type of solar power plant chosen, it is worthwhile to understand that it is better to purchase high-quality solar panels for reliable and efficient operation. Despite the higher cost, they are more efficient and durable. Solar Energy in Pakistan Battery life can be up to 30 years or more. Buyers often ask the question: “Why is the output in winter less?” Do not think that the cold will make the battery work worse. Precipitation in the form of snow, which must be removed, plus shorter daylight hours with high clouds, have a negative effect on work efficiency – this is precisely what negatively affects electricity generation in winter. In summer, the solar panel generates less voltage than in winter. In hot weather, the temperature on the surface of the solar panel can reach 50–55 ° С, which reduces the efficiency of photovoltaic cells.

News