Choosing a set of solar panels for a summer residence
Choosing a set of solar panels for a summer residence
As a rule, in the country there are consumers of electricity of low power. In addition, the number of electrical appliances here is small and they are used periodically. If electricity is not supplied to the site and the country house, then the problem of power supply to these devices must be solved. In some cases, the way out of the situation may be the purchase and installation of a set of solar panels for summer cottages. If you correctly design, buy and mount such a kit, then the problem of powering lighting fixtures, a refrigerator, and electric tools will be solved. Solar panels operate silently, do not emit harmful substances and the electricity generated by them is free. The service life of such panels is up to 30 years. But for the successful use of the kit, you must first estimate the feasibility of the acquisition and take into account a number of parameters when buying. It is also worth noting the low efficiency of solar panels. This article is about those moments.
As sad as it sounds, no one will switch to solar panels for the sake of preserving the environment. First of all, this is done for the sake of economy. And a solar panel kit really saves on your energy bills. But the payback in this case will not be quick, and it depends on a number of factors. Besides, just buying solar panels is not enough. At a minimum, you will also need an inverter to convert the current, a charge controller, as well as batteries, a control unit, wires, and panel fasteners. In general, the amount is decent.
In order to independently install solar panels and receive electricity without any problems, experts recommend purchasing the entire system at once as a kit. On sale has a fairly large selection of such kits of various capacities. There are sets of solar panels that are used as the main power source in the country, and there are used as auxiliary ones. The cost of a kit that includes 2 solar panels averages about 50 thousand rubles. For the general population, the price is unaffordable. If such a kit is installed on a house where they live permanently, then it will pay off in 3-5 years. In the country, the period is even longer, since the devices are switched on much less frequently. But if there is no electricity in the country, then the use of solar panels is more profitable than a diesel generator. In addition, you can always increase the power by simply adding solar panels.
It should be noted right away that solar panels outside the kit without batteries and an inverter are useless. A certain power reserve is required to provide power to the refrigerator, lighting, household appliances. The value is about 1.3 kW. It is impossible to directly turn on devices with high energy consumption from solar panels. For normal operation, they do not have enough voltage in the network. Therefore, a mandatory accumulation of energy is needed.
It must be said that the profitability of a set of solar panels in the country increases significantly when using equipment and energy-saving class light bulbs (A, A +). If you want to save money, in principle, it is allowed to use supported batteries in the circuit. If you periodically turn on some of the devices, then such a kit will be enough for work. If you are going to turn on a lot of equipment with high energy consumption every day, then you should consider buying an autonomous solar power plant.
What does a solar panel kit consist of?
So, what is included in the standard set of solar panels for a summer residence?
- Solar panels. The number may vary depending on the task. The connection is made both in series and in parallel. It depends on what voltage is required at the inverter;
- charge controller. It is connected in series in the circuit between the batteries and the solar panels. Its role is to provide a stable voltage to the inverter;
- inverter. Used to convert current. It is connected in parallel to the batteries;
- Batteries;
- Wires, connectors and other accessories.
Photovoltaic or solar panels are semiconductor wafers connected in series. The kits for summer cottages use silicon modules with an efficiency of 13-20%. They can be monocrystalline or polycrystalline. Flexible solar panels are not used in such systems due to low efficiency. To protect the semiconductor wafers, the modules are covered with glass or other material that does not transmit infrared rays. Module frames are usually made of aluminium.
The base of such panels is perforated to improve heat dissipation. This is important because excessive heat will degrade the performance of the photocells. Among the main characteristics, the output power of the panels should be highlighted. As you can imagine, the bigger it is, the better. The power output by the panels depends on the following parameters:
- type of photocells and their number;
- intensity and angle of incidence of sunlight;
- temperature of the modules during operation.
When they calculate and buy a set of solar panels, they usually rely on the average electricity consumption per day. It also takes into account the reduction in power generated by the panels over several days. It already depends on the climate in a particular region. To generate 1 kilowatt, as a rule, a kit is required with a capacity of at least 200 watts. If you plan to provide a completely autonomous power supply at home, then the performance should be at least 600 watts. The voltage applied to the input of the inverter can be 12 or 24 volts. And at its output is already 220 volts.
In care, photovoltaic panels are unpretentious. Periodically they should be cleaned of dust. As for the snow, then you can meet different opinions. Some say that the snow slides off the surface of the panels on its own and does not interfere with the absorption of solar energy. Other experts advise installing fasteners for panels that allow you to put them in a vertical position if necessary. In general, it is highly desirable to be able to change the angle of the solar panels.
Characteristics, features and selection of a kit for giving
What are the types of solar panels?
On the market you can find many varieties of photovoltaic cells used in electrification systems in the country. The following types of panels are suitable for these tasks:
- Monocrystalline. They have the highest cost. Their efficiency is 15-20 percent. With the help of such panels, you can use the area as efficiently as possible, getting maximum power;
- Polycrystalline. They are cheaper than monocrystalline by about 15-20% Their area is a quarter larger than the first. Accordingly, more space for their installation will be required with equal power. The modules themselves are rectangular photocells connected in series. The efficiency of this type of panels is 12-15%;
- amorphous silicon. Such panels are cheaper than the previous type by 15 percent. In this case, the photocells are fixed on a flexible base. The efficiency is low (about 7 percent). Such panels absorb scattered light and partially infrared radiation well. Experts recommend installing them in regions with high cloudiness. Due to the flexible base, their installation is simplified. But they serve much less than monocrystalline and polycrystalline panels.
There are even less common micromorph panels. This type represents a symbiosis of amorphous panels in which there are micro-inclusions of silicon crystals. Their efficiency is 8-12 percent and a long service life.
Power selection
When choosing the power of a set of solar panels for a summer residence, one should take into account the number of energy consumers, as well as the frequency and duration of their use. There are special reference tables for insolation, where you can find out the power of solar radiation by months for different regions. The data there are given in kWh per square meter and they depend on the weather, the length of daylight hours.
To calculate the minimum panel power that is required for your conditions, you can use 2 options.
- The insolation value for your region (the worst month of the year) is multiplied by the efficiency of the solar module. As a result, you will get the maximum monthly generation from one square meter of panels. Next, you need to divide the planned costs of electrical energy by this value. You will get the total area of panels that is required to meet your needs;
- The second calculation method involves dividing the estimated electricity costs by the amount of insolation from the tables (worst month). Get the minimum power, expressed in kilowatts. 20 percent is added to the resulting value to account for equipment losses. To be completely sure of the electricity supply, add another 25 percent.