Calculation of solar panels for the home

In our modern time, various technologies that provide maximum comfort in human activity are actively developing. In particular, it is worth noting that the development of alternative energy sources is in full swing. A striking example of this is solar panels, which can now be installed on the roof of your own home. And anyone can buy them. This is especially true in cases where the house is located away from power lines. But in order to feel all the benefits and advantages of such a solution, the correct calculation of solar panels is necessary.

General information

The photoelectric effect is a physical phenomenon that was discovered back in 1887 and became the basis for the development of solar panels for generating electricity. Under the influence of light (photons) or any other electromagnetic radiation, the energy of these particles is transferred to the electrons of the substance. In other words, you can use the sun to get electricity.

After the discovery of this physical phenomenon, there was a need for its control. For this purpose, photocells were created - special electronic devices of compact size. They include semiconductor materials.

In the context of industrial production, it has become possible to combine microscopic transducers into massive and efficient panels. Many modern enterprises produce silicon modular structures in large volumes. Their efficiency is about 18-22%.

The solar battery includes several such modules through which the photons of sunlight enter the electric circuit in the form of direct current. Then they go to storage devices or are converted into an alternating current charge (220 Volts). The resulting electrical energy allows home appliances to function.

Features of calculating solar panels for the home

This operation is reduced, first of all, to determining their power. And for this it is necessary to know what energy load will fall on the entire structure. In other words, how many kilowatts of energy will be consumed monthly.

These indications can be determined by observing the electric meter. And if the value is within 100 kW, then the panels should be purchased exactly those that are capable of generating such an amount of energy.

It is also worth considering that the operation of solar panels in full mode is possible only in daylight. Full delivery will be only if the sky is clear. With a change in the angle of incidence of sunlight, as well as the appearance of clouds on the horizon, the power will decrease by 20%. The same thing will happen in cloudy weather. You should not forget about all this.

That is, in the process of calculating solar panels for a private house, you should take the period of time when they work at full strength. As a rule, this is 7 hours - a period from 9 am to 4 pm. At the same time, in the summer season, panels can work from dawn to dusk. But in the past, the percentage of health will be only in the region of 20-30%. In the above hours, you can get the remaining 70%.

Power

As we have already understood, the fundamental factor that should be taken into account when calculating solar panels is the energy load. After all, the performance of the batteries largely depends on the amount of electricity required to provide the home:

• Creating a full-fledged station requires the use of powerful panels - from 150 to 250 watts.
• To maintain the efficiency of only country lighting, you can do with low-power batteries - no more than 50 watts, which is quite enough.

How to make such calculations?

Basic power consumption

Before calculating the solar battery and battery, it is necessary to determine the total power of all used consumers of electric current. For this purpose, the energy consumption of each unit (devices, bulbs, etc.) is multiplied by the number of hours of its use during the day.

After that, all the data obtained should be added up. As a result, we get the norm of electricity consumption per day (in kilowatt hours). That is how many solar panels must produce, and this is the minimum value. Subsequent calculations regarding the number of panels, their cost and other parameters will depend on these data.

However, the entire system consists not only of solar panels, other components are also included here:

• inverters;
• batteries
• charging controllers.

When calculating the power of solar panels for the home, this also should not be discounted! In batteries, a decrease in energy is observed - up to 20%. In this regard, in further calculations, the obtained base value must be increased by this value.

Electricity consumers

In each house you can find a number of the most necessary appliances. The following equipment will always work at certain hours:

• refrigerator;
• TV;
• a computer;
• Washer;
• boiler;
• iron;
• a microwave oven (however, not everyone has it).

There are also other devices, in the absence of which life loses the desired level of comfort. In addition, in the territory of private real estate, a certain number of light bulbs come on every day, which can reach hundreds.

The table below shows the power of electrical appliances that are used most often.

With this table it is convenient to carry out a simple mathematical calculation of solar cells. In this particular example, the daily consumption value is 18.9 kWh. Only this, without taking into account what we usually do not use every day - an electric kettle, hairdryer, pump, food processor, etc. Thus, on average it can turn out up to 25 kWh (at least).

The important point is insolation

Before you start counting the number of solar panels, you should consider such a thing as insolation. Roughly speaking, this term should be understood as the amount of energy of sunlight falling on a unit area. This is a very important parameter, without which it is impossible to determine exactly how many panels should be purchased.

After all, even if sunlight is not enough, no matter how productive the battery may be, it will not be able to give the necessary power. Therefore, you need to understand the importance of this parameter when calculating solar panels. After all, the required level of energy supply will depend on this.

Of course, this parameter is purely individual for each particular region of the country. You can get this necessary information in two ways:

• specialized reference books;
• meteorological electronic resources.

As you can understand, the maximum value of insolation will fall on the summer period. The minimum values ​​are mainly in the cold months.

Number of batteries

Now you can do the calculation of the number of panels. For this, the found value of the basic consumption of electric energy per day should be divided by the insolation data of the required month.

At the same time, it is important to understand that the calculation must be carried out on a monthly basis, since the data can vary to different and sometimes significant degrees. Now it remains to divide the obtained value as a result of calculating the number of solar panels, only by the power parameter of the selected panel. This characteristic is indicated in the passport. If the result is a fractional number, it is rounded to the nearest integer value and only to the larger side. This will be the final result.

Of course, the greater the productivity of the panel, the smaller their number will have to be taken. And here everything mainly depends on the size of the family budget and the roof area. At the same time, it is necessary to take into account the period of operation of the entire system. After all, with a decrease in the insolation of solar panels, more is required than under normal conditions.

Rational consumption

Thinking about the calculation of solar panels, it is worth paying attention to lighting. But as already noted earlier, the number of lamps in a private house can be large - 100 or more. For this reason, it is worth paying attention to energy-saving light bulbs. As a result, significant savings in terms of energy consumption can be achieved.

Everything else should be purchased household appliances not lower than class A and even A +, A ++, A +++. Ultimately, such a measure will significantly reduce the costs that will be spent on the purchase of solar panels. In addition, most modern devices are designed for 12 V.

Namely, so many photo panels can produce without using additional devices for converting direct current to alternating voltage.

Mathematical example

In calculating the number of solar panels for a home, you should consider what season the whole system will work in full mode. And here again, everything is due to insolation. Depending on the month, a different number of photo panels may be required.

For a clearer understanding, it is worth giving a specific example:

• For example, the daily electricity consumption in the house will be 15 kW * hour.
• The insolation parameter is 3 kW * h / m ² .
• The power of one panel is 300 W or 0.3 kW.

Calculation of the required number of batteries (denoted by the letter N): N = 15/3 / 0.3 = 16.6. Rounding the resulting value up to an integer upwards, we get the result - 17 panels.

However, in winter, insolation is significantly reduced and can reach 1 kW * h / m ² . In this case, much more batteries will be needed - up to 50.

A number of nuances

On the one hand, the refusal about the dependence of central power supply implies certain advantages. But there is a flip side to the coin - such a measure is fraught with some nuances that should not be discounted. And first of all, you need to understand that the sun will not shine all month long, without a “break” - because the luminary also needs a “rest”.

For this reason, in the course of calculating solar panels, one should consult the archive of weather conditions in the region of residence in order to determine the number of cloudy days. You may notice that at least 7 days in one month is a period of adverse weather. At this time, the solar panels will not be able to give the necessary amount of electrical energy.

Everything else, you must not forget about shortening the day in the fall and spring. Accordingly, the number of cloudy days is increasing. In this regard, to obtain solar energy from March to October, it is necessary to increase the array of panels up to 50%, depending on the region of residence.