How to choose solar panels for a residential power station?

The Sun is one of the most important renewable energy sources. In addition, a mini version of a solar power plant can be built in your own yard or on the roof of your house.

It is widely known that using renewables to provide your home with green electricity is not only a great way to take care of the environment but also a profitable investment. And what do you need to know to choose the right solar panels for your home solar power plant?

The main components of a residential solar power station

To have solar energy converted to electricity, you will need to purchase:

– solar panels (while choosing them, you have to keep in mind the desirable capacity of your electric system);

– charge controller (for proper charging voltage for the system’s battery or batteries);

– a battery or battery pack (accumulates charge to make possible further autonomous operation of the station; as capacity of one battery can be not enough to provide the entire house with electricity, installation of a battery pack may be required);

– inverter (for conversion of direct current power to alternating current required by  household appliances).

It is also important to consider all power and technical parameters of the solar system’s components – they must be compatible with each other.

Choosing solar panels is one of the key points while preparing for home solar power plant installation. These modules are DC drives that convert solar energy to electricity, which can be used to satisfy the energy needs of your house.

What do you need to take into consideration?

When selecting solar panels, you should take into consideration that their cost depends on their dimensions and power (for example, a 100-W solar panel will be much smaller and cheaper than a 200-W one).

In addition, since solar panel dimensions vary depending on the material they are made from, it is advisable to select the type of material in advance and measure an area on which you want to have them installed. In addition, they must be installed in an accessible place.

As to the solar panels’ efficiency, their potential owners should also know the energy needs of their household to make their solar power station profitable. For example, we recommend purchasing a number of panels that can satisfy from 40 to 80% of your heating needs.

 You should also take into account the climate and the illumination level of an area on which the photovoltaic system is to be installed.

Types of solar panels

Depending on the photocells used, there are 3 types of solar panels:

– monocrystalline;

– polycrystalline;

– thin-film (or amorphous).

Monocrystalline solar panels are named after single-crystal silicon they are made from (dark blue or black color). Such panels are the most efficient (performance about 23%) and occupy less space than others. Thus, monocrystalline solar panels are a perfect option for households with limited space for installation, although they will cost more. This type of modules is preferred by those household owners who plan to sell the excess electricity or who always want to have some electricity as a reserve.

Polycrystalline solar panels can be interesting to those homeowners for whom space is not a problem and who are looking for a more low-budget option. These panels consist of polycrystalline silicon and have a slightly lower performance than monocrystalline ones (15-18%). Moreover, as they have different color and texture, it’s easier to distinguish them by nonuniform color (from dark blue to blue).

Thin-film (or amorphous) panels are another option for a residential solar power station. Such modules differ from the above mentioned types both in structure and mounting method.Today, such solar panels are rarer than mono and polycrystalline options.

How many solar panels do you need?

First of all, to find out the number of modules required to meet your energy needs, you have to determine the energy intensity of your house, the nominal capacity of the solar panels themselves, and the coefficient of solar exposure (can be found on specialized meteorological sites) for the area where they will be installed. You can determine your houses’s energy intensity can be by the average daily electricity consumption, kWh.

Let’s get down to the calculations. If your houses’s daily average is 8 kWh, the nominal solar panel capacity is 200 watts and you are going to use the solar power station from March to  November (given that the coefficient of solar exposure for your area is 4), we will have the following:

1) amount of energy that will be generated by one solar panel: the power of the solar module by the coefficient of solar exposure – 200 x 4 = 800 Wh;

2) required number of modules to provide you with 8 kW (8000 watts): divide the average daily capacity by the power of one solar module – 8000/800 = 10 (if the results you get is not a whole number, round it up).

If the solar station is intended to work all year round, your calculations should be based on the indicators of a season (seasonal indicators), during which the coefficient of solar exposure is the lowest.


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