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Dimensions of photovoltaic panels: how to choose them correctly?

In this article we will talk about the dimensions or size of solar panels, this is a very important variable that must be considered when buying.

Dimensions of photovoltaic panels: how to choose them correctly?

The dimensions of the photovoltaic panels largely depend on the size of the roof surface or the place where we want to install them, as well as our electricity demand. The type of roof is also important.

Dimensions of the photovoltaic panels
Approx. 200 cm x 100 cm x 40 mm
Weight of the photovoltaic panels
Approx. 21.00 kg
Number of cells: 72
Power of the photovoltaic panels
The power of the photovoltaic module is 380-400 W

Once we have made the decision to obtain cheap and ecological energy produced with the use of solar rays with the help of photovoltaic panels, it is time to ask ourselves more detailed questions. For the most general, that is, in the first place: why do we need photovoltaic energy? – is relatively easy to answer. Although you have to bear some investment costs up front, the goal is to save electricity in the years following the return on investment (usually after 6-8 years). On the other hand, the problem arises when it is necessary to select the appropriate dimensions of the photovoltaic panels to, on the one hand, cover the domestic electricity demand, and on the other, not to overload the roof on which the panels are installed. most of the time (although this is not a rule).

Therefore, the best answer to the question posed in the title will be: wisely. In practice, it will be the result of the size and structure of the surfaces on which they are to be placed, as well as the power that we want to obtain.

Estimating your home’s energy needs

At the beginning of the adventure with photovoltaic panels, you need to answer the key question: what is the electricity demand of the home? According to statistics, a household in the 2 + 2 model (parents plus children) consumes an average of 1,900 kWh per year, and even 2,100 kWh in rural areas  . The next step to consider is whether the planned PV installation will ultimately cover all of the demand or only part of it. It does not always depend on our decision.

 It will also be greatly influenced by the surface and construction possibilities of the roof or well-sunny areas of the floor. After determining the   annual demand for  electricity.  You can start calculations related to the power of the photovoltaic panels that we will need and the area that they will occupy.

Dimensions of photovoltaic panels

The dimensions of photovoltaic panels  have been gradually standardized over the years, in contrast to the initial period, when their size was highly dependent on a certain manufacturer. Photovoltaic panels are made up of photovoltaic cells (60 or 72, depending on the type of equipment). At present, the dimensions of the panels are similar, their width is about 100 cm and the length is about 165-170 cm (the thickness is about 40 mm), with a power of about 280 W.

It is extremely important, when checking the dimensions of the individual PV panels, to ensure that they are provided together with the mounting clearances. However, when it comes to weight, the average photovoltaic panel weighs approximately 19 kilograms (most of the time, although it is not a rule). In turn, the efficiency of the photovoltaic modules ranges between 15 and 17 percent, which is a very satisfactory result.

Roof area and photovoltaic installation

We already have more or less specific dimensions of the photovoltaic panels and the annual electricity demand of a certain home. Now we can begin to calculate the area of ​​the ceiling that will be needed for installation. It is not uncommon for photovoltaic modules to cover the entire available roof area, in other cases only a part. It is also important if the panels are placed in special structures on a flat roof or if it will be a sloping roof. We have to answer the following questions: How many windows? How are they distributed? With or without “swallows”? etc. In the first case, it is necessary to maintain the appropriate distance between the modules related to the width of the shadow area. If installed on a sloping ceiling, the modules can be placed very close to each other, filling almost the entire ceiling surface.

The method of calculating the required roof area for the structure is very simple. Assuming that we need a photovoltaic generator of 5 kW of power,  with modules of 102 cm x 165 cm and 250 W of power, we need about 35 square meters of roof surface  . We divide the dimensions of the module by the power of the module and multiply it by the power of the generator. So actually, it comes out a bit more. Rectangular PV modules rarely fill the roof perfectly, especially if it is cut with windows or “swallows.”

The decision is up to us

In the end, the  size of a photovoltaic micro installation will depend on what type of energy we want to get  . In the case of small or medium-sized companies, they will necessarily occupy a slightly larger area. In the case of households, the demand for electricity is often easily met with installations mounted on the ceiling or on the floor. Interestingly, these ground facilities are also becoming increasingly popular. For example, on farms (sometimes even replacing agricultural activities), but not only. In any case, we can make preliminary calculations of how much space a possible photovoltaic installation will occupy. It is enough to collect basic data on the power, the dimensions of the panels and the surface on which they will be installed.