Insolation in Poland – where is the best place to build solar farms?

The efficiency of photovoltaic panels increases with the development of this technology, but one condition still has to be met. It is, of course, about access to sunlight, with the longest possible exposure to them. Poland is one of the countries where undoubtedly there are good conditions for the development of solar energy. However, it is important to know that these conditions can vary considerably depending on the specific location. Therefore, when planning an investment in a photovoltaic farm, it is worth checking which places have the best sunshine. Thanks to the selection of the optimal location, the costs will pay off faster.

What is insolation?

Before we move on to a detailed discussion of which regions of Poland we deal with the greatest sun exposure, let’s explain what it actually is. Insolation is understood as the average intensity of solar radiation that falls on a given surface in a specific time period. Intensity is the power density of solar radiation, given in watts, that reaches per square meter of surface in one second. Accordingly, this parameter is mostly expressed in watts per square meter (W / m²). However, the level of intensity depends on so many factors that it is constantly changing. Therefore, the values over a longer period of time should be averaged. Most often, the average insolation of a given area during the year and specific months is given, expressed as kWh / m² with an indication of the period of time this value applies to. Insolation is a synonym for insolation, so we will use these terms interchangeably later in this article.

How does Poland’s insolation affect photovoltaics?

The level of insolation has a great influence on the efficiency of solar panels, i.e. the amount of energy produced over a period of time. It is desirable that the first value be as high as possible. By obtaining sufficiently large amounts of electricity thanks to solar radiation, we can cover our current needs with it, and also store the surplus for later use and possible resale. The efficiency of the installation depends on various factors, such as its size, parameters of the given elements, correct assembly – including pointing the cells in the right direction and at the right angle – or just sunlight. Even the most modern and technically advanced photovoltaic panels will not be able to meet our energy needs if they do not receive enough solar radiation. The good news, however, is that the level of insolation in Poland turns out to be satisfactory, thanks to which a properly installed installation will fulfill its function regardless of the location of the farm, although the results in different parts of the country may differ significantly.

Which voivodship in Poland has the highest average annual insolation?

It has already been confirmed many times that insolation in our country is conducive to investments in photovoltaics. The average annual total insolation in Poland is about 1000 kWh / m², which is more than enough for the effective operation of the installation. However, this sum is slightly different for individual voivodeships. The greatest insolation in Poland occurs in the central-eastern part of the country. In the Lubelskie Voivodeship, the average annual value reaches even 1,200 kWh / m². In the Mazowieckie, Wielkopolskie, Małopolskie, Łódzkie, Świętokrzyskie and Kujawsko-Pomorskie voivodships, this value ranges from 1000-1100 kWh / m². The situation is similar in the north of the Dolnośląskie, Opolskie, Śląskie and Podkarpackie voivodeships, as well as in the south of Podlasie. In other regions, that is also in the Lubuskie, Zachodniopomorskie, Pomorskie and Warmińsko-Mazurskie voivodships, the average annual insolation is in the range of 900-1000 kWh / m².

Insolation in Poland in individual months

The level of sunlight also depends on the season. This is of course related to the changing times of sunrise and sunset, which affects the operating time of the installation. According to the latest estimates, it is assumed that between mid-April and the beginning of October, approximately 77% of annual radiation is obtained, while for the second half of the year – only 23%. The greatest insolation in Poland should be expected in summer, when the day lasts more than 16 hours, and in spring, when it is about 12-15 hours. By far the greatest insolation occurs in May, June and July. In autumn, the daytime drops below 12 hours, and in winter it is only 7-8 hours. In December and January, the performance of the panels is by far the lowest. The differences between insolation in Poland in individual months are therefore very large and affect the amount of electricity obtained to a much greater extent than is determined by the geographical location.

Is it profitable to build solar farms in Poland?

Taking into account the average annual insolation in Poland, photovoltaics in our country turns out to be a very good solution. The level of insolation is fairly equal across the country. The range from 900 to 1,200 kWh / m² is a relatively small difference that does not affect the usability of the installation, although in regions with better sunshine it will, of course, be more efficient. However, you do not have to be afraid of investments in voivodships with weaker insolation, because there are sufficiently good conditions there for a properly designed installation to fully meet the demand. Differences in insolation in individual months turn out to be a bigger problem. In winter, the amount of daylight is so small that even the most efficient panels may not be able to generate enough electricity. For this reason, the installation should be supplemented with an excess energy storage device and it is best to start it after the end of winter to accumulate surplus throughout the spring and summer, which may be useful later. It is also possible to transfer the generated electricity to the power grid and then collect it for your own needs.