The solar system uses the energy of the sun and converts it into electricity. Rightly, the question arises what happens to PV systems in winter, when the number of hours of sunshine is less and the sun, which is already lower, is more often covered by clouds. Let’s take a look at how the PV system works in winter!
Operation of the PV system in winter
The assumption that the performance of the PV system decreases somewhat in winter is basically true. However, it is a misconception that it would be useless, as it can produce energy even in such conditions.
A solar system, as the name suggests, works as a system. This is evident not only in its structure, but also in how we see its usefulness. In summer, PV systems can usually produce more energy, meaning they produce in excess thanks to the radiant sunshine. This surplus is fed back into the network, i.e. “pitched in”. Then, when winter comes and the output drops, the energy produced is replaced by the consumers from the “community network”, i.e. by connecting to the central system, they supplement the available electricity according to the demand.
What affects the power generation of a PV system?
The operation, performance and efficiency of the PV system depend on several environmental and non-environmental factors.
Among the non-environmental factors, the most important are:
- the orientation: in which cardinal direction the plane of the roof points,
- the angle of inclination: what is the angle of inclination of the roof, what angle it forms,
- shading: how much shadow is cast on the system due to its location?
- the type: it is important whether the solar cell is polycrystalline, monocrystalline or thin film.
- the quality: an important factor is the quality of the solar panel, the inverter and the design of the installation.
Environmental factors that affect performance:
- the number of hours of sunshine: how many hours the sun shines in a given period,
- the altitude of the sun: how high the sun is,
- climate: what are the temperature conditions in the given area.
In the following, we will look at these individually and see where the cold is an influencing factor, i.e. what the operation of the PV system in winter depends on.
The number of hours of sunlight and the height of the sun
How long a PV system is exposed to sunlight affects how much energy it ultimately generates. In winter, the sun shines less each day, so the number of hours of sunlight is lower, which can contribute to the decrease in energy production.
An important factor is the height of the sun in the sky, as this affects the angle of incidence of the sun’s rays falling on the system. As the sun is lower, the angle of incidence is less, which means it cannot produce as much energy as it would under ideal conditions.
The temperature and efficiency of the PV system in winter.
In winter, efficiency is a key issue in solar energy production. Some PV systems are extremely sensitive to temperature changes. Neither too hot nor too cold is good for them, because then their efficiency decreases.
In general, monocrystalline and polycrystalline solar cells withstand temperature drop best, while thin-film solar cells respond less well. However, when it comes to temperature rise, thin-film panels hold up much better.
Cloud and fog formation and winter performance
The type of PV system also determines the performance value. There are some that provide average performance even in cloudy weather, but there are also those that are less able to take advantage of the scattered light. Types that belong to the former category have a good chance to pass the test even in winter.
With regard to types, it can be said that the performance of monocrystalline solar cells decreases significantly in cloudy weather, so it is not recommended to install them in regions with a low number of hours of sunshine.
Where the sun shines less, lower temperatures also cause problems. As we wrote above, thin film systems cannot tolerate this drop in temperature and their performance degrades. The best choice for this is the polycrystalline solar cell, which can tolerate both stray light and low temperatures. Its indicators react less strongly to environmental influences.
In Germany, the solar module types have almost the same performance. Matched with summer production, the surplus and deficit complement each other when needed. We can see that the energy production of the PV system is influenced by several factors. If we take them into account, we can build a system that works well all year round.
Comments are closed