Within renewable energies, Solar energy It is one of the most widely used and recognized globally. In particular, small self-consumption installations on the roofs of homes and businesses in Spain have grown significantly in recent years. As the costs of solar panels decrease and environmental concerns increase, more people find photovoltaic installations a viable alternative to reduce their electricity bills and contribute to environmental sustainability. However, many people still wonder how solar panels work.
In this article, we'll go into great detail about how solar panels work, their many benefits, and the features that make them suitable for different uses. We'll also explore the types of solar panels, their power, and other important factors to consider.
How photovoltaic solar panels work
Photovoltaic solar energy works by harnessing solar radiation to generate electricity. This process is based on the photoelectric effect, which occurs when certain materials, such as silicon, generate an electric current when exposed to sunlight. The energy of the photons (light particles) releases electrons from their atoms, creating a flow of electric current.
It is important to understand that a photovoltaic solar panel It is made up of a series of solar cells. These photovoltaic cells are composed of layers of silicon that have been treated with other elements such as phosphorus and boron. Thanks to this treatment, the silicon layers can create a difference in charge between the positive and negative parts, which allows the generation of electricity when light falls on them.
The electricity generated by the photovoltaic panel is direct current (DC), which is not the one that can be used directly in our homes. To do this, it is connected to a power inverter, which converts direct current into alternating current (AC), which is the current used by most household appliances and electrical devices.
The performance of solar panels depends on several factors, such as the amount of sunlight received. That is, on sunny days, the panels generate more electricity than on cloudy days. Other elements such as panel orientation and tilt angle also play fundamental roles in efficiency.
Components of a photovoltaic solar system
A photovoltaic solar energy system includes not only solar panels, but several key components that work together to ensure the supply of electricity to the home or facility. These are:
- Solar panels: They capture solar energy and convert it into electricity.
- Investor: converts the direct current generated in the panels into alternating current.
- Bidirectional counter: It measures the electricity produced by the installation and the amount sent to the grid, in case there is any surplus.
- Battery (optional): stores excess energy to use when there is no sun.
Power of a solar panel and its performance
One of the most common questions is how power is measured of a solar panel and its performance. The power of a solar panel is measured in peak watts or WpThis indicator reflects the maximum amount of electricity that a plate can generate under ideal conditions, with standard sunlight and temperatures.
However, the amount of electricity a solar panel actually produces varies significantly throughout the day and year, as it directly depends on the amount of sunlight available. This is why peak watt measurements are used, but you shouldn't assume that the panel will generate that amount at all times.
When evaluating the installation of solar panels, it is important to consider several factors that affect actual performance. geographic location is one of the most important factors, since not all areas receive the same amount of sun throughout the year. In addition, the roof orientation and the Inclination angle play a crucial role in the efficiency of the panels. A south-facing roof with an optimal pitch will maximize sunlight capture.
The power inverter is another component that also influences the overall efficiency of the system. Some inverters feature advanced technologies that optimize the amount of energy converted from DC to AC, but their efficiency also depends on the type of installation.
Diversity in types of solar panels
There are several solar panel technology options available on the market today, each with their respective advantages and disadvantages. The most popular types are amorphous, polycrystalline, and monocrystalline panels.
- Amorphous solar panels: These are less common because they have a lower performance. Their main advantage is that they are cheaper, but with the disadvantage that they lose efficiency quickly during the first months of use.
- Polycrystalline panels: They are made from multiple silicon crystals and are usually cheaper to manufacture. However, they offer lower efficiency compared to monocrystalline ones. They have a characteristic bluish color.
- Monocrystalline panels: These are the most efficient on the market. They are made from a single crystal of high-purity silicon, which allows electrons to move more freely, generating more electricity per square meter. Although they are more expensive, their efficiency justifies the investment.
Advantages of monocrystalline plates
While polycrystalline panels are more affordable, monocrystalline They are considered the best option for several reasons:
- Superior efficiency: Monocrystalline panels have higher efficiency, meaning they can generate more electricity using less space.
- Better performance under low solar radiation: These panels perform better on cloudy days or with low sun exposure.
- Greater Durability: Monocrystalline ones resist the passage of time better and maintain their performance for longer.
- Esthetic: Visually, these panels tend to be more aesthetically pleasing, given that their black colour blends in better with roofs.
Factors that influence the performance of a solar system
Although solar panels are an excellent solution, their performance can be affected by several factors. One of the main problems is the appearance of shadows on the panels. Shade, whether from nearby trees or buildings, directly affects the amount of light reaching the photovoltaic cells, which decreases their electricity production.
Another factor to consider is the dirt on solar panelsOver time, dust, leaves and other debris can build up on the surface of the panels, blocking sunlight. To maintain optimal performance, regular cleaning is essential.
Furthermore, the high temperatures They can also affect performance, as panels work best at moderate temperatures. For every degree above 25ºC, solar panels can lose between 0,25% and 0,35% of their rated power.
The batteries Batteries are another optional component that can affect the performance of your solar system. In areas where sunlight is scarce, or for those who want to make the most of the energy generated during the day, batteries allow you to store excess energy for use at night or on cloudy days.
Furthermore, the orientation and inclination The angle of the solar panels must be optimal. A southerly orientation is ideal in the northern hemisphere. In addition, the inclination of the panels varies between 30 and 45 degrees depending on the geographical location.
What happens when there is no sun?
One of the most common questions about using solar panels is what happens when there is no sun, such as on cloudy days or at night. Although cloudy days still retain some solar radiation, allowing solar panels to generate electricity, their output is considerably lower than on a sunny day.
At night, when there is no sun, grid-connected solar systems use electricity from the public grid to compensate for the lack of energy from the solar system. However, if the system has storage batteries, these will supply the energy stored during the day.
Using solar energy provides not only considerable savings on your electricity bill, but also a sustainable alternative that helps reduce your carbon footprint. As technology advances, solar systems are becoming more and more efficient and affordable, allowing more homes and businesses to benefit from this clean, renewable source.
Knowledge about how solar panels work and the different technologies available is key to making informed decisions when investing in a solar installation. If you are looking for a long-term solution that allows you to save and contribute to the environment, photovoltaic solar panels are an excellent option.