Solar energy has been consolidating itself as one of the main solutions for reducing electricity costs and expanding the use of renewable sources in Brazil.
At the heart of this transformation is the photovoltaic module, the component responsible for capturing sunlight and transforming it into clean and sustainable electrical energy.
With different technologies, formats and efficiency levels, photovoltaic modules are essential in both residential and commercial systems as well as in large solar plants.
Therefore, understanding how they work, what types are available, and the selection criteria is essential for anyone who wants to invest in this sector safely and profitably.
In this guide, you'll learn what a photovoltaic module is, how it operates, the main differences between models on the market, and the necessary care to ensure maximum performance throughout the system's lifespan. Let's dive in!
What is a photovoltaic module?
The photovoltaic module, also known as a solar panel, is the equipment responsible for capturing solar radiation and converting it into electrical energy.
It is made up of several interconnected photovoltaic cells, normally made of silicon, a semiconductor material.
Each cell has the function of transforming sunlight into electric current through the photovoltaic effect.
When grouped into a module, these cells generate a significant amount of energy, enough to power homes, businesses, industries and even large solar plants.
The modules are designed to withstand weather conditions such as rain, wind and temperature variations, and can have a useful life of 25 years or more, maintaining efficiency over time.
Are a photovoltaic module and a solar panel the same thing?
Although the terms are used synonymously in everyday life, technically there is a slight difference:
- Photovoltaic module: is the correct technical term to designate the unit composed of solar cells encapsulated in a structure with glass, protective film and frame;
- Solar panel: is the most popular expression and can refer to both the photovoltaic module and other types of panels, such as solar thermal collectors (used for heating water, not for generating electricity).
In other words, every photovoltaic module can be called a solar panel, but not every solar panel is photovoltaic.
This distinction is important to avoid confusion, especially in solar energy system projects and budgets.
How a photovoltaic module works
The operation of the photovoltaic module is based on the photovoltaic effect, a phenomenon discovered in 1839 that explains how light can be transformed into electricity. Understand how it works:
- Sunlight capture: when the sun's radiation hits the silicon cells, the photons of light interact with the atoms of the semiconductor material;
- Release of electrons: this interaction causes electrons to be released from their original position, creating a flow of particles;
- Formation of electric current: this ordered movement of electrons is what we call direct current (DC) electric current;
- Conversion into usable energy: The direct current goes to the solar inverter, which converts it into alternating current (AC), the form of energy we use in homes, businesses and industries.
The efficiency of the module (i.e. the ability to transform solar radiation into electricity) depends on factors such as the type of cell (mono or polycrystalline, thin film), the quality of the materials, the ambient temperature and the intensity of the solar radiation available at the site.
In short, the photovoltaic module is the starting point of the entire process that allows sunlight to be transformed into clean, renewable and economical energy.
Main types of photovoltaic modules
Photovoltaic modules available on the market can vary in design and technology, directly impacting their efficiency and the way they capture solar energy.
Currently, the two most common models are monofacial and bifacial. Understand the differences between them in the topics below:
Monofacial modules
Monofacial modules are the most traditional and still the most used in residential and commercial roofs.
They capture solar radiation only through the front side, which is the part facing directly towards the sun.
For this reason, its performance depends exclusively on direct light incidence, without taking advantage of reflections or extra brightness.
They are reliable, extensively tested and usually have an efficiency of over 20%, in addition to offering a good cost-benefit ratio.
As for durability, most manufacturers provide a 25-year warranty for this type of module, ensuring that it will continue to generate energy within acceptable parameters during this period.
Bifacial modules
Bifacial modules represent a technological evolution in relation to monofacial modules.
The big difference is that they can generate energy from both the front and back, taking advantage of light reflected from nearby surfaces, such as sand, light concrete, metal roofs or even the ground in photovoltaic plants.
This feature allows for a generation gain that can vary between 5% and 20% more compared to monofacials, depending on the installation environment and the soil reflectivity level.
Additionally, these modules come with an extended warranty, up to 30 years, which reinforces their durability and reliability over time.
Read also Difference between bifacial and monofacial modules
Advantages of investing in quality photovoltaic modules
Choosing modules with recognized market quality ensures not only immediate efficiency but also long-term reliability. Some clear advantages include:
- Greater energy efficiency: high-performance modules generate more energy per square meter, reducing the need to install many panels;
- Durability and robustness: established manufacturers offer warranties of up to 25 years (30 years in the case of bifacial modules), ensuring minimum energy production even after decades of use;
- Weather resistance: Quality modules are more likely to withstand heavy rain, hail, and temperature fluctuations, which are essential in a country with a diverse climate like Brazil. However, it's important to note that in cases of actual damage caused by natural phenomena, such as intense hail, the manufacturer's warranty does not cover module replacement.
- Faster financial return: the greater the generation and reliability, the sooner the system pays for itself, increasing the attractiveness of the investment;
- Security and certifications: Certified modules follow international standards, ensuring protection against electrical and performance risks.
Investing in quality means fewer headaches with unexpected maintenance and greater predictability in the results of the photovoltaic system.
Factors to consider before choosing a photovoltaic module
Choosing a photovoltaic module shouldn't be limited to price alone. Several technical factors directly influence efficiency, durability, and return on investment.
Below, we highlight the main points that need to be evaluated before purchasing:
Conversion efficiency
Efficiency indicates the module's ability to transform solar radiation into electrical energy.
Higher-efficiency modules generate more energy in the same installation area, a crucial factor on small roofs or locations with limited space.
Although they cost more, they can offer better value for money over time.
Manufacturer's warranties
Warranties are generally divided into two: product warranty, against manufacturing defects, which varies between 10 and 15 years, and performance warranty, which ensures a minimum level of energy generation over time.
For most modules, this performance guarantee extends to 25 years. For more advanced models, such as double-glazed or bifacial, it can reach up to 30 years.
Evaluating the manufacturer's solidity and reputation is essential to ensure that these guarantees are actually fulfilled.
Nominal power and tolerance
Nominal power (W) is the maximum capacity of the module under ideal test conditions (STC). Tolerance shows whether the panel can deliver more or less than the indicated value.
Quality modules usually have positive tolerance, meaning they can generate even more than specified, offering greater safety in system sizing.
Local climate and conditions
Temperature, shading, and dust can impact module performance.
In hot regions, modules with a lower temperature coefficient perform better, as they lose less power as the temperature increases.
This means that even on very sunny and hot days, its efficiency drops more slowly compared to modules that have a higher coefficient.
In places with pollution, dust, or sea air, it is important to choose modules with glass and structures that are more resistant to corrosion and dirt accumulation.
Certifications and standards
International certifications such as IEC 61215 (performance), IEC 61730 (safety) and UL 1703 ensure that the module has passed rigorous quality testing.
In Brazil, modules also require the INMETRO seal, which ensures compliance with minimum efficiency and safety standards.
Compatibility with other components
The module must be compatible with inverters, cables, connectors and mounting structures.
Voltages, currents and maximum power must be checked to ensure that the system operates stably, without risk of overload or loss of efficiency.
Additionally, considering modules from brands that offer technical support and comprehensive manuals makes integration easier.
Care and maintenance of the photovoltaic module
Although photovoltaic modules require little maintenance, taking preventive care of them is essential to ensure efficiency, safety, and to extend the system's lifespan.
The following are key best practices:
Periodic cleaning
Dust, pollution, leaves, and even bird droppings can reduce the efficiency of modules by blocking sunlight.
Cleaning should be done with clean water and a soft cloth or soft-bristled brush, avoiding the use of harsh chemicals.
In very dry or highly polluted regions, cleaning should be more frequent. The same applies to installations with low slopes, as the self-cleaning effect of rain is reduced, favoring the accumulation of dirt.
Visual inspection
A regular visual check helps identify cracks in the glass, stains, delamination, oxidation in connections or structural deformations.
These problems, if ignored, can compromise energy generation and even create safety risks.
Electrical check
In addition to the physical inspection, it's important to perform electrical measurements of the system. Specialized technicians check the integrity of cables, connectors, and junction boxes, as well as measure voltage and current to identify potential performance issues.
Performance monitoring
Most modern systems offer online monitoring platforms that show generation in real time.
Monitoring this data allows you to quickly identify drops in production, which may indicate excessive dirt, equipment failures, or problems with the electrical grid.
Shading prevention
Partial shading (caused by trees, neighboring buildings or antennas) can significantly reduce production.
Periodically evaluating the system's surroundings and performing pruning or structural adjustments helps prevent efficiency losses.
Safety during maintenance
Maintenance must always follow electrical safety and working at height protocols.
This includes the use of Personal Protective Equipment (PPE), shutting down the system when necessary, and the recommendation that more complex interventions be carried out by qualified professionals.
O Canal Solar and photovoltaic modules
O Canal Solar has established itself as one of the main channels for information and technical training on solar energy in Brazil, and this includes an in-depth look at photovoltaic modules.
On our portal, you can find comparisons between different brands and technologies, performance tests, efficiency analyses, and market trends.
Additionally, the educational platform of Canal Solar offers specialized courses in the design and sizing of solar power plants, in which photovoltaic modules are studied in detail.
In this way, both professionals already working and those new to the sector find in Canal Solar provides the support you need to choose the most suitable equipment and understand its impact on energy generation.
Conclusion
The photovoltaic module is more than just a piece of equipment: it represents the direct link between the sun and the electricity that supplies homes, businesses, and industries.
Carefully choosing the manufacturer's technology, efficiency, and reliability is essential to ensure system longevity and the best financial return.
At the same time, follow specialized publications and stay up to date with reliable sources, such as Canal Solar is the way to make informed technical and strategic decisions.
In this way, investing in solar energy ceases to be just an economic choice and becomes a sustainable and conscious decision for the future.
