The functionality of photovoltaic systems. A simplified explanation of a complex topic.

Photovoltaic systems are a great way to save money and contribute to environmental protection. But how exactly do they work? Modern urban settings whithout photovoltaic systems are hardly imaginable. They are increasingly found on rooftops as well as balconies, terraces, and building facades. These systems are used to generate electricity from sunlight. But how does this process work? Let's take a simplified look at this complex topic together.

What is photovoltaics?

Photovoltaics, a term derived from the Greek words "photos" (light) and "Volt" (electric voltage), describes a process in which the energy of sunlight is converted into electrical energy. This is done through the use of the photoelectric effect in solar cells, which convert sunlight into direct current. This direct current is then converted into alternating current usable in households through the use of an inverter. By the way: The term "solar system" is often used interchangeably with "photovoltaic system," although it actually refers to a collection of technologies that use sunlight to generate energy. This includes both photovoltaics and solar thermal systems. 

Components of every photovoltaic system

Whether it's traditional rooftop solar systems, balcony power plants, or industrial installations, photovoltaic systems consist of several consistent components: solar modules, mounts, various cables, and an inverter form the basic equipment. Optionally, a storage system can be connected to become even more independent from the grid provider and fluctuations in electricity supply. 

photovoltaic solar modules

Solar modules are the central building blocks of photovoltaic systems. They consist of multiple solar cells connected in series. These cells directly convert sunlight into electrical energy by utilizing the photoelectric effect. Most solar modules are made of silicium and are encapsulated with glass and aluminum frames to protect them from weather influences.

photovoltaic solar cables

Special cables are required to transport the direct current from the solar modules to the inverter and further into the power grid. They are designed to withstand weather conditions and are particularly robust and durable. Solar cables play a crucial role in the safe and efficient transmission of generated solar energy.

photovoltaic mounting brackets

There are various mounting brackets used for balcony power plants,depending on the type of installation of the system. These brackets are specially designed to securely and stably attach the solar modules to the balcony. These include mounts for flat roofs, balcony railings, building facades, concrete balconies, or pitched roofs. Each bracket is designed to ensure optimal alignment of the solar modules to maximize sunlight exposure and enable efficient energy generation.

photovoltaic inverter

The inverter is a crucial component in photovoltaic systems. It converts the generated direct current from the solar cells into alternating current usable in households. It enables the injection of the generated electricity into the public grid or its direct use in the household. There are also battery inverters that can store the electricity for later use.

photovoltaic battery storage

A storage system for your power plant allows the intermediate storage of surplus generated electricity that is not immediately consumed. This stored electricity can then be used at a later time when solar energy is not available, such as at night or on cloudy days. By integrating a storage system, the independence from external power sources is increased, and the self-consumption of generated solar electricity is optimized. Therefore, a storage system contributes to increasing the profitability and efficiency of a solar system. 

Structure and Functionality of

photovoltaic solar modules

Solar modules consist of multiple solar cells connected with each other. Each solar cell comprises two silicon semiconductor layers separated by a junction layer. When sunlight strikes the solar cells, it sets electrons in motion, generating a flow of electricity. The solar cells are connected with metallic conductive pathways through which the generated electricity is collected.

The performance of a solar module depends on the number and efficiency of the enclosed solar cells, as well as the intensity of the incident sunlight. Monocrystalline silicon cells typically exhibit higher efficiency compared to polycrystalline or thin-film modules. The maximum power output of a solar module is indicated in Watt-peak (Wp) and can vary depending on the size and type of the module.

The amount of energy solar cells can produce also depends on various factors, including the size of the system, the orientation and tilt angle of the modules, and the solar irradiance at the location. A typical solar installation can generate enough energy to cover a significant portion of a household's electricity demand and even feed surplus electricity back into the grid.

Types of Solar Modules Currently Available on the Market

There are several types of solar modules available on the market, each with its own construction and characteristics:

Monocrystalline Silicon Cells: These modules are made from a single silicon crystal and are known for their high efficiency. They require less space but often come with higher upfront costs.

Polycrystalline Modules: Unlike monocrystalline modules, polycrystalline modules consist of multiple crystalline structures. They are generally slightly less efficient but offer better performance in diffuse light conditions.

Bifacial Modules: These modules can capture sunlight on both the front and back sides, increasing their efficiency. They are particularly suitable for installations where they can be mounted slightly elevated or receive light reflected from bright surfaces. However, they typically come with higher acquisition costs.

Thin-Film Modules: These modules use alternative semiconductor materials applied in a thin layer on carrier materials such as glass, plastic, or metal. They are flexible and can often perform better in diffuse light conditions but have lower efficiency compared to crystalline modules.

Flex-Solar Modules: These modules also utilize thin-film technology but use a flexible carrier material, making them ideal for curved surfaces such as rounded balconies or caravan roofs. They often have lower efficiencies than other modules.

Each type of solar module has its own advantages and disadvantages, which should be considered when selecting the most suitable option based on the specific requirements and conditions of the project.