When it comes to a photovoltaic system, many wonder what it contains. This is an essential question because understanding the components of such a system can help you make an informed decision. So, let’s explore together the components of a photovoltaic system and better understand the role of each.

Components of a photovoltaic system:


Photovoltaic Panels (PV Modules): When talking about solar panels, it’s important to distinguish between photovoltaic and thermal panels. Photovoltaic panels convert sunlight into electrical energy using semiconductor cells like silicon. They can be monocrystalline, polycrystalline, or thin-film, and have a lifespan of approximately 25 years, being resistant to hail, snow accumulation, strong winds, and many other factors.

Inverter: The inverter is the heart of the photovoltaic system as it converts the direct current produced by the panels into alternating current, which can be used by household electrical devices. There are inverters for On-Grid systems, which are not designed to work with batteries, and inverters for Off-Grid and Hybrid systems, which have this capability, often referred to as “battery ready.”


Battery Management System (BMS): If you choose a photovoltaic system with batteries for energy storage, a Battery Management System (BMS) is essential. It protects the batteries from overcharging, overvoltage, and undercharging, ensuring that all cells are charged uniformly. It also monitors battery parameters such as temperature, voltage, and current.


Batteries: Batteries are used to store the electrical energy produced by panels and can power electrical devices when the panels are not generating energy. There are several types of batteries, such as lead-acid batteries, Li-Ion batteries, and Lithium Iron Phosphate (LiFePO4) batteries, which are appreciated for their long lifespan and safety.


Backup Box: Hybrid photovoltaic systems include an important component called the “backup box,” which isolates the system from the power grid in case of a power outage, protecting maintenance workers. It can be single-phase or three-phase, ensuring power supply to essential consumers.


Smart Meter: A smart meter measures electric current in both directions and monitors energy consumption from the grid and from the photovoltaic installation. It can help identify peak consumption periods and is useful for electric utility companies for accurate billing.


DC/AC Protections for the Photovoltaic System: These protections act as shields for the photovoltaic system, guarding against unforeseen events such as short circuits and overvoltages. They ensure a longer system lifespan and reduce the risk of fires.


Mounting and Installation System for Photovoltaic Panels: Mounting and installation components are essential for panel stability and safety. They are made from alloys such as aluminum or steel to withstand extreme weather conditions and are available for all types of roofs or ground installation.


Cables and Connectors: Cables carry electrical energy and must be of high quality and suitable for the voltage they will carry. Connectors ensure a secure connection between cables and come in various types, such as MC4, which provides a quick push-in connection.


Composition of Photovoltaic Systems: On-Grid, Hybrid, and Off-Grid


On-Grid Photovoltaic System:

Solar panels: These convert solar energy into direct current.

Inverter: Converts direct current into alternating current suitable for household use.

Smart meter: Measures consumption and, if you are a prosumer, also measures energy production.

Mounting structures: Ensure secure attachment of solar panels.

Connecting cables: Establish the connection between panels, the inverter, and the smart meter. There are no batteries, and the system relies on the power grid. It may consume or inject surplus energy into the grid.


Hybrid Photovoltaic System:

All components of the On-Grid system.

Backup box: Isolates the system from the grid in case of power outages, protecting workers during maintenance.

BMS (Battery Management System): Manages batteries, ensuring uniform charging and protection against overcharging, overvoltage, and undervoltage.

Batteries: Store excess solar energy for later use in case of insufficient production or grid outages. The system also allows surplus energy to be injected into the grid.


Off-Grid Photovoltaic System:

Solar panels: Generate solar energy.

Inverter: Converts direct current into alternating current.

Mounting structures: Securely attach the panels in place.

Connecting cables: Connect the system components.

Batteries: Store energy for use when panels are not producing or in the absence of the power grid.

BMS (Battery Management System): Protects and manages the batteries.

A complete system independent of the electric grid, ineligible for subsidies. Provides an autonomous energy source.

It is important to consider these components when deciding to install a photovoltaic system. However, consulting experts in the field and supervising a licensed electrician are essential to ensure that everything is installed and maintained correctly. The correct choice of a photovoltaic system can have a significant impact on the energy efficiency of your home.


sisteme fotovoltaice