In this article we will take a closer look at the key components of photovoltaic installations, We will learn how they work and what role they play in the overall system
A photovoltaic installation consists of the following components: photovoltaic modules, inverter, support structure, cables and connectors and protection. Depending on the type of system, an additional component may be, for example, energy storage. We invite you to read more
Photovoltaic modules, are a key component of any photovoltaic installation. They are devices that convert solar energy into electricity using the photovoltaic phenomenon. Photovoltaic modules consist of a number of photovoltaic cells that are connected in series or in parallel. These cells are usually made of silicon, which is a semiconductor capable of generating electricity when exposed to sunlight. The cells are protected by a transparent coating, which protects them from weather conditions such as rain, wind or dust. The modules are also equipped with a frame that provides them with strength and facilitates their installation on the roof or other ground
Photovoltaic modules are available in a variety of shapes and sizes, allowing them to be used on different substrates. They can be mounted on the roofs of buildings, on the ground, on structures designed to track the sun (trackers) or even on floating platforms. The appropriate choice of modules depends on individual needs, such as available space, budget or the desired level of energy generated
They are constructed to convert as much solar energy as possible into electricity. Their efficiency is determined by an efficiency factor, which indicates how much of the solar energy is converted into electricity. This coefficient is usually expressed as a percentage and can vary depending on the type and quality of the modules
Photovoltaic modules do not emit any harmful substances into the atmosphere when generating electricity
Thanks to the development of photovoltaic technology, modules are becoming more efficient and cheaper, making solar energy increasingly accessible and competitive compared to traditional energy sources
The photovoltaic inverter is responsible for converting the solar energy stored as direct current (DC) by the photovoltaic modules into alternating current (AC). When photovoltaic modules absorb sunlight, they generate DC current, which is not compatible with the requirements of most electrical appliances as well as the power grid. This is where the role of the inverter comes in. Its task is to convert the direct current into alternating current of the correct voltage and frequency for use in the household
The photovoltaic inverter is equipped with various features and protections to ensure the reliability and safety of the entire photovoltaic system. This includes, among others, protection against overheating, overloads or surges. In addition, some inverters have built-in monitoring systems to check the performance of the system and identify any faults
The inverter plays a key role in the conversion of solar energy into electricity. It is a compulsory component of photovoltaic systems, enabling the optimal use of solar energy to power buildings
The energy storage facility allows for the storage of surplus electricity in situations where the production of electricity by PV installations is greater than its current consumption. Such a mechanism allows the stored excess energy to be used during periods of increased consumption
When the energy consumption of the home is lower than the amount of energy produced by the PV panels, it is possible to extract DC electricity from the panels and use it to charge the energy storage. When the batteries reach full charge, any surplus is sent to the electricity grid. At night, when the demand for electricity in the home increases, the battery discharges to power appliances and devices, allowing renewable energy to be used even after the sun goes down
An important component in the energy storage system is the Battery Management System (BMS), which monitors parameters such as voltage, current, temperature and charge level. The BMS is designed to ensure the safety and efficiency of the battery by controlling the charging and discharging processes and protecting the battery from potentially dangerous situations such as overcharging, discharging or overheating
Figure 3: Pylontech Force H2 energy storage unit
The conductors used in photovoltaic installations are divided into DC and AC conductors
DC cables transmit the direct current (DC) generated by photovoltaic modules. They must be resistant to UV radiation and atmospheric factors such as rain, wind and temperature changes. DC cables are usually double-insulated and have special markings for tolerated voltages and currents
AC cables are used to transmit alternating current to electrical appliances in the home or to the power grid. After converting the DC current into AC current in the inverter, the resulting mains voltage of 230/400V is transmitted to the central switchgear of the building via the AC cables
To make sure that the photovoltaic installation is safe, safeguards are essential. These are designed to protect against overload, short-circuit, damage to plant components and to minimise the risk of fire or electric shock. The most commonly used protections in photovoltaic installations are
- Surgeprotection (surge arrester) – is intended to protect against voltage spikes resulting from lightning or other phenomena. The surge arrester is installed on both the DC and AC lines of the photovoltaic installation to prevent damage to the modules, inverter and other electrical equipment.
- Overload protection – connecting an overloaded PV circuit to the installation can lead to component damage and increase the risk of fire. Therefore, various types of protection, such as fusible links, are used.
- Short-circuit protection – the occurrence of a short circuit in a PV installation, carries the risk of the installation catching fire. To avoid this, protection devices such as residual current circuit breakers are used, which automatically disconnect the photovoltaic installation circuit from the grid when a short-circuit current is detected.
All of the listed components of photovoltaic installations are necessary for the proper operation of the system. Module mounting systems, or support structures, also play an important role. They enable the modules to be positioned at an angle that ensures maximum exposure to the sun’s rays
There are three types of substructures
- Systems for sloping roof s – the type of fixing depends on the roofing, e.g. on tiled roofs the modules are mounted on an aluminium rail.
- Systems for flat roofs – are in the form of large metal frames. They are fixed to the roof surface with concrete blocks.
- Systems on the ground – single-leg or multi-leg support structures. They are fixed on a concrete foundation poured on the ground.
Photovoltaic installations are an important part of the global energy transition, allowing renewable energy to be used more efficiently and sustainably. Learning more about the components of the system and understanding how they work is crucial for anyone interested in using solar energy as a power source. By investing in a photovoltaic system and focusing on efficient energy management, we can contribute to a greener world.