Photovoltaic
Composition, efficiency and duration
Photovoltaic modules, commonly known as solar panels, are a web that captures solar power to transform it into sustainable energy. A semiconductor material, usually silicon, is the basis of each individual solar cell. It is light sensitive and generates electricity when struck by the rays of the sun thanks to a physical phenomenon called the photovoltaic effect.
Photovoltaic modules are made up of many individual, interconnected photovoltaic cells. To ensure the modules are tilted correctly and facing the sun, they are housed in support structures. Every module has two output terminals that collect the generated current and transfer it to the management systems at a solar power station.
A photovoltaic module’s efficiency is quantified as the ratio between the electrical power going out of the terminals and the power of the sun’s rays striking the module’s surface. The standard value used to indicate solar radiation is 1,000 watt/sqm. If every square meter is struck by 1,000 watts of sunlight, the percentage of energy actually converted into usable electricity is what constitutes the efficiency. The average life of a photovoltaic module is around 30 years.
What is a photovoltaic system and how does it work?
there are two types of photovoltaic systems:
Grid-connected systems
Grid-connected systems are systems that are integrated with conventional residential and industrial electricity systems. These can be used when required in alternation or in combination with the electricity grid in order to meet the energy requirements of the end user.
Stand alone systems
Stand alone systems are designed in such a way as to include a battery system in order to ensure “service continuity”, i.e. the supply of electric energy also during the night or when the level of solar irradiation is insufficient or absent.
How does a photovoltaic system produce electricity?
A photovoltaic (PV) panel, commonly called a solar panel, contains PV cells that absorb the sun’s light and convert solar energy into electricity. These cells, made of a semiconductor that transmits energy (such as silicon), are strung together to create a module. A typical rooftop solar panel has 30 modules. When the semiconductor in the photovoltaic panels absorbs the sunlight, this knocks the electrons (which form the basis of electricity) free from their place, and they can now flow through the semiconductor. These dislodged electrons, each carrying a negative charge, flow across the cell toward the front surface, creating an imbalance in charge between the front and the back. Photovoltaic cells produce electricity because this imbalance, in turn, creates a voltage potential like the negative and positive terminals of a battery.
What are the components of a solar PV system?
Photovoltaic modules
a photovoltaic system captures the energy radiated by the sun thanks to the use of special components called photovoltaic modules that is able to produce electricity when hit by sunlight.
Support structures of the modules
Support structures of the modules: these structures support the modules by fixing them to the roof. In the case of flat roofing, support structures exist that can also modify the orientation of the panels, optimizing their exposure by tilting them towards the sun's rays.
Inverter
Inverter: this is the electronic device that transforms the energy produced by the modules (so-called direct current - DC) into the type of energy used by residential or industrial users (so-called alternating current - AC).
Electric cables
Electric cables these are the cables that carry energy from the system to the users.
A monitoring system
this enables the remote monitoring of the photovoltaic systems, energy production and consumption as well as verifying the status of the inverter.
Energy storage
this is an innovative system that enables users to improve the efficiency of their solar PV systems by storing the energy produced during the day in order to use it later, when the system is not producing energy.
