How a PV system works

Due to both the upcoming goal of climate neutrality by 2050, the growing awareness of households and businesses toward issues pertaining to sustainability in a broader sense and clean energy, renewable energy has certainly been a widely discussed topic in recent years. Today, thanks to renewable energy, it is possible to combine greater sustainability and energy efficiency. PV energy represents one of the most widespread sources of renewable electricity production in Italy as well as globally. This means more efficient and sustainable power generation systems based on the use of a renewable and endless source of energy, a symbol of life since the beginning of time: the sun. Today, PV systems constitute the ideal technology for managing business and household energy costs, while meeting the ever-increasing needs for environmental sustainability and climate neutrality. In this article, we will explore how a photovoltaic system works, from solar radiation, to the main components of a solar system and power generation.

Solar energy and PV systems

Solar energy – the main renewable energy source on the planet – is the energy associated with solar radiation. It is a precious form of energy for the production of electrical and thermal power using solar radiation. Among its considerable associated advantages is certainly its inexhaustible and clean nature, as well as its “availability” to everyone. Spanning a range of different methodologies, it is possible to obtain electricity and heat from solar energy: solar photovoltaic, solar thermal, and solar thermodynamic. PV systems certainly represent one of the most popular options for enhancing the value of solar energy. Specifically, when we talk about photovoltaics we are referring to a system that can transform solar radiation into electrical energy. This process can find its application not only in domestic settings, but also in a wide variety of industrial sectors for large-scale electricity production.

Definition of a PV system

A PV system consists of several components working together in order to convert solar energy into electricity. In simple terms, a photovoltaic system consists of a number of essential elements including:

• Photovoltaic modules: the solar panels, typically crystalline silicon photovoltaic cells, are assembled and interconnected in order to achieve the desired power and size values. The sunlight hitting the cells is able to cause the photovoltaic effect in direct current.
• Inverter: The inverter is an essential device which converts the direct current produced by photovoltaic modules into alternating current used in most domestic and industrial applications.
• Storage systems: Some PV systems incorporate energy storage systems, also known as storage batteries. Storage batteries have a significant impact in terms of increasing the efficiency of the system itself. In other words, during the system’s peak production period, storage systems allow for the storage of electricity, so it is thus available later, such as at night or during times of low solar production.
• Monitoring system: This system allows for the monitoring of a series of parameters such as consumption, electricity production, energy fed into the grid and other information to maximise the efficiency of the PV system itself and more easily detect faults.
• Bidirectional metre: Used for domestic or grid-connected installations, it tracks the amount of energy produced by the PV system and the energy consumed. This metre records both the energy taken from the grid when the PV system is unable to meet demand, and the energy injected into the grid when the system produces more energy than it consumes.

The operation of a PV system

With its precise and articulated system, it can be divided into the following phases:

• Solar energy capture: PV modules are designed to capture solar radiation. The photovoltaic effect is created when solar radiation impacts the photovoltaic cells located inside the modules, thereby interacting with the electrical charges within the semiconductor material.
• DC generation: electric current is determined by the presence of an electric field within the semiconductor which allows the movement of electric charges. This current is continuous.
• Conversion from direct current to alternating current: The direct current produced by PV modules is sent to the inverter which converts it to alternating current, compatible with most domestic and industrial electrical systems.
• Use of electricity: The electricity produced by the photovoltaic system can be used directly to electrically power devices in homes or businesses. If the energy produced exceeds the requirement, any excess is sold to the power grid resulting in valorisation.
• Energy storage (optional): If the PV system is equipped with storage systems, such as batteries, the excess electricity produced during the day can be stored and used at times of low solar production, such as at night.
• Integration with the electricity grid: PV systems are connected to the electricity grid. The excess energy produced can be injected into the grid, helping the production of clean energy for the community. During periods of low solar output, the energy can be taken from the grid to meet demand.

Conclusion Solar energy represents a real revolution in the field of electricity production. After considerable technological upgrades, it is now considered as an investment of sustainable value, a source of numerous environmental, economic and social benefits. Nowadays, a PV system can help reduce energy costs and limit the negative environmental impact linked to the use of traditional energy sources. With the aim of spreading an energy culture based on respect, competence, quality and efficiency, Southenergy has been working in the renewable energy sector for 15 years according to the principles of sustainability. From the design and construction of turnkey PV power plants to the upgrading of pre-existing plants through repowering and revamping projects, Southenergy operates by fully preserving projects through crucial activities such as O&M (operation and maintenance), due diligence, asset management and monitoring. Discover our PV systems and turnkey solutions we have already implemented for some of our clients: visit our website and find out more. Contact us (tel. +39 0831 33 15 94; email: info@southenergy.it) and we will identify the best solutions specific to your needs.