Photovoltaic inverter: a complete guide to features and functions

The photovoltaic inverter is an essential component of solar plants. Its task is to convert the energy produced by solar panels into a usable form for homes and businesses. In this comprehensive guide, we will explore what an inverter is, how it works, its main features, and tips for choosing the most suitable model for your needs.

What is a photovoltaic inverter?

A photovoltaic inverter is an electronic device that converts the direct current (DC) generated by solar panels into alternating current (AC). Only then does the produced energy become compatible with the electrical grid and usable to power appliances and electronic devices. Without an inverter, solar energy would not be usable for self-consumption or for feeding into the electrical grid.

What is this device used for?

The photovoltaic inverter performs several fundamental functions:

• Energy conversion: it transforms direct current into alternating current, making the use of solar energy possible.

• Production optimization: thanks to MPPT (Maximum Power Point Tracking) algorithms, it maximizes the efficiency of the system by adapting to changes in solar irradiation and temperature.

• Monitoring and safety: it allows real-time control of energy production and integrates protective devices against surges and short circuits.

Main features of photovoltaic inverters

1. Power and sizing

The power of the inverter must be proportionate to the capacity of the photovoltaic system. For a 3 kW plant, for example, an inverter of equal power is used. In residential contexts, single-phase inverters have powers between 3 and 6 kW, while in commercial plants, three-phase inverters with higher powers are preferred.

2. Types of inverters

• String inverters: connect a series of panels to one or more strings, very common in residential plants.

• Micro-inverters: installed on each individual panel, they allow detailed monitoring and are ideal in cases of shading.

• Central inverters: used in large commercial and industrial plants.

• Hybrid inverters: manage both solar production and energy storage, optimizing self-consumption.
  
  
  

3. Durability and maintenance

The average lifespan of an inverter is over 10 years, but it can vary based on the quality of the component and maintenance. High-end models can last up to 15 years, while cheaper ones may require replacement after 5 years.

How to choose the right photovoltaic inverter

1. Power assessment

The choice of inverter must take into account the power of the system. An undersized inverter limits production, while an oversized one may not be economically viable.

2. Type of connection

Single-phase inverters are generally used in homes because domestic power supply is almost always single-phase. In larger buildings, such as companies or commercial structures, a three-phase supply is more common: for this reason, three-phase inverters are employed.

3. Additional functionalities

Many inverters offer advanced features such as:

• Remote monitoring: via Wi-Fi or dedicated apps.

• Compatibility with storage systems: some hybrid inverters are designed to work only with batteries from a specific brand, while others offer extended compatibility with multiple manufacturers, ensuring greater flexibility in choice or subsequent integration of storage.

• Software updates: to improve performance and ensure greater efficiency.

Performance and efficiency of photovoltaic inverters

The performance of an inverter indicates its ability to convert direct current into alternating current efficiently. High-quality models achieve efficiencies above 98%, reducing losses and ensuring excellent energy yield.

Maintenance and lifespan of the inverter

Regular maintenance is essential to extend the useful life of the inverter and ensure optimal operation. It is recommended to perform periodic checks to verify:

• The presence of dust or moisture.

• The absence of visible damage.

• The status of the indicator lights and displays, which signal any anomalies.
  
  
  

Regulations and incentives in Italy

Inverters must comply with CEI 0-21 (low voltage) and CEI 0-16 (medium voltage) regulations to ensure safety and efficiency. Moreover, in Italy, incentives and tax deductions are available for the installation of photovoltaic systems, which also include expenditures for storage systems.

The photovoltaic inverter is a crucial element for the operation and efficiency of a solar system. Choosing the right model, installing it correctly, and providing the necessary maintenance allows for optimal performance and maximizes the benefits of solar energy.

FAQ about Photovoltaic Inverter

1. What is the average lifespan of a photovoltaic inverter?

The average lifespan is over 10 years, but it depends on the quality and maintenance.

2. How can I monitor the performance of the inverter?

Many models have built-in displays or mobile applications for real-time monitoring.

3. Is it possible to integrate a storage system after installation?

Yes, hybrid inverters are compatible with storage systems and can be integrated subsequently as well.

4. What are the signs of malfunctioning of the inverter?

Lit red lights, error messages, or production below expected levels indicate possible failures.

5. How much does the inverter impact the overall cost of the system?

The inverter represents about 10-15% of the total cost of the system, but it is a fundamental investment for efficiency and safety.