Characteristics of the photovoltaic inverter – Lavorincasa.it

What does photovoltaic inverter mean

L’inverter it is the fulcrum of a photovoltaic system, because it allows the sun’s energy to be used inside homes. In fact, the device transforms direct current (DC) into alternating current (AC).

Typically, the inverter for photovoltaic panels consists of a metal box of medium size which has an electrical panel inside.
The life of the device is approximately 10 years thanks to the electronic components that can be easily replaced.

Inverter what is it for

In addition to carrying out the main function of converting electricity, the solar inverter has the task of consuming as little energy as possible produced by photovoltaic panels.

In particular it must:

• run the monitoring of the electrical network to protect the system from possible short circuits and overloads;
• control its own temperature which is strictly connected to the place where it is positioned (a cool environment is preferable);
• decrease energy dispersion which occurs at the moment of conversion;
• improve system powerfinding the exact operating point;
• send a report if there are any breakdowns;
• adjust the voltage and frequency of electricity;
• communicate data via the display on system operation.

Inverter operation

After seeing the different tasks performed by the device, let’s find out in detail how a inverter for photovoltaic system.

The panel absorbs the sun’s energy which is converted into electricity.

However, this is direct current that cannot be exploited at a domestic level.
This is where the inverter comes into play, which has the function of transforming this current into alternating current, so that it can be used in homes and offices.

To perform an installation in a workmanlike manner it is good practice to take into consideration some factors:

• where is the inverter for the photovoltaic panel located;
• the proper functioning of the electrical circuits;
• what are the dimensions of the inverter;
• the connections between the inverter and the electrical panel.

It is essential to contact experts in the sector who are able to support you in choosing the best device.

How to choose a photovoltaic inverter

To make a correct choice of photovoltaic inverters, various parameters must be taken into consideration, including the power which varies according to the type of system.

It is essential that all the energy generated by the photovoltaic panel can be converted by the inverter without problems, also taking into account the peaks caused by strong radiation.

If the inverter were to be undersized, the final production of electricity would be greatly limited, since the energy produced by the panels would be higher than that which the inverter would be able to convert, without forgetting that this could cause damage to the device same.

So you have to do one estimation of maximum energy consumption of the household or commercial activity, adding up the amount of energy consumed by all the devices connected to the network at the same time.

In the case of a domestic system, the power varies from 2 kW a 5 kWfor a commercial plant the power is between 10 e 20 kW. Even higher is the power for an industrial plant (ranging from 500 to 800 kW).

Inverter efficiency

To evaluate the efficiency of the solar panel inverter consider its degree of performancei.e. the percentage of energy introduced in the form of direct current which is transformed into alternating current.

The efficiency is related to the solar radiation, the voltage of the incoming current and other parameters.

To date, inverters are more than 90% efficient.
This is possible thanks to the function MPPT (Maximuum Power Point Tracker) which has the task of extrapolating the maximum available power of the system as the weather conditions change.

Types of inverters for photovoltaics

There are two types of solar inverters on the market: single-phase and three-phase.

The single phase inverter they consist of two connectors, one for phase and one for neutral. They are used in small photovoltaic systems for residential use with a power of less than 6 kW.

The three-phase inverter instead they are formed by three phases and three different alternating currents. They are ideal for large plants for industrial use.
There are also transformerless and transformerless photovoltaic devices.

Il transformer allows the galvanic separation and grounding of the photovoltaic modules. In general, transformerless inverters that are small and light and have a higher degree of efficiency are preferable.

The connection of the panels to the inverter

According to the connection of the modules, inverters for solar panels are divided into:

• inverts centralized;
• inverter of string;
• micro inverter;
• inverter hybrids.

Centralized inverter

This type is used in photovoltaic systems big dimensions for direct and simple use. The modules connect in series, forming strings that reach 1000 V open circuit voltage.

A single inverter connects to strings connected in parallel.
The disadvantages of this device are the impossibility of monitoring the performance of each solar panel and the fact that it cannot be used in case of shade.

String inverters

This type is the most widespread as it is cheap and requires easy maintenance.
They are ideal for geographical areas where the radiation remains constant all year round and the panels are not affected by the shade.

Micro inverter

I micro inverter they are installed on the single solar panel, therefore each module has the possibility of converting energy into alternating current.

The production of a panel, unlike a string inverter, does not influence the performance of the total photovoltaic system.

The advantages of the micro inverter are several, among these:

• it’s possible to monitor the performance of the individual panels;
• medium life and high duration;
• it’s easy expand the plant;
• the modules are connected in parallel;
• the dissipated power is low;
• it is easy to spot a failed module.

Hybrid inverter

The function of a hybrid inverter it is the same as a string inverter but in addition it ensures the charging and discharging of energy in systems with storage.

In addition to hybrids, there are also hybrids on the market smart inverter capable of charging the batteries with energy from the electricity grid when the price is low to use it at times when the photovoltaic system is unable to guarantee the electricity requirement.

Even if it allows a considerable energy saving, it has a very high cost.

Single-phase inverter for residential systems

Among the photovoltaic devices, the inverters of the range stand out RS Of Riello Solartech that combine cutting-edge technologies and high quality components.

They are equipped with an innovative digital control of the power states and have a series of icone led which allow the status of the solar installation to be identified.

Inverter Riello Solar Tech

The design is light e compact such as to make the product adaptable to any context.
Some of the main features are the natural convection cooling technology and multiple remote monitoring.

The inverters Riello Solartech allow the achievement of a maximum yield of 97.6%.

String inverter type

The company FIRE offers a single-phase inverter with power classes ranging from 1.2 and 3 kWideal for residential installations.

The device is characterized by a compact and light design, such as to achieve high performance with a small footprint.
Fimer photovoltaic inverter

It is equipped with MPPT and connectors Plug and Play, on the DC and AC side, which make installation quick and easy. It features dynamic network feed control and remote monitoring using the Aurora Vision cloud.