Inverters, what they are and what they are used for

Currently, there are many models of inverters available on the market, so it is not surprising that making a decision about which one to choose gives some people sleepless nights. What exactly is an inverter and what is it used for, as well as what are the differences between their different types – this is covered in today’s article.

It is nothing more than a device that converts direct current, which is simultaneously powered, into alternating current with an adjustable frequency, which is exactly the one we know from our electrical sockets. Inverters are also known as transducers or inverters. You can also find inverters called frequency converters, but not everyone agrees on whether this nomenclature is correct – although the converters work similarly, experts emphasize that the inverter is only a part of the entire device of this type, because the final effect of the converter’s operation is constant frequency alternating current at the input.

The task of inverters in a PV installation results from their very definition, namely to transform direct voltage generated by panels or batteries into alternating voltage with a specific phase, appropriate for the building that is to be powered. Apart from photovoltaics, inverters are used in packaging machines, fans and trams, where they change direct traction current into alternating current that drives the engine.

Types of inverters available on the market:

• network (on-grid) – adapted to work in an environment with a connection to the general network,
• not compatible with the grid (off-grid/island inverters) – they work without being connected to the general grid, to use them you need a battery that will store the electricity generated by the batteries,
• hybrid – enable the connection of two work systems – simultaneous energy storage and connection to the general grid.

There is also a second division of inverters, depending on the number of connection phases:

• single-phase inverters – used for small installations, mainly home installations, where there is little power demand,
• three-phase inverters – used mainly in industry and large facilities, such as hotels or office buildings, although three-phase inverters are sometimes installed in home PV installations, where the demand for power is higher than average to some extent.

However, this division is not a general rule – all installation elements should always be adjusted to the individual needs of the building that is to be powered by this type of energy.

When it comes to popularity, grid inverters are the most common in Poland due to the still high prices of home energy storage facilities. If you don’t know what energy storage is and whether it is a suitable solution for your home, please refer to our previous article on this topic.

Apart from the obvious differences resulting from the model specifications of a given manufacturer, most photovoltaic inverters fulfill a very important and extremely practical function from the user’s perspective. They allow you to monitor the operation of the installation via a mobile application, often also on the built-in LCD display. Thanks to this, you can constantly observe the efficiency of the panels on a given day, track the amount of energy produced, but also react on an ongoing basis in the event of failures that could not be detected only visually, and whose effects would be noticeable only in the long run (e.g. damage to one battery of the entire set).

The inverter can therefore be called the heart of the PV installation, because apart from the panels themselves, it is its most important part. In addition to changing the voltage of the electricity produced by photovoltaics, inverters materialize the benefits of switching to this type of home power supply. It is easier to translate the information provided by the application on the specific example of our home into electricity costs than to speculate on this topic based only on the technical parameters of the panels.