Áram, áramszünet esetén? – A backup mód végre engedélyezett Magyarországon!

Why doesn't the battery indicate island operation?

Many people believe that if a solar system has a battery, a continuous power supply is guaranteed even in the event of a power outage. This misconception stems from the fact that although the battery is capable of storing energy, it cannot independently disconnect the system from the grid and does not ensure island operation. The real solution to this requires a special backup or EPS (Emergency Power Supply) mode, which allows the system to continue operating even during a power outage.

Why do many people believe that a battery = island operation?

This consumer misconception stems from the fact that batteries are indeed capable of storing energy, and many people think that if they have a battery, their power supply is guaranteed under any circumstances. The truth is, however, that although a battery can store energy, it cannot automatically disconnect the household from the grid. In order for the household to continue functioning during a power outage, a system is needed that can automatically switch to island mode, and this is provided by the backup mode or EPS function.

The difference between island mode and grid mode

The most important difference between island mode and grid mode is that while in grid mode the system is constantly connected to the public grid, in island mode the system is completely independent of the grid. This means that a grid power outage does not affect the operation of the system because it is not dependent on the grid.

Grid operation: The system is constantly connected to the utility grid, and if the system is suitable, the inverter, battery (if any), and production work together with the grid. In the event of a power outage, if there is no separate backup/EPS, there will be no power because the system is dependent on the grid.

Island mode: The system completely disconnects itself from the grid, and the battery and solar panels provide the power supply. In this case, the system operates completely independently and does not depend on the utility grid.

Hybrid approach: In a hybrid system, the system operates in grid mode when the grid is available, but automatically switches to island mode in the event of a power outage, provided that backup or EPS mode is installed.

Why has backup mode not been available in Hungary until now?

Hungarian regulations have not previously allowed inverters to automatically switch to backup mode in the event of a power outage. There were several reasons for this:

Feedback hazard: If the utility grid is faulty or de-energized, the inverter cannot reconnect because feedback would endanger workers on the grid.

Anti-islanding requirements: Regulations require inverters to prevent islanding when the grid fails so that they do not cause problems with grid operation.

Safety delay: Inverters must wait until the grid voltage stabilizes to avoid causing current surges that could cause problems with grid stability.

Lack of regulation: While many inverters had hardware EPS or backup functions, regulations did not allow for their widespread use.

Regulatory changes – hybrid/backup operation now possible

The latest regulations, which will come into force in 2025, allow the installation of systems with hybrid and backup modes in Hungary. Under the new regulations, co-located BESS (energy storage systems), hybrid inverters, and systems with backup functions are now permitted, provided that the installation complies with technical, licensing, network, and safety requirements.

How does backup/EPS mode work in the event of a power outage?

The key to backup mode is the battery and hybrid inverter, which can automatically disconnect the household from the grid in the event of a power outage. During normal operation, the inverter can also use power from the grid, but in the event of a power outage, it immediately takes control and ensures power supply.

Role of the inverter: The inverter continuously monitors the grid voltage and automatically switches to island mode if the grid voltage fails. Some inverters, such as Deye, do not require a separate device, while others (such as SolaX and Huawei) use additional devices to ensure island mode.

Consumption planning: It is important to consider the capacity of the battery and the consumption of the household, because if we connect high-consumption devices (such as a car charger or dishwasher), we can quickly drain the battery.