Siemens Zrt. has delivered switchgear to serve new energy storage systems.
With the sudden surge in grid load and the proliferation of solar power plants, the role of energy storage in maintaining grid stability and ensuring continuity of supply is becoming increasingly significant—something every consumer can feel during heat waves.
Energy storage systems help manage temporal discrepancies and fluctuations in electricity generation and consumption, thereby enabling more flexible and resilient grid operation while also contributing to the achievement of self-sufficiency and the transition to green energy.
To this end, the MVM Group commissioned two new energy storage facilities at the end of June, whose substation power supply is supported by Siemens’ medium-voltage, air-insulated switchgear—which is free of environmentally harmful insulating gases.
Power that can be mobilized in seconds
MVM Tisza Erőmű Kft. has installed a battery energy storage unit with a rated output of 31 megawatts (MW) and a capacity of 62 megawatt-hours (MWh) in Tiszaújváros. The storage facility was built in the immediate vicinity of the new 1,000-megawatt Tisza Combined Cycle Gas Turbine (CCGT) Power Plant, one of the country’s largest energy projects. Although the two facilities can be operated independently of one another, they will work together to support the integration of renewable energy sources into the power grid.

Energy storage facility at the MVM Tisza Power Plant. Source: MVM Group
When fully charged and operating at full load, the energy storage facility will be able to continuously supply power for approximately 2 hours, covering the average two-hour electricity demand of about 120,000 households. It thus serves as a rapidly deployable reserve: within a few seconds, it can supply the grid with significant power, thereby balancing out any fluctuations.
At the electrical substation serving the site, a 10-bay NXAIR M switchgear unit will be installed, equipped with specialized current and voltage transformers to ensure the power plant’s electrical protection and the necessary measurements.
Significant Energy Reserves in Transdanubia as well
MVM Balance Zrt. commissioned a similar project in Ajka. The Bakony Gas Turbine Power Plant was supplemented with a battery energy storage system with a capacity of 57 MW and 57 MWh, thus creating the Bakony Hybrid Power Plant.
The new storage facility will also play a key role in balancing fluctuations. It can mobilize its full capacity within a few seconds and, under full load, will be able to provide enough energy for one hour to cover the average one-hour electricity demand of more than 200,000 households.
In the power plant’s new switchgear building, a 16-bay NXAIR medium-voltage switchgear system—designed for complex networks and high short-circuit capacity—along with an 8-bay SIVACON S8 low-voltage switchgear system with drawer-type design will ensure the power supply.
These technologies are not new to the MVM Group. They were selected based on positive operational experience gained from previous projects, and NXAIR switchgear units were also recently installed at the Szeged, Mezőkövesd, and Lajosmizse electrical substations of MVM Émász and MVM Démász.

A tour of the electrical substation at the Bakony Hybrid Power Plant, with Siemens NXAIR switchgear in the background. Pictured: Károly Mátrai, CEO of the MVM Group. Source: MVM Group.
