They are considering a huge battery storage facility. It is to be built near Bratislava.

Battery storage facilities have become an increasingly important part of the energy sector in recent years and are also increasing in Slovakia. In addition to standard projects, there are also those that require a closer look. We took a look at one of them.

A new investment plan has recently appeared with a location in the village of Hviezdoslavov in the Dunajská Streda district. The project is currently in the stage of the investigation procedure under the Environmental Impact Assessment Act (EIA), which began after the delivery of the plan in April 2026.

The documentation is currently working with the designation "large-capacity battery storage", while this is a new activity that is still going through the first permitting steps. However, the first details are already known.

Capacity of tens of MWh, construction in stages
The investor that entered the EIA process with the project is the company AH Slovakia Invest. The company, founded in 2023, is not a well-known name in the energy industry. Its sole owners and managers are Rudolf and Ana Hajduk. In 2024, it generated sales of 700,000 euros.

According to the submitted plan, the battery system is to have a capacity of approximately 49.9 MWh, with construction to take place gradually in several stages. In the first phase, a storage facility with an output of around 10 MW is being considered, which is to be subsequently expanded to the final capacity.

Technically, it is to be a container system consisting of battery modules, converters and control technologies, placed on a concrete foundation plate measuring approximately 30×58 meters.

The batteries are to be of the lithium-ion type (LiFePO4), which is today the standard for large-capacity storage facilities. The facility is to be connected to the distribution system at 22 kV and its operation is to be fully automated through an energy management system (EMS).

The declared parameters significantly exceed the projects that are actually in operation in Slovakia today. The largest currently operating battery storage in the country has a capacity of 16.7 MWh and an output of 10 MW. The project in Hviezdoslavov thus expects approximately three times the capacity.

Small photovoltaics vs. large storage
An interesting aspect of the plan is the relationship between the planned storage and the energy source that is to power it.

According to the documentation, the main source of electricity is to be a photovoltaic power plant with an output of approximately 1.25 MW, located on the roof of the planned hall. Compared to the capacity of the storage, this is a significantly smaller source. Although the documents speak of a “primary” source, they do not provide a detailed charging mode in the full range of capacity. The plan also includes a two-way exchange of energy with the grid and the possibility of charging during times of low electricity prices, which indicates that the storage can also be used in interaction with the distribution system, not just with a local source.

The storage is intended to stabilize the grid and trade in electricity
The functions of the battery system correspond to the common use of such devices in the energy sector. According to the plan, the storage is intended to serve mainly for: stabilizing the electricity grid, balancing fluctuations in electricity supplies, backup power, optimizing the use of renewable sources and trading in electricity depending on prices.

Such systems can react within seconds and provide support services for the grid, which is especially important with the growing share of unstable renewable sources.

The project is at the beginning of the permitting process
The plan is currently undergoing a screening procedure that will determine whether its full environmental impact assessment will be necessary.

Construction is tentatively estimated for 2027, but these are indicative dates tied to the further permitting process. The documentation itself also states that the specific type of technology and supplier will only be determined in the next stages of project preparation.

The available documents show that the project is still in the design phase and several of its aspects have not been worked out in detail.

This mainly concerns:

the final technical solution and technology supplier,

the exact charging and use regime of the storage facility,

the economic operating model,

the real sequence of construction of the individual stages.
The plan thus represents an ambitious project for now, which would be among the largest battery storage facilities in the country in terms of its parameters. Whether it will ultimately be implemented to the proposed extent will only be shown by the further progress of the permitting processes and preparation.