Croatia’s First Large-Scale Battery Energy Storage System Connected to the Transmission Grid Opens in Šibenik

NextGrid Energy has officially inaugurated BESS Šibenik, the first standalone battery energy storage system of this scale connected to Croatia’s transmission grid. Located within the IMPOL-TLM industrial complex, the 60 MW / 120 MWh facility represents one of the most significant investments in new energy infrastructure in Croatia, with a total investment value of approximately €60 million.

The project was financed through a combination of grants from the European Modernisation Fund and equity investments by the European Bank for Reconstruction and Development (EBRD), Raiffeisen pension funds and IE-ENERGY.

The opening ceremony was attended by Vedran Špehar, State Secretary at the Ministry of Economy and representative of the Prime Minister of the Republic of Croatia; Paško Rakić, Prefect of Šibenik-Knin County; Željko Burić, Mayor of Šibenik; as well as representatives of the investment, business and technology partners involved in the project.

New Infrastructure for a More Secure and Flexible Energy System

BESS Šibenik comprises Tesla Megapack XL battery modules connected to the 110 kV transmission grid. The system can absorb or deliver electricity at its full capacity of 60 MW for up to two hours, responding almost instantaneously to the needs of the power system.

Its primary role is to enhance grid flexibility and stability while enabling more efficient integration of the growing share of electricity generated from solar and wind power plants. Since September 2026, the system's entire installed capacity has been included in HOPS's contract for the provision of automatic Frequency Restoration Reserve (aFRR) services.

“The BESS Šibenik project is important for the modernisation of Croatia’s power system and the more efficient integration of renewable energy sources. It represents a concrete contribution to the Government of the Republic of Croatia’s energy policy objectives, focused on security of supply and the development of infrastructure capable of meeting the needs of Croatian industry and the wider economy,” said Vedran Špehar, State Secretary at the Ministry of Economy and representative of the Prime Minister of the Republic of Croatia.

A Financing Model That Creates Opportunities for Further Investment

The project received support from the European Union’s Modernisation Fund, with grants of up to €19.8 million approved for its second phase. Following project optimisation and reductions in capital expenditure, the expected amount of grant funding to be utilised is approximately €15 million.

The EBRD invested €16.8 million in the project, with an equivalent amount provided by Raiffeisen mandatory and voluntary pension funds. For the EBRD, this represents its first equity investment in a standalone, market-oriented battery energy storage system.

A distinctive feature of the project is its market-based business model, which operates without guaranteed revenues. The system generates income by providing services required by the power system, with investors bearing the associated market risks.

“Government support through the Modernisation Fund was crucial for us. It reduced the initial investment risk to a level that enabled the EBRD and Raiffeisen pension funds to become co-investors. Without this combination of public funding and institutional capital, BESS Šibenik would not have been built in its current form,” said Željko Šmitran, CEO of NextGrid Energy.

A Foundation for a New Generation of Energy Investments

The development of BESS Šibenik required new technical, regulatory and operational solutions, ranging from connection to the transmission grid to integration into the electricity market and ancillary services markets.

“Croatia has gained important new energy infrastructure, and we have demonstrated that we can develop, finance, build and integrate a battery energy storage system of this scale in accordance with the highest international standards. The participation of prominent investors confirms the quality of the project and the potential for further investment in the energy transition,” Šmitran said.

For NextGrid Energy, the opening of BESS Šibenik provides a foundation for further development of energy storage projects and a broader platform for managing flexibility within the energy system. Together with its partners, the company continues to develop renewable energy, energy storage and flexibility projects in Croatia and across Central and Southeastern Europe.

“Šibenik has opened the door to our next phase of growth. We are no longer talking only about plans, but about built infrastructure and a proven delivery model that we can replicate at new locations. With the support of our shareholders, the EBRD and Raiffeisen pension funds, NextGrid Energy will continue investing in renewable energy, energy storage and flexibility projects in Croatia and across Central and Southeastern Europe. Our ambition is to work with development partners on new projects that will address the energy system’s growing need for flexibility and the European industry’s demand for affordable energy. We want Šibenik to be more than an isolated example – we want it to be the first in a series of successful next-generation projects,” Šmitran concluded.

BESS Šibenik is an important example of how European development funding, international financial institutions and domestic institutional capital can be brought together to deliver strategic energy infrastructure. Its successful implementation highlights Croatia’s potential to attract investment in advanced energy solutions that will play an increasingly important role in security of supply, renewable energy integration and the long-term competitiveness of the economy.