Massive new $58.5 billion AI data center for Croatia to be anchored by 8 GWh BESS

Transatlantic investment group Pantheon Atlas has unveiled plans for a €50 billion ($58.5 billion) hyperscale AI data center campus in central Croatia, pairing 500 MW of on-site solar power running behind the meter with a 2,000 MW / 8,000 MWh battery energy storage system (BESS).

Pantheon Atlas described what it is calling Pantheon AI as a grand play at a new level of compute for Croatia, called the infrastructure “as designed in accordance with NVIDIA GW-Scale AI factory standards” and a campus, that will be built in Topusko, around 45 minutes south of Zagreb, on a 310-acre site that is expandable to 450 acres. The company said that the investment represents the largest in Croatian history, and it is also one of the largest private US investments in Europe. 

In addition to the behind-the-meter 500 MW solar plant and 2,000 MW / 8,000 MWh BESS, four independent 400-kV transmission lines are planned to enable up to 5.2 GW of new renewable capacity onto Croatia’s national grid. The project also includes four independent optic fibre routes across three EU corridors, with the GreenMed subsea cable extending connectivity to Milan by 2028.

Croatia’s grid has a strong supply from renewables, at close to 52% of all electricity consumed in 2025, with nuclear generation delivering another 15%, and electricity prices are below European averages.

Portugal’s Greenvolt International Power signed a letter of intent to build the solar-plus-battery project.

Construction of the initial €12 billion phase is scheduled to begin in early 2027 and is expected to be fully operational by Q1 2029. Local electrical and energy company Končar Group supports substation development, Dalekovod Projekt will lead the transmission design and Ravel Ltd. will lead the substation design. Advisory partners include Eastdil Secured, Parsec Lab, Latham & Watkins, Hodgson Russ, PwC and KPMG.

Pantheon Atlas said the project will create 1,500 permanent jobs and 3,000 construction roles.

Ryan Rich, managing partner of Pantheon AI, outlined a key problem that needs to be solved in Europe.

“We have assembled a transatlantic partnership to solve one of the most pressing challenges in global digital infrastructure: enabling hyperscale operators to meet AI-driven demand at scale,” Rich said. 

“We have lined up the power, fiber, regulatory stability, and institutional support to solve that problem in Europe, and we will establish Croatia and Central Europe as a premier destination for world-class digital infrastructure.”

Jako Andabak, founding partner of Pantheon AI outlined the company engaged local experts to meet data-center demand. 

“Pantheon AI is a signal to the world that Croatia is open for the highest-caliber investment,” Andabak said.

“This project is the culmination of years of work to bring world-class digital infrastructure to Croatia, and we have assembled the deep local expertise, grid relationships, and regulatory groundwork required to meet demand for data center capacity.”