US investment group Pantheon Atlas has announced plans for an up to €12 billion ($14.1bn) hyperscale AI data center and innovation campus in Topusko, Croatia.

The 310-acre campus is set to be located in open land 90km (56 miles) south of Zagreb and will have the potential for expansion to 450 acres.

The company claims an up to 1GW total capacity and 800MW usable IT load built to Nvidia Gigawatt Scale AI Factory standards.

Pantheon Atlas said that the project will be fully powered by renewable energy from an on-site 500MW solar plant and 8,000MWh battery storage. KKR-owned Greenvolt International Power is set to develop the farm and battery system.

It will also enable the integration of up to 5.2GW of renewable energy into Croatia’s national grid through four independent 400kV lines.

Construction is expected to start in early 2027 and is scheduled to be fully operational by the first quarter of 2029. The company claims the total investment in the project, including IT gear, is expected to bring more than €50bn ($58.8bn).

The announcement was made at the Three Seas Initiative Summit in Dubrovnik, an initiative to promote infrastructure development in Central and Eastern Europe and the Baltic states. Pantheon Atlas said the project is “the largest investment” in Croatian history and “among the largest” private US investments in Europe.

There are currently 17 data centers listed in Croatia.

Jako Andabak, Pantheon AI’s founding partner, said: “Pantheon AI is a signal to the world that Croatia is open for the highest-caliber investment. 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.”

Pantheon Atlas LLC is the investment vehicle through which a "group of US institutional investors and high-net-worth individuals" is deploying capital into the project

Ryan Rich, managing partner of Pantheon AI, said: “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.

“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.”

Joshua Volz, special envoy for global energy integration at the US Department of Energy, added: “The race to lead in artificial intelligence is global, and we are pleased to see American capital and investment expertise like Pantheon AI anchoring that leadership in allied, democratic nations.

“Critical infrastructure of this scale, built by the private sector responding to real market demand, is exactly how US interests and European security advance together.”

Learn more about the data center market in Italy and Southern Europe, and meet with other executives and experts from the region at the DCN Milan event later this year