Pantheon Atlas Wins Grid Approval for 1GW Hyperscale Data Center in Croatia

Pantheon Atlas, the developer behind a massive up-to-1GW data center project in Topusko, Croatia, has secured a critical regulatory milestone. The country’s transmission system operator, HOPS, approved plans for more than €500 million ($569 million) in transmission and distribution infrastructure to power the campus, marking a major step forward for what is being touted as Croatia’s largest private investment.

The approved infrastructure package includes 280 kilometers (173 miles) of new transmission lines, fiber-optic cables, a 400kV substation in Topusko, and new access roads. Under the agreement, Pantheon Atlas will transfer ownership of the completed infrastructure to the Croatian government. The approval confirms the technical and regulatory feasibility of supplying electricity at scale to the project, which is expected to begin construction in early 2027.

Mario Gudelj, Pantheon AI Project Director, said: “Croatia’s largest-ever private investment is moving forward as a direct result of momentum from the unique partnership driving this project: Croatian expertise, US capital, world-class partners in Končar and Greenvolt, and continued support from the Ministry of Economy of the Republic of Croatia and HEP.” The project is a collaboration between US investment group Pantheon Atlas and local partners, with a total planned investment of up to €12 billion ($14.1 billion).

Beyond powering the data center itself, the transmission buildout is expected to unlock grid access for more than 5GW of renewable energy capacity that is currently bottlenecked in the country. The 310-acre campus, located on open land 90 kilometers (56 miles) south of Zagreb, will have the potential to expand to 450 acres. It is designed to deliver up to 1GW total capacity with 800MW of usable IT load, built to Nvidia’s Gigawatt Scale AI Factory standards. Pantheon Atlas says the facility will be fully powered by renewable energy from an on-site 500MW solar plant and 8,000MWh battery storage system.

The approval signals a significant vote of confidence in Croatia’s ability to host hyperscale AI infrastructure, leveraging its improving grid and renewable resources. For the broader European data center market, the project demonstrates how large-scale AI capacity can be integrated with national transmission upgrades and clean energy development, potentially serving as a model for other regions facing similar grid bottlenecks.