Rhomberg plans €2 billion underground data centre in Hohenems

The Rhomberg Group and the city of Hohenems have unveiled plans for a large underground data centre in a former quarry in Hohenems-Unterklien, ORF reports. The project is currently estimated to cost around €2 billion, but that figure could rise substantially.

Rock extraction at the quarry is nearing its end, after which parts of the land would need to be refilled and replanted. Rhomberg plans to use the location for server facilities that would store and process data and provide computing capacity for artificial intelligence applications.

The data centre is intended primarily to serve businesses and research institutions in Vorarlberg. Project initiator Hubert Rhomberg said it could help keep critical data and computing capacity in the region and Europe, reduce reliance on foreign technology providers and strengthen control over digital value creation.

The project is at an early planning stage. The data centre could cover up to 25,500 square metres, on land owned by the city and the Rhomberg Group. Its promoters say building underground would allow the quarry to be reused without additional land being sealed. A comparable facility built on undeveloped land would use about 20,000 square metres, they said.

Hohenems is advancing the project with Rhomberg. The city council approved the plans by 32 votes to three on Tuesday evening. Mayor Dieter Egger said the project could benefit the city and the wider region. Vorarlberg also supports the initiative, with state councillor Marco Tittler saying digital infrastructure is important for business competitiveness and the region’s development as an innovation hub.

The facility would require an initial electrical capacity of 50 megawatts, with plans to increase that to as much as 100 megawatts later. Thomas Hilbe, head of Vorarlberger Energienetze GmbH, said 50 megawatts would equal about eight per cent of the electricity network’s annual peak capacity of 600 megawatts. A dedicated substation connected to the high-voltage grid would be needed.

Cooling water would circulate in a closed loop to limit the need for additional water. The project also plans to feed the data centre’s waste heat into the regional heating network.

Rhomberg hopes construction can begin in two years. The final cost remains uncertain, in part because of the price of the chips used in servers. Project representatives say costs could double if chip prices rise sharply.