Austria’s energy landscape has taken a significant step forward with the official opening of the Limberg III pumped storage power plant in Kaprun. After four years of construction, the facility was inaugurated in the presence of political and business representatives, marking a notable addition to the country’s energy infrastructure.
The new plant adds 480MW of capacity to the existing Kaprun power group, boosting turbine capacity by 53% to 1382MW and pump capacity by 75% to 1120MW. VERBUND, the operator of the facility, emphasizes that Limberg III strengthens Austria’s grid stability and security of supply by providing flexible storage and generation. “Limberg III makes a decisive contribution to maintaining the country’s grid stability and security of supply by providing highly efficient flexibility. The expansion of the ‘Green Battery’ in the heart of Austria is an important building block for the successful energy transformation,” the company stated.
The project, supported by AFRY as the local site supervision partner for VERBUND Hydro Power GmbH, involved complex engineering tasks including tunnelling, cavern construction, a 558-meter pressure shaft, and a machine cavern located 450m underground. AFRY provided technical and commercial supervision, geological documentation, and consulting on natural hazards. “With a total installed capacity of 480 MW and a partial converter, Limberg III is designed to respond flexibly to grid demands, storing and releasing energy during peak periods. It uses existing reservoirs Mooserboden and Wasserfallboden without requiring new surface storage,” AFRY noted.
Ernst Zeller, Head of Hydro at AFRY, expressed pride in the team’s dedication and precision throughout the project. “I’m incredibly proud of our team’s dedication and precision throughout this project, from the first geological surveys to the final inspections. Their expertise and commitment have been instrumental in delivering such a complex and forward-looking facility. I also want to sincerely thank our client, VERBUND Hydro Power GmbH, for the trust they placed in AFRY,” he said.
The project required lifting a 355-tonne rotor into place in May 2025, assembled underground over the course of a year and consisting of 80,000 stacked sheets. Each generator unit at Limberg III can operate at variable speed, with an output range of 20 to 240MW in turbine mode and 100 to 240MW in pumping mode. VERBUND invested around €572 million in the project.
The inauguration of Limberg III underscores the growing importance of pumped storage facilities in Europe’s energy transition. As renewable energy sources like wind and solar become more prevalent, the need for flexible storage solutions to balance supply and demand becomes critical. Limberg III’s ability to respond quickly to grid demands highlights the potential for similar projects to enhance grid stability and support the integration of renewable energy sources.
Moreover, the project’s success demonstrates the value of collaboration between energy companies and engineering firms. The expertise and commitment shown by AFRY and VERBUND in overcoming technical challenges and delivering a complex facility set a precedent for future energy projects. As Austria and other European countries strive to meet their renewable energy targets, the lessons learned from Limberg III could inform the development of similar infrastructure, contributing to a more resilient and sustainable energy landscape.