Breakthrough of the Energy Transfer Tunnel to the Cavern at Forbach Pumped Storage Power Plant
Pumped storage power plants are a technology that has been used for energy storage for over 100 years. In view of the energy transition, they are once again coming into the spotlight as they offer a flexible and sustainable solution for the power supply. EnBW Energie Baden-Württemberg AG is actively promoting this expansion and has commissioned Porr Tunnelling with the conversion of the Rudolf Fettweis plant in Germany.
The advance of the energy transfer tunnel towards the cavern began on 10 August 2024. The last two metres of rock were removed by a targeted explosion
Credit/Quelle: Porr
Porr Tunnelling is carrying out the conversion of the Rudolf Fettweis plant in Forbach on behalf of EnBW Energie Baden-Württemberg AG. The aim is to transform the existing storage and run-of-river power plant in Forbach into a modern pumped storage power plant that can be put into operation in 2027 in order to make its contribution to the energy transition. After the access tunnel reached the power plant cavern on schedule in September 2024, another milestone has now been reached: On 13 January 2025, the energy transfer tunnel has been successfully connected to the cavern.
The next step in the energy transition: on 13 January 2025, the advance of the energy diversion tunnel successfully reached the cavern of EnBW's Rudolf Fettweis plant in Forbach
Credit/Quelle: Porr
The advance of the energy transfer tunnel towards the cavern began on 10 August 2024 at the junction with the access tunnel. Since 2 January 2025, work had also been carried out in the opposite direction from the cavern to create the connection. The last two metres of rock were removed by a targeted explosion. The energy transfer tunnel is now fully connected to the cavern.
Status of Work in Early 2025
In addition to the energy transfer tunnel, the Porr tunnelling team is currently working on the advance of the side tunnels. The formwork, reinforcement and concreting work for the crane runway beams in the cavern will also be completed by February 2025. A further important step is the excavation of the cavern at depth, which is considered the next milestone for the project.
Porr's special civil engineering division is also currently involved. In the cavern crown, a back-anchoring system is being constructed for the crane runway, as well as for the support of the power plant ceiling. The special civil engineering team is installing 52 four-strand permanent anchors with double corrosion protection here.
