New construction of the Pumped Storage Plant Forbach ‐ intermediate state of construction works

Abstract In Forbach in the Northern Black Forest, EnBW is currently constructing a new underground pumped‐storage power plant to replace an existing above‐ground facility that has been in operation at this site for over 100 years. The new pumped‐storage plant consists of a powerhouse cavern, two separate power stations and a transformer cavern, along with an underground water reservoir consisting of six storage caverns connected by the main tunnel. This reservoir serves as the lower basin for pumping operations, with the Schwarzenbach Reservoir acting as the upper basin. The upper water conduits run down two vertical shafts that are being excavated via the raise‐boring method. Additional tunnels are being constructed for water conveyance and logistical access to the power plant. This report presents the current status of the construction work. Construction began on 1 January 2024, and the first tunnel excavation for the muck haulage tunnel commenced in April 2024. Currently, approximately half of all underground cavities have been excavated. The top heading excavation of the future power plant cavern has been completed, as have the excavation and support works for other tunnel structures. An overview of the implementation of existing project boundary conditions is also provided.