An important building block of the Energiewende: the official opening of the pumped storage power plant Obervermunt II
Karlsruhe. Today’s opening of the pumped storage power plant Obervermunt II in Montafon, Austria, constitutes another milestone in the partnership between EnBW Energie Baden-Württemberg AG and Vorarlberger Illwerke (VIW). The two companies have worked closely together for nearly 100 years. In addition to a long-term electricity procurement agreement which most recently was renewed until 2041 and to EnBW’s use of VIW’s power plants, this also includes collaboration in new construction projects. Flexible pumped storage continues to be the only established technology which allows for the cost-effective storage of fairly large amounts of energy, including from renewable sources. With Obervermuntwerk II, the Rellswerk plant – a smaller facility which was commissioned in 2017 – and the Kopswerk II plant (525 MW, commissioned in 2008) VIW and EnBW have now jointly carried out three pumped storage projects over the course of the past ten years.
“Together with our partner of many years we are happy about the successful completion of the project. Given the significance of storage technologies for system stability and security of supply, they will continue to be an integral part of the energy supply in Europe in the future. This applies to pumped storage power plants as well as, increasingly, the new storage technologies. With Obervermunt II we are once again considerably expanding our pumped storage capacities and can now store even more electricity from renewable sources, such as wind and solar energy. This is another important step for us towards making the Energiewende a reality,” says EnBW Chief Technical Officer Hans-Josef Zimmer.
The new power plant Obervermunt II was built with the support of EnBW AG in a mere four and a half years. With its two turbines and two pumps, Obervermuntwerk II achieves an output of 360 megawatts. The plant uses the existing water reservoirs, Lake Silvretta and Lake Vermunt, which also continue to be used by the storage power plant Obervermunt I (about 36 megawatts) that was built in the 1940s. Thanks to the new construction, the capacity of both storage basins can now also be used for pumped energy storage for the first time.
Storage technologies of ‘enormous significance’ for system stability
Due to their enormous significance for system stability and the security of supply, storage technologies are an integral part of EnBW’s portfolio. The company’s commitment in this area is accordingly solid. It includes, for instance, cooperation agreements concerning new storage technologies such as the construction of a lithium-ion storage facility with Bosch at the company’s power plant site in Heilbronn and the energy management pilot project with ALDI Süd, among other projects. Moreover, EnBW continues to advance plans for upgrading the Rudolf Fettweis plant at its Forbach site into a modern and powerful pumped storage power plant. In January 2018 an application for approval was submitted to the Regional Administrative Authority in Karlsruhe. The final investment decision for the new downstream power station can only be taken on the basis of a planning approval and an examination of the general energy-industry-related conditions.
Obervermunt II:
The cavern power plant (height 33 metres, width 25 metres, length 123 metres) is located at the end of an 800-metre-long tunnel inside the Silvretta Massif. The cavern is the starting point of the about 3-kilometre-long underground Silvretta gallery (excavated diameter almost 8 metres) and part of a complex tunnel and gallery system up to Lake Silvretta at Bielerhöhe – the highest point of the well-known Silvretta High Alpine Road.