Since 2007, Tractebel Hydroprojekt GmbH has been planning the renewal of the traditional power plant site in Forbach for EnBW. With the preparation of the tender documents for the new lower stage, the planning services are now entering a new phase.
The new lower stage comprises the renewal of the two existing power plants Schwarzenbachwerk and Murgwerk. Both power plants are to be renovated with extensive use of the existing facilities. Both the Schwarzenbach dam and the Kirschbaumwasen reservoir will be integrated into the new plant concept without any structural or operational changes. The new waterways of the two power plants branch off from the existing moated castles and are led via inclined shafts into the new power plant cavern, where the machines of both the new Schwarzenbach and the new Murgwerk will be installed. The new lower stage will replace the existing Schwarzenbach plant with a fully-fledged pumped storage plant. In order to increase the storage volume, a cavern water reservoir with a usable volume of 200,000 m³ is excavated, which is hydraulically connected to the existing equalizing reservoir and forms a common storage volume with it. The cavern storage facility consists of a main gallery and six secondary galleries. The total length of the tunnel system is around 2,700 m.
The new Schwarzenbach plant will be equipped with a reversible pump turbine with a rated output of 50 MW. The combination with electrical full converter technology enables very short changeover times as well as variable-speed operation of the machine and thus the greatest possible flexibility of the new pump storage plant.
The new Murgwerk will be equipped with three Francis turbines with outputs of 13 MW, 5 MW and 0.8 MW (domestic machine) and will make frequent use of plants and equipment from the new Schwarzenbachwerk.
The approval procedure for the new lower stage has already been initiated. During the approval procedure, the necessary construction and assembly services, divided into 12 lots, are to be put out to tender and their placing prepared. The start of construction of the new lower stage is currently scheduled for the beginning of 2021.
Since the beginning of the year, the engineering consortium Forbach, consisting of Tractebel Hydroprojekt GmbH, Tractebel Engineering GmbH and Geoconsult ZT GmbH, under the leadership of Tractebel Hydroprojekt, has been commissioned with the preparation of the necessary tender planning and tender documents for the complex and technically demanding overall project. The engineering consortium will also support EnBW in the preparation of the awarding of the contract.
Robert Achatz – Munich