Construction is planned to begin June 2010, with completion set for January 2013. At the moment, the project is in the midst of environmental impact studies the strictest permitting procedure in Europe.
After receiving approvals, the project company Gemeinschaftskraftwerk Inn GmbH will open a tender to select the engineering firm, equipment supplier and subcontractors.
The powerhouse will be constructed between the Austrian villages Prutz and Ried, close to the Inn River. Two 44-MW Francis turbines and generators will be placed in a subterranean shaft. The turbines will be driven by the Inn River, which will be dammed more than 20 kilometers upstream. The pressure tunnel, which will conduct the water to the turbines, will have a diameter of 6.5 meters and will be 130 to 1,200 meters deep. After being used, the water will re-enter the Inn via a subterranean duct.
Gemeinschaftskraftwerk Inn GmbH is a joint venture of Verbund AG (50%), TIWAG (36%) and Engadiner Kraftwerke AG (14%). At the moment TIWAG is conducting the permitting process for the 180-MW Kuehtai II Pumped storage plant. The Verbund subsidiary Verbund-Austrian Hydro Power is also advancing with the company's Reisseck II (430 MW) and Limberg II (480 MW) projects.