VERBUND’s Greifenstein power plant is a run-of-river power plant on the Danube, situated in the municipality of Stockerau in Lower Austria.
In the course of the first framework plan of 1956 for the expansion of the Danube in Austria, three reservoir stages were planned between Vienna and Ybbs: Grafenwörth, Tulln and Klosterneuburg. However, on account of the further development of power plant and dam technology, by the end of the 1960s it was possible to reduce the three smaller reservoir stages to two large ones: Altenwörth and Greifenstein. The project envisaged the dry construction of power house, weir system and locks on an area to the north of the old section of the Danube. The left curve of the Danube was truncated by means of a "tendon", enabling the entire structure to be built in a single construction pit without interfering with shipping traffic. Following the construction decision of 24 June 1981, two months later saw the start of preparatory works with the logging of the 295-hectare floodplain forest to make room for the construction site facilities. The official start of construction took place on 1 November of that year with the excavation of the construction pit, drainage works and the creation of the foundations. With a total excavation volume of 10.7 million m³, the excavation works at the avulsion of the Danube took place in summer 1983 and, in the November, the construction had been completed to the extent that it was possible to flood the new bed of the Danube. The first hydroelectric generating set was commissioned on 28 April 1984, followed just under three weeks later by the first complete filling of the reservoir. The official opening of Greifenstein power plant began on 21 May. The following months saw the successive commissioning of all nine hydroelectric generating sets, enabling the construction to be completed on 23 April 1985 with hydroelectric generating set no. 9.
Geographically, Greifenstein represented the final Danube power plant outside the federal capital of Vienna and,
in terms of order of development, the penultimate Danube power plant in Austria.