Assembly of the first large components in Reisseck II power plant

8/10/2012Mühldorf

50 Ton Turbine Inlet Spirals Transported to an Altitude of 1,600 Metres via 16 Hairpin Bends

The assembly phase is beginning at Austria’s highest power plant construction site: This week saw delivery of the first large components for VERBUND’s pumped storage power plant, Reisseck II. Two 50-ton, steel inlet spirals for the pump turbines had to be transported from the Möll Valley via 16 hairpin bends to the power plant cavern, located at a height of just under 1,600 metres above sea level.

Withstanding two exceptional heavy loads, the access road to Austria’s highest power plant construction site passed its practical test. Starting from the Möll Valley national highway, the just under 13-kilometre-long construction site access road for Reisseck II, VERBUND’s pumped storage power plant, leads up to the Mühldorf Graben via 16 tight hairpin bends and a difference in altitude of 1,000 metres. It is here that the power plant cavern is located in the mountain at just under 1,600 metres above sea level.

As the first of a series of large components, this week saw delivery in the Möll Valley of the inlet spirals, which were manufactured in Linz for the two pump turbines. In the later power plant operation, the steel spirals will transfer the water with a pressure of up to 100 bar from the distribution pipeline and guide it evenly through the special spiral construction to the turbines.

Reisseck II pumped storage power plant will feature two turbines with generators, each with a capacity of 215 megawatts. The two spirals alone weigh more than 50 tons, which is why two towing vehicles were enlisted for the transportation up the mountain. The spirals were hoisted into the large power plant cavern with the aid of a truck-mounted crane and a special crane system.

880 ton tunnel drilling machine accelerates progress on the headrace tunnel
The installation of the two spirals signals the start of the power plant assembly phase. Reisseck II pumped storage power plant is being erected entirely in the mountain; the rock cavern required for this purpose was excavated last year. The first half of 2012 saw the application of a drilling machine, with a weight of 880 tons and a length exceeding 200 metres, in order to advance the headrace tunnel up to the large Mühldorf Lake at a height of 2,300 metres. This work was also completed exactly within the time schedule; the dozen casing elements of the plated pressure tunnel are meanwhile being welded in the mountain. In parallel to this, the first section of the power discharge or power supply, respectively, is being laid.

During daytime hours requiring a large amount of electricity, Reisseck II power plant will supply peak energy using the turbine operation, with water from the upper reservoir of Mühldorf Lake being processed via the turbines. By way of contrast, if there is more electricity in the European grid at periods of low consumption than is required by consumers, Reisseck II can be switched to pump operation mode and water pumped from the lower equalisation reservoir back into the upper reservoir. In this way Reisseck II pumped storage power plant is transformed into a "green battery" in the Alps.

The main power plant components, such as the turbines, generators and the two heavy transformers, will be transported to the power plant next year; the commissioning of VERBUND’s pumped storage power plant of Reisseck II will take place in 2014. Amounting to 385 million euro, the total investment will be carried by VERBUND, Kelag and Energie AG Upper Austria.