Hydroelectric power plants in the Ulten Valley
The hydropower plants in Ultental are a series of storage power plants in South Tyrol ( Italy ) that use the hydropower of the Falschauer and its tributaries and streams to generate energy. For this purpose, six reservoirs were built in the Ulten Valley .
The power plant chain
The Falschauer is the main river of the Ulten Valley in South Tyrol. This extends in a south-west-north-east direction from the Stilfserjoch National Park to the valley of the Adige , into which the Falschauer flows at Lana . With a length of 40 kilometers it bridges a difference in altitude of over 2000 m and covers a water catchment area of 301 km². Several reservoirs serve to continuously supply the five power stations in the valley with water. Starting from the mountain side, these are the Weissbrunn power plant, the Kuppelwieser Alm power plant, the St. Walburg power plant, the St. Pankraz power plant and the Lana power plant.
In order to increase the energy content of the water, the power plants are each several hundred meters lower than the reservoirs supplying them and receive the water through pressure tunnels or pressure pipes. They discharge the runoff water into the next reservoir, on whose banks they are mostly located. Some of the power plants also have high-performance pumps with which they can pump water back into the reservoir through the pressure pipe during periods of low consumption (at night) ( pumped storage operation ).
The total installed capacity of all power plants together is 250 MW . The operator is Alperia Greenpower GmbH, a subsidiary of Alperia AG .
history
As early as the 1930s there were plans to use hydropower in the Ulten Valley. But it was only after the Second World War , when industrialization began to flourish in Italy, that the Ulten hydropower plants were built. This started with the start of construction of the Lana power plant and stretched up the valley for two decades. The construction phase ended in 1968 with the commissioning of the Kuppelwieser Alm power plant. During this time, six reservoirs and five hydropower plants were built and around 30 km of pressure tunnels were built.
The construction work brought the residents of the until then agrarian Ulten valley significant problems. The residents felt at the mercy of the Italian central government, defenseless against the differences between South Tyrol and the Italian state that existed at the time . With the construction of the dams, numerous farmers lost their farms and land in the valley floor. The noise and dirt pollution in the valley were considerable. Thousands of workers from the southern provinces of Italy came to the German-speaking Ulten Valley. On the other hand, new conditions arose for the hospitality and service industry as well as the infrastructure .
The STE company was the initial builder and operator of the systems. In the course of the nationalization of power generation, the plants were transferred to the state-owned company Enel SpA, founded in 1962, in the early 1960s . In 2010, the power plants in the Ulten Valley were taken over by SE Hydropower GmbH. The 60% shareholder of this company is the Südtiroler Elektrizitätsgesellschaft SEL AG, while Enel retains 40%. In 2015 there was a realignment in the energy sector in South Tyrol. The Alperia company is born and most of the South Tyrolean hydropower plants become part of Alperia Greenpower, as do all the hydropower plants in the Ulten Valley.
The power plants
Weissbrunn power plant
The Weißbrunn pumped storage power plant is the highest in the main chain of hydropower plants in the Ulten Valley. It was put into operation in 1963 and is located near the southern bank of the Weißbrunnsee, opposite the dam wall. It gets its water via a pressure pipe from the Grünsee lake, 641 m higher . The power plant's turbine is a Pelton turbine with a horizontal axis. The installed line is 10.2 MW. After passing through the turbine, the water is released to the Weißbrunnsee. (For a description of the barrages of the reservoirs, see the articles on the reservoirs.)
The system has a pump with which 1.4 m³ / s of water can be pumped up to the Grünsee in low-consumption times in pump storage mode. This water is taken from the small fishing lake just 200 m above the Weißbrunnsee . ( Location of the Weissbrunn power plant )
Kuppelwieser Alm power plant
The pumped storage power plant, which went into operation in 1968, draws its water from the Arzkar reservoir, 358 m higher . It is fed to the power plant via a pressure tunnel. The power plant was built in a cavern in the mountain and can be reached via a 310 m long tunnel. The system can process a water volume of 13 m³ / s. The Francis turbine with a horizontal axis has an installed capacity of 42 MW. The electrical energy is brought into the daylight via an oil cable . The wastewater flows through a tunnel to a moated castle , where it combines with the water from the Weißbrunnsee and from there via a pressure line to the St. Walburg power station.
The system has a high-performance pump that can pump incoming water from the Weißbrunnsee at the moated castle up to the Arzkar reservoir. Their delivery rate is up to 8.5 m³ / s. ( Location of the Kuppelwieser Alm power plant )
St. Walburg power plant
The St. Walburg power station is at the end of the Zoggler reservoir . It draws its process water from the Weißbrunnsee and the runoff water from the Kuppelwieser Alm power plant. The tunnel from the Weißbrunnsee to the connection with the runoff water at the moated castle takes in four water wells from tributaries of the Falschauer in its length of around 10 km and without any significant gradient . Then a pressure pipe leads from the surge tank over a height of 729 m to the power plant. Here the water meets two Pelton turbines with a horizontal axis and an installed capacity of 44 MW. The power plant discharges the runoff water into the Zoggler reservoir. The first expansion stage of the plant was put into operation in 1959. ( Location of the St. Walburg power plant )
St. Pankraz power station
The Zoggler reservoir feeds the St. Pankraz power station
... and the Pankraz reservoir the Lana power plant
The St. Pankraz power plant at the end of the Pankraz reservoir went into operation in 1957. Its Francis turbine with a vertical axis receives its process water through a pressure tunnel with a subsequent pressure pipe from the Zoggler reservoir. The water transport facility has a length of 5.6 km and a diameter of 2.5 m. The height of fall of the water is 318 m. The runoff water goes into the Pankrazer reservoir. ( Location of the St. Pankraz power plant )
Lana power plant
The Lana power plant, which was commissioned for the first time in 1953, is the oldest of the Ulten power plants. It is located in a cavern. Its three double Pelton turbines with an installed capacity of 120 MW provide almost as much energy as the other four power plants combined. They are supplied with 25 m³ / s of water from the Pankraz reservoir via a 6.8 km long pressure tunnel and at the end a 2.5 m thick pressure pipeline at a height of 478 m. ( Location of the Lana power plant )
The electrical energy generated in Ultental is passed on via the Lana substation. ( Location of the Lana substation )
literature
- Christoph Gufler: The lost legacy: the power plant and reservoir construction in Ulten and Lana , Verlag-Anst. Athesia Bozen, 2007, ISBN 978-88-8266-096-3
- SE Hydropower GmbH: hydropower plants Ultental , folder, ( digitized )
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