San Colombano hydropower plant
Map with all coordinates: | San Colombano hydropower plant | |||
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| location | |||
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| Coordinates | 45 ° 52 '49 " N , 11 ° 3' 43" E | ||
| country | Italy | ||
| Waters |
Lago di San Colombano Leno di Terragnolo Rio Cavallo |
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| Data | |||
| Primary energy | Hydropower | ||
| power | 8.29 MW (1 × 1.34 MW, 1 × 6.95 MW) | ||
| owner | AGSM Verona Dolomiti Energia Spa. |
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| operator | Dolomiti Energia Spa. | ||
| Project start | 1957 | ||
| Start of operations | 1965 | ||
| turbine | 1 × Francis turbine 1 × Pelton turbine |
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| Energy fed in on an annual average | 60 GWh | ||
| was standing | 2015 | ||
The San Colombano hydropower plant ( Italian Impianto idroelettrico di San Colombano ) is a storage power plant that was commissioned in 1965 near Rovereto in Trentino Italy . The electrical output of the power plant is 8.29 MW. It is operated by Dolomiti Energia Spa.
history
A first project for a hydroelectric power station on the Torrente Leno was presented in 1957 by the municipality of Verona . The latter had already built the Speccheri dam on the upper reaches of the municipality of Vallarsa a few years earlier . This first project envisaged four drop stages with two power plants. A year later, the municipality of Rovereto also presented a project with only two case levels. In 1961, through the mediation of the Senator and President of the Rovereto Public Utilities Giovanni Spagnolli , the two municipalities agreed on a joint project and founded the company Comunità elettrica di Terragnolo (CET), which was divided equally between the two municipal utilities , and dealt with the planning. The public utility company AGSM from Verona was entrusted with the construction of the power station, while the public utility company from Rovereto would later ensure the operation of the plant.
In 1964, CET presented a new project with three case levels. These three fall levels covered a catchment area of 137.50 km² and had three storage facilities with a usable storage space of 3,839,000 m³ at 820, 640 and 280 m slm. The first storage facility was to be on the upper reaches of the Leno di Terragnolo with a usable storage space of 1,469. 000 m³ will be created into which the tributary of the Rio Pàssaul should also be drained. A fully automated machine house was planned for this first stage . The second storage tank with a storage basin of 170,000 m³ was to be built in the middle reaches of the Leno di Terragnolo and to absorb the runoff of the first storage tank and the residual water of the Leno and the water of the Rio Cavallo near Folgaria from an underground overpass over 10 km long. The water was then to be fed to a second machine house near San Colombano at the gates of Rovereto by means of a pressure pipeline , which was also largely underground . The third stage of the fall, on the other hand, was not planned in Val Terragnolo , but was intended to collect the residual water from the Leno di Vallarsa, which was already used in the upper reaches for power generation, at Toldo, a fraction of the Trambileno municipality . This storage facility, known as the Moscheri Basin or Lago di San Colombano , was laid out for a usable storage space of 2,200,000 m³ and was also to be connected with an underground pressure pipeline to the power station at San Colombano, which is about 45 meters above sea level. The bottleneck capacity should total 9,453 MW.
The first construction work on the later second stage had already started in 1962. In addition to the inlet structures on the middle reaches of the Leno di Terragnolo and the Rio Cavallo and their transitions, the machine house at San Colombano was also built in this construction phase. In 1963 the construction of the San Colombano dam and thus the third stage of the project began. With the opening of the machine house in 1965, the power plant was finally put into operation , initially as a run-of-river power plant and fed by the second stage. With the completion of the third stage a few months later, it was also possible to start operation as a storage power plant.
Due to extensive sediment deposits, which made it very likely that the dammed water would seep through, and the geologically unstable valley edges, the construction of the first stage on the upper reaches of the Leno di Terragnolo had to be abandoned. The project was then changed twice, in 1970 and 1986. Both changes concerned the second drop level, which should be enlarged due to the abandonment of the first barrage. The project presented in 1970 envisaged two smaller reservoirs lying one behind the other instead of a single reservoir. This project did not receive the relevant permits until 1984. Two years later, CET presented another project change with which the lower of the two planned basins was to be enlarged from 32,000 m³ to 58,000 m³, while the construction of the first 133,000 m³ reservoir was put on hold for the time being. In 1989 the construction of the lower stedileri basin with a slightly modified capacity of 59,245 m³ was finally completed. Since the construction of the second basin had been abandoned in the meantime, the second fall stage was also completed. In 2002 the power plant management went to the Società Trentini Servizi Spa. which arose from the merger of the Trento and Rovereto municipal utilities . The latter became the Dolomiti Energia Spa in 2008 and has been operating the power plant ever since.
functionality
The San Colombano hydropower plant draws its water from the catchment areas of the Leno di Terragnolo, Leno di Vallarsa and Rio Cavallo, and is around 137.50 km² in size. It has two storage facilities: the Stedileri storage facility ⊙ in Val Terragnolo with a capacity of 59,245 m³ and the Moscheri storage facility, known as Lago di San Colombano ⊙ in Vallarsa, with a capacity of 2,200,000 m³. The water of the Rio Cavallo and the two tributaries Scarabozza and Val delle Pignatte in the municipality of Folgaria, on the other hand, is fed to a single intake structure ⊙ for transfer without a reservoir . The inflow volume and the size of the storage facilities do not allow continuous use of the power plant, but only a temporary use.
Second case level
The second drop level uses the Leno di Terragnolo on its middle course and the Rio Cavallo and its tributaries. The Leno di Terragolo is a weir with inlet structure at 634 m slm conducted and an open transfer duct, which also receives the water of Rio Pàssaul in the Stedileribecken. The latter has a dam wall that is 12.80 m high. On the orographically right-hand side of the basin is the fully automatically controlled intake structure with flotsam rake and subsequent pressure tunnel. This pressure tunnel crosses the Leno di Terragnolo above ground after about 500 m and then always runs underground on the orographic right side of the valley. After about 2900 m, the water from the Rio Cavallo overpass, which also runs underground, is fed into the pressure tunnel. The underground water lock is located at km 7.385, the drop shaft extending from it is almost 1500 m long and ends directly at the machine house, with the penstocks only running a short distance above ground. The water of the second drop level overcomes a height difference of almost 416 m and operates a Peltron turbine with a vertical axis and five nozzles.
Third case level
The third drop has a drop height of 46 m and is mainly fed by the dammed water of the Leno di Vallarsa. The 36 m high arch dam of the Lago di San Colombano is 82.6 m long at the crown. The storage target is at 280 m slm and the overflow threshold at 284 m slm. On the orographically right side of the valley there is a weir flap and the bottom outlet . On this side there is also the intake structure with the pressure tunnel, which is 650 m long. The water of the Leno di Terragnolo is fed to the latter shortly before the above-ground moated castle. An old weir system with a transition is used for this, which was already used in the 1920s for a small and now derelict power plant of the Jacob paper mill , formerly Fedrigoni . The 75 m long fall shaft leads from the tower-shaped moated castle to the machine house, where it operates a Francis turbine .
Machine house
The machine house is located on the orographic right side of the Leno just a few meters after the confluence of the two Leno arms below Strada statale 46, which leads from Rovereto to Passo Pian delle Fugazze . A little above the power station is the hermitage of San Colombano , whose access branches off from the access road to the machine house.
There is a small substation in front of the building for feeding into the supply network. The two turbines in the nacelle operate two alternating current generators with a total output of 25,000 kVA , of which 22,500 kVA fall on the Pelton turbine of the second stage. The average annual output of the San Colombano hydropower plant is around 60 GWh, of which the second drop level contributes 51 GWh and the third drop level 9 GWh.
After it has passed through, the water is returned directly to the Leno via a drainage channel.
photos
Dam crest of San Colombano dam, 3rd drop
Stedileri reservoir 2nd drop level
San Colombano moated castle 3rd drop
Weir with inlet structure, 3rd drop level
Weir and inlet structure Stedileri 2nd drop level
Disused Pelton turbine runner of the San Colombano hydropower plant
Web links
literature
- Renzo Dori: Le grandi derivazioni idroelettriche del Trentino , Fondazione Museo Storico del Trentino, Trento 2015 ISBN 978-88-7197-201-5
- Silvio Sala, Giuseppe Zanella: Gli impianti idroelettrici del torrente Leno di Terragnolo, Rio Cavallo di Folgaria e basso Leno di Vallarsa delle Aziende Elettriche Municipalizzate di Rovereto e Verona . In: L'energia elettrica Volume 44, Issue 1 (1967), Società editrice riviste industrie elettriche, Milan 1967.
- Giuseppe Zanella: La Comunità elettrica del Terragnolo. In: I Quattro Vicariati. Rivista semestrale di cultura e vita. Anno XXXVIII - Numero 75 - Luglio 1994.
Individual evidence
- ^ Renzo Dori: Le grandi derivazioni idroelettriche del Trentino pp. 254-255
- ^ Giuseppe Zanella: La Comunità elettrica del Terragnolo p. 67
- ^ Renzo Dori: Le grandi derivazioni idroelettriche del Trentino p. 256
- ^ Giuseppe Zanella: La Comunità elettrica del Terragnolo p. 70
- ^ Renzo Dori: Le grandi derivazioni idroelettriche del Trentino p. 257
- ↑ Silvio Sala, Giuseppe Zanella: Gli impianti idroelettrici del torrente Leno di Terragnolo, Rio Cavallo di Folgaria e basso Leno di Vallarsa delle Aziende Elettriche Municipalizzate di Rovereto e Verona p. 19
- ^ Renzo Dori: Le grandi derivazioni idroelettriche del Trentino p. 257
- ^ Renzo Dori: Le grandi derivazioni idroelettriche del Trentino. P. 259
- ^ Renzo Dori: Le grandi derivazioni idroelettriche del Trentino. P. 260
- ↑ a b Renzo Dori: Le grandi derivazioni idroelettriche del Trentino p. 261
- ↑ Silvio Sala, Giuseppe Zanella: Gli impianti idroelettrici del torrente Leno di Terragnolo, Rio Cavallo di Folgaria e basso Leno di Vallarsa delle Aziende Elettriche Municipalizzate di Rovereto e Verona p. 11