1 MW hydroelectricity plant on the Salzana river

Val Taleggio is a valley in Bergamo that begins west of the Brembana valley, in the vicinity of the hamlet of San Giovanni Bianco, and extends as far as the province of Lecco, along the course of the river Enna. Between Taleggio and San Giovanni Bianco, this forms the ravine known as the ‘Orrido di val Taleggio’ (‘Val Taleggio Gorge’). Originating in the Brembana valley and flanking the gorge along provincial road 25, it reaches the mouth of the Madonna valley, from which the river Salzana descends. Continuing to follow the road in the direction of the hamlet of Sottochiesa, just before the confluence between the Salzana and Enna rivers, in the vicinity of an old neglected mine, we find the central structure of the new Taleggio hydropower plant. The plan for the Taleggio hydropower plant, overseen by Sinergo throughout the design and execution phases, takes advantage of a drop of 273 metres – from 861m to 588m above sea level – in the flow of the river Salzana. The waters of this river are conveyed along a penstock via an intake structure constructed north of Pizzino, and returned to the river Salzano just downstream of the hydropower plant itself. As the system guarantees electrical power of just less than one megawatt, it is classified as a ‘mini’ hydropower plant. Nevertheless, anyone who examines the engineering and architectural elements of the project in more detail may well conclude that this categorisation does not do justice to the level of commitment evident in the planning and architecture of this project. Indeed, the altitude drop that the hydropower plant exploits was achieved through a steel penstock that follows a predominantly underground course of 2,700 metres, and whose final section is clamped to the slope that dominates the plant. Furthermore, the impressive nature of the project is illustrated by the dimensions of the vertical well (5 metres in diameter and 40 metres in depth) that was excavated into the rock to connect the structure of the plant to the artificial cave that houses the turbines. This features a face of 12 metres in height, which is connected to a subterraneous gallery used to discharge the waters required for the drilling of the mountain for 40 metres. As well as the construction of the hydropower plant, the penstock, and the structures for the uptake and release of water, Sinergo also oversaw the authorisation procedure to connect the plant to the national energy distribution network – with works carried out along a total stretch of five kilometres.

For a detailed description of the project, visit the relevant ISSUU page