Enel - Visita alle Centrali


	Hydroelectric

	Basin
	Dam
	Turbine
	Penstock
	Valves
	Restitution Infrastructure
	Transformer
	Alternator

Dam
Photo gallery	Download pdf

An infrastructure meant to obstruct a water course, thus forming a basin or a tank with entrance infrastructures, tunnels or channels, and infrastructures for the overflow of excess water and spillways. The dams can be divided into two broad categories: gravity dams and arc dams. Gravity dams are generally carachterized by a triangular or trapezoidal vertical section, and by a straight horizontal section, which may sometimes be curved instead. The stability and resistance to buoyancy (hydrostatic push) are entrusted only to the weight of the building. With arch dams, the buoyancy (hydrostatic push) of water flooded is transferred on the side walls upon which the dam itself leans. Convex shaped ones can be built only to osbtruct not very wide valleys with rocky sides to which the dam is anchored.

The term “small hydro” is conventionally used for hydroelectric systems with a capacity up to 10 MW, which differ from plants with a higher capacity. In fact, while the latter require large barrages (dams) and extended artificial lakes for water accumulation, small hydro systems practically work like the old wind mills (obviously as a high-tech version), without almost any environmental impact.
On the contrary, they offer several environmental advantages. First of all they supply energy without emitting polluting substances, dust particles, heat and greenhouse gasses, thus helping to reduce local pollution and global warming.
From the point of view of energy, even if small hydro plants do have a limited individual capacity, they can be installed in arrays that include several systems, thus making a significant contribution to the national electricity production. In fact, this is an energy source that is considered essential to achieve European emissions reduction targets by increasing the amount of renewables that is deployed.