In those places where the topography was suitable, water power traditionally held pride of place, thanks to a number of indisputable advantages, among which were the continuous natural replenishment of the energy consumed, the very low operating costs and the long operating life of the generating plant.
Fra essi va ricordato, in primo luogo, il rinnovo automatico e permanente dell'energia utilizzata, i costi di esercizio molto bassi e la lunga durata degli impianti.