Auxiliary equipment and services, electrical equipment
Electricty Production by Small Hydroelectric Power Plants

On low heads, the choice of the most suitable turbine leads to a low rotation speed and therefore a very expensive generator. It is therefore preferable to optimize the turbine to make the best use of the head and to drive the generator via a gearbox to achieve lower generator costs, i.e. generators running at 750, 1,000 or 1,500 rpm.

Older installations feature belt-driven gearboxes, with the turbine driving a large-diameter pulley...