Turbine Types

There are two classes of turbines.  Impulse turbines are most efficient in high head, low flow situations, and reaction turbines are most efficient in low head, high flow scenarios.  A variety of turbines in each of these classes have been developed and are appropriate for different circumstances, primarily dictated by the combination of head and flow, secondarily according to design constraints, efficiency and cost.  The graph below summarizes the head-flow regimes in which types of turbines are most efficient.

Pelton-Turbine-Runner P1110732