1. Impulse Turbines
Impulse turbines are used in high-head, low-flow conditions. They convert the potential energy of water into kinetic energy through a nozzle, which directs a high-velocity jet of water onto the turbine’s blades.
According to a Hydropower Turbine Market report, the industry is expected to grow significantly in the coming years.
Types of Impulse Turbines:
Pelton Turbine:
Uses spoon-shaped buckets mounted around a wheel.
Water jets hit the buckets, causing the wheel to spin.
Suitable for heads above 300 meters.
Applications: Mountainous regions with steep waterfalls, small hydro installations.
Turgo Turbine:
A variation of the Pelton, but with angled jet entry.
Allows higher rotational speed and smaller generator size.
Applications: Medium-head sites, mini-hydro projects.
2. Reaction Turbines
Reaction turbines operate fully submerged and use both pressure and velocity of water to generate energy. They are ideal for low to medium head and high-flow applications.
Types of Reaction Turbines:
Francis Turbine:
The most widely used turbine globally.
Water enters radially and exits axially.
Operates in a head range of 20–300 meters.
Applications: Large hydroelectric dams like those on the Columbia and Yangtze Rivers.
Kaplan Turbine:
A propeller-type turbine with adjustable blades.
Designed for low-head (less than 30 meters), high-flow applications.
Extremely efficient under variable flow conditions.
Applications: Tidal power stations, run-of-river hydro systems.
Propeller Turbine:
Similar to Kaplan but with fixed blades.
Less adaptable but simpler and cheaper to construct.
Applications: Small-scale installations with consistent water flow.
3. Other Specialized Turbines
Crossflow (Banki-Michell) Turbine:
A type of impulse turbine where water flows transversely through a cylindrical rotor.
Simple design and suitable for small-scale operations.
Applications: Community-based micro-hydro systems.
Bulb Turbine:
A horizontal-axis turbine integrated into a bulb housing the generator.
Ideal for low-head, high-flow conditions.
Applications: Large river systems, tidal barrages.