Kaplan turbines are a type of water turbine used in hydroelectric power plants. They are designed to operate efficiently in low-head sites, where the height of the water drop is relatively small. The turbine features adjustable blades, allowing it to adapt to varying water flow conditions, which enhances its efficiency. Invented by Viktor Kaplan in the early 20th century, these turbines are particularly effective for generating electricity from rivers and dams. Their design includes a propeller-like rotor and a guide vane system, which helps direct the water flow, maximizing energy extraction while minimizing environmental impact.