Answer :
Answer: Pelton Wheel
Explanation: This design is the most efficient for very high heads and stable water flows, allowing for several hundreds of megawatts of unit capacity.
Pelton wheel, which is an impulse type turbine invented by an American engineer L. Pelton in the 19th century and has proven to be among the most efficient hydroturbines. ... This design is the most efficient for very high heads and stable water flows, allowing for several hundreds of megawatts of unit capacity.