This document provides an overview of hydroelectric power plants. It introduces hydroelectric power and notes that China is the largest producer and India generates 129 TWh annually. The history section discusses the first uses of hydro power dating back over 2000 years and the establishment of early power stations in the late 1800s/early 1900s. Key components of hydroelectric plants are described like turbines, generators, governors and draft tubes. Francis turbines directly coupled to generators are highlighted. Advantages include renewable energy generation and flood control, while disadvantages include high capital costs and dependence on water availability.