This document provides information on hydro and tidal power. It discusses how hydroelectric power works using dams, penstocks, turbines and generators to harness the kinetic energy of moving water. Tidal power similarly uses structures like tidal barrages and tidal stream generators to capture the kinetic energy of ocean tides. Both have advantages as renewable sources but also disadvantages like high initial costs and potential environmental impacts. The document outlines the basic components and functioning of hydroelectric plants and compares tidal energy to other renewable sources.