This document discusses tidal power and provides details about how it works. It describes two types of tidal power facilities: tidal barrages and tidal current turbines. Tidal barrages utilize potential energy by building dams across estuaries and bays, while tidal current turbines capture the kinetic energy of moving water using underwater turbines similar to wind turbines. The document outlines some of the first tidal power plants built, including one in France from 1960-1966, and provides advantages like predictability and efficiency, and disadvantages like high construction costs and potential environmental impacts.