The document discusses different renewable energy sources including hydro, wind, and solar energy. It provides details on how hydro power harnesses the energy of falling and running water and has been used for centuries. It also explains the basic principles of how wind turbines convert kinetic energy from wind into electrical power and lists the typical components. Finally, it outlines how solar panels work by using photovoltaic cells to convert sunlight into electricity and notes the various parts that make up a solar panel.