Electricity is called a secondary energy source because it is generated from other sources (primary).   Examples of primary sources are coal and natural gas.   Electricity is easily transmitted over long distances through cables.   Electricity can be used in many ways. (Lighting, heaters, computers, TVs, motors...)   Renewable energy resources are resources that can be replaced as we use them.    Energy from renewable resources can be used to drive turbines directly which then drive     generators which produce electricity.      Generating electricity from non renewable energy sources does not produce carbon dioxide.   Examples of renewable energy resources and how they generate electricity   The wind      The wind turns the blades which turn a turbine that is connected to a generator that generates      electricity.   The waves       The water inside the tube rises and falls forcing the air in and out of the hole at the top of the       tube. The air turns the turbine that is connected to a generator that generates electricity.        Hydroelectric power        Water is held in a reservoir in a dam. As the water flows down through the turbine, it turns the       turbine that is connected to a generator that generates electricity.                                                                The tides       As the tide comes in, water flows through a turbine that is connected to a generator that       generates electricity.       As the tide falls, water flows through the turbine in the opposite direction. The generator       generates electricity.       Geothermal        Steam from deep underground sometimes rises to the surface. This steam can be used to        turn a turbine that is connected to a generator that generates electricity.        Sunlight is used by solar cells to produce electricity.