Sources Of Energy Chapter 5---Section 3

Energy Resources Energy cannot be made or destroyed! The two main sources of energy are: The Sun Radioactive atoms in Earth’s interior

Nonrenewable Resources Energy sources that are used up much faster than can be replaced Fossil fuels Nuclear energy When Fossils Fuels burn: Stored chemical energy is released Releases pollutants into the air

Fossil Fuels Oil and Natural Gas: Coal: Made from remains of microscopic marine organisms Coal: Formed from remains of ancient plants All contain stored chemical energy that originated from the sun All are formed by heat and pressure

Nuclear Energy Comes from the nuclei of unstable atoms Advantages- Ex. Uranium Advantages- Can be used to generate electricity instead of fossil fuels Doesn’t cause air pollution Disadvantages- Uranium is nonrenewable Waste produced is radioactive

Hydroelectricity Using water to make electricity Water is a RENEWABLE resource - energy source that is replenished continually Advantage- pollution free Disadvantage- disrupts life cycles of aquatic organisms As long as there is precipitation to keep rivers flowing, energy can be produced

Alternative Sources Are less harmful to people and environment Help to conserve fossil fuels Most are INEXHAUSTIBLE resources -energy resources that can’t be used up Include: Solar Energy Geothermal Energy Energy From Oceans Wind

Solar Energy Is really expensive Collected by: Thermal collectors Use black pipes to collect sun’s rays Photovoltaic collectors Photo means light / voltaic means electrical Transform light energy directly into electrical energy

Geothermal Energy Generated from heat deep inside Earth: Radioactive decay Molten rock or magma Hot springs or geysers

Electrical Energy From Oceans Oceans are always in motion Inexhaustible source of mechanical energy Does not produce pollution Tidal power plants: Generate electricity as the tide comes in or goes out Limited usage

Wind Energy Windmills Advantage Disadvantage Convert kinetic energy into electrical energy Propeller is the turbine which is connected to generator Advantage Does not produce pollution Disadvantage Produce noise May kill birds

Conserving Energy Reducing the use of energy Turn off lights and unused appliances Close doors or windows to trap heat Use proper insulation Recycling Consolidate trips or passengers to reduce oil usage