1. Sources Of Energy
Chapter 5---Section 3

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

3. 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

4. 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

8. 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

10. 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

12. 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

13. 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

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

16. 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

18. 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

20. 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