Sources of

Energy

Forms of Energy

• All forms of energy are related.

• Each form can be converted into any other form.

• You can not create or destroy energy, only change its form.

Classifications of Energy Sources

Limited

Petroleum

Coal

Natural gas

Uranium

Unlimited Solar

Wind

Gravitational

Tidal

Geothermal

Fusion

Renewable

Biomass

Animal Power

Human Muscle Power

Energy Sources

Nuclear Power

• Generated by fission of uranium, a metal that is mined

• Produces around 11% of the world's energy needs

• Produces huge amounts of energy from small amounts of fuel

U.S. Nuclear Reactor Locations

http://crasstalk.com/2011/03/where-are-all-the-nuclear-power-plants-in-the-us/

World Nuclear Reactor Locations

http://incontiguousbrick.wordpress.com/2007/08/21/nuclear-reactors-of-the-world/

Biomass • Organic (once-living) matter such as wood,

crops, landfill gas, manure, alcohol fuels, garbage

• Burned directly or converted into flammable liquids/gases.

(corn ethanol + gas = gasohol)

• Biofuels provide about 3% of our energy in the United States.

Geothermal Power

• Comes from heat trapped deep within the earth.

• Natural steam geysers are used to generate electricity.

• Hot water can also be pumped out of the ground to heat buildings.

• Geothermal sources account for less than 1% of the total energy produced in the United States.

Hydropower • Moving water holds a tremendous amount of potential

energy.

• Dams are built to direct failing water through a turbine to generate electricity.

• About 3% of our total energy in the United States comes from waterpower.

Free flow underwater turbine (no dam)

Solar Power • The sun's energy can be used to directly heat

buildings or to provide hot water. It can also be converted to electricity.

• Photovoltaic devices (often called "solar cells") can produce only small amounts of electricity.

• Provides less than 1% of our energy.

1911 – Solar water heater

Photovoltaic Cells 1. Sunlight strikes the solar

cell

2. Electrons are knocked loose

3. Electrons move toward the treated front surface creating an electron imbalance

4. A wire connecting the 2 surfaces conducts the electrical current between the + and - sides

Wind Power

• Windmills can pump water or grind flour, and generate electricity.

• Less than 1 % of our energy is now being produced by wind power.