1. Alternative Energy Sources

2. Renewable Energy Sources
Energy sources that are replaced almost as fast as they are used:
Water power
Wind power
Solar energy
Geothermal energy
Each of these is limited in some way

3. Water Power
Water power is the most efficient way to produce electricity: hydroelectric power
The turbine blades are turned directly by the moving water
Only rivers suitable for damming can produce hydroelectric power
New technologies may harness tidal power to produce electricity
Revelstoke Dam (BC)

4. Wind Power
Wind power depends on the force of moving air against a windmill
Windmill farms can produce significant amounts of electrical energy
Wind power is most useful in coastal areas, or other areas with consistently strong winds

5. Solar Energy
Uses the limitless energy of the sun for heat and electricity
Passive solar heating traps heat; such as through special windows
Active solar heating collects the heat, transfers it to a storage area, and then moves it through a building
Active Solar Heating
Passive Solar Heating

6. Solar Cells Photovoltaic cells convert sunlight into electricity
Simple explanation
Photons in sunlight hit the solar panel and are absorbed by semiconducting materials, such as silicon.
Electrons (negatively charged) are knocked loose from their atoms, allowing them to flow through the material to produce electricity. Due to the special composition of solar cells, the electrons are only allowed to move in a single direction. The complementary positive charges that are also created (like bubbles) are called holes and flow in the direction opposite of the electrons in a silicon solar panel.
An array of solar cells converts solar energy into a usable amount of direct current (DC) electricity.

7. Photovoltaic Cells

8. Geothermal Energy Heat from the interior of the Earth
Brought to the surface by steam or hot water, where it can run a generator or heat homes
Geothermal energy needs no fuel and gives off no pollution
Superheated steam is difficult and expensive to move around