1. Chapter 15 Section 4 What is are some alternate energy sources?
Objective:
Describe five alternate energy sources.

2. Solar Energy
Alternate energy refers to energy not produced by burning fossil fuels or wood.
Like fossil fuels, all alternate energy sources have problems related to their use.
solar energy: energy from sunlight
An alternate energy source
Currently used to heat homes and produce electricity

3. Solar Energy Solar collectors collect the Sun’s energy.
solar cells: devices on the solar collectors that convert the sunlight into electricity
Solar energy
is a renewable resource
does not pollute
is only good in places that receive above average amounts of sunlight all year

4. DEFINE:
What are solar cells?

5. Geothermal Energy geothermal energy: heat produced deep inside Earth
Melts rocks and warms ground water
In some places steam is produced and can generate electricity for heating homes
In other places the heated water is piped directly into homes
In Iceland about 80% of homes get their hot water and heat from geothermal energy

6. 2. IDENTIFY:
Where is geothermal energy produced?

7. Wind Energy
The energy from moving air, or wind energy, is another renewable resource.
Windmills have been used for many years to pump water and produce electricity
In California, big windmill farms are used to make electricity in some areas.
Windmills do not pollute the air

8. 3. EXPLAIN:
What are windmills mostly used for?

9. Energy from the Tides tidal energy: energy of rising and falling tides
can be used to produce electricity
can be used only near a shoreline where the tides vary from very high to very low

10. 4. APPLY:
Where in the United States could tidal energy be produced?

11. 15-4 Classwork
CHECKING CONCEPTS
What devices change sunlight into electricity?
What is geothermal energy?
Why can we not rely on windmills for energy?

12. 15-4 Classwork THINKING CRITICALLY
4. ANALYZE: Which alternate energy source do you think is best? Why?
5. INFER: If you were building a house, where would you put your solar collectors? Why?
6. EXPLAIN: How does a pinwheel or a kite show that wind has energy?