1. Alternative Energy Resources. 1. Solar. 2. Wind. 3. Nuclear. 4
Alternative Energy Resources 1. Solar 2. Wind 3. Nuclear 4. Hydroelectric 5. Geothermal 6. Tidal

2. 4.2 Alternate Energy Sources
Solar energy has two advantages:
1. Solar energy’s “fuel” is free.
2. Solar energy is non-polluting.
How do we use solar energy?
Solar collectors provide hot water for more than 80% of Chinese homes.

3. 4.2 Alternate Energy Sources
Photovoltaic Cells – Converts the sun’s energy directly into electricity

4. 4.2 Alternate Energy Sources
Example of solar energy use
Solar One – Barstow California

5. 4.2 Alternate Energy Sources
Disadvantages to Solar Energy
High start up costs to buy panels
Must have a battery back-up when there is no sunlight
Solar panels
30 W Foldable panels = $300
or about $40,000 start up cost per household
125 W = $500/year

6. Hot Water Solar Panel costs about $1200 per household to install

7. 4.2 Another Alternative Energy Nuclear Power Plant

8. 4.4 Nuclear Power
 Fuel for nuclear plants comes from radioactive materials (uranium ) that release energy through nuclear fission
 In nuclear fission, the nuclei of heavy atoms such as uranium-235 are bombarded with neutrons.
 The uranium nuclei split into smaller nuclei and emit neutrons and heat energy.
Uranium atom
Release heat

9. Shearon Harris Nuclear Plant-Apex NC There are 2 other nuclear power plants in NC

10. 4.2 Alternate Energy Sources
Advantages of nuclear power
1. no air pollution emitted
2. greater output of electrical energy than coal
Disadvantages of nuclear power
Cost of building safe facilities (about $1 billion)
Disposal of waste (stored in underground tunnels)
Concern of a serious accident (melt down)

11. Chernobyl Disaster-Russia-1987

12. 4.2 Alternate Energy Sources Wind Power
 In the next 50 to 60 years, wind power could meet between 5 to 10 percent of the country’s demand for electricity.

13. Wind Turbines. Advantage: A renewable energy source Disadvantages:. 1
Wind Turbines Advantage: A renewable energy source Disadvantages: 1. Noisy 2. Kill Birds Require a lot of land or coastal area

14. 4.2 Alternate Energy Sources
 Hydroelectric power is the power generated by falling water.
Water held in a reservoir behind a dam
Water can be released through the dam to produce electric power.
 Strong water flow that results drives propellers of turbines and creates electric power from generators.

15. How Does Hydroelectric Power Work?
Generator
Turbine

16. Advantages of Hydroelectric power
Does not cause air pollution
Renewable source of electrical energy

17. Disadavantages of hydroelectric power: 1
Disadavantages of hydroelectric power: 1.Use water that could be used to water crops and drinking water 2. Dams block migration of fish upstream

18. 4.2 Alternate Energy Sources Geothermal Energy- How does it work?
electricity
Geothermal energy is harnessed by tapping natural underground reservoirs of steam and hot water.
 Hot water is used directly for heating and to turn turbines that generate electric power.
turbine
Hot steam
from underground geysers

19. The Geysers Is the World’s Largest Electrical Geothermal Facility

20. Geothermal Energy Advantage Does not cause air pollution Disadvantage:
1. Only available in areas with geyser activity

21. 4.2 Alternate Energy Sources Tidal Power- How does it work?
Tidal power is harnessed by constructing a dam across the mouth of a bay or an estuary in coastal areas.
2. The strong in-and-out flow of tidal water drives turbines and electric generators.

22. Tidal Dams

23. Tidal Power Disadvantage:
Can use tidal power only in areas that experience tides (coastal areas)
Advantages:
Renewable energy source
No air pollution