1. Chapter 4 Earth Resources
Section 4.2
Alternate Energy Sources

2. Alternate Energy Sources
Solar Energy
Nuclear Energy
Wind Energy
Hydroelectric Energy
Geothermal Energy
Tidal power

3. Solar Energy Earths most abundant energy resource
Solar energy technologies use the sun’s rays to supply heat or electricity
Solar energy is free and nonpolluting

4. Solar Energy Pros Free Abundant Nonpolluting Cons
Costly equipment and installation
Supplemental heating is needed during reduced sunlight ie., on cloudy days, in the winter, and at night

5. Nuclear Energy
In nuclear fission,the nuclei of heavy atoms such as Uranium-235 are bombarded with neutrons. The uranium nuclei then split into smaller nuclei and emit neutrons and heat energy.

6. The Birth of Nuclear Energy
“At one time, energy experts thought nuclear power would be the cheap, clean energy source that would replace fossil fuels.”(Tarbuck & Lutgens, 104)

8. What obstacles slowed the development of nuclear energy?

9. Set backs for nuclear energy
Cost of safe facilities has increased
Hazards associated with disposal of nuclear waste
Possibilities of serious accidents allowing radioactive material to escape

10. Nuclear Accidents
Three Mile Island, low water levels lead to reactor damage
Chernobyl, Ukraine, much more serious, out of control reactor, fire and explosions, 18 deaths and thousands faced increased risk of death from cancer due to fallout

11. Wind Energy Wind is not a new energy source
Wind turbines harness the most energy in areas with strong steady winds like mountain passes and sea coasts

12. The Future of Wind Energy
5%-10% of the countries energy needs could be met in the next years by wind power

13. Difficulties and obstacles facing wind energy
Need for technical advances
Noise pollution
Cost of large areas of land in populated areas
Not practical in all locations

14. Hydroelectric Energy
The power that falling water generates to drive turbines and produce electricity

15. Hydroelectric energy
At a hydroelectric power plant water is held in a reservoir behind a dam.
Lake Mead is the largest reservoir in the USA and is held behind the Hoover Dam
Hydro electric power plants are limited by the availability of suitable sites

16. Geothermal Energy
Is harnessed by tapping natural underground reservoirs of steam and hot water
The heated water is used to turn turbines to create electricity

17. Tidal Power
Is harnessed by constructing a dam across the mouth of a bay or an estuary in coastal areas with a large tidal range. The strong in-and-out flow that results drives turbines and electric generators