1. ALTERNATIVE ENERGY SOURCES
Nonrenewable energy sources take a toll on our natural resources and pollute the environment.
Alternative energy sources do not impact our environment as badly.

2. SOLAR ENERGY
1. Uses the Sun’s radiation to produce energy. Solar panels collect solar energy & photovoltaic cells convert the sun’s energy into electricity.
2. Advantages – non-polluting, makes lots of energy

3. SOLAR ENERGY CONTINUED…
3. Disadvantages – photovoltaic cells produce a very small electrical current = need many to meet needs, takes up lots of space, expensive to install, not always sunny
4. Where - areas with lots of sunlight & open space (desert)

4. WATER ENERGY (Hydroelectric)
1. Hydroelectric power - water falls on turbine which causes them to turn, producing energy.
2. Advantages – non polluting, recreational opportunities, drinking water, water for irrigation

5. WATER ENERGY CONTINUED…
3. Disadvantages – floods behind dam, destroys wildlife habitat, interrupts migrating fish, changes natural pattern of water flow
4. Where – Must have flowing water source (river)

6. WIND ENERGY 1. Wind turns propeller that then generates energy.
2. Advantages – unlimited, built quickly, expandable, non polluting, land under wind farms can be used for cattle, least expensive alternative energy source

7. WIND ENERGY CONTINUED…
3. Disadvantages – need steady winds, interfere with birds, noisy, difficult to transport produced energy to far away locations.
4. Where – coastal areas, areas with constant winds and open ground, or high elevations

8. GEOTHERMAL ENERGY 1. Uses Earth’s internal heat to produce energy
2. Advantages – abundant, reliable, steam doesn’t pollute

9. GEOTHERMAL ENERGY CONTINUED…
3. Disadvantages – water needed, minerals clog pipes, steam impacts birds
4. Where – near plate boundaries or hot spots (Iceland, Yellowstone)

10. BIOMASS FUELS Biomass fuels are obtained from organic materials.
1.Wood, dried crops (hay), dried fecal material from animals (manure)
2.Methane – produced when bacteria decompose organic wastes (decomposition of trash, fermenting manure – both can be used to produce gas and fuel power
3.Alcohol – ethanol can be made by fermenting agricultural waste (corn)
Can be used in vehicles (gasohol) – produces less air pollution

11. Biomass Advantages ~ Environmentally friendly (limited air pollution)
~ Reduces the amount of wastes entering a landfill or polluting the earth

12. Biomass Disadvantages
~ It takes many resources to grow crops for biomass
~ Burning of biomass does release greenhouse gases into the air
~ Ethanol (from corn) is less efficient than fossil fuel

13. NUCLEAR ENERGY
1. Nuclear fission of radioactive uranium creates energy
2. Advantages – no release of greenhouse gases, very efficient

14. NUCLEAR ENERGY CONTINUED…
3. Disadvantages – high cost of operation, safety with radioactive materials, nonrenewable
4. Where – near a water source for cooling the reactor

15. Other Alternatives… Tidal Power
1. As ocean tides rise, water flows behind a dam; when tides fall, the water is trapped behind the dam. The trapped water is released to turn a turbine.
2. Advantages – non-polluting, renewable

16. Tidal Power Continued
Disadvantages – expensive to build and maintain, not many suitable locations.
Where? – coastlines (France, Russia, Canada)

17. Other Alternatives…
Hydrogen – an abundant element found in all living things and water.
Advantages – abundant, produces harmless water vapor when burned
Disadvantages – producing hydrogen right now is expensive and causes pollution. Needs to be compressed to be as effective as gasoline = explosive.

18. Other Alternatives…
Ocean Thermal Energy Conversion (OTEC) – warm surface ocean water (in the tropics) is brought to boil in a vacuum chamber, turns to steam, & turns a turbine.
Disadvantage - expensive, possible environmental impacts of pumping deep ocean water to the surface

19. THINK ABOUT IT…
If you were a politician and it was up to you to decide how the US should produce energy, which type of energy would you choose and why?