1. 11.3 A Sustainable Energy Future
Unit 11: Energy
May 26, 2009
Unit 11: Energy

2. Energy Conservation
The average American uses twice as much energy as the average European.
Ways to counteract consumption
Conservation:
Use less energy
Modify systems:
Increase energy efficiency
Cars
Buildings
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Unit 11: Energy

3. Energy for the Future
As fossil fuels dwindle, we need alternative energy resources.
Buoy at left harness ocean waves.
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Unit 11: Energy

4. Solar Energy The energy from the sun is known as solar energy.
Harnessing the sun’s energy is known as solar energy.
May 19, 2019
Unit 11: Energy

5. Passive Solar
In a passive solar house, double paned windows facing south let in the winter sun but prevent heat from escaping.
Overhangs on the house prevent summer sun from coming in.
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Unit 11: Energy

6. Active Solar Heating
Water heated from the sun is carried away from the solar box by use of a pump.
Heated water can go to a boiler or house heating.
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Unit 11: Energy

7. Solar Cells
Solar cells are devices that collect energy in photovoltaic cells.
Converts sun’s energy directly into electricity.
Photovoltaics is the direct conversion of light into electricity at the atomic level. Some materials exhibit a property known as the photoelectric effect that causes them to absorb photons of light and release electrons. When these free electrons are captured, an electric current results that can be used as electricity.
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Unit 11: Energy

8. Wind Energy Wind energy harnesses energy of the wind.
The energy is captured by windmills.
Mechanical energy transferred to electricity.
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Unit 11: Energy

9. Hydroelectricity Water is used to push heavy turbines and generators.
Hydroelectricity is
Clean
Renewable
No waste
Niagara Falls is a natural waterfall that provides electricity to the greater Buffalo area.
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Unit 11: Energy

10. Hydroelectric: Damming
Advantages:
Offers recreational activities.
Provides drinking water
Controls flooding
Disadvantages:
Disrupts the river’s ecosystem.
Dam construction cost.
Limited to areas with rivers and streams.
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Unit 11: Energy

11. Geothermal Energy
Heat energy from inside the earth drives electric generators.
Geothermal is a clean energy.
Disadvantages of this energy is that it is a limited place.
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Unit 11: Energy

12. Biomass
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Unit 11: Energy

13. Hydrogen Hydrogen is a clean fuel. Hydrogen is very voluminous.
To use as a fuel would require a large tank.
Expensive to condense.
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Unit 11: Energy

14. Summary There are alternatives to fossil fuels.
Most applications work only is certain areas.
Our energy needs continue to grow.
A sustainable energy future will require the efficient use of all forms of energy.
May 19, 2019
Unit 11: Energy