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

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

• Solar energy has two advantages

1. Solar energys 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.

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4.2 Alternate Energy Sources
Photovoltaic Cells Converts the suns energy
directly into electricity
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4.2 Alternate Energy Sources

• Example of solar energy use
• Solar One Barstow California

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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
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Hot Water Solar Panel costs about 1200 per
household to install
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4.2 Another Alternative EnergyNuclear Power Plant
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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
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Shearon Harris Nuclear Plant-Apex NCThere are 2
other nuclear power plants in NC
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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)

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Chernobyl Disaster-Russia-1987
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4.2 Alternate Energy SourcesWind Power
? In the next 50 to 60 years, wind power could
meet between 5 to 10 percent of the countrys
demand for electricity.
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Wind Turbines AdvantageA renewable energy
sourceDisadvantages 1. Noisy 2. Kill Birds
http//www.youtube.com/watch?vRtgBWNKwBkE 3.
Require a lot of land or coastal area
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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.
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How Does Hydroelectric Power Work?
Generator
Turbine
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Advantages of Hydroelectric power

1. Does not cause air pollution
2. Renewable source of electrical energy

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Disadavantages of hydroelectric power1.Use
water that could be used to water crops and
drinking water2. Dams block migration of fish
upstream
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4.2 Alternate Energy SourcesGeothermal 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
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The Geysers Is the Worlds Largest Electrical
Geothermal Facility
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Geothermal Energy

• Advantage
• Does not cause air pollution
• Disadvantage
• 1. Only available in areas with geyser activity

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4.2 Alternate Energy SourcesTidal Power- How
does it work?

1. 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.
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Tidal Dams
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Tidal Power

• Disadvantage
• Can use tidal power only in areas that experience
  tides (coastal areas)
• Advantages
• Renewable energy source
• No air pollution