Earth and Space

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Earth and Space

• Energy Resources
• Wind, Sun, and Moon

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Wind Energy

• Convert energy from wind to mechanical energy-
  windmills
• Convert energy from wind to electrical energy-
  wind turbines
• A 1-megawatt wind turbine provides enough energy
  to supply 150-300 households.

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Wind Energy

• Advantages
• Renewable resource
• Do not produce greenhouse gases while in use

• Disadvantages
• Interfere with the natural beauty of the
  landscape
• Can not predict winds in terms of time and speed

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Effect of Sun and Moon on Earth

• Sun is most important in terms of energy emission
  of light and heat
• Moon exerts gravitational force causing tides

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Energy Emission of Sun

• The Sun is a star that is composed of 75
  Hydrogen and 25 Helium
• Energy is transported by rays
• Infrared
• Visible Light
• Ultraviolet
• 8 minutes for the rays to travel from the Sun to
  the Earth (150 million Km)

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SUN

• The rays heat the atmosphere, oceans and the
  ground
• Tropical regions receive more solar energy than
  the poles
• WHY?

• The Earths curve

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SUN

• These different temperatures create the winds and
  the oceanic circulation
• This leads to natural phenomena

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Solar Energy

• Solar energy the energy that is given from the
  sun by the rays that travel to earth
• In 1 hour the earth receives enough solar energy
  in the form of heat and light to supply us with
  enough energy for our needs for a year but
  capturing this energy is difficult

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Solar Energy Technology

• 3 Types
• 1. Passive Heating
• 2. Photovoltaic Cells
• 3. Thermal Collectors

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Solar Energy Technology

• Passive Heating This system consists of
  orientating the house to get the maximum light
  from the sun. The rays pass through windows and
  heat the air inside. Material inside like
  concrete trap heat and can give it off when the
  sun goes down

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Solar Energy Technology

• Photovoltaic Cells serves as feeding devices
  with electricity
• The material in the cells is usually Silicon. The
  light hits the cell and causes movement of
  electrons, creating a current
• More than one cell, ie. panel is needed

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Solar Energy Technology

• Thermal Collectors use the sun's energy to heat
  water or another fluid such as oil or antifreeze.
  The panels are made from copper covered tubes,
  which have water passing through.
• Very costly and sun is not always out

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Solar energy

• Renewable resource
• No greenhouse gases
• Can be used in isolated areas where there are no
  power lines ex. North or space

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Moon

• The moon moves around the earth as well as it
  turns on owns its own axes
• Moon formed when a meteorite crashed into Earth
  and exploded pieces went into space

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Tides

• Side of Earth facing moon changes throughout the
  day
• Moon exerts gravitational force and masses of
  water facing Moon are attracted to it

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Tides

• Water balloons out and creates a bulge
• Water on other side of Earth is less attracted to
  Earth and balloons out too
• Causes high and low tides

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Tides

• 2 high tides and 2 low tides per day
• Difference between high tide and low tide is
  known as amplitude and it varies depending on
  place and season
• Bay of Fundy- amplitude is 17 m
• Sun also has an affect on tides but much smaller

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Tidal Energy

• Energy obtained using force of tides rising and
  falling
• Can convert to electrical energy
• Catch high tide water in basin and release at low
  tide
• Turns a turbine to transform to electrical energy

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Tidal Energy

• Advantages
• No greenhouse gases produced
• Renewable
• Predictable

• Disadvantages
• Costly to install factories
• Factories must resist hostile conditions of
  oceans
• Few suitable sites
• Need 5 m amplitude minimum

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In class work

• P.246
• 1,2,3,5,6,7,9