Transcript Sun & Moon
Earth and Space
Energy Resources:
Wind, Sun, and Moon
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 150300 households.
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
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
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)
SUN
The rays heat the atmosphere, oceans
and the ground
Tropical regions receive more solar
energy than the poles
WHY?
The Earths curve
SUN
These different temperatures create the
winds and the oceanic circulation
This leads to natural phenomena
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
Solar Energy Technology
3 Types
1. Passive Heating
2. Photovoltaic Cells
3. Thermal Collectors
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
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
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
Solar energy
Renewable resource
No greenhouse gases
Can be used in isolated areas where
there are no power lines ex. North or
space
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
Tides
Side of Earth facing moon changes
throughout the day
Moon exerts gravitational force and
masses of water facing Moon are
attracted to it
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
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
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
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