Transcript Energy - SchoolRack

Energy
S6E6.a Explain the role of the sun as
the major source of energy and the
sun’s relationship to wind and water
energy.
S6E6.b Identify renewable and
nonrenewable resources
What is energy?
• Energy is the ability to
do work.
Why is energy important?
• We use energy to do
everything we do.
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–
–
–
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Thinking
Playing
Working
Cooking
You name it!
What is the ultimate source of all
energy on Earth?
• The Sun!
– The sun’s energy
powers all other
energy sources.
– The sun’s energy
powers wind and
waves.
– Plants convert the
sun’s energy into fuel
we can use through
photosynthesis.
What are the two types of energy?
• Potential Energy
– Stored energy
• Kinetic Energy
– Energy of motion
In what forms are potential energy
and kinetic energy found?
• Heat or thermal
energy
• Light (radiant)
• Mechanical/kinetic
• Electrical,
• Chemical,
• Nuclear energy
How are these forms of energy
stored?
• Renewable resources
– an energy source that can be
replenished in a short period of
time
• Nonrenewable resources
– an energy source that we are
using up and cannot recreate in
a short period of time
Secondary Energy Sources
• An energy source (or
carrier) derived from
the conversion of
other sources of
energy, such as coal,
nuclear, or solar
energy. These are
called primary
sources.
• Electricity
• Hydrogen
How is energy used in homes?
• Most energy in homes
is used for heating.
What are the sources of renewable
energy?
What are the pros (good
things) about using
these resources?
What are the cons (bad
things) about using
these resources?
Solar Energy
Energy from the Sun
• Solar energy is the
sun’s rays (solar
radiation) that reach
the earth.
• Solar energy can be
converted into other
forms of energy, such
as heat and
electricity.
Solar Energy
• Solar energy can be converted to thermal
(or heat) energy and used to:
• Heat water – for use in homes, buildings,
or swimming pools.
• Heat spaces – inside greenhouses,
homes, and other buildings.
Solar Power
Advantages
• Solar energy is free
• Its supplies are unlimited.
• Using solar energy
produces no air, sound,
or water pollution
• Low maintenance on
equipment because no
moving parts
• Photovoltaic cells can be
used on a variety of
products (The little panel
on your calculator)
Solar Power
Disadvantages
• The initial investment in
equipment can be very
expensive
• Solar power plants
require a lot of room and
can affect environment in
areas where they exist
• Requires sunlight so it is
not produced 24 hours a
day
• Requires expensive
batteries to store energy
for use on cloudy days
and at night