Transcript Energy 101 - Kentucky Department of Education

Energy 101
LT #1 I can describe what energy is.
LT #2 I can identify and explain the sources of energy.
LT #3 I can identify and explain the forms of energy.
What is Energy?
 Energy is the ability to do work.
 Energy is in everything! We use energy for everything we
do, from making a jump shot to baking cookies to sending
astronauts into space.
 Energy makes change possible. Modern civilization is
possible because we have learned how to change energy
from one form to another and use it to do work for use
and to live more comfortably.
 We use it to do things for us. It moves cars along the road
and boats over the water.
 It bakes a cake in the oven and keeps ice frozen in the
freezer.
 It plays our favorite songs on the radio and lights our homes.
 Energy is needed for our bodies to grow and it allows our
minds to think.
Energy Sources
 When we use electricity in our home, the electrical power
was probably generated by burning coal, by a nuclear
reaction, or by a hydroelectric plant at a dam. Therefore,
coal, nuclear and hydro are called energy sources. When
we fill up a gas tank, the source might be petroleum or
ethanol made by growing the processing corn.
 Energy sources are divided into two groups – renewable
(an energy source that can be easily replenished) and
nonrenewable (an energy source that we are using up
and cannot recreate).
Renewable Energy Sources
 Solar
 Geothermal
 Wind
 Hydropower (water)
 Biomass
 wood and wood waste
 municipal solid waste
 landfill gas and biogas
 ethanol
 biodiesel
Many paper mills use wood
waste to produce steam and
electricity
What Role Does Renewable Energy
Play in the United States?
 The use of renewable energy is not new. More than 150 years
ago, wood, which is one form of biomass, supplied up to 90% of
our energy needs. As the use of coal, petroleum, and natural
gas expanded, the United States became less reliant on wood
as an energy source. Today, we are looking again at renewable
sources to find new ways to use them to help meet our energy
needs.
 Over half of renewable energy goes to producing electricity.
The next largest use of renewable energy is biomass (wood
and waste) for the production of heat and steam for industrial
purposes and for space heating, mostly in homes. Biomass
also includes biofuels, such as ethanol and biodiesel, used for
transportation.
What Role Does Renewable Energy
Play in the United States?
 Renewable energy plays an important role in the supply of
energy. When renewable energy sources are used, the
demand for fossil fuels is reduced. Unlike fossil fuels, nonbiomass renewable sources of energy (hydropower,
geothermal, wind, and solar) do not directly emit greenhouse
gases.
Radiant energy from the sun
has powered life on Earth for
many millions of years.
Why Don’t We Use More
Renewable Energy?
 In the past, renewable energy has generally been more
expensive to produce and use than fossil fuels. Renewable
resources are often located in remote areas, and it is expensive
to build power lines to the cities where the electricity they
produce is needed. The use of renewable sources is also
limited by the fact that they are not always available — cloudy
days reduce solar power; calm days reduce wind power; and
droughts reduce the water available for hydropower.
Wind Farm at The Cerro Gordo
Project, West of Mason City,
Iowa
Why Don’t We Use More
Renewable Energy?
 The production and use of
renewable fuels has grown
more quickly in recent years as
a result of higher prices for oil
and natural gas, and a number
of state and federal government
incentives, including the Energy
Policy Acts of 2002 and 2005.
The use of renewable fuels is
expected to continue to grow
over the next 30 years, although
EIA projects that we will still rely
on non-renewable fuels to meet
most of our energy needs.
Nonrenewable Energy
Sources
 Propane
 Uranium (nuclear
energy)
 Coal
 Natural Gas
 Petroleum
 Gasoline
 Diesel fuel
Nonrenewable energy sources
come out of the ground as
liquids, gases, and solids.
Crude oil (petroleum) is the only
commercial nonrenewable fuel
that is naturally in liquid form.
Natural gas and propane are
normally gases, and coal is a
solid.
Fossil Fuels Are Nonrenewable,
but Not All Nonrenewable
Energy Sources Are Fossil Fuels
 Coal, petroleum, natural gas, and propane are all
considered fossil fuels because they were formed from the
buried remains of plants and animals that lived millions of
years ago.
 Uranium ore, a solid, is mined and converted to a fuel used
at nuclear power plants. Uranium is not a fossil fuel, but is
a nonrenewable fuel.
Forms of Energy
 Potential Energy – stored
energy
 Chemical
 Mechanical
 Nuclear
 Gravitational
 Kinetic Energy – motion of
waves, electrons, atoms,
molecules, substances, and
objects
 Radiant
 Thermal
 Sound
 Motion
 Electrical
Chemical Energy
 is energy stored in the
bonds of atoms and
molecules. Batteries,
biomass, petroleum, natural
gas, and coal are examples
of stored chemical energy.
Chemical energy is
converted to thermal
energy when we burn wood
in a fireplace or burn
gasoline in a car's engine.
Mechanical Energy
 is energy stored in objects
by tension. Compressed
springs and stretched
rubber bands are
examples of stored
mechanical energy.
Nuclear Energy
 is energy stored in the
nucleus of an atom — the
energy that holds the
nucleus together. Very
large amounts of energy
can be released when the
nuclei are combined or
split apart. Nuclear power
plants split the nuclei of
uranium atoms in a
process called fission.
The sun combines the
nuclei of hydrogen atoms
in a process called fusion.
Gravitational Energy
 is energy stored in an
object's height. The higher
and heavier the object, the
more gravitational energy is
stored. When you ride a
bicycle down a steep hill
and pick up speed, the
gravitational energy is
being converted to motion
energy. Hydropower is
another example of
gravitational energy, where
the dam "piles" up water
from a river into a reservoir.
Radiant Energy
 is electromagnetic
energy that travels in
transverse waves.
Radiant energy includes
visible light, x-rays,
gamma rays and radio
waves. Light is one type
of radiant energy.
Sunshine is radiant
energy, which provides
the fuel and warmth that
make life on Earth
possible.
Thermal Energy
 or heat, is the vibration and movement of the atoms and
molecules within substances. As an object is heated up, its
atoms and molecules move and collide faster. Geothermal
energy is the thermal energy in the Earth.
Sound Energy
 is the movement of energy through substances in
longitudinal (compression/rarefaction) waves. Sound is
produced when a force causes an object or substance to
vibrate — the energy is transferred through the substance in
a wave. Typically, the energy in sound is far less than other
forms of energy.
Motion Energy
 is energy stored in the movement of objects. The faster they
move, the more energy is stored. It takes energy to get an
object moving, and energy is released when an object slows
down. Wind is an example of motion energy. A dramatic
example of motion is a car crash, when the car comes to a total
stop and releases all its motion energy at once in an
uncontrolled instant.
Electrical Energy
 is delivered by tiny charged particles called electrons, typically
moving through a wire. Lightning is an example of electrical
energy in nature, so powerful that it is not confined to a wire.