Energy Sources
Gateway – Energy and the Environment
© 2011 Project Lead The Way, Inc.
Energy Source Classifications
Renewable
Non-Renewable
A resource that can be
replaced.
A resource that cannot be
replaced.
Inexhaustible
Exhaustible
A resource that will never
run out.
A resource that cannot be
replaced.
Exhaustible
Any source of energy that is limited and
cannot be replaced when it is used, such
as oil, coal, and natural gas.
Exhaustible Energy Sources
• Limited availability
• Cannot be replaced
• Currently provides 85% of
energy consumed in US
Examples
• Fossil fuels - fuels
produced by deposits of
ancient plants and
animals (Oil, coal and
natural gas)
Exhaustible Energy Sources
• It is possible that
readily available oil will
be used up by 2050
• Foreign countries
provide most US oil
• Oil can be used as an
energy source and to
make plastics
Exhaustible Energy Sources
Effect on the Environment
Burning fossil fuel produces air
pollution
– Acid rain is rain contaminated by the
by-products of combustion which
condense in our atmosphere. Acid rain
kills plants and trees and pollutes
ponds and lakes, killing fish and
altering the ecosystem.
– Air pollution can cause lung cancer in
humans.
Exhaustible Energy Sources
Effect on the Environment
• Greenhouse effect – Greenhouse
gases surround our planet, which
prevents heat produced by the sun
from escaping the earth’s
atmosphere as easily as it once did.
• The greenhouse effect leads to
climate change, which could cause
melting of ice caps and changing
weather patterns.
Renewable
A resource that can be replaced when
needed.
©iStockphoto.com
©iStockphoto.com
Renewable Energy Sources
• Energy that can be
replaced
• Biological materials
that can be grown
and harvested
• Less pollution than
exhaustible energy
sources
• Currently provides
3.5% of energy
consumed in US
Renewable Energy Sources
• Ethanol – Plants such as corn, soybeans,
seaweed, sugar beets, and sugar cane
can be used to make ethanol.
• Methanol is made from coal or renewable
sources like wood, plants, and manure.
• Methanol and Ethanol can be used as a
substitute for gasoline.
Renewable Energy Sources
• Biomass – Waste products like trees,
plants, grains, algae, manure, garbage,
sewage, and paper can be converted into
energy.
• Biomass conversion creates
petroleum substitutes and
methane gas.
Renewable Energy Sources
Effect on the Environment
• Substituting biomass for fossil fuels
reduces emissions of greenhouse gases.
• Combustion of biomass produces air
emissions. The amount of emissions
varies widely depending upon the
technology being used.
Inexhaustible
An energy source that will never run out.
Inexhaustible Energy Sources
• Any energy source
that cannot be used
up
• Currently provides
3.5% of energy
consumed in US
Inexhaustible - Solar Energy
• Solar energy can be
captured to provide
heating or electrical
power
• Solar energy is used
in homes, cars,
satellites, and in the
international space
station.
Inexhaustible –
Hydroelectric Energy
• Force of falling water
turns giant turbines to
create electricity
• Hydroelectric power
plants are located
inside dams
Inexhaustible –
Geothermal Energy
• Energy stored in the
earth in the form of
heat
• Geothermal energy
turns water into steam
which escapes
through cracks in the
Earth
• Forms geysers and
hot springs
Inexhaustible - Wind Energy
• Wind powers large
turbine generators
that generate
electricity
• Wind farms
contain several
large wind turbines
in a location with
strong and
frequent wind
Inexhaustible Energy Sources
Effect on the Environment
• Minimal pollution
or hazardous
waste produced
• Readily available,
without mining or
drilling
So Why Don’t We Use More
Renewable and Inexhaustible
Energy?
• Renewable energy tends to be
remote from where the electricity is
needed, thus transmission is needed.
• Renewable energy does have
environmental impacts associated
with land use.
• Many renewable resources are
intermittent and are not always
available when the electricity is
needed (example: No sunlight at night
for lighting homes and businesses).
Image Resources
Microsoft, Inc. (2008). Clip Art. Retrieved September 10, 2008, from
http://office.microsoft.com/en-us/clipart/default.aspx