Alternative Energies
Alternative Energies
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Energies that are not
fossil fuels. Most are
renewable.

The following are
renewable:
hydropower, solar,
wind, geothermal,
biomass, hydrogen,
tidal, and wave.

About 10% of today’s
energy in the U.S. is
renewable.
Why did we start to research
alternative energies?
 Research
toward
alternative energies
started in the 70’s due
to the oil embargo and
are continuing today
due to foreign oil
dependency and
environmental
concerns.
Alternative Energy Overview
 Alternative
Energy Video
Hydropower

This uses the mechanical
power of flowing water to
generate electricity.
Power depends on the
amount of water (flow)
and the distance it falls
(head). (diagram pg.
450)
 Accounts for 42 % of
U.S. renewable energies
and is the largest
renewable source for
electricity – 10%.
Why can’t we increase hydroelectric usage?
 Will
not increase in the U.S. because most
suitable sites have been used.
HydropowerImpacts
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Renewable, nonpolluting,
and reliable, BUT….
Costly to build and funds to
build new dams have not
been approved in more than
a decade.
Dams disrupt the
environment and create
different habitats.
Block fish migration (fish lifts)
Dams can fill with sediment
becoming useless if not
maintained.
Hydropower is on the decline
Fish Ladder Video
Natural
The Rundown on Wind

Use of wind to spin turbine to
generate electricity.
 Researches are looking for
ways to store energy and
reduce cost.
 Fastest growing energy
source in the world. (costal
Europe)
 Electricity is almost as cheap
as fossil fuel in areas with
strong winds.
 Most effective on coasts,
mountains, and open plains
 Winds farms now exist in PA,
West Virginia, and New York
 Accounts for only 1% of our
alternative energy.
Wind Impacts

Few environmental impacts (noise, space, damage
to bats and birds)

No air pollution
Poor Bird
Commentary
Wind Energy Issues
Why is wind energy limited?
 Limited
due to varying winds…
Biomass
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The burning of wood,
agricultural wastes,
sewage, algae, and
processed trash. Also
includes fuels made from
organic matter.
Various methods are
used to create fuels that
can be used for heating
or transportation. (could
possibly replace
petroleum)
Corn, Sugar, and grains
can be converted through
fermentation by yeast to
produce ethanol. (can be
blended with gasoline)
Ethanol
 Usually
put more
energy into making
it then you get out
of the product
itself!!!!
 Why
do you think
people still produce
it?
Biomass

Biodiesel is a substitute for
diesel engines and is made
from animal fat or vegetable
oils.

Use is increasing with new
technologies.

Accounts for close to 50% of
alternative energy in this
country. Major source for
Hawaii.
Biodiesel
Bagasse-Hawaii
What are the impacts of Biomass?
 Some
air pollution.
 Processing of
some organic
wastes release
hazardous
chemicals.
 Responsible for
forest destruction
and soil erosion in
rainforests.
(burning of wood)
Geothermal
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Uses the natural heat
(dry heat, steam, or
hot rock) tapped in the
earth to heat homes or
produce electricity.
(diagram pg. 476)
Power plants must be
near the source
because too much
energy is lost during
transportation.
Only Hawaii, Nevada,
Utah, and California
have the potential
Accounts for 6% of our
renewable energy.
What are the effects of Geothermal?

It is limited to certain areas.
 Nothing is burned so there is limited air pollution.
 Harmful gases can sometime be vented with heat
and land surfaces may collapse.
Tidal
 Converts
the
mechanical energy
from ocean tides to
electricity.
 Limited to coastal
regions and
therefore will never
be a major energy
source in this
country. (Canada,
China, and France)
 Cool
Tidal Video
Wave

Waves force water up a large tower pushing the
air up over a turbine to generate electricity.
(Norway)
Hydrogen Fuel
 The
changing of hydrogen gas into a
fuel source (gas or liquid)
 Makes up ¾ the mass of the universe
and is the lightest element.
 Requires H2 (methane) and water
vapor is the only product given off
when burned
 The Department of Energy is looking
into expanding its use (fuel cell
technology)
 It
HFuel
would require new equipment and
engines to burn it (fuel cells)
 Hydrogen fueled cars have been made.
 * Check out this web site:
http://www.youtube.com/watch?v=8rofx6Ga
z40
 http://www.toyota.com/fuelcell/
Impacts
 Pollution
free.
 It is too expensive and difficult to
store.
 It could one day replace gasoline
engines and our dependency on
foreign oil.
 A transition from fossil fuels to
hydrogen fuel will take a lot of time
and money.
is the so-called “chicken and egg”
problem that hydrogen developers are
working hard to solve. Namely: who will
buy hydrogen cars if there are no refueling
stations? And who will pay to build a
refueling station if there are no cars and
customers?
 This