• LEARNING OBJECTIVE:
• Relate how hydroelectric power, geothermal
energy, and tidal power contribute to our energy
resources.
• Evaluate wind power’s potential for providing
energy in the future.
• Explain how nuclear power plants use nuclear
fission to produce energy.
UNIT 4 ENERGY AND EARTH’S
RESOURCES: Alternative Sources of
Energy
• Automotive & Truck (Transportation)
– Electrical battery
– Hydrogen
– Solar & battery
– Alternative sources of gasoline-type fuels
(ethanol based)
– Alternative sources of diesel-type fuels (algae,
etc.)
Transportation Energy Alternatives
Automobiles I – Non-petroleum fuel
• Advantages of alternative energy
vehicles:
– Represents existing technology
– 71% of petroleum used in U.S. is utilized for
gasoline, diesel & jet fuel.
– Some alternative energy vehicles maybe
carbon neutral, and thus not produce CO2 as a
waste
• Disadvantages:
– Currently all non-combustion vehicles are more
expensive than their combustion counter-parts
– There are infrastructure modifications
necessary to have many types of these cars
usable nation-wide
– Two of the alternatives; hydrogen & battery
vehicles have a number of technological issues
to have them be cost-effective
Battery powered cars themselves have zero
emissions
However the source of the electricity can still be a
problem regarding CO2 emissions and the global
climate.
Chrysler Envi
Utilizing nickel-hydride & lithium ion batteries has
lightened weight of vehicle batteries, however batteryonly cars probably still need to use heavier lead-acid
batteries.
Between battery powered
cars & combustion are
hybrid vehicles
Nissan’s Leaf
Battery production does
involve energy & other
environmental impacts
(including mining and
disposal issues)
Hydrogen vehicles by definition emit only water
vapor.
Costs for hydrogen vehicles has remained relatively
high, though technological innovation should bring
this cost down.
Honda FCX
Current filling station infrastructure under
consideration involves using natural gas as hydrogen
source, rather than dissociation of water.
GM Sequel
• There are a number of alternative fuel
sources that are available as a alternative to
petroleum fuels (or other fossil fuels;
natural gas, etc.)
• These alternatives include following fuel
sources
– Corn, sugar cane or sugar beets to ethanol
– Cellulosic fuel sources to ethanol (switch grass,
willow, etc.)
– Algae and other lipid sources for diesel
• Not all of these sources are necessarily
carbon neutral in terms of CO2 in
atmosphere
• Usage may increase cost of food worldwide
• Any increase in the amount of CO2 to
atmosphere is due to fossil fuel in
producing fertilizer or to plant & harvest
the crop
Alternative Sources of Energy
• Heating (homes & buildings)
–Passive heating
–Geothermal
Heating Energy Alternatives
Passive Heating
Utilization of solar
radiation to heat water,
and heat or cool indoor
space.
For domestic water
heating this process is
best suited for regions
south of Pennsylvania.
Heating Energy Alternatives
Homes/Buildings I
Thermal (passive) heating for buildings involves
utilizing construction materials that store solar
radiation, and thereby absorbing solar radiation
during the day and
radiating that heat during
night.
Involves increased
construction costs that are
off-set by lowering heating
& cooling costs.
• Learning objectives: How do hydroelectric power,
geothermal energy, and tidal power contribute to
our energy resources.
Geothermal Energy Alternatives
• Geothermal energy utilizes higher
temperatures within Earth to heat water to
either heat buildings or generate electricity.
• Advantages of geothermal energy:
– Represents an existing technology
– Does not generate any CO2 as a waste
– They are relatively cheap to operate (<½ coal)
Geothermal Energy Alternatives
• Advantages of geothermal energy:
– Represents an existing technology
– Does not generate any CO2 as a waste
– They are relatively cheap to operate (<½ coal)
• Disadvantages:
– For large scale electricity generation it is
restricted to areas that are volcanically active
– Geothermal facilities are relatively expensive to
build
– Geothermal energy facilities are relatively large
and with their piping systems they can cover
an even larger area
Geothermal Energy I
Large-scale
geothermal plants
have large ‘footprints’, and are
located in regions
that are volcanically
active.
Countries with large-scale geothermal operations
include; Iceland, New Zealand, Costa Rica, Kenya,
El Salvador, & The Philippines. The largest group of
plants are located in California (The Geysers).
Geothermal Energy II
Home heating applications utilize
at heat exchanger that allows an
exchange of warm or cold water
(depending on the season) to
preheat or cool water for home
heating and air conditioning.
This type of system is very cost efficient to run
However installation costs (including drilling of closedloop system in the ground) generally runs in the
$20,000 to $30,000 range.
Alternative Sources of Energy
• Electrical Energy
– Hydroelectric (dams, turbines, tidal,
ocean currents, etc.)
– Stored Energy
– Nuclear Energy
– Wind Energy
– Solar (multiple sources)
– Biomass/Algae
Electrical Energy Alternatives
Hydroelectric I - Dams
• Advantages of Dams
– Existing form of energy production (2.4 % in the U.S.)
– Have a very low relative cost to operate (<½ coal)
– Do not produce hazardous by-products (waste or air
pollution)
– Once built can have a very long life decades or longer
– Reservoir can be used for recreation purposes &
irrigation
– Stored water is a constant energy source
Electrical Energy Alternatives
Hydroelectric I - Dams
• Disadvantages of Dams
– Expensive to build, especially if they are to last
(sediment issue)
– Impact large area upstream (reservoir – people &
wildlife)
– Jurisdiction issues on rivers between adjoining
states/nations
– Rise of local water table is possible
– Interruption of sediment flow on rivers
– Impact on flushing of water pollution
Three-Rivers Gorge Dam, China
Sediment build-up behind this
dam is of special concern
But it will produce electricity
for 100 million people
Three-Rivers Gorge Dam
Environmental Impact
Baiji, Yangtze
River Dolphin
Siberian
Crane
Electrical Energy Alternatives
Hydroelectric II - Dams
• Of the 80,000 dams in the U.S. only ~3% are used
to generate electricity.
• Though expensive to build, dams that generate
electricity are relatively inexpensive to operate –
therefore the U.S. is missing a large opportunity
to use an already expensively built resource.
Electrical Energy Alternatives
Stored Energy I – Pumped Stored Hydroelectricity
Due to energy losses in the turbines and during pumping
this system is a net energy consumer, but if run correctly
will run at a net profit.
Electrical Energy Alternatives
Hydroelectric II - Tidal
• Usually involves creation of ‘tidal-dams’ or
free standing turbines in estuaries to
capture flow and drive turbines
• Advantages
– Do not produce hazardous by-products (waste
or air pollution)
– Located in areas that are otherwise not being
utilized
Electrical Energy Alternatives
Hydroelectric II - Tidal
• Disadvantages
– Relatively costly to build & cost to operate is
variable
– Would be limited to coastal regions, and only
those with relatively large tidal fluctuations
– Has intermittent energy production (though
this is completely predictable)
– Can impact organisms that live in these areas
(especially those associated with estuaries –
which generally have larger tidal effects)
Examples of Tidal Energy
Production
Tidal energy dam in La Rance, France; 240 MW
Electrical Energy Alternatives
Hydroelectric III – Ocean Currents
• A potentially very
important source of
electrical energy
• Currently it is only
speculative in nature
Electrical Energy Alternatives
Nuclear Energy I
• Existing form of electricity production,
producing >8% of electricity for U.S.
• Advantages:
– Existing form of energy production
– Does not produce CO2, and therefore does not
increase our impact on Global Warming
Electrical Energy Alternatives
Nuclear Energy I
• Disadvantages:
– Extremely expensive (in many aspects)
– Produces extremely toxic wastes that need to
be secured for (very) long periods of time
– Requires very sophisticated and complex
operations
– Accidents at these types of facilities can result
in widespread contamination by radioactive
materials
Nuclear Energy III
Some other industrial countries depend heavily on
nuclear power for their electrical generation.
Japan generates 34.5% of
their electricity from
nuclear power.
Kashiwazaki, Japan
World’s largest nuclear plant
Nuclear Energy III
France generates 78.8%
of their electricity
from nuclear power.
Paluel, France
• Public confidence has also been shattered by the explosion at Chernobyl in
1986, worlds worst nuclear accident.
• A 19 mile “zone of alienation” has been formed around the reactor.
• In 1979 an accident at Three Mile Island occurred in Pennsylvania.
• This accident allowed radioactive steam to escape and resulted in the
partial core meltdown.
• On march 11, 2011 the worlds second worst nuclear disaster occurred in
Fukushima, Japan after the 9.0 earthquake and associated tsunami.
• There was a meltdown in three units and radioactive steam was released.
• Highly radioactive water spilled into the ocean.
• There have been a total of 98 accidents worldwide.
Electrical Energy Alternatives
Wind Generation I
• Existing form of electricity production,
producing <1% of electricity for U.S.
• Advantages:
– Existing form of energy production
– Does not produce CO2
– Though tall, wind turbines do not cover a large
area
– Turbines come in a range of sizes and can be
used for a number of applications both on &
off the grid
Electrical Energy Alternatives
Wind Generation I
• Disadvantages:
– Has intermittent energy production (based on
the consistency of the wind)
– The public may consider wind turbines to be
unsightly
– Can be a hazard to bird (& migrating bird) and
bat populations
Electrical Energy Alternatives
Wind Generation II
Relative costs for wind
generation are a fifth of
what they were in the
1980’s; and based on
relatively conservative
estimates are only 5%
more then electricity
from coal-fire power
plants.
Electrical Energy Alternatives
Wind Generation IV – Wind Strength
Locations of consistent
wind generation in
U.S.
Note locations in
upstate New York; the
Adirondacks, southern
tier, and great lakes.
To distribute this
power to market would
especially require an
integrated power grid.
Electrical Energy Alternatives
Wind Generation V – Power Grid
To distribute
electrical energy
effectively from
wind source areas
to high-use regions
(urban areas)
requires a more
integrated nationwide power grid
system
This is also a factor for other alternative energy sources
like: nuclear power plants and large scale solar farms.
NPR Story on Power Grid & Alt. Energy
Electrical Energy Alternatives
Power Grid Considerations II
The perception is that high
voltage power lines are
unhealthy. However several
studies conducted in the 1990’s
on the effects of electromagnetic
fields (associated with power
lines) concluded “that there was
no evidence that showed exposure to EMF from power lines
presented a human health hazard.” Two of these studies were
conducted with under the supervision of the National Academy
of Science and by the National Cancer Institute.