File envsci11_c17_pr

Nonrenewable Energy
Oil of Wilderness on Alaska’s
North Slope?
• Oil has been extracted from parts of Alaska’s North
Slope since 1977.
• The Arctic National Wildlife Refuge (ANWR) contains
oil deposits but oil exploration has been forbidden.
• In 1980, a region called the 1002 Area was
designated for future decision making. Today, a
debate rages as to whether oil drilling should be
Talk About It How might oil exploration in the
1002 Area affect the surrounding people and
Lesson 17.1 Energy: An Overview
The United States has
only 4.5% of the
world’s population but
uses 21.1% of the
world’s energy.
Lesson 17.1 Energy: An Overview
What Is Energy?
• The ability to do work or cause a change
• Kinetic energy: Due to motion
• Potential energy: Due to an object’s position or shape
Lesson 17.1 Energy: An Overview
Forms of Energy I
• Mechanical: Associated with the motion and position
of an object; can be kinetic or potential
• Electrical: Associated with
electric charges; can be kinetic
or potential
• Thermal: Kinetic energy of
atoms and molecules—
the faster atoms and
molecules move in an
object, the warmer it
Overhead transmission lines carry
electrical current.
Lesson 17.1 Energy: An Overview
Forms of Energy II
• Electromagnetic: Kinetic energy that travels as waves
• Chemical: Potential energy stored in molecular bonds
• Nuclear: Potential energy stored by forces that hold
atomic nuclei together
Chemical energy is
stored in food.
Lesson 17.1 Energy: An Overview
Energy Conversion and Efficiency
• Energy cannot be destroyed; it can only be converted, or
changed, from one form to another.
• Energy efficiency is an expression of how much of the
energy put into a system actually does useful work.
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
First Flight
The combustion of gasoline powered the first airplane as it flew over the beach in
Kitty Hawk, North Carolina, on December 17, 1903.
Lesson 17.1 Energy: An Overview
Energy Sources and Uses
• Energy Sources
• Renewable: Nearly always available or
replaceable in a relatively short time;
includes sunlight, wind, flowing water, heat
from Earth
• Nonrenewable: Cannot be replaced in a
reasonable time; includes fossil fuels and
nuclear energy
• Energy Use
• Four uses of energy: Industrial,
transportation, residential, commercial
• Developed nations tend to use more energy
than developing nations.
Wind power is a renewable
energy source.
Lesson 17.2 Fossil Fuels
One quarter of global coal reserves
are found in the United States.
Lesson 17.2 Fossil Fuels
Fossil Fuels
• Include coal, oil, and natural gas
• Formed from the remains of organisms over millions of years
• Different conditions produce different fossil fuels
A front loader
piles coal at a steam
station in Dunkirk,
New York.
Lesson 17.2 Fossil Fuels
• Formed from plant remains subjected to high heat and
pressures over millions of years
• Provides 1/4 of
the world’s energy
• Compared to other
fossil fuels, coal is
cheap, needs little
processing, and is
easy to transport.
Did You Know? Coal is the
most abundant fossil fuel on
How Coal Forms
Lesson 17.2 Fossil Fuels
Coal Mining
Strip mining: Overlying
rock and soil are
removed to access coal
(safer for miners).
Subsurface mining: Underground
shafts are dug to access coal under
Earth’s surface.
Lesson 17.2 Fossil Fuels
• Dark, liquid fossil fuel made up mostly of hydrocarbons
• Formed from the remains of ancient marine organisms
and found in underground deposits
• Used in fuel for
cars, trucks,
planes, ships
• Used in chemical
• Also know as
Lesson 17.2 Fossil Fuels
Drilling and Refining Oil
• After crude oil
is extracted
from the
ground, it is
separated into
different fuels
in a refinery.
QuickTime™ and a
are needed to see this picture.
• Primary extraction:
Oil flows out of the well,
because it is already
under pressure.
QuickTime™ and a
are needed to see this picture.
• Secondary extraction:
Increased pressure or
injections needed to
remove oil
Lesson 17.2 Fossil Fuels
Natural Gas
• Primarily methane gas with small amounts of other gases
mixed in
• Often found above oil or coal
• Much less polluting than
coal or oil and releases
more energy when
• Used for heating,
appliances (stoves, dryers),
and making electricity
Lesson 17.2 Fossil Fuels
Fossil Fuel Supply
• Consumption is still rising, but new fossil fuels do not form
on a human timescale.
• New oil sources—oil sands, oil shale, methane hydrates—
are expensive,
and can be
hazardous to obtain.
• Coal sources are still
relatively abundant,
but not infinite.
Did You Know? Some studies
suggest we have extracted
nearly half Earth’s oil, and that
U.S. coal supplies may last
just 130 years.
Lesson 17.3 Consequences of Fossil Fuel Use
The United States imports two
thirds of its crude oil.
Lesson 17.3 Consequences of Fossil Fuel Use
Pollution, Climate Change, and
Public Health
• Burning fossil fuels releases carbon dioxide, which
contributes to global climate change.
• When coal and oil burn, sulfur dioxide and nitrogen oxides
are released, which contribute to smog and acid deposition.
• Oil spills, equipment ruptures, and oil in runoff pollute
waterways, oceans, and coastal areas.
• Coal-fired power plants release
mercury, which harms human
health. Crude oil contains trace
amounts of lead and arsenic.
Did You Know? Coal-burning power plants
cause 40% of mercury emissions due to
human activity in the United States.
Lesson 17.3 Consequences of Fossil Fuel Use
Gulf of Mexico Oil Well Explosions
• 1979: Ixtoc I exploratory oil well
• 50 m below surface
• Released 126 million gal oil; containment
efforts took 9 months
• What didn’t work: cap, siphoning,
controlled burn, “top kill”
• What did work: relief wells
• 2010: Deepwater Horizon oil well
• 1500 m below surface
• Largest U.S. offshore oil breach as of 2010—
21.2–33.5 million gal oil released during first 6
weeks, based on USGS rough estimates
• Hundreds of miles of coastal habitats threatened
• Methods tried: dome, cap, siphoning, controlled
burns, “top kill,” “junk shot,” and relief wells
Controlled burns attempt to
contain oil pumping into the
Gulf, one month after the
2010 well blow-out.
Lesson 17.3 Consequences of Fossil Fuel Use
Damage Caused by Extracting Fuels
• Mining:
• Humans risk lives and respiratory health.
• Ecosystems are damaged by habitat
destruction, extensive erosion, acid drainage,
and heavy metal contamination downslope
of mines.
• Oil and gas extraction:
• Roads and structures built to support drilling
break up habitats and harm ecosystems.
• The longterm consequences of accidents can
be uncertain or unpredictable
Acid drainage from a coal mine
Lesson 17.3 Consequences of Fossil Fuel Use
Dependence on Foreign Sources
• Fossil fuels are not evenly distributed over the globe, so
some countries must import fuel sources.
• Nations that import fuel may be
vulnerable to changes in fuel prices
set by suppliers.
• Nations can import less fuel by
developing domestic oil sources
and renewable energy sources.
Lesson 17.3 Consequences of Fossil Fuel Use
Energy Conservation
• Practice of reducing energy use to make fossil
fuels last and to prevent environmental
• Transportation: Gas-efficient cars and higher gas
prices could help conserve energy in the U.S.
• Personal choices: Individuals can save energy by
turning off lights, taking public transit, and buying
energy-efficient appliances.
Did You Know? Transportation accounts
for 2/3 of U.S. oil consumption.
Lesson 17.4 Nuclear Power
Scientists estimate that
nuclear power helps us avoid
emitting 600 million metric
tons of carbon each year
Lesson 17.4 Nuclear Power
Nuclear Fission
• Splits an atomic nucleus into two smaller nuclei
• Releases neutrons and large amounts of energy. If enough
unstable nuclei are present, a nuclear chain reaction can
Did You Know? About 20% of electricity
produced in the United States comes
from nuclear power.
Lesson 17.4 Nuclear Power
Generating Electricity Using
Nuclear Energy
Lesson 17.4 Nuclear Power
Benefits and Costs of
Nuclear Power
No air pollution
Expensive to build
and maintain
Requires little
uranium fuel and
little mining
accidents are
Under normal
conditions, nuclear
power plants are
safer for workers
than coal-burning
power plants.
Nuclear waste must
be stored for
thousands of years.
Lesson 17.4 Nuclear Power
Nuclear Waste
• Waste is currently held at power plants as a stopgap, but a
long-term storage location is needed.
• Long-term storage sites must be distant from population
centers, protected from sabotage, have a deep water
table, and be geologically stable.
• Yucca Mountain, Nevada, was
chosen by the U.S. government
in the 1980s, and a storage site
was constructed there. But, as of
2010, the Yucca Mountain project
is no longer under development.
Yucca Mountain storage site
Lesson 17.4 Nuclear Power
Nuclear Fusion
• Joining two atomic nuclei to form one nucleus
• Releases much more energy than fission
• Currently impractical because very high temperatures are
needed, but scientists continue exploring fusion for our
future energy needs