“Typical citizens of advanced
industrialized nations each
consume as much energy in 6
months as typical citizens in less
developed countries consume
during their entire life.”
Maurice Strong
Nonrenewable Energy Resources
Unit 11
FYI: Laws of Thermodynamics
1st Law: energy cannot be created nor
destroyed
2nd Law: high-quality energy is degraded to
low- quality energy
Net Energy
• Net energy: total amount of useful energy
available from a resource minus energy
needed to make it available to consumers
-ratio: energy produced to energy used to
produce it
Net Energy Ratios
• the higher the net energy ratio, the greater the
net energy available
• ratios < 1 indicate a net energy loss
• EROEI: Energy Return On Energy Investment
EROEI= energy from fuel
or
energy invested in fuel
Energy Out
Energy In
Space Heating
Passive solar
Natural gas
Oil
Active solar
Coal gasification
Electric resistance heating (coal-fired plant)
Electric resistance heating (natural-gas-fired plant)
Electric resistance heating (nuclear plant)
5.8
4.9
4.5
1.9
1.5
0.4
0.4
0.3
High-Temperature Industrial Heat
Surface-mined coal
Underground-mined coal
Natural gas
Oil
Coal gasification
Direct solar (highly concentrated by mirrors,
heliostats, or other devices)
Transportation
Natural gas
Gasoline (refined crude oil)
Biofuel (ethyl alcohol)
Coal liquefaction
Oil shale
28.2
25.8
4.9
4.7
1.5
0.9
4.9
4.1
1.9
1.4
1.2
Fig. 16-4, p. 358
Fossil Fuels
Fossil fuels: solid, liquid, gaseous forms of
ancient vegetation, animal matter buried inside
the earth’s crust
• Coal
• Oil/petroleum
• Natural gas
Coal
• Most abundant fossil fuel
• Produces most of world’s electricity
• Formation begins with peat: decomposed plant
debris buried for millions of years
• Stages of coal (from youngest to oldest):
-peat: lowest energy content
-lignite
-sub-bituminous coal
-bituminous coal
-anthracite coal: highest energy content
Increasing heat and carbon content
Increasing moisture content
Peat
(not a coal)
Lignite
(brown coal)
Bituminous
(soft coal)
Anthracite
(hard coal)
Heat
Heat
Heat
Pressure
Pressure
Pressure
Partially decayed
plant matter in
swamps and bogs;
low heat content
Low heat content;
low sulfur content;
limited supplies in
most areas
Extensively used as a
fuel because of its high
heat content and large
supplies; normally has
a high sulfur content
Highly desirable
fuel because of its
high heat content
and low sulfur
content; supplies
are limited in
most areas
Fig. 16-12, p. 368
Coal
• Coal reserves in the United States, Russia, and
China could last hundreds to over a thousand
years.
– the U.S. has 27% of the world’s proven coal
reserves, followed by Russia (17%), and China
(13%).
– in 2005, China and the U.S. accounted for 53% of
the global coal consumption.
Define the Following
Coal
• Coal can be converted into synthetic natural gas
-SNG or syngas- and liquid fuels- methanol or
synthetic gasoline- that burn cleaner than coal.
-conversion costs are high
-adds more CO2 to the troposphere than burning
coal
(U.S. coal-burning plants aren’t likely to invest in
coal gasification due to cost)
Coal Use Trade-Offs
Advantages
Ample supplies (225–900
years)
Disadvantages
Severe land disturbance, air
and water pollution
High net energy yield
High land use
Low cost
(with huge subsidies)
Releases mercury into
environment
Air pollution can be reduced Severe threat to human
with improved technology health
(but adds to cost)
Crude Oil/Petroleum
• Formed from remains of ancient
phytoplankton
• Mixture of liquids, gases, solids
-liquid form: fuel oil, gasoline for heating,
transportation
-gaseous form: propane, butane for heat,
cooking
-solid form: grease, wax, petroleum jelly,
asphalt
Refining Crude Oil
• Oil refinery: separates, purifies crude oil at
layers in a distillation column
• Fractional distillation: different boiling points
separate parts of crude oil
-most volatile components with lowest boiling
points are removed at the top
• Petrochemicals: products of distillation used
in plastics, pesticides, paints, clothing fibers
Gases
Gasoline
Aviation fuel
Heating oil
Diesel
oil
Naptha
Heated
crude oil
Furnace
Grease
and wax
Asphalt
Fig. 16-5, p. 359
Global Oil Supplies
• Global peak production: maximum rate of oil
production (after which prices rise)
-oil is single largest source of energy
-expected to increase by 37% by 2030
• Largest oil producers: Saudi Arabia, Russia, US,
Iran, China, Canada, Mexico
• Largest oil consumers: US (23%), China(8%),
Japan (6%)
Proven Reserves
• OPEC: Organization of Petroleum Exporting
Countries have 78% of world’s oil proven
reserves (and most of the world’s unproven
reserves)
-include Iran, Iraq, Saudi Arabia, Kuwait,
Venezuela, Russia
-rising oil prices threaten global economies
that have not shifted to new energy
alternatives
Hubbert Curve: Projects Peak Oil
Production
Case Study: U.S. Oil Supplies
• U.S. has only 2.9% of the world’s proven oil
reserves
• 60% of U.S oil imports goes through refineries
in hurricane-prone regions of Gulf Coast
• May result in drilling environmentally sensitive
areas
ex. Arctic National Wildlife Refuge(ANWR)
Oil Use Trade Offs
Advantages
Disadvantages
Ample supply for decades Water pollution from
spills, leaks
High net energy yield (but Environmental costs not
decreasing)
included in market price
Low land disruption
Releases CO₂ when
burned
Efficient distribution
system
Vulnerable to
international supply
interruptions
Oil Spills
• 1989 Exxon Valdez, Prince William Sound,
Alaska: 11 million gallons of oil
• 2010 BP Deepwater Horizon, Gulf of Mexico,
11 workers killed: 206 million gallons of oil
Natural Gas
•
•
•
•
•
Formed, found alongside crude oil, coal
90% methane (CH₄), propane, ethane, butane
High net energy yield
Produces less CO₂ than coal, oil
Can be converted to liquified natural gas
(LNG) at high temp. for transport in pipelines
-requires energy to compress, transport gas
Global Gas Supplies
• Russia has ≈25% of gas reserves, followed by
Iran, Qatar
• US has ≈3% of gas reserves, but uses 22% of
global reserves
Gas Trade-Offs
Advantages
Disadvantages
Ample supply
Difficult, costly to transport
long distances
High net energy yield
Low energy yield for LNG
Emits fewer greenhouse
gases than other fossil
fuels
Releases greenhouse gases
Hydraulic Fracturing: “Fracking”
• Extraction of gas by “thumper” trucks
• Fractures host rock with water, sand,
chemicals
• Contaminated water is injected back into
ground
• Evidence links fracking with earthquakes
Oil Shale, Tar Sands
• Oil/tar sands: mixture of clay, sand, oily bitumen
• Oil shale: oily rocks
-potentially large supply, especially in Canada
-easily transported
-low net energy yield (requires natural gas)
-releases greenhouse gases, air pollutants, high
land use (strip-mined), high water use, toxic
sludge
Synfuels
• Liquids, gases produced from coal by
liquefaction, gasification
-large quantity of energy
-produce low net energy yield
Synfuel Trade-Offs
Advantages
Disadvantages
Ample supply
Low to moderate net energy
yield
Can be used as vehicle fuel Requires mining 50% more
coal so increased land
disruption, increased
pollution
Lower air pollution than
coal
Higher CO₂ emissions than
coal
Nonrenewable Energy
Unit 11: Part 2
FYI: Nuclear Fission Review
• Isotope: element with the same atomic #
(protons), but different # of neutrons
ex. U-238 and U-235 (both have 92 protons)
• Fission: process of splitting a large atom into
two smaller atoms of different elements,
releasing neutrons
• Fission reaction: neutron of one atom collides
with and splits another, creating a chain
reaction of energy release.
Nuclear Energy
• Converts nuclear bonds into thermal energy
• Goal: produce electricity
• Task: use nuclear fission to boil water, produce
steam, spin turbine, generate electricity (same
goal as fossil fuels, wind, etc)
• Fuel used: Uranium-235
-mined from ore with U-238
-must be enriched from 1% to 3% U-235
-pelletized (each has the energy equivalent of 1
ton of coal)
Nuclear Reactor
• Site of “controlled” fission reaction
• Most common type: light-water reactors
(LWR)
-produce 85% of global nuclear energy (100%
in US)
-France, Japan are biggest
producers of nuclear
power
Nuclear Reactor (cont’d)
• Fuel rods: packed with U pellets; placed in
reactor core
• Control rods: contain neutron-absorbing
material (graphite) to control amount of heat
from fission reaction; moved between fuel
rods
Nuclear Reactor (cont’d)
• Moderator: slows down neutrons to trigger
chain reactions (near pure water)
• Containment shell: steel-reinforced concrete
shell around the reactor core
• Coolant: usually water, circulates in 3 loops
around core for backup cooling to prevent
meltdown
Small amounts of
radioactive gases
Uranium fuel input
Control rods
(reactor core)
Containment shell
Heat exchanger
Steam
Turbine
Generator
Electric power
Waste heat
Hot
water
output
Coolant
Cool
water
input
Moderator
Shielding
Pressure
vessel
Periodic removal and
storage of radioactive
wastes and spent fuel
assemblies
Coolant passage
Water
Periodic removal
and storage of
radioactive liquid
wastes
Useful energy
25%–30%
Waste heat
Condenser
Water source (river,
lake, ocean)
Fig. 16-16, p. 372
Trade-Offs
Coal vs. Nuclear
Coal
Nuclear
Ample supply
Ample supply of uranium
High net energy yield
Low net energy yield
Very high air pollution
Low air pollution (mostly from
fuel reprocessing)
High CO2 emissions
Low CO2 emissions (mostly from
fuel reprocessing)
High land disruption from surface
mining
Much lower land disruption from
surface mining
High land use
Moderate land use
Low cost (with huge subsidies)
High cost (even with
huge subsidies)
Fig. 16-20, p. 376
Costs of Nuclear Energy
Nuclear power is globe’s slowest-growing
form of energy due to:
• Dependence on huge government subsidies;
multi-billion-dollar construction
• High operation costs
-every 3-4 yrs fuel, fuel rods must be replaced
• Corrosion, embrittlement of equipment
shortens reactor life from 17- 40 yrs
Hazards of Nuclear Energy
No long term safe storage of spent equipment
(wastes must be stored for a min. of 10,000 yrs)
• Currently stored in water-filled pools, dry
casks. Other options:
• deep burial (in 60 years, no country has
figured out how to do this)
• shoot into space
• bury in Antarctic ice sheet
Nuclear Waste Containment
(After spent fuel rods are cooled considerably, they
are sometimes moved to dry-storage containers
made of steel or concrete)
Figure 16-17
Decommissioning of
reactor
Fuel assemblies
Enrichment
of UF6
Conversion of
U3O8 to UF6
Reactor
Fuel fabrication
(conversion of enriched UF6 to
UO2 and fabrication of fuel
assemblies)
Uranium-235 as UF6
Plutonium-239 as PuO2
Spent fuel
reprocessing
Temporary storage of
spent fuel assemblies
underwater or in dry
casks
Low-level radiation with
long half-life
Geologic disposal of
moderate & highlevel radioactive
wastes
Open fuel cycle today
“Closed” end fuel cycle
Fig. 16-18, p. 373
Hazards of Nuclear Energy (cont’d)
• Leaking radioactivity is harmful to life
• Thermal pollution from released coolant
Political Concerns
• Materials could be used for nuclear weapons
• Nuclear accidents could spread radiation
across countries
• Terrorist attacks
• Not profitable
Case Study: Three Mile Island
• 1979: nuclear meltdown in Pennsylvania
nuclear power plant was narrowly avoided
Case Study: The Chernobyl Nuclear
Power Plant Accident
• 1986: world’s worst nuclear power plant accident
occurred in Ukraine.
• The disaster was caused by poor reactor design
and human error.
• By 2005, 56 people had died from radiation
released.
– 4,000 more are expected from thyroid cancer and
leukemia.
Case Study: Yucca Mountain
• 1987: first proposed high-level radioactive
waste repository in world
-100 mi. north of Las Vegas
-$10.4 billion spent on research ($2 billion
spent by power company)
• 2009: site was scrapped due to instability of
rock formations in area
New and Safer Reactors
• Pebble bed modular
reactor (PBMR) are
smaller reactors that
minimize the
chances of runaway
chain reactions.
Figure 16-21
Nuclear Fusion Energy
• Nuclear fusion is a nuclear change in which
two isotopes are forced together.
-No risk of meltdown or radioactive releases
-May also be used to breakdown toxic
material
-Still in laboratory stages.
Exam Focus: Part One
• Definition of “net energy”
• Types of fossil fuels- advantages and
disadvantages of all three
-which releases mercury
• Stages of coal (pay attention to water, sulfur
content)
• Types of natural gas
• How fossil fuels are related to solar energy
• OPEC (countries)