V. Energy
75% of our oil is imported (Canada, Saudi Arabia), majority of US energy is used by industry,
For each nonrenewable resource: know how it’s recovered, problems from recovery, uses, and problems from usage
Source
Coal
Advantages
Inexpensive, Easy to recover (in U.S.,
Russia, and China)
Nuclear
Fuel is inexpensive, Energy generation is the
most concentrated, Waste is more compact
than any source, Extensive scientific basis
for the cycle, Easy to transport as new fuel,
No greenhouse or acid rain effects
Good distribution system for current use
levels, Easy to obtain (sometimes), Better as
space heating energy source
Gas /
Oil
Fusion
Hydrogen and tritium could be used as fuel
source, Higher energy output per unit mass
than fission, Lower radiation levels assoc.
with process than fission-based reactors
Disadvantages
Requires expensive air pollution controls (e.g. mercury, sulfur
dioxide), Significant contributor to acid rain and global
warming, Requires extensive transportation system
Requires larger capital cost because of emergency,
containment, radioactive waste and storage system, Requires
resolution of the long-term high level waste storage issue in
most countries, Potential nuclear proliferation issue
Very limited availability as shown by shortages during winters
several years ago, Major contributor to global warming, Very
expensive for energy generation, Large price swings with
supply and demand, Liquefied Natural Gas storage facilities
and gas transmission systems have met opposition from
environmentalists.
Breakeven point has not been reached after ~40 years of
expensive research and commercially available plants not
expected for at least 35 years.
Energy Units to MEMORIZE (sorry, but its on the AP exam every year!)
1joule (J)= the force exerted by a current of 1 amp per second flowing through a resistance of 1 ohm
1 watt (W) = 1 joule per sec (J/sec)
1 kilowatt-hour (kWh) = 1,000 (or 103) watts exerted over 1 hour
1 megawatt (MW) = 1 million (or 106) watts
1 gigawatt (GW) = 1 billion (or 109) watts
1 petajoule (PJ) = 1 quadrillion joules = 947 billion BTU’s (British Thermal Units = 0.278 billion kWh
1 BTU = energy to heat 1 lb of water 1 oF
1 standard barrel of oil (bbl) = 42 gallons = 5.8 million BTU’s
1 metric ton of standard coal = 27.8 million BTU’s = 4.8 bbl oil
Coal: fossilized remains of ancient plant material, nonrenewable resources, peatsedimentary rock coals (lignite,
bituminous coal), anthracite (least sulfur, 95% C, metamorphic, and greatest heat capacity); greatest reserves in US,
Russia, Canada. Coal mining: surface mining (lignite): strip mines or mountaintop removal, area removed is called
overburden, SMCRA requires that the mined lands are restored by replacing the overburden and replanting the area;
subsurface mining (bituminous and anthracite): dangerous occupation (asphyxiation from toxic gases, methane
explosions, cave-ins, black lung disease, now wear masks, and use exhaust fans), some coal mines catch on fire and
smolder for years, may strike groundwater and contaminate it with heavy metals; mining creates scars on the earth’s
surface, its ugly, disturbs habitat, increases erosion, contaminates groundwater, subsurface mining creates lots of solid
waste (tailings); coal combustion: more CO2 than any other fuel, also NOx and SO2 (acid deposition), releases more
radiation than any nuclear plant, particulates in flyash contain heavy metals (arsenic, lead, cadmium, mercury, zinc),
responsible for 25% of mercury released in US, thermal pollution of water; SO2 removed in: precombustion by using
anthracite, washing coal, coal gasification or liquefaction, combustion by fluidized bed combustion, postcombustion by
using catalytic converters, lime scrubber, wet scrubber; particulates are usually removed postcombustion by bag filters,
electrostatic precipitators, cyclone collectors. Oil: formed from ancient organisms under heat and pressure, usually
found with natural gas, primary recovery, secondary recovery (injecting water to force oil up), can remove 15-40% of a
well’s reserve, tertiary can remove another 5-15% (injecting steam or carbon dioxide into the well); Arctic National
Wildlife Refuge (ANWR): contains a reserve of oil, calving ground of caribou, summering site for snow geese, swans,
and migratory waterfowl, polar bears, arctic foxes and wolves, people in Alaska favor drilling because they work for oil
or receive royalties, oil tankers and pipelines leak, 1991 Iraqi army purposely dumped a huge volume of oil into the
Persian Gulf, erosion and habitat destruction; petrochemicals make plastics, paraffin wax, mineral oil, petroleum jelly,
dyes, pesticides, and industrial solvents; combustion releases CO2 and NOx. Natural gas: cleanest burning fossil fuel
and highest net energy, 90% of natural gas is methane and found close to surface, US has abundant reserves, liquefied
natural gas (LNG) used in rural areas, methane pumped into urban homes, can be found frozen in ice (methane hydrate):
if ice caps melt global warming will be amplified, withdrawal of natural gas from water is causing wells to dry up.
Nuclear power: US has never had an accident where a significant amount of radiation was released, public concern, and
rising construction costs, no new nuclear plants since 1975, twice as expensive as coal, produce 20% of US electricity,
uranium is a nonrenewable resource, it is mined, mine tailings are radioactive, miners are susceptible to lung cancers
from radon gas, U-235 is desired isotope, 0.71% but must be enriched to 3%, fuel is formed into 1 inch pellets =1 ton
coal = 4 barrels of oil, 1999 Tokaimura, Japan accident resulted in 2 deaths, Nuclear fission: splitting of an atom to
release energy and particles, when fuel rods are spent, they are replaced, 1/3 replaced at a time, control rods are inserted
in between the fuel rods to slow down a reaction or removed to increase the rate of fission, Light Water Reactors: 70% in
US are pressurized water reactors (PWR), 30% boiling water reactors (BWR), cause thermal pollution of water, built on
geologically stable sites, have redundant safety measures to prevent accidents, air above is a no-fly zone, reinforced
concrete to withstand an attack, other reactor designs: Canadium deuterium (CANDU) reactors,; graphite can be used as
a moderator but can catch fire if the cooling system fails, like at Chernobyl; Breeder reactors create fuel rather than
consume it, but not many due to safety concerns: coolant is unstable, and plutonium created is weapon grade; if there is a
loss of coolant the fuel will overheat causing a meltdown, releasing radioactive material, 1979 Three Mile Island,
Pennsylvania a partial meltdown occurred (no disease or death occurred), 1986 Chernobyl, USSR (now Ukraine)
meltdown (30 died, 135,000 had to be evacuated, thyroid cancer has increased dramatically), Radioactive wastes: used
to be dumped in the ocean (pre 1970s), low level radioactive waste disposal sites (3 in US), high level radioactive wastes
are temporarily stored on site in deep pools of water (have been there for over 40 years), Nuclear Waste Policy Act
(1982): federal government is responsible for developing a permanent site for high level radioactive wastes, Yucca
Mountain (Nevada) was supposed to open years ago, now predicted to open in 2010. Its located on an active fault,
transport of wastes to Yucca Mtn is worrisome
a. coal b. oil c. natural gas d. nuclear power e. methane hydrate
1. recovery of resource is not feasible with current technology and prices
2. combustion releases large amounts of mercury into the atmosphere
3. the most clean burning of the fossil fuels
4. must be distilled prior to use of the resource
5. Which of the following energy conversions is correct?
a. 1 BTU = energy required to heat 1 lb of water 1F b. 1 megawatt = 1,000 watts c. 1 watt = 1 joule per second
d. 1 newton = force needed to accelerate a 1 lb mass 1 ft per second e. 1 kilowatt hour = number of megawatts used in
an hour
6. The greatest proportion of US electricity is provided by
a. coal powered plants b. nuclear power plants c. oil burning power plants d. refuse derived power plant e.
hydroelectric power
7. Which of the following nations has the greatest supply of natural gas?
a. United States b. Canada c. Saudi Arabia d. Russia e. China
8. Which of the following is associated with mining uranium?
a. mesothelioma b. pneumoconiosis c. lung cancer d. radiation sickness e. gastrointestinal disease
9. Which of the following is not released by coal combustion?
a. sulfur dioxide b. carbon dioxide c. ozone d. mercury e. particulates
10. Coal mining has all of the following environmental effects except
a. increased erosion due to topsoil removal b. subsidence due to collapse of subsurface mines c. acid mine
drainage in abandoned mines d. transport of coal results in damage to aquatic systems if tanker is damaged e.
increased habitat disruption due to deforestation
11. Which of the following structures in a pressurized water nuclear power plant is correctly paired with its function?
a. primary water circuit cools the fission reaction b. secondary water circit is heated and spins the turbine to
generate electricity c. water in the cooling tower is used to cool the primary water circuit d. moderator absorbs
neutrons to stop the fission reaction e. containment vessel encompasses the electrical generator to prevent explosions
12. Which of the following is not an argument against drilling in the Arctic National Wildlife Refuge?
a. growing season is very short making it difficult for the ecosystem to recover b. permafrost makes soil formation
very difficult, resulting in a long succession time c. area is calving ground for caribou d. high levels of biodiversity
will allow the ecosystem to recover quickly e. cold temperatures decrease the rate of nutrient cycling
13. A typical oil well can extract what percentage of the oil in the reserve by using primary recovery and secondary
recovery?
a. 10 b. 30 c. 50 d. 80 e. 100
14. All of the following methods will reduce NOx emissions from gasoline combustion except
a. catalytic converters in automobiles b. controlling the combustion temperatures c. switch fuel to ethanol or
ethanol mixed fuel d. switch to hybrid vehicle e. decreasing the release of ozone from auto emissions
15. The fissionable component of nuclear fuel in a conventional nuclear power plant is
a. Uranium-238 b. Uranium-235 c. Uranium-234 d. Plutonium-239 e. Radon-222
Source
Hydroelectric
Advantages
Very inexpensive once dam is built,
Government has invested heavily in building
dams, particularly in the Western U.S.
Wind
Wind is free. US has many potential areas.
Generation and maintenance costs have
decreased alot. Reasonable cost renewable
source. Well suited to rural areas. Ex: areas
of Oregon and Washington, western
Minnesota, Atlantic Ocean off Cape Cod.
Sunlight is free when available, Costs are
dropping.
Solar
Biomass
Refuse
Based Fuel
Hydrogen
Industry in its infancy, Could create jobs
because smaller plants would be used, no
net CO2
Fuel can have low cost, Could create jobs
because smaller plants would be used, Low
sulfur dioxide emissions
Combines easily with oxygen to produce
water and energy
Disadvantages
Very limited source since depends on water elevation,
Many dams currently exist (not much of a future source
[depends on country]), Dam collapse usually leads to loss
of life, Dams have affected fish (e.g. salmon runs),
Environmental damage for areas flooded (backed up) and
downstream
Need 3x the amount of installed generation to meet
demand, Limited to windy areas. Limited to small generator
size; need many towers. Highly climate dependent - wind
can damage equipment during windstorms or not turn
during still summer days. May affect endangered birds,
however tower design can reduce impact.
Limited to southern areas of U.S. and other sunny areas
throughout the world (demand can be highest when least
available, e.g. winter solar heating), Does require special
materials for mirrors/panels that can affect environment,
Current technology requires large amounts of land for small
amounts of energy generation
Inefficient if small plants are used, Could be significant
contributor to global warming because fuel has low heat
content
Inefficient if small plants are used, Could be significant
contributor to global warming because fuel has low heat
content, Flyash can contain metals as cadmium and lead,
dioxins and furans in air and ash releases
Very costly to produce, Takes more energy to produce
hydrogen then energy that could be recovered.
a. geothermal energy b. passive solar power c. active solar power d. hydroelectric power e. biomass power
1. uses the natural decay of radioactive isotopes in the earth’s crust to heat water to spin turbines
2. exemplified by photovoltaic cells
3. examples include dung, peat, and ethanol
4. has the greatest net energy of all of the alternative energy resources
5. If your laptop computer uses 50 watts per hour and you use it for 3 hours per day, how much will the electricity cost to
run the computer for one year if your utility charges $0.08 per kilowatt (kWh) hour?
a. $10.46 b. $8.52 c. $5.00 d. $4.38 e. $2.98
6. Which of the following are environmental costs associated with the generation of geothermal power?
I. land subsidence II. groundwater depletion III. carbon dioxide emissions
a. I only b. II only c. I and II d. I and III e. I, II, and III
7. Which of the following is a passive solar design?
a. increased insuation to keep warm air in a home in the winter b. using reflective roofing to decrease cooling costs
in the summer c. using photovoltaic cells to generate electricity d. installing energy efficient windows to keep hot
air out in the summer, decreasing air conditioning costs e. planting a tree line of conifers to block wind from reaching
a house in northern climes, decreasing winter heating costs
8. Which of the following would occur downstream from a hydroelectric dams?
I. increased temperature II. decreased dissolved oxygen III. increased sediment downstream
a. I only b. II only c. III only d. I and II e. I, II, and III
9. All of the following are biomass sources of energy except
a. methanol b. wood c. crop residues d. lignite e. charcoal
10. Which of the following are associated with commercial active solar power generation?
I. little land use and habitat disruption II. mining silicates for PV cells causes erosion
III. thermal pollution from cooling power plants
a. I only b. II only c. III only d. I and II e. I, II, and III
11. Which of the following has the greatest net energy for heating homes?
a. coal b. nuclear c. hydroelectric d. biomass e. natural gas
12. Which of the following are problems associated with wind power?
I. bird deaths II. aesthetic pollution III. noise pollution
a. I only b. II only c. III only d. I and II e. I, II, and III