Chapter 15 Flashcards
1
Q
Renewable Energy Sources
A
biomass energy, hydropower, solar, wind, geothermal, tidal and wave energy
2
Q
Nonrenewable Energy Sources
A
crude oil, natural gas, coal, nuclear energy
3
Q
U.S. Energy Flow
A
oil, coal and natural gas supply 82% of energy demand and two-thirds of global electricity; industrialized nations apportion roughly one-third to transportation, one-third to industry and one-third to all other uses
4
Q
Reliance on fossil fuels: coal, oil and natural gas
A
annual global consumption of fossil fuels has risen greatly over the past half-century; oil remains our leading energy source; fossil fuel dominate the global energy supply
5
Q
Distribution of fossil fuels
A
Table 15.2
6
Q
Net energy
A
expresses the difference between energy returned and energy invested
7
Q
Energy return on investment (EROI)
A
EROI=energy returned/ energy invested; higher EROI ratios mean that we receive more energy from each unit of energy that we invest; fossil fuels are widely used because their EROI ratios have been historically high
8
Q
Coal formation
A
Fossil fuels begin to form when organisms die and end up in oxygen-poor conditions; coal results when plant matter is compacted so tightly that there is little decomposition; water is squeezed out of the material as pressure and heat increase over time (Fig 15.6)
9
Q
Coal Quality
A
.
10
Q
Strip mining
A
heavy machinery scrapes away huge amounts of earth
11
Q
Subsurface mining
A
for deposits deep underground this is used by digging vertical shafts and blasting out networks of horizontal tunnels to follow seams or layers of coal
12
Q
Mountaintop removal
A
entire mountain peaks are leveled and fill is dumped into adjacent valleys; happens in West Virginia in the Appalachian Mountains
13
Q
Coal Production and Consumption
A
% world production; China is the largest then the U.S.
14
Q
Primary Uses of Coal
A
electricity; cook food, heat homes and fire pottery; coal-fired steam engines during the industrial revolution powered factories, trains and ships; coal fueled furnaces
15
Q
Pros of Using Coal
A
- abundance
- continuous, reliable source of power
- low capital investment
- low cost
16
Q
Cons of Using Coal
A
- greenhouse gas emissions and emissions of harmful substances
- coal mining deaths
- devastation of Earth and scenery around coal mines
- displacement of humans due to mining destruction
17
Q
Natural Gas Formation Biogenic
A
created at shallow depths by the anaerobic decomposition of organic matter by bacteria; one source is the decay process in landfills
18
Q
Natural Gas Formation Thermogenic
A
results from compression and heat deep underground; it may form directly or from coal or oil altered by heating; most gas extracted commercially is thermogenic and is found above deposits or oil or seams of coal
19
Q
Traditional well
A
.
20
Q
Hydraulic fracking
A
AKA hydrofracking or fracking; involves drilling deep into the earth and then angling the drill horizontally once it meets a shale formation; an electric charge sets off targeted explosions that perforate the drilling pipe and create fractures in the shale; drillers then pump a slurry of water, sand and chemicals down the pipe under great pressure
21
Q
Landfill Capture
A
.
22
Q
Natural Gas Production and Consumption
A
U.S. and Russia are the leading producing and consuming countries
23
Q
Primary Uses of Natural Gas
A
industrial, commercial, residential and electricity generation
24
Q
Pros of Natural Gas
A
- produces less soot
- abundant supply
- infrastructure in place
- cheaper
- easier to transport
25
Cons of Natural Gas
- highly flammable
- greenhouse gas emissions
- nonrenewable and non-sustainable
- not easy to use
- expensive pipelines
26
Formation of Oil
formed from organic material (esp dead plankton) that drifted down through coastal marine waters millions of years ago and was buried in sediments on the ocean floor
27
Primary Drilling
The process of drilling holes in a solid rock ledge in preparation for a blast by means of which the rock is thrown down
28
Secondary Drilling
The process of drilling the so-called 'popholes' for the purpose of breaking the larger masses of rock thrown down by the primary blast.
29
Directional Drilling
the practice of controlling the direction and deviation of a wellbore to a predetermined underground target or location.
30
Oil Sands
AKA tar sands; consist of moist sand and clay containing 1-20% bitumen, a thick and heavy form of petroleum; oil sands represent crude oil deposits degraded and chemically altered by water erosion and bacterial decomposition
31
Oil Shale
a liquid form of petroleum produced by a sedimentary rock filled with organic matter that can be processed; formed by the same processes that form crude oil but occurs when organic matter was not buried deeply enough or subjected to enough heat and pressure to form oil
32
Oil Production and Consumption
Leading producers are Saudi Arabia and Russia and the leading consumers are U.S. and China
33
Refining
produces a range of petroleum products; at oil refineries crude oil is boiled
34
Primary Uses
vehicles, including gasoline for cars, diesel for trucks and jet fuel for airplanes; fewer homes use oil for heating these days but industry and manufacturing continue to use it a lot
35
Peak Oil
describes a peak in production; U.S. oil production peaked in 1970
36
Pros of Using Oil
- abundant
- easy to use
- creates jobs
- no new technology required
- moves vehicles faster and longer than any other energy source
- easy to transport in liquid form
37
Cons of Using Oil
- emits CO2
- nonrenewable
- drilling can lead to spilling
- endangers/destroys the environment
- expensive
- dangerous
- U.S. consumption is a lot
38
Methane Hydrate
an ice-like solid consisting of molecules of methane embedded in a crystal lattice of water molecules
39
Methane Hydrate formation
occurs in sediments in the Arctic and on the seafloor because it is stable at temps and pressure conditions found there
40
Methane Hydrate Extraction
Japan extracting it by sending down a pipe and lowering pressure within it so that the methane turned to gas and rose to the surface; do not know whether extraction is safe and reliable
41
Methane Hydrate Primary Uses
see natural gas
42
Pros of Methane Hydrate
- combustion reaction is much cleaner
- has about 80% the heat content of crude oil
- reserves widely across the globe
43
Cons of Methane Hydrate
- can destabilize the hydrates and release gas into the atmosphere
- technology to extract is new and underdeveloped
- destabilization of ocean floor- land slides
- climate changes
44
Mountaintop mining risks and benefits
unleashes soil erosion and destroys large areas of habitat; sends chemical runoff into waterways in the form of acid drainage (sulfuric acid); destroys hillsides and scenery; economically efficient due to massive coal removal
45
Offshore drilling risks and benefits
holds tons of oil; boosting oil and gas production; risks of oil spills b/c of broken pipes and explosions; affects fish and other aquatic organisms; pollution
46
Secondary oil extraction risks and benefits
more expensive
47
Directional drilling risks and benefits
lessens impacts b/c fewer drill pads are needed and the surface footprint of drilling is smaller
48
Arctic Ocean drilling risks and benefits
pollution risks; conditions challenging for drilling and accidents likely; spills; new shipping lanes are opening due to ice melting
49
Oil sands risks and benefits
could supply citizens for centuries; major fuel source; profitable; difficult and expensive to extract and process; consumes large volumes of water, devastates landscapes and pollutes waterways
50
Hydraulic fracturing risks and benefits
ignited a boom in extraction in the U.S.; power plants switch from coal to gas and CO2 emissions have fallen in the U.S.; pollutes communities near fracking; puts humans health in danger; pollutes drinking water and env
51
External costs
emissions from fossil fuel combustion; carbon dioxide mostly; gasoline combustion releases cancer-causing pollutants such as benzene and toluene; working in drilling operations exposure to sulfide, lead and arsenic
52
Clean coal technologies
techniques, equipment and approaches that aim to remove chemical contaminants during the generation of electricity from coal at power plants; ie. scrubbers are devices that chemically convert or physically remove pollutants ; another approach is dry coal that has high water content making it burn cleaner
53
Carbon capture and carbon sequestration
capturing CO2, converting the gas to a liquid and then storing it in the ocean or underground in a geologically stable rock formation
54
Imbalance between production and consumption
Japan, Germany and the U.S. are among nations that consume more oil than they produce
55
Organization of Petroleum Exporting Countries (OPEC)
predominantly Arab nations in the Middle East; 1973 stopped selling oil to the U.S.
56
Instability of world oil prices
world prices of oil have changed a lot over the decades; often a results of political and economic events in oil producing countries, particularly the Middle East
57
Energy efficiency
the ability to obtain a given amount of output while using less energy input
58
Energy conservation
the practice of reducing wasteful or unnecessary energy use
59
Per capita energy consumption and intensity
U.S. trails other developed nations in energy efficiency but has made much progress; U.S. per-person energy use has fallen slightly since 1979 but remanis greater than that of most other nations; energy intensity has fallen steeply and now approaches that of other developed nations
60
Personal choices
driving less; carpooling; dialing down thermostats; turning off lights when rooms are not in use; cutting back on the use of energy intensive machines and appliances; saves money and conserves resources
61
Automobile efficiency
rose in the U.S. in the late 1970s as a result of legislative mandates but stagnates once no further laws were enacted to improve fuel economy; driven by public policy
62
CAFE standards
Corporate average fuel efficiency sets benchmarks for auto manufacturers to meet; the average fuel efficiency of new vehicles fell from 22.0 mpg in 1987 to 19.3 mpg in 2004 as sales of sport utility vehicles increased relative to sales of cars
63
Rebound effect
the phenomenon by which gains in efficiency from better technology are partly offset when people engage in more energy-consuming behavior as a result; can hamper conservation and efficiency efforts
64
CARS act
AKA cash-for-clunkers
65
Nuclear fission
the reaction that drives the release of nuclear energy inside nuclear reactors; the splitting apart of atomic nuclei; the nuclei of large, heavy atoms are bombarded with neutrons; each split nuclei emits energy in the form of heat, light and radiation
66
Nuclear reactor overview (fig 15.26 and 15.27)
in a pressurized light water reactor (the most common) uranium fuel rods are placed in water, which slows neutrons so that fission can occur; control rods are moved into and out of the reactor core, absorbing excess neutrons to regulate the chain reaction. Water heated by fission circulates thru primary loop and warms water in the secondary loop which turns to steam; steam drives turbines, which generates electricity; the steam is then cooled in the cooling tower by water from an adjacent river or lake and returns to the containment building to be heated again by heat from the primary loop
67
Radioisotopes
radioactive isotope
68
Half-life
the time taken for the radioactivity of a specified isotope to fall to half its original value.
69
Uranium-235
makes up less than 1% of the total isotopes of Uranium in nature; used for commercial nuclear power b/c Uranium-238 does not emit enough electrons to maintain a chain reaction
70
Uranium-238
over 99% of uranium in nature occurs as this isotope; mined uranium is this kind so it has to be enriched
71
Enrichment
235U is processed to enrich the concentration of 235U to at least 3%; enriched uranium is formed into pellets of uranium dioxide which are used as fuel rods
72
Fuel rods
pellets of uranium dioxide
73
Moderator
most often water or graphite used to slow down the neutrons bombarding with uranium for fission to begin
74
Control rods
made of metallic alloy that absorbs neutrons to soak up excess; are placed among the water-bathed fuel rods of uranium; engineers move control rods in and out of water to maintain fission at the desired rate; all this takes place within the reactor core and is the first step in electricity-generating process of a nuclear power plant
75
Breeder nuclear reactor
.
76
Plutonium-239
.
77
Liquid sodium coolant
.
78
Nuclear fuel cycle
.
79
Environmental impact to coal for electricity production
table 15.5; land and ecosystem disturbance from mining; greenhouse gas emissions; other air pollutants; radioactive emissions; occupational health among workers; health impacts on nearby residents; effects of accident or sabotage; solid waste; radioactive waste; fuel supplies remaining
80
CO2 emissions compared to other forms of energy production
.
81
Nuclear production
table 15.4; Top is U.S. then France, Japan, Russia, South Korea, China, Canada, etc
82
Nuclear meltdown
the accidental melting of the uranium fuel rods inside the core of a nuclear reactor causing the release of radiation
83
Three Mile Island (PA)
in 1979 combination of mechanical failure and human error caused coolant water to drain from the reactor vessel, temperatures to rise inside the reactor core and metal surrounding the fuel rods to melt releasing radiation; most of the radiation remained inside the contaminated building
84
Chernobyl (Ukraine)
in 1986 suffered the most severe accident in history: engineers had shut off safety systems to conduct tests and human error along with unsafe reactor design led to explosions that destroyed the reactor and sent clouds of radioactive debris billowing into the atm; winds carried to debris across the Northern Hemisphere
85
Fukushima (Japan)
March 11, 2011 a 9.0 earthquake struck eastern Japan and nearly 19,000 people were killed; the earthquake affected the operation of several nuclear plants; the power shut down and the tsunami flooded the plant's emergency power generators; the fuel began to overheat as fission proceed uncontrolled; the reactors were flooded with seawater to try and prevent meltdowns; several explosions and fires occurred; parts of the plant was inaccessible for months; radioactivity was released into the atm as a result
86
Radioactive waste disposal
high-level radioactive waste from civilian reactors is currently stored at over 120 sites in 39 states across the U.S.
87
Wet storage
.
88
Dry storage
.
89
Nuclear fusion
a nuclear reaction in which atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of energy.
90
Yucca Mountain, Nevada
single site in the desert 100 mi from Las Vegas where scientists and others want to store nuclear waste but it has not yet been approved nu the government
91
Current status of nuclear energy
remains one of the few currently viable alternatives to fossil fuels with which we can generate large amounts of electricity; environmental advocates want to expand nuclear capacity
