Nonrenewable Energy Sources, Their Impacts, and Energy Conservation Flashcards
1
Q
Cabot Oil and Gas Corporation in Dimock, Pennsylvania
A
began drilling for natural gas in exchange for job opportunities and royalties on gas sales, but drilling (fracking) brought on a series of negative consequences (noise, nighttime light, air pollution, heavy truck traffic, toxic wastewater spills, cloudy and contaminated drinking water, and a well explosion from methane); back-and-forth ruling on what it owed to the town + all but 2 of 44 lawsuits ended in NDAs + the EPA seemed to downplay its harm
2
Q
Why has more powerful technology (which is more disruptive and potent) become necessary to access oil and natural gas in the U.S.?
A
almost all of the most accessible has already been dug up; remaining deposits are deep, underwater, in hard-to-access places (like the Arctic) or at low concentrations
3
Q
Fossil fuel consumption in most developed vs. least developed nations
A
50x more energy used per person (or greater)
4
Q
What is the purpose of pumping sand in hydraulic fracturing?
A
it lodges into the fractures in the shale and holds them open
5
Q
What are seen as the benefits of fracking?
A
resulted (along with the political influence of oil and gas corporations) in a boom of natural gas production; created job opportunities; lowered the price of natural gas; decreased the use of coal for electricity; could be used as a bridge between other fossil fuels and renewable energy if impacts are lessened
6
Q
How have policymakers affected regulation on fracking?
A
many support it, and therefore companies that employ fracking have been made exempt from 7 major federal environmental laws; don’t have to report the chemicals used, test for the chemicals in their wastewater (many of which are radioactive from tracers and natural sources in the ground) or give access to collected data that could be used to judge the environmental impact
7
Q
Nuclear energy is a renewable form of energy.
A
false
8
Q
Fossil fuels
A
highly combustible substances formed underground over millions of years from buried remains of ancient organisms; come in solid form as coal, liquid form as oil, and gas form as natural gas; high-energy content makes it efficient to ship, store and burn
9
Q
Electricity
A
a secondary form of energy that can be transferred over long distances; has many uses
10
Q
Proportions of energy and electricity that come from fossil fuels (global)
A
more than 80%; 2/3
11
Q
Fossil fuels ranked from most to least used (for energy)
A
oil, coal, natural gas
12
Q
All energy forms ranked from most to least used (for energy)
A
oil, coal, natural gas, bioenergy, nuclear energy, hydropower, new renewables
13
Q
All energy forms ranked from most to least used (for electricity)
A
coal, natural gas, hydropower, nuclear energy, bioenergy and new renewables, oil
14
Q
Aside from negative environmental effects, what is the primary concern regarding accelerating fossil fuel consumption?
A
the risk of using up finite reserves (use exceeds rate of formation - 1000 years are needed to generate the amount of organic matter to produce one day’s worth of fossil fuels)
15
Q
The U.S. represents ___ % of the total human population but ___ % of the world’s energy use
A
4.4; 18
16
Q
How energy is used under industrialization
A
about 1/3 goes to transport, 1/3 to industry and 1/3 to other uses; results in more energy going towards subsistence (e.g., food growing, food prep, heating) as more mechanized technology is used
17
Q
What percentage of energy demand do fossil fuels supply in the U.S.?
A
82%
18
Q
Net energy
A
the difference between the energy returned and the energy invested (for harnessing, extracting, processing and delivering the energy + for inputs into things like chemicals, pipes, equipment, machines, water, vehicles, storage, waste areas, and processing facilities)
19
Q
Energy returned on investment (EROI)
A
the energy returned divided by the energy invested; a way to assess energy sources where a higher value means more energy is produced for each unit of energy invested; high for fossil fuels; can change over time as technology advances/efficiency increases or as resources are depleted/become harder to extract
20
Q
What conditions are necessary for fossil fuels to form?
A
the remains of an organism must be buried quickly in sediment after death (in an anaerobic environment); during decomposition chemical energy can then be concentrated in the tissue and the hydrocarbons within it can be compressed
21
Q
Kerogen
A
the first substance that forms when organic matter slowly decomposes in an anaerobic environment; becomes coal when little decomposition occurs overall due to tight compaction or crude oil/natural gas when it is geothermally heated and dense, impervious rock surrounds porous rock
22
Q
How are fossil fuel deposits located?
A
geologists drill cores and conduct ground, air and seismic surveys to map underground rock formations and predict where they may be found; pressure naturally drives oil and natural gas upwards through pores and cracks until they reach an impermeable layer, so exploratory drilling of deep and small holes brings them to the surface when a deposit is tapped
23
Q
Coal
A
the most abundant fossil fuel; most commonly forms from woody plant material being compressed under high pressure to create dense and solid carbon structures; water is squeezed out of it as temperature and pressure increase and little decomposition occurs; large deposits located where swamps were 300-400 million years ago
24
Q
How might coal be extracted?
A
through strip mining near the Earth’s surface (where machinery scrapes away large amounts of soil), subsurface mining for deeper deposits (where vertical shafts are dug and horizontal tunnels are blasted out to follow the seams/layers) and mountaintop removal mining (where the tops of mountains are blown off)
25
Oil
a liquid mix of many types of hydrocarbons
26
Crude oil
oil that has been extracted but not refined
27
Natural gas
mostly consists of methane and lesser, variable amounts of other volatile hydrocarbons
28
Petroleum
another word for oil, but often used to refer to both oil and natural gas
29
How is petroleum formed?
especially occurs with the remains of plankton in the ocean; natural gas forms directly or from coal/oil altered by heating and is often above coal/oil seams
30
Oil sands (tar sands)
an unconventional fossil fuel consisting of moist sand and clay with 1-20% bitumen, a thick and heavy form of petroleum; forms from crude oil being degraded and chemically altered by erosion from water and bacterial decomposition
31
How might the oil from oil sands be extracted?
by a process similar to strip or open-pit mining where a shovel-truck removes soil and digs it out (so it can be mixed with hot water and solvents at an extraction factory for purification) OR by injecting steam and solvents down a drilling shaft to liquefy and isolate the bitumen, then pumping it out (in the case of deeper deposits)
32
Synthetic crude oil (syncrude)
the product of refining and processing bitumen
33
Roughly ___ barrels of water are needed to process 1 barrel of oil.
3
34
Oil shale
an unconventional fossil fuel in the form of sedimentary rock (shale) that contains organic matter; can be processed to shale oil, which forms by the same process as crude oil but only when it is not as deep (i.e., not subjected to enough heat and pressure to turn it to oil); extracted by strip or subsurface mining
35
Pyrolysis
a way to process oil shale where it is baked in the presence of hydrogen gas and in the absence of air in order to extract petroleum (though it can also be burned directly)
36
Oil shale vs. crude oil
the world's reserves of oil shale would generate more petroleum than all the reserves of crude oil, but it is more expensive to extract and has a lower EROI (1.1:1 compared to 4:1)
37
Methane hydrate
an ice-like solid of methane embedded in a crystal lattice of water molecules; found in the sediments of the Arctic and the ocean floor (where the temperature and pressure keep it stable); estimated to exist in such massive amounts that it represents possibly double the carbon of all coal, oil and natural gas deposits combined
38
How may methane hydrate be extracted?
by sending a pipe into the deposit and lowering the pressure so that the methane turns to a gaseous form and rises; not yet known to be safe and reliable (destabilized deposit = landslide, tsunami and a large amount of methane released into the atmosphere)
39
What primarily determines how much of an energy source will be extracted?
economics - the cost of extraction increases as more of the source is removed and market prices fluctuate, so extracting the entire amount is rarely profitable (creates "economically recoverable" vs. "technically recoverable" amounts)
40
Proven recoverable reserve
the amount of a fuel/energy source that is technologically and economically feasible to remove in current conditions; increases as technology improves or prices increase and decreases as the resource is depleted or prices decrease
41
Refining
a process that separates hydrocarbon molecules in crude oil by their size and chemically transforms them to create specialized fuels for different purposes (since chain length affects chemical properties and thus use)
42
What does the refining process involve?
boiling crude oil so its hydrocarbons volatilize and ascend through a distillation column (heavy oils and lighter oils condense at different heights and separate)
43
History of coal usage
used for thousands of years for a variety of purposes; drove the industrial revolution by powering steam engines used in industry and transport; today used largely for electricity
44
How do coal-fired power plants work?
the combustion of pulverized coal heats water and turns it into steam that rotates turbines (which rotate magnets past copper coils in a generator); electricity is distributed to consumers by transmission lines; the water is cooled and pollutants in the air are filtered while toxic ash residue from combustion goes to a hazardous waste landfill
45
How is natural gas used for electricity?
exists in a liquefied form at lower temperatures (as liquefied natural gas or LNG) which can be transported long distances in refrigerated tankers and used to generate electricity in power plants just like coal
46
Benefits of natural gas
versatile, clean-burning; emits half as much carbon dioxide per unit of energy released as coal and 2/3 as much as oil; seen as a "bridge fuel" to renewable energy by some (though others think it delays the transition)
47
Common uses of oil today
fuel for vehicles (gasoline for cars, diesel for trucks, jet fuel for planes) + in industry and manufacturing + in many daily products thanks to chemical manufacturing and refining processes (like plastics, lubricants, fabrics, pharmaceuticals)
48
Reserves-to-production ratio (R/P ratio)
a way to estimate how long the reserves of a fossil fuel will last; divide the amount of reserves remaining by the annual rate of production
49
What can increase the R/P ratio of a fossil fuel?
a decrease in demand or consumption due to an increase in efficiency OR an increase in proven recoverable reserves (due to better technology, new deposits or price increases)
50
Peak oil
refers to the point in time when oil production will reach its maximum before declining, estimated to be when reserves are about halfway used up; a steady or increasing demand during the decline represents a shortage
51
Hubbert's peak
refers to the peak of oil extraction in the U.S. calculated by a geologist in 1956 to be around the year 1970 (turned out to be accurate); has since risen close to the same amount with unconventional sources
52
Why is it difficult to estimate another peak in oil extraction in present day?
many companies and governments don't reveal reserve data and estimates for existing reserves vary
53
"The long emergency"
a scenario pictured by James Howard Kunstler where the world's demand for cheap oil for transport is not met and isolated local economies form when people can no longer rely upon it; might not allow for everyone to be fed and survive, especially in suburbs where automobiles are most necessary
54
Alternative scenarios to "the long emergency"
a) a decrease in fossil fuel supply will increase prices and incentivize everyone to conserve them while developing new energy sources, so no major disruptions to society will occur OR b) enough new deposits will be discovered to put off supply issues for decades, but climate change will become a bigger issue with more greenhouse gas emissions
55
In addition to a lower EROI, what do less accessible energy sources result in?
more pollution (and more climate change)
56
Benefits of fossil fuel use
lessened travel constraints, increased life spans, increased standard of living
57
Dangers of fossil fuel use
health risks, worsened environmental quality, decreased social/political/economic stability
58
How can mountaintop removal mining be harmful despite its economic efficiency?
can cause a lot of rock and soil to slide downslope (erode) and pollute or bury streams, habitat, etc.; can send aid drainage into waterways if sulfide minerals are exposed and react with oxygen and water to form sulfuric acid; essentially magnifies the harms of strip mining; in most developed nations mining companies must restore the area mined but rarely manage to recreate the ecological community
59
How can subsurface mining be harmful?
primarily through health risks posed to miners (accidents, breathing coal dust and toxic gases in confined spaces lead to black lung disease, etc.)
60
Why have Americans on the west coast opposed coal transport by rail?
dust can be released into the air and pollute it + the ultimate goal is often to ship it to China, which facilitates China's reliance upon it
61
Primary extraction
refers to the first extraction of oil/gas from a well which may leave up to 2/3 the total deposit behind
62
Secondary extraction
refers to methods and technology used after initial oil/gas extraction to collect more from a deposit; involves applying pressure with solvents, flushing with water/steam or fracking; is more costly and only used when prices are high enough to make a profit
63
Requirements for drilling to extract fossil fuels
access roads, housing for workers, transport pipelines, waste piles and ponds (for soil and toxic sludge); all pollute, fragment habitat and/or disturb wildlife and people
64
Directional drilling
an alternative to standard drilling that has lower impacts because it allows for vertical drilling followed by curved --> horizontal drilling that minimizes drill pads and surface damage
65
Benefits of unconventional fossil fuel sources
decreased reliance on imports, lower prices, more transitions to cleaner natural gas
66
Examples of the drawbacks of fracking
intense pollution issues (fluids can leak out of shafts into aquifers + methane can contaminate groundwater + methane and toxic volatile compounds can pollute the air), uses up water resources (especially freshwater, which returns with salts + radioactive elements + toxic chemicals that may not be removed properly by certain sewage treatment plants, though public outcry has led to wastewater reuse), provides high-paying jobs but they can be lost easily when oil prices drop, has caused minor earthquakes
67
Where is most of the remaining oil and natural gas in the U.S. likely located?
offshore (extracted especially off the coast of southern California and in the Gulf of Mexico)
68
Deepwater Horizon spill, 2010
largest oil spill in history; resulted from faulty equipment that let the natural gas in a deposit shoot up through a well shaft and ignite; killed 11 workers and sank the platform; emergency shutoff failed and oil gushed out of the broken pipe on the ocean floor; spilled oil and gas for 3 months (no solutions worked); killed a variety of organisms in the ocean, including the plants in coastal marshes that prevented erosion and flooding; took away jobs in tourism and fishing
69
What was the response to the 1989 Exxon Valdez spill?
led to regulations and the creation of an oil spill response procedure, but in 2008 gasoline prices increased and many offshore drilling prohibitions were lifted to reduce dependence on foreign oil
70
What was the response to the 2010 Deepwater Horizon spill?
access was left open only to areas with 75% or more technically recoverable oil (including off Alaska and in the Gulf of Mexico) and banned for the states that didn't want access; more regulations put into place (such as a requirement that ships be double-hulled)
71
Where does most water pollution by oil come from now?
various nonpoint sources - automobiles, homes, gas stations, businesses
72
What does melting sea ice due to climate change mean for the global economy?
new shipping lanes are opened and companies/governments potentially have new areas to search for fossil fuels to extract (race to claim them)
73
What are the problems with drilling for fossil fuels in the arctic?
frigid temperatures, ice floes that can damage ships, winds, waves, storms = likely accidents and harsh working conditions; harder to respond in the case of an oil spill and oil degrades more slowly due to the ice, storms, cold, and/or darkness
74
Royal Dutch Shell
the first and only company to attempt to pursue drilling around Alaska; gave up and wasted billions of dollars trying after several damages and other issues
75
Drawbacks of unconventional fossil fuels
low net energy, consume lots of water, devastate landscapes during extraction, pollute waterways and kill wildlife; burning ultimately emits more greenhouse gases than conventional sources (as they tend to be less clean); more specific problems (e.g., most oil sands are in Alberta, Canada, and are lower quality so need more refining and resources + lots of boreal forest must be cleared and dug into to extract it)
76
Keystone XL pipeline project by TransCanada Corporation
idea to construct an additional pipe segment on the Keystone Pipeline that runs through the Great Plains; opposed for health, water quality, property rights, and climate change concerns (also the potential for a spill to contaminate the Ogallala Aquifer); supported for jobs, decades of dependable oil supply, and less reliance on oil-producing nations that have poor human rights records or authoritarian governments; approved in 2008 but led to lawsuits, conflicts and protests; decided against in 2015 by Obama, then re-approved by Trump in 2017; requires funding and local permits that may not make it economically viable
77
Dakota Access Pipeline
a proposed oil pipeline to carry oil from the Bakken Formation in North Dakota; protested by Native Americans (Sioux) and others for damage it would cause to sacred burial grounds and to the Missouri River (which it would run underneath and could pollute); denied by the U.S. Army Corps. of Engineers but then expedited by Trump
78
How can transporting oil be risky?
oil can leak out of pipelines and cause spills; pipelines don't always provide enough capacity and instead pressurized tank cars may transport it by rail, several of which have derailed and exploded (worst = 2013 Lac-Mégantic, Quebec, killed 47 and destroyed the town center); regulations have improved safety but may not be enough (+ those in industry complain about the costs)
79
How does burning fossil fuels affect the carbon cycle?
alters natural fluctuations of carbon in the atmosphere by removing carbon from long-term reservoirs and adding it "prematurely" to the air through combustion
80
What kinds of hazardous chemicals do people risk exposing themselves to (through the air) when burning fossil fuels?
mercury (in coal, bioaccumulates) + carcinogenic pollution (in gasoline, ex. benzene and toluene) + hydrogen sulfide, lead, and arsenic (in oil) + sulfur dioxide and nitrous oxides (in coal and oil, --> smog and acid deposition)
81
Air pollution is ___ in industrializing nations and ___ in developed nations.
increasing; decreasing
82
How did scientists evaluate the impact of the Deepwater Horizon spill?
tracked oil movement with underwater imaging, aerial surveys and water samples and used that data to predict where the oil was headed and when it would arrive (especially in relation to the shore); attempted to seal the well with remotely operated submersibles; followed the movement of animals in the area with radio to see how their populations recovered
83
What were the possible outcomes for the Deepwater Horizon oil?
could remain in the water/in sediment/on shore, be chemically dispersed, be naturally dispersed, evaporate/dissolve, be directly recovered from the wellhead, burn, or be skimmed off the water
84
What damage was done to the marine ecosystem by the Deepwater Horizon spill?
evidence of hypoxia (some bacteria can consume oil/gas and use oxygen to do so) that caused a sharp decline in plankton and potentially the larvae of larger animals; observed gill damage, tail rot, lesions, and reproductive issues; deep water coral survey found dead organisms covered in a brown material (which turned out to be oil) close to the oil well; birds, turtles and mammals were saved by wildlife rescue but many also died and populations could or could not rebound
85
What was the concern with using Corexit 9500 to disperse the oil from the Deepwater Horizon spill?
a biologist found that it was more toxic than the oil itself and a lot was used; also split the oil into trillions of tiny droplets which could extend its impacts farther
86
How did the Deepwater Horizon spill affect the coastal wetlands of Louisiana?
fortunately not much; already lost many wetlands to subsidence + dredging + sea level rise + silt capture by dams on the Mississippi River but the oil failed to enter the roots of most plants and erosion did not really increase because plants survived
87
How did the Deepwater Horizon spill affect local industries?
thousands of fishermen lost their jobs; tourism decreased; sales of fish caught in the area dropped even when it was safe to continue fishing and catches were tested for chemicals; amounts of fish and shellfish caught decreased in general (can take decades to return to normal)
88
Why were scientists hopeful about the recovery of the Gulf of Mexico after the Deepwater Horizon spill?
a warm climate can speed up the breakdown of oil (volatile compounds in it evaporate), which also means fewer toxins last and affect the ecosystem; bacteria that consume hydrocarbons were already thriving in the area because of natural seafloor leaks and minor leaks from pipes and tankers
89
Oil Pollution Act of 1990
created after the Exxon Valdez oil spill to help prevent and appropriately respond to spill incidents; increased penalties, expanded response efforts and required federal/state agencies to research and restore affected areas
90
Clean coal technologies
techniques, equipment and approaches that aim to remove chemical contaminants (such as sulfur, mercury, arsenic, nitrous oxides and particulates) during the generation of electricity from coal; includes scrubbers, drying coal that has high water content and gasification
91
Gasification (coal)
reacting coal with oxygen and water at high temperatures to produce a cleaner synthesis gas (syngas) that also provides more power and can be used to turn a gas turbine or heat water for a steam turbine; can also be used to help extract the remaining fossil fuels in a deposit while sequestering carbon
92
Clean Power Plan
a strategy introduced by the Obama administration to (in part) retrofit old coal-fired power plants with newer and cleaner technology; not necessarily effective since coal companies spend money to fight regulations and some believe coal should just be replaced with cleaner energy sources
93
Carbon capture and storage (CCS)
involves capturing carbon dioxide emissions, converting them to a liquid form and sequestering (storing) them in the ocean or underground in geologically stable rock formations (such as depleted fossil fuel deposits, deep saline aquifers, or deposits undergoing secondary extraction); has been attempted and successful (one coal-fired power plant in Germany was the first to approach 0 emissions) but efficacy still unknown (unsure how to ensure carbon remains stored) + injection into ground could contaminate groundwater or cause earthquakes + can increase the ocean's acidity + lowers the EROI of coal and is very energy-intensive + could prolong fossil fuel reliance by removing some of the burden of emissions from other companies
94
The benefits of fossil fuel extraction, like high-paying jobs and economic activity, are usually ___ and ___ than the drawbacks.
temporary; less significant
95
How can the negative effects of fossil fuel extraction be magnified in oil-rich, developing countries?
they often lack thorough environmental regulations and will often not enforce regulations if it decreases profit
96
Shell Oil Company in Nigeria
extracted oil from native Ogoni land and took the profits (alongside military dictatorships) while the Ogoni were left with chronic illness, a lack of water and no electricity; Ogoni activist and leader Ken Saro-Wiwa tried to get compensation and was persecuted by the government for 30 years before being killed after a sham trial; represents a common trend in lawsuits to get compensation for the effects of fossil fuel extraction (usually fail to get companies to pay)
97
What issues come with excessive reliance on fossil fuels?
virtually all technology and services somehow depend on them and are threatened if resources run low (especially true for nations that lack their own sources); must depend on other countries to provide and have to deal with higher prices
98
What did the Organization of Petrol-Exporting Countries (OPEC) do in 1973?
stopped selling oil to the United States to oppose its support of Israel; substantially rose oil prices in the U.S. and caused a panic that resulted in more gas pipelines (similar oil supply and price fluctuations with crises in the Middle East where most oil reserves are located)
99
What does the U.S. do in an attempt to secure its long-term fossil fuel access?
relies heavily on domestic sources, only importing about 1/4 of its oil (and obtaining it from diverse sources); most imported oil now comes from countries that are not part of OPEC or located in the Middle East; has also invested in efforts to conserve them and research renewable energy; created an emergency stockpile in deep salt caverns in Louisiana (the Strategic Petroleum Reserve); pushing for drilling in the Arctic
100
Energy efficiency
the ability to obtain a given amount of output while using less energy input; comes from technological improvements; a type of energy conservation
101
Energy conservation
reducing wasteful or unnecessary energy use; comes from changes in behavior regarding energy
102
Many countries have a(n) ___ standard of living to the U.S. and use ___ energy per capita.
similar; less
103
Energy intensity
energy use per inflation-adjusted dollars of GDP; has decreased a lot in the U.S. in recent years (which signifies increased energy efficiency)
104
What are some choices individuals can make to reduce their energy use?
driving less far/often, turning thermostats down, turning off lights when they're not in use and using energy-efficient devices/appliances (all of which also save money)
105
More than ___ of the energy used in automobiles and power plants is lost as heat.
2/3 (can improve with better technology and strategies)
106
Cogeneration
refers to capturing excess heat during the generation of electricity and using it to heat nearby workplaces/homes or produce other power; almost doubles the efficiency of a power plant; treats coal to create hot gases and turn turbines (exhaust from turbines heats water to drive a steam turbine)
107
What can help prevent the needless loss of heat in winter and gain of heat in summer within buildings?
proper insulation, using passive solar design (constructing buildings to collect/store/distribute heat appropriately in each season), choosing better locations to build, planting vegetation nearby and altering the roof color
108
___ heat is lost from windows than walls.
more
109
Energy-efficient lighting can decrease energy use by up to ___ %.
80
110
Compact fluorescent bulbs are ___ efficient than incandescent bulbs.
more (many countries are phasing out the latter)
111
The EPA's Energy Star Program
certifies appliances, electronics, doors, windows, etc. that surpass designated energy efficiency standards; requires some manufacturers to post efficiency test results on Energy Guide labels on the product for comparison with other products; has decreased energy consumption/demand and carbon emissions and saves customers billions per year on utility bills
112
$1 extra spent on an Energy Star product means $___ saved on energy costs and preventing the emission of ___ pounds of greenhouse gases.
4.50; 35
113
What are some ways that fossil fuel use can be reduced in the realm of automotive technology?
with electric cars, electric/gas hybrids, plug-in hybrids, and hydrogen fuel cells
114
Electric/gas hybrid cars have had ___ the fuel economy ratings of standard cars, while electric cars have had ___ the fuel economy ratings.
double; quadruple
115
How can fuel efficiency be increased for gas-powered vehicles?
using more lightweight materials, continuously variable transmissions and more efficient engines
116
What effect did OPEC's decision in 1973 have on automobile efficiency?
government mandated an increase, but as oil prices dropped again the economic motivation to conserve fuel decreased (without a shortage) and efforts subsided
117
As sport-utility vehicle sales increase, average fuel efficiency ___ .
decreases
118
Even though a higher fuel economy rating increases the price of a vehicle ...
more money is saved throughout the lifetime of the vehicle on gas
119
What is the tax on gas in the U.S. like compared to other countries?
quite low; pay 2-3x less per gallon than many in Europe; does not account for production and external costs (as it would otherwise cost more than $13/gal.), which decreases the incentive to conserve gas
120
Rebound effect
refers to the possibility that increased energy efficiency will result in more energy-consuming behavior (e.g., driving a car more often) and partially or entirely offset its own benefits
121
Efficiency and conservation could save ___ barrels of oil per day in the U.S.
6 million
122
Nuclear energy
the energy that holds together the protons and neutrons in an atom's nucleus; can be harnessed by converting to thermal energy using nuclear reactors within nuclear power plants (which can then be used to heat water for turbines, --> electricity)
123
Benefits of nuclear energy
does not contribute to air pollution and can combat climate change effectively; virtually emission-free after the construction of power plants and equipment and generates much less solid waste; decreases chronic health risks and associated deaths for people living downwind of energy facilities and for workers; gives more power by weight or volume so less mining is necessary (+ thus less damage/waste)
124
Concerns regarding nuclear energy
increased development of nuclear weaponry, radioactive waste disposal needs, long-term effects of accidents (which contribute to emissions), unknown if supplies would last longer than coal supplies, very costly to build/maintain/operate power plants and keep them safe
125
Nuclear power
the generation of electricity using nuclear energy
126
Nuclear fission
the reaction (splitting of atomic nuclei) that drives the release of nuclear energy
127
How is nuclear fission initiated in nuclear power plants?
the nuclei of heavy atoms are bombarded with neutrons that are slowed down with a moderator (often graphite or water) since they often move too fast to split nuclei otherwise; each split nucleus emits energy as heat, light and radiation and releases neutrons that can bombard more atoms in a self-sustaining chemical reaction; also produces smaller atoms (of different elements)
128
What happens if nuclear fission is not controlled?
it creates a positive feedback loop and continue almost endlessly until it creates the explosive power of a nuclear bomb
129
How is nuclear fission controlled in a nuclear power plant?
in a reactor core, excess neutrons are soaked up with control rods of a metal alloy that have been placed among the fuel rods made of the large atoms that are being split; control rods are moved in and out of water to continue the reaction at the desired rate, but only a few of the neutrons emitted in each reaction remain "active"
130
When was nuclear power first developed?
in the 1950s (but most development occurred in the 70s and 80s)
131
The U.S. generates ___ of the world's nuclear power and receives ___ of its energy from it.
1/4; <20%
132
What makes nuclear power nonrenewable?
radioactive elements must be used because they can decay, and minerals containing them are both rare and finite
133
What isotope of uranium must be used for nuclear power?
U-235 (U-238 represents more than 99% of all uranium in nature but doesn't emit enough neutrons to maintain the chain reaction)
134
How is uranium ore prepared for use in a nuclear power plant?
it is enriched to at least 3% uranium, then turned to pellets of uranium dioxide, then turned into fuel rods
135
Uranium fuel has a lifespan of a few years.
true (reprocessing is possible but costly; most becomes radioactive waste)
136
Three Mile Island nuclear power plant incident
in Pennsylvania, 1979, due to human error and a mechanical failure; coolant water drained from the reactor vessel so the core overheated and melted the metal rods around the fuel rods, leading to a meltdown (massive release of radiation) from just half of one core; most radiation was contained within the building but residents were prepared to evacuate; had to shut down the damaged reactor and spend lots of money on years of cleanup
137
Chernobyl nuclear power plant incident
in now-Ukraine, 1986; the worst nuclear accident in history; safety systems were shut off for testing and the reactor was designed in an unsafe way, leading to explosions; wind carried radiation across much of the northern hemisphere; emergency crews risked their lives to put out the fire and more than 100,000 were evacuated; encased the destroyed reactor in concrete and later in a new confinement structure as concrete will deteriorate; 31 people were killed directly and thousands became ill (estimate most thyroid cancer cases soon after were caused by radioactive iodine, especially since they also occurred in children) and raised cancer rates/deaths from cancer in general; had to scrub buildings and roads to remove irradiated material but the area within 30 km of the plant remains contaminated and radioactivity has continued to leak out
138
Fukushima Daiichi nuclear power plant incident
in Japan, 2011; a magnitude 9.0 earthquake and the resulting tsunami shut down the power and flooded the emergency generators, meaning that moderators and control rods could not be used and the fission spiraled out of control; most escaped radiation traveled over the ocean but help was slow to arrive amidst the chaos; 3 reactors had full meltdowns and 3 more were very damaged; 1/10 the radiation of Chernobyl but decades of cleanup still; thousands evacuated and had to receive screening for effects, plus restrictions were placed on food and water from the area; radioactive groundwater flowed for years to the ocean
139
How did the Japanese government respond to the Fukushima Daiichi incident?
provided funds to monitor the long-term health of those affected and idled all of Japan's reactors until safety inspections could be completed, but protests halted efforts to restart them (other nations reassessed their own nuclear plants)
140
How could the Fukushima Daiichi incident been avoided?
if the emergency generators were not located in the basement (where they could be flooded)
141
What choice by the workers at the Fukushima Daiichi power plant made the incident worse?
they flooded the reactors with seawater in an attempt to stop the meltdowns, which made some areas inaccessible for months due to the water being contaminated
142
What happens as nuclear power plants age?
they need more maintenance and become less safe
143
Megatons to Megawatts program (1993-2013)
implemented by the U.S. and Russia to address concerns about stolen fuel (ex. the former USSR left hundreds of sites without sufficient security for years) and decrease stockpiles of nuclear weapons; the U.S. purchased weapons-grade uranium and plutonium from Russia and let Russia process it to lesser fuel for other uses
144
___ % of the U.S.'s electricity in recent years has been recycled from Russian weapons that once had a U.S. target.
10
145
Radioactive waste will cease to emit radiation in a reasonable amount of time.
false (half-life of U-235 is 700 million years)
146
What is currently done with radioactive waste from nuclear power plants?
temporarily stored at the power plants; decrease leakage by placing it in cooling water or thick casks of steel, lead and concrete
147
Most citizens in the United States live within 125 km of radioactive waste.
true
148
Benefits of a single guarded repository for nuclear waste
nuclear waste creates many potential hazards, so having it all in one location minimizes widespread risks (proposed = Yucca Mountain in Nevada desert)
149
Risks of a single guarded repository for nuclear waste
seismic activity could potentially unearth it; transport of future waste by rail and truck (on public highways) across the country would be dangerous
150
The growth of nuclear energy has ___ in recent years.
slowed
151
About the aging of nuclear power plants
occurs faster than expected (even with the corrosion and deterioration of parts like coolant pipes); plants that have shut down have served on average less than half their expected time; shutdown can be more expensive than building; lifetime makes electricity from the plants more expensive (governments subsidize still but few private investors remain)
