Nonrenewable Energy Sources, Their Impacts, and Energy Conservation Flashcards
Cabot Oil and Gas Corporation in Dimock, Pennsylvania
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
Why has more powerful technology (which is more disruptive and potent) become necessary to access oil and natural gas in the U.S.?
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
Fossil fuel consumption in most developed vs. least developed nations
50x more energy used per person (or greater)
What is the purpose of pumping sand in hydraulic fracturing?
it lodges into the fractures in the shale and holds them open
What are seen as the benefits of fracking?
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
How have policymakers affected regulation on fracking?
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
Nuclear energy is a renewable form of energy.
false
Fossil fuels
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
Electricity
a secondary form of energy that can be transferred over long distances; has many uses
Proportions of energy and electricity that come from fossil fuels (global)
more than 80%; 2/3
Fossil fuels ranked from most to least used (for energy)
oil, coal, natural gas
All energy forms ranked from most to least used (for energy)
oil, coal, natural gas, bioenergy, nuclear energy, hydropower, new renewables
All energy forms ranked from most to least used (for electricity)
coal, natural gas, hydropower, nuclear energy, bioenergy and new renewables, oil
Aside from negative environmental effects, what is the primary concern regarding accelerating fossil fuel consumption?
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)
The U.S. represents ___ % of the total human population but ___ % of the world’s energy use
4.4; 18
How energy is used under industrialization
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
What percentage of energy demand do fossil fuels supply in the U.S.?
82%
Net energy
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)
Energy returned on investment (EROI)
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
What conditions are necessary for fossil fuels to form?
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
Kerogen
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
How are fossil fuel deposits located?
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
Coal
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
How might coal be extracted?
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)
Oil
a liquid mix of many types of hydrocarbons
Crude oil
oil that has been extracted but not refined
Natural gas
mostly consists of methane and lesser, variable amounts of other volatile hydrocarbons
Petroleum
another word for oil, but often used to refer to both oil and natural gas
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
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
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)
Synthetic crude oil (syncrude)
the product of refining and processing bitumen
Roughly ___ barrels of water are needed to process 1 barrel of oil.
3
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
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)
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)
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
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)
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)
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
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)
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)
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
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
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
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)
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)
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
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)
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
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
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
“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
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
In addition to a lower EROI, what do less accessible energy sources result in?
more pollution (and more climate change)
Benefits of fossil fuel use
lessened travel constraints, increased life spans, increased standard of living
Dangers of fossil fuel use
health risks, worsened environmental quality, decreased social/political/economic stability
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
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.)
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