apes unit 7

quality

an energy's usefulness to do work

high quality energy

energy that is organized, concentrated, great ability to perform useful work (coal, electricity, gasoline, sunlight)

low quality energy

energy that is disorganized, dispersed, can't perform much useful work (energy stored in ocean, low-temperature heat)

net energy

amount of high-quality energy available from a given quantity of energy resource, minus the energy needed to make the energy

first law of thermodynamics

energy is neither created nor destroyed, but may be converted from one form to another

second law of thermodynamics

when energy is converted, come useful energy is always degraded to lower-quality, less useful energy

solar, wind, hydropower, biomass, geothermal

examples of renewable energy

coal, natural gas, oil, nuclear

examples of nonrenewable energy

80% nonrenewable, 20% renewable

what percentage of energy in US is nonrenewable and renewable?

ample supply, medium net energy, low land disruption, efficient distribution system

pros to conventional oil

releases CO2 when burned, environmental costs not included in market price

cons to conventional oil

venezuala

where is world's largest conventional oil reserve?

large, existing supplies, efficient distribution

pros to heavy oil from shale

low net energy, severe land destruction from surface mining, CO2 emissions, water pollution, high water use

cons to heavy oil from shale

natural gas

a mixture of gases with 50-90% being methane and smaller amounts of propane and butane, medium net energy

oil sands

deposits of bitumen (crude oil) mixed with sand, water, and clay

cleared boreal forests

extraction of oil sands results in \_____________________

low productivity from cold temperatures (occurring in Canada)

why won't the cleared boreal forests from oil sand extraction regrow fully?

US

where is the largest coal reserve?

russia

where is the largest natural gas reserve?

US

where is largest shale oil reserve?

canada

where is largest tar sands reserve?

nuclear energy

created by fission reactions where atoms are split and broken apart, releasing energy (heat from reaction boils water --\> steam to spin turbine --\> activates generator)

fuel rods

produce fission reaction

control rods

slow down fission reaction

moderator (water)

transfers energy produced in reaction to heat exchanger

large fuel supply, low CO2 emissions and environmental impacts

pros to nuclear energy

no acceptable storage solution for radioactive wastes, high cost, low net energy

cons to nuclear energy

price anderson act

act that limits the liability of nuclear industry companies in the event of an accident, fed govt assumes responsibility for incidents involving the operation, transportation, and storage of nuclear energy

copper wire, magnets

what are the 2 things a generator is made of?

coal

a fossil fuel formed from the remains of land plants that were buried and exposed to intense heat and pressure for 300-400 million years

ample supply, high net energy, low cost, well-developed technology

pros to coal

high CO2 emissions, releases mercury and radioactive toxins, acid deposition from high sulfur, severe land disruption from mtn top removal, water pollution from acid mine draining

cons to coal

Bituminious coal

extensively used type of fuel because of high heat and large supplies, but high sulfur content

anthracite coal

highly desirable fuel because of its high heat content and low sulfur content; supplies are limited in most areas

ample supplies, less CO2 and nitrogen oxides compared to coal, no sulfur oxides emitted

pros to natural gas

methane can leak from pipelines, releases CO2 when burned, fracking uses and pollutes water

cons to natural gas

injects gallons of water, sand, and chemicals with high pressure into wells --\> pressurized mixture causes rock layer to crack --\> fissures help open so gas/oil from shale can flow up well

what is fracking in extracting natural gas or heavy oil?

clean

natural gas is a \____________ fossil fuel

efficiency

natural gas has a greater \_________________ compared to coal and oil because it is faster to build and lower the cost

coal, electricity, gasoline, sunlight

examples of high quality energy

energy stored in ocean, low temperature heat

examples of low quality energy

high

net energy for coal

medium

net energy for conventional oil

low

net energy for nuclear energy

low

net energy for shale/heavy oil

carbon still needed in the production of uranium into fuel

how does nuclear energy still release carbon if uranium does not contain carbon?

greater population density --\> more energy needed

why are there more nuclear power plants on the East coast compared to the West?

Chernobyl

nuclear power plant incident where operators conducted an unauthorized test which involved shutting off safety systems, 32,000 deaths

three mile island

nuclear power plant incident where a mechanical error occurred but no lives were permanently affected, least severe, worst accident in US, only partial meltdown of reactor

fukushima

nuclear power plant incident where a tidal wave hit the reactors and the backup energy source was under sea level so reactors partially melted

lignite coal

low heat, low sulfur, limited supplies, least amount of energy

thermal energy

motion of molecules in a substance, heat flows and increases kinetic energy and thus, increases the temperature

(movement of molecules \= energy \= heat)

chemical energy

energy stored in molecules and compounds in the form of bonds, release heat when broken

electrical energy

unbalanced forces between protons and electrons create the movement of electrons in electrical currents, creating energy

radiant energy

energy emitted and transmitted by waves of particles through electromagnetic radiation

nuclear energy

changes that occur in the structure of nuclei of atoms, matter converted to energy through fusion or fission reactions

mechanical energy

kinetic or potential energy associated with the motion or position of an object

10% of energy transferred to each trophic level

example of second law of thermodynamics

nitrogen causes nutrient pollution but from an atmospheric source rather than water

what is the issue with having nitrogen in crude oil?

saudi arabia, nigeria, iraq, iran, algeria, venezuala, etc

major countries of OPEC

acid deposition

both oil and coal release nitrogen and sulfuric oxides into the atmosphere, resulting in \______________________

sulfuric oxides and nitrogen oxides mix in the atmosphere, creating sulfuric acids and nitric acids

how does acid deposition occur?

medium

net energy for natural gas

smelting

chemical or heat separation of desired material from the gangue

gangue

unwanted elements of the ore (while still in ore)

tailings

unwanted elements / waste remaining after extraction

depletion time

how long it takes to use of 80% of reserves

ore

rock that contains enough mineral to be extracted

strip mining

surface soil and rock is stripped away to reveal mineral

overburden

surface soil and rock masses that are removed to reveal the minerals underneath

open-pit mining

machines dig holes to remove ores, sand, gravel, and stone

mountain top removal

removing entire top of a mountain with explosives, heavy machinery called draglines, and 20-story tall shovels to reveal coal seams

spoils

piles of overburden leftover after mining

restore most surface land

Surface Mining Control and Reclamation Act of 1977 requires mining companies to \_____________________

biodiesel

liquid biofuel produced from vegetable oils

ethanol

liquid biomass with a low net energy, produced from corn and other plants & plant wastes

biomass sources have little carbon in them (like wood and plants)

why does biomass lack energy?

good net energy, low cost

pros to biodiesel

tropical rainforest destruction, loss of biodiversity, decreased CO2 sequestration

cons to biodiesel

perennial

a crop that comes back on its own each year, does not need to be reharvested

5x net energy, perennial, grows faster without the use of pesticides or fertilizers

why should we switch to switch grass over corn for producing ethanol?

releases CO2 and other GHGs, deforestation from overharvesting trees

cons to biomass

photovoltaic cells

cells with thin walls of silicon covered with cadmium (or gallium) that are struck with sunlight, activating elections (which in turn creates an electrical current)

although biomass requires carbon to burn for fuel, the plants used in biomass fuel take in carbon to grow, neutralizing carbon levels

why is biomass considered carbon neutral?

active solar energy

solar energy involving a motor that pumps water or blows air, used for heat

passive solar energy

captures and stores heat from sun directly within the structure (energy efficient windows collect energy, brick or stone walls store heat), uses architecture of that building

solar plants require lots of water, disrupts desert ecosystems, toxic materials enter environment if not recovered after solar cell retirement

environmental effects of solar energy

feed-in tariffs

force power companies to purchase excess electricity produced by homeowners and communities (when electricity is from renewable resources and can be put back onto the grid)

high net energy, least expensive

pros to dams

extensive environmental impacts

con to dams

submerged turbines

small turbines float in the water, used for small-scale electricity like lighting bridges or powering individual homes

pumped storage

when energy is in high demand, water from upper reservoir is released to generate electricity; when in low demand, energy taken from power grid to pump water back up to reservoir for storage

tidal energy

dams built across mouths of bays to capture energy in tidal flows, rare, minor energy contribution globally

destroy upstream biodiversity by impeding migration, restricts fish and nutrient movement, destroys downstream sediment, undermines food webs by restricting nutrients for producers

environmental impacts of hydropower

over 150,000 birds killed by wind turbines, noise pollution, not consistent source of energy, solid waste created by removal of turbines

environmental impacts of wind energy

break down blades and press them into pellets to be used for flooring and walls

solution to solid waste by wind turbines

geothermal energy

the energy produced by heat stored in soil/Earth

it extracts leftover heat (energy) from the air and ground and converts it into useful energy (fuel)

how does geothermal energy work?