Evaluating Energy Resources Renewable energy Non-renewable energy Future availability Net energy...
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Transcript of Evaluating Energy Resources Renewable energy Non-renewable energy Future availability Net energy...
Evaluating Energy ResourcesEvaluating Energy Resources
Renewable energy Renewable energy
Non-renewable energy Non-renewable energy
Future availability Future availability
Net energy yield Net energy yield
Cost Cost
Environmental effects Environmental effects
Extracting Energy and Mineral ResourcesExtracting Energy and Mineral Resources
Surface, subsurface mines, wellsSurface, subsurface mines, wells
Removing Nonrenewable Mineral ResourcesRemoving Nonrenewable Mineral Resources
Surface miningSurface mining Subsurface miningSubsurface mining
Overburden Overburden
Points of ViewPoints of View
Cornucopians - we will not run out ofnon-renewable resources because ofeconomics and technology
Cornucopians - we will not run out ofnon-renewable resources because ofeconomics and technology
Neo-Malthusians - we will run out ofnon-renewable resources (limitedsupply)- must control population, conserve
Neo-Malthusians - we will run out ofnon-renewable resources (limitedsupply)- must control population, conserve
Supplemental EnergySupplemental Energy
Solar energy - 99% of all energy used
Supplemental energy - everything else
History of Supplemental Energyin United StatesHistory of Supplemental Energyin United States
Wood through mid-1800s-Renewable-Maximum sustained yield limits supply
Wood through mid-1800s-Renewable-Maximum sustained yield limits supply
Coal replaced wood by 1900Coal replaced wood by 1900Oil, natural gas exploited (since mid-1900s)
#1-oil, #2-natural gas, #3-coal- all non-renewable
Oil, natural gas exploited (since mid-1900s)
#1-oil, #2-natural gas, #3-coal- all non-renewable
Use growing dramaticallyUse growing dramatically
Year
210020251950187518000
20
40
60
80
100
Con
trib
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tot
al e
nerg
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ptio
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erce
nt)
Wood
Coal
Oil
Nuclear
HydrogenSolar
Natural gas
How long will supplies last?How long will supplies last?
U.S. (5%) uses 25% of energyU.S. (5%) uses 25% of energyDepends on:
- rate of use- discovery of new supplies
Depends on:- rate of use- discovery of new supplies
Resource supply lifetime- oil - 30-60 years- natural gas - 50-200 years- coal - 65-900 years
Resource supply lifetime- oil - 30-60 years- natural gas - 50-200 years- coal - 65-900 years
North American Energy ResourcesNorth American Energy Resources
Oil ResourcesOil Resources
Petroleum (crude oil)Petroleum (crude oil)Primary recovery - 1/3 recoverablePrimary recovery - 1/3 recoverableSecondary recovery - heavy oil (10%)Secondary recovery - heavy oil (10%)
U.S. is major oil importer- thousands of low-output wells
U.S. is major oil importer- thousands of low-output wellsSaudi Arabia - largest known reserves
- supply world for 10 years- Alaskan supply - 6 months
Saudi Arabia - largest known reserves- supply world for 10 years- Alaskan supply - 6 months
OPECOPEC
Organization of Petroleum ExportingCountries
Organization of Petroleum ExportingCountries
Supplies ~30% of U.S. oil importsSupplies ~30% of U.S. oil imports
#1 Mexico#2 Canada#3 Venezuela (OPEC member)
#1 Mexico#2 Canada#3 Venezuela (OPEC member)
Oil Shale and Tar SandsOil Shale and Tar Sands
Oil shale3X conventional
Oil shale3X conventional
Kerogen25 gallons/ton
Energy in=energy out
Kerogen25 gallons/ton
Energy in=energy out Tar sands Tar sands
Bitumen3X return on energy inputs
Bitumen3X return on energy inputs
Natural GasNatural Gas
50-90% methane 50-90% methane
Propane, butaneremoved, liquified
Propane, butaneremoved, liquified
Cleanest burning,lowest costs
Cleanest burning,lowest costs
Problems: leaks,explosions
Problems: leaks,explosions
Unconventional: tight sands- 1-3 X conventional supply, but expensive
Unconventional: tight sands- 1-3 X conventional supply, but expensive
CoalCoal
Carbon (energy content) and sulfur
CoalCoal
Bituminous most abundant (52%), buthigh in sulfur
Bituminous most abundant (52%), buthigh in sulfur
Anthracite most ideal (high energy, lowsulfur), but least abundant (2%)
Anthracite most ideal (high energy, lowsulfur), but least abundant (2%)
Subbituminous (38%) moderate energy,moderate pollution potential
Lignite (8%) low energy, low pollutionpotential
Subbituminous (38%) moderate energy,moderate pollution potential
Lignite (8%) low energy, low pollutionpotential
CoalCoal
Surface versus subsurface mines Surface versus subsurface mines
North American Energy ResourcesNorth American Energy Resources
Coal Mining in United StatesCoal Mining in United States
Western surface mines Western surface mines
Mostly subbituminous, lignite Mostly subbituminous, lignite
Used mostly for generating electricity,steel-making industry
Used mostly for generating electricity,steel-making industry
Most used east of Mississippi River Most used east of Mississippi River
Transportation vs. volume costs, sulfur- slurry pipeline?
Transportation vs. volume costs, sulfur- slurry pipeline?
Burning Coal More CleanlyBurning Coal More Cleanly
Fluidized-Bed Combustion
Fluidized-Bed Combustion
-calcium-calciumsulfate usedsulfate usedin dry wallin dry wall
Coal Gasification - methaneCoal Gasification - methane
Raw coal
Pulverizer
Air oroxygen
Steam
Pulverized coalSlag removal
Recycle unreactedcarbon (char)
Raw gasesCleanmethane gas
Recoversulfur
Methane(natural gas)
2CCoal
+ O2 2CO
CO + 3H2 CH4 + H2O
Remove dust,tar, water, sulfur
Coal Liquefaction - liquid fuelsCoal Liquefaction - liquid fuels
Both gasification and liquefaction lose30-40% of energy contained in coal
Both gasification and liquefaction lose30-40% of energy contained in coal
Nuclear EnergyNuclear Energy
Big question mark in energy industryBig question mark in energy industryTremendous potential, plagued by
safety and cost problems
Tremendous potential, plagued bysafety and cost problems
3 ways to produce nuclear power1) conventional nuclear fission reactor2) breeder nuclear fission reactor3) nuclear fusion reactor
3 ways to produce nuclear power1) conventional nuclear fission reactor2) breeder nuclear fission reactor3) nuclear fusion reactor
Nuclear EnergyNuclear Energy
Use radioactive isotopesUse radioactive isotopesIsotopes - different forms of same
element- atoms have differing masses- e.g. U-238, U-235
Isotopes - different forms of sameelement- atoms have differing masses- e.g. U-238, U-235
Radioactive - unstable atoms emitradiation (rays and particles)
Radioactive - unstable atoms emitradiation (rays and particles)
Nuclear EnergyNuclear Energy
Conventional fission reactors
Conventional fission reactors
Uranium-235(U-238 common)
Uranium-235(U-238 common)
Nucleus split by moving neutron
Nucleus split by moving neutron
- Core, heat exchanger, generator
Reactors in the United StatesReactors in the United States
Nuclear EnergyNuclear Energy
Breeder fission reactorsBreeder fission reactorsUses plutonium-239 as fuel
U-238 + neutron = Pu-239
Uses plutonium-239 as fuelU-238 + neutron = Pu-239
Pu-239 fissioned, but more producedfrom U-238- produces more Pu-239 than it uses
Pu-239 fissioned, but more producedfrom U-238- produces more Pu-239 than it uses
Nuclear EnergyNuclear Energy
Nuclear fusion reactorsNuclear fusion reactorsCombine atoms of hydrogen isotopes
- deuterium, tritium
Combine atoms of hydrogen isotopes- deuterium, tritium
Requires high temperature- 100 million °C- experimental- uncontrolled fusion - hydrogen bomb
Requires high temperature- 100 million °C- experimental- uncontrolled fusion - hydrogen bomb
Problems with Nuclear PowerProblems with Nuclear Power
Safety Safety Disposal of radioactive wastesDisposal of radioactive wastesUse of fuel for weaponsUse of fuel for weaponsReduced growth in demand for
electricity
Reduced growth in demand for electricity
High construction, operating costsHigh construction, operating costs
Funding Funding
Safety ConcernsSafety Concerns
Radiation concerns Radiation concerns Susceptible tissues: reproductive
organs, bone marrow, digestive tract, spleen, lymph glands, fetuses
Susceptible tissues: reproductive organs, bone marrow, digestive tract, spleen, lymph glands, fetuses
Rem - unit of radiation exposure- 10 rems: low level, few effects- 100 rems: sterility, no short-term deaths- 1000 rems: death in days
Rem - unit of radiation exposure- 10 rems: low level, few effects- 100 rems: sterility, no short-term deaths- 1000 rems: death in days
Annual Radiation ExposureAnnual Radiation Exposure
Average 230 mrem (0.230 rem)Average 230 mrem (0.230 rem)
130 mrem from natural sources100 mrem from human activities
- 0.1 mrem from nuclear reactors
130 mrem from natural sources100 mrem from human activities
- 0.1 mrem from nuclear reactors
Lifespan reduced by 1 minuteLifespan reduced by 1 minute
Big FearsBig Fears
Core meltdown- Chernobyl ‘86
Core meltdown- Chernobyl ‘86
Containment shell ruptureContainment shell rupture
Both have potential for releasing huge amounts of radiation
Both have potential for releasing huge amounts of radiation
Disposal of Radioactive WastesDisposal of Radioactive Wastes
Nuclear fuel cycle
Disposal of Radioactive WastesDisposal of Radioactive Wastes
No long-term storage facility- protected for 10,000 years- radiation declines to low levels
No long-term storage facility- protected for 10,000 years- radiation declines to low levels
Most wastes stored on-siteMost wastes stored on-site
Site under development- Yucca Mountain in Nevada
Site under development- Yucca Mountain in Nevada
Yucca MountainYucca Mountain
Temporary StorageTemporary Storage