chapter 14: squeezing power from a stone: energy resources earth: portrait of a planet, 3 rd...

Chapter 14: Squeezing Power from a Stone: Energy Resources Earth: Portrait of a Planet, 3rd edition, by Stephen Marshak

Chapter 14Squeezing Power from a Stone:

Energy Resources

©2008 W. W. Norton & Company, Inc.

Portrait of a PlanetThird Edition

earthearth

LECTURE OUTLINE

Squeezing Power from a Stone:Energy Resources

Squeezing Power from a Stone:Energy Resources

Prepared by

Ronald ParkerEarlham College Department of Geosciences

Richmond, Indiana

Prepared by

Ronald ParkerEarlham College Department of Geosciences

Richmond, Indiana


Energy ResourcesEnergy Resources Energy is the capacity to do work.Energy is the capacity to do work. An energy resource is matter that can…An energy resource is matter that can…

Produce heat.Produce heat. Power muscles.Power muscles. Generate electricityGenerate electricity Move machinery. Move machinery.

In usable form, an energy resource is called a fuel. In usable form, an energy resource is called a fuel. Energy stored in chemical bonds fuels biotic life.Energy stored in chemical bonds fuels biotic life. Many energy resources are geological materials. Many energy resources are geological materials.


Human energy consumption has grown steadily. Human energy consumption has grown steadily. Early humans had modest energy requirements.Early humans had modest energy requirements.

Food. Food. Fuel for fires. Fuel for fires.

We consume 110x as much. We consume 110x as much. Food for livestock.Food for livestock. Agriculture. Agriculture. Transportation. Transportation. Mining.Mining. Manufacturing. Manufacturing. Industry.Industry.

Industrial societies depend mostly on fossil fuels. Industrial societies depend mostly on fossil fuels.

EnergyEnergy


Sources of EnergySources of Energy There are 5 fundamental sources of energy. There are 5 fundamental sources of energy.

Nuclear fusion in the Sun. Nuclear fusion in the Sun. The pull of gravity. The pull of gravity. Nuclear fission reactions. Nuclear fission reactions. Energy in the interior of the Earth. Energy in the interior of the Earth. Energy stored in chemical bonds.Energy stored in chemical bonds.


Sources of EnergySources of Energy Energy directly from the Sun’s nuclear fusion reactor. Energy directly from the Sun’s nuclear fusion reactor.

Heat and light radiate outward from the Sun. Heat and light radiate outward from the Sun. A tiny portion of the solar output strikes Earth. A tiny portion of the solar output strikes Earth. Direct solar energy can be used by humans.Direct solar energy can be used by humans.

Conversion into electricity by photovoltaic cells. Conversion into electricity by photovoltaic cells. Conversion into heat.Conversion into heat.

Controlled fusion is currently beyond human technology. Controlled fusion is currently beyond human technology.


Sources of EnergySources of Energy Energy directly from gravity. Energy directly from gravity.

Gravitational pull of the Moon on the Earth causes tides. Gravitational pull of the Moon on the Earth causes tides. Tidal flow can be harnessed to drive turbines. Tidal flow can be harnessed to drive turbines.


Sources of EnergySources of Energy Energy involving both solar energy and gravity.Energy involving both solar energy and gravity.

Solar radiation heats air and evaporates water.Solar radiation heats air and evaporates water. Gravity…Gravity…

Causes cooler air to sink and condense water vapor.Causes cooler air to sink and condense water vapor.Pulls condensed water back to Earth, where it flows downhill.Pulls condensed water back to Earth, where it flows downhill.

Energy can be extracted from flowing wind and water. Energy can be extracted from flowing wind and water.


Sources of EnergySources of Energy Energy via photosynthesis.Energy via photosynthesis.

Chlorophyll stores solar energy in H-C bonds.Chlorophyll stores solar energy in H-C bonds.Water and carbon dioxide react to form sugar and oxygen.Water and carbon dioxide react to form sugar and oxygen.6CO6CO22 + 12H + 12H22O + light > CO + light > C66HH1212OO66 + 6O + 6O22 + 6H + 6H22OO

H-C bonds release stored energy when broken (oxidized).H-C bonds release stored energy when broken (oxidized).Organic respiration (breakdown of food by organisms).Organic respiration (breakdown of food by organisms).Rapid thermal oxidation (combustion).Rapid thermal oxidation (combustion).


Sources of EnergySources of Energy Energy from chemical reactions.Energy from chemical reactions.

Energy stored in chemical bonds drives reactions. Energy stored in chemical bonds drives reactions. When bonds are broken, this energy may be used.When bonds are broken, this energy may be used.

Exothermic reactions produce heat. Exothermic reactions produce heat. Some also produce light and usable energy.Some also produce light and usable energy.


Sources of EnergySources of Energy Energy from fossil fuels.Energy from fossil fuels.

Oil, natural gas, and coal derive from living organisms. Oil, natural gas, and coal derive from living organisms. These materials store energy in preserved H-C bonds.These materials store energy in preserved H-C bonds.

Created by photosynthesis; solar energy from the past. Created by photosynthesis; solar energy from the past. Thus, oil, gas, and coal represent “fossilized sunshine.” Thus, oil, gas, and coal represent “fossilized sunshine.”


Sources of EnergySources of Energy Energy from nuclear fission.Energy from nuclear fission.

Certain radioactive atoms can be fragmented. Certain radioactive atoms can be fragmented. This process, called fission, yields tremendous energy. This process, called fission, yields tremendous energy. Fission energy is used to run nuclear power plants. Fission energy is used to run nuclear power plants.


Sources of EnergySources of Energy Energy from Earth’s internal heat.Energy from Earth’s internal heat.

Earth’s internal (geothermal) energy has 2 sources.Earth’s internal (geothermal) energy has 2 sources.Residual heat from planet formation. Residual heat from planet formation. Heat from radioactivity. Heat from radioactivity.

Geothermal energy drives Geothermal energy drives

tectonic plates. tectonic plates. Heat lost through the Heat lost through the

crust can be harnessed.crust can be harnessed.


Oil and GasOil and Gas Industrial society depends on Industrial society depends on

oil and natural gas. oil and natural gas. Oil and gas are hydrocarbons.Oil and gas are hydrocarbons.

Complex organic molecules.Complex organic molecules. Made of hydrogen and carbon.Made of hydrogen and carbon. From once-living creatures. From once-living creatures.

Many hydrocarbon types.Many hydrocarbon types. Found as complex mixtures.Found as complex mixtures. Pure compounds are separated Pure compounds are separated

by refining. by refining.


Oil and GasOil and Gas Hydrocarbon properties due to size and structure.Hydrocarbon properties due to size and structure.

Viscosity – Tendency to flow.Viscosity – Tendency to flow. Volatility – Tendency to evaporate.Volatility – Tendency to evaporate.

Short-chain hydrocarbons (1 to 4 carbon atoms).Short-chain hydrocarbons (1 to 4 carbon atoms). Low viscosity and high volatility. Low viscosity and high volatility. Vapors at room temperature.Vapors at room temperature. Examples: Methane, propane.Examples: Methane, propane.


Oil and GasOil and Gas Moderate-chain hydrocarbons (5 to 40 C atoms).Moderate-chain hydrocarbons (5 to 40 C atoms).

Medium viscosity and volatility; liquids at room temp. Medium viscosity and volatility; liquids at room temp. Examples: Hexane, octane, nonane.Examples: Hexane, octane, nonane.

Long-chain hydrocarbons (> 40 C atoms).Long-chain hydrocarbons (> 40 C atoms). High viscosity and low volatility; solids at room temp. High viscosity and low volatility; solids at room temp. Examples: Tar.Examples: Tar.


Oil and Gas GenesisOil and Gas Genesis Oil and gas hail from plankton and marine algae.Oil and gas hail from plankton and marine algae.

Dead plankton and algae sink in quiet water.Dead plankton and algae sink in quiet water. This organic material accumulates with fine mud. This organic material accumulates with fine mud. Under anoxic conditions, organic matter is preserved.Under anoxic conditions, organic matter is preserved. Lithification forms a black shale petroleum source rock. Lithification forms a black shale petroleum source rock.


Oil and Gas GenesisOil and Gas Genesis Burial to depths of 2 to 4 km heats the black shale.Burial to depths of 2 to 4 km heats the black shale.

Heating breaks the organics down into waxy kerogen.Heating breaks the organics down into waxy kerogen. Kerogen-rich source rocks are called oil shales.Kerogen-rich source rocks are called oil shales.

Continued heating breaks Continued heating breaks

down kerogen.down kerogen. Oil and gas form in Oil and gas form in

specific T ranges.specific T ranges. Oil and gas – 90Oil and gas – 90o o to 160to 160ooC.C. Gas only – 160Gas only – 160oo to 250 to 250ooC.C. Graphite – >250Graphite – >250ooC.C.


Oil and Gas GenesisOil and Gas Genesis The “oil window” T range is quite narrow. The “oil window” T range is quite narrow. Oil window depth dictated by geothermal gradient.Oil window depth dictated by geothermal gradient.

2525ooC/km – 3.5 to 6.5 km depth.C/km – 3.5 to 6.5 km depth. 1515ooC/km – Below 11 km depth.C/km – Below 11 km depth.


Hydrocarbon SystemsHydrocarbon Systems Oil and gas preservation is geologically rare.Oil and gas preservation is geologically rare. A known supply of oil is called an oil reserve.A known supply of oil is called an oil reserve. Oil reserves are geographically limited.Oil reserves are geographically limited. Most oil is in super-giant fields in the Persian Gulf.Most oil is in super-giant fields in the Persian Gulf.


Hydrocarbon SystemsHydrocarbon Systems Creation of an oil reserve is Creation of an oil reserve is

dependent on 4 features. dependent on 4 features. A source rock.A source rock. A migration pathway. A migration pathway. A reservoir rock.A reservoir rock. A trap. A trap.

These features must develop in These features must develop in a specific order.a specific order.


Hydrocarbon SystemsHydrocarbon Systems Source rocks and hydrocarbon generation.Source rocks and hydrocarbon generation.

Organic-rich black shale is the source of oil and gas.Organic-rich black shale is the source of oil and gas. The organic matter is transformed within the oil window. The organic matter is transformed within the oil window. The source rock does not store oil or gas.The source rock does not store oil or gas.


Hydrocarbon SystemsHydrocarbon Systems Reservoir rocks and hydrocarbon migration.Reservoir rocks and hydrocarbon migration.

Recoverable oil and gas are found in reservoir rocks. Recoverable oil and gas are found in reservoir rocks. Reservoir rocks can store and transmit fluids. Reservoir rocks can store and transmit fluids.

Porosity – Open space in the rock that stores fluid.Porosity – Open space in the rock that stores fluid.Permeability – Ease of fluid movement through pore space. Permeability – Ease of fluid movement through pore space.

Low – Small well yields.Low – Small well yields. High – Large well yields.High – Large well yields.


Hydrocarbon SystemsHydrocarbon Systems Reservoir rocks and hydrocarbon migration.Reservoir rocks and hydrocarbon migration.

Oil and gas must migrate from source to reservoir.Oil and gas must migrate from source to reservoir. Migration is facilitated by density/buoyancy differences. Migration is facilitated by density/buoyancy differences.

Oil floats on water; gas floats on oil. Oil floats on water; gas floats on oil. Migration is promoted by fractures in rock.Migration is promoted by fractures in rock. Reservoirs can leak to form an oil seep at the surface.Reservoirs can leak to form an oil seep at the surface.


Hydrocarbon SystemsHydrocarbon Systems Traps and seals.Traps and seals.

An oil or gas reserve requires trapping in the reservoir. An oil or gas reserve requires trapping in the reservoir. Trap – A geological configuration that holds oil and gas.Trap – A geological configuration that holds oil and gas. Seal – A low-permeability rock layer above a reservoir.Seal – A low-permeability rock layer above a reservoir. Trap geometry is often crucial for fluid collection.Trap geometry is often crucial for fluid collection.



Anticline trap – A structural arch traps oil. Anticline trap – A structural arch traps oil.



Salt-dome trap – Plastic flow in salt faults and folds rock, Salt-dome trap – Plastic flow in salt faults and folds rock, forming traps.forming traps.



Fault trap – Displacement juxtaposes rocks with varying Fault trap – Displacement juxtaposes rocks with varying permeability.permeability.



Stratigraphic trap – Subtle depositional features create Stratigraphic trap – Subtle depositional features create traps.traps.


Birth of the Oil IndustryBirth of the Oil Industry Oil from seeps has been used for millennia.Oil from seeps has been used for millennia. The 1The 1stst oil well was drilled in Titusville, Pa., in 1859. oil well was drilled in Titusville, Pa., in 1859.

Eased petroleum recovery.Eased petroleum recovery. Initiated an oil boom.Initiated an oil boom.

Within years, 1,000s of oil wells Within years, 1,000s of oil wells

had been drilled.had been drilled.


Oil ExplorationOil Exploration The modern search for oil: The modern search for oil:

Early exploration involved searching for rare oil seeps.Early exploration involved searching for rare oil seeps. Investors realized systematic exploration was needed.Investors realized systematic exploration was needed. Petroleum exploration became a subdiscipline of geology. Petroleum exploration became a subdiscipline of geology.


Oil ExplorationOil Exploration Complex, dangerous, and exciting; many steps. Complex, dangerous, and exciting; many steps. Geologists map sedimentary rocks.Geologists map sedimentary rocks.

Guide searches for source rocks, reservoirs, and traps.Guide searches for source rocks, reservoirs, and traps. Rock sequences compiled from outcrops and drill cores.Rock sequences compiled from outcrops and drill cores.

Cross-sections show rock geometry, aid search. Cross-sections show rock geometry, aid search.


Oil ExplorationOil Exploration Seismic reflection profiles subsurface layers.Seismic reflection profiles subsurface layers.

Sound is “bounced off’ subsurface layers.Sound is “bounced off’ subsurface layers. Permits geologists to look for traps without drilling.Permits geologists to look for traps without drilling. Seismic imaging is conducted on land and at sea. Seismic imaging is conducted on land and at sea. Seismic studies are sophisticated and expensive.Seismic studies are sophisticated and expensive.


Oil ExplorationOil Exploration Expensive drilling required to tap a potential trap. Expensive drilling required to tap a potential trap.

A diamond rotary bit pulverizes rock.A diamond rotary bit pulverizes rock.High-density drilling mud cools the bit and lifts cuttings. High-density drilling mud cools the bit and lifts cuttings. The heavy mud reduces blowouts.The heavy mud reduces blowouts.


Oil ExplorationOil Exploration As the bit advances, the open borehole deepens. As the bit advances, the open borehole deepens. Drill pipe is added by a drill derrick. Drill pipe is added by a drill derrick. Some derricks are mounted on offshore platforms.Some derricks are mounted on offshore platforms. Platforms can drill many holes in many directions.Platforms can drill many holes in many directions.


Oil ProductionOil Production When a reservoir is encountered, drilling ceases.When a reservoir is encountered, drilling ceases. Steel casing prevents collapse of the hole.Steel casing prevents collapse of the hole. After casing, the well is pumped. After casing, the well is pumped.


Oil ProductionOil Production Primary recovery. Primary recovery.

Uses reservoir pressure and pumping to extract oil.Uses reservoir pressure and pumping to extract oil. Inefficient; only able to recover about 30% of the oil.Inefficient; only able to recover about 30% of the oil.

Secondary recovery.Secondary recovery. Fluids (steam, COFluids (steam, CO22) are injected to heat and push oil. ) are injected to heat and push oil. Hydrofracturing – Artificially increases permeability. Hydrofracturing – Artificially increases permeability.


Oil ProductionOil Production Crude oil must be refined. Crude oil must be refined.

Crude oil is distilled into separate compounds.Crude oil is distilled into separate compounds. Lighter molecules rise to the top of distillation columns.Lighter molecules rise to the top of distillation columns. Heavier molecules remain at the bottom.Heavier molecules remain at the bottom.


Alternative HydrocarbonsAlternative Hydrocarbons Tar sands – Deposits of residual petroleum in sand. Tar sands – Deposits of residual petroleum in sand.

Heavy oil, or bitumen, is residue of a former oil field. Heavy oil, or bitumen, is residue of a former oil field. Lighter hydrocarbons are removed by bacterial digestion. Lighter hydrocarbons are removed by bacterial digestion. The remaining hydrocarbon is too viscous to be pumped. The remaining hydrocarbon is too viscous to be pumped. Tar sands must be mined and processed.Tar sands must be mined and processed. Extensive deposits in Extensive deposits in

Alberta and in Venezuela. Alberta and in Venezuela.


Alternative HydrocarbonsAlternative Hydrocarbons Oil shale – Shale containing abundant kerogen. Oil shale – Shale containing abundant kerogen.

An oil source rock that has not been in the oil window. An oil source rock that has not been in the oil window. Burning transforms the kerogen into liquid hydrocarbon. Burning transforms the kerogen into liquid hydrocarbon. Large supplies occur in…Large supplies occur in…

Estonia.Estonia.Scotland.Scotland.China.China.Russia.Russia.Western United States. Western United States.


Alternative HydrocarbonsAlternative Hydrocarbons Natural gas – Volatile, short-chain hydrocarbons. Natural gas – Volatile, short-chain hydrocarbons.

Methane, ethane, propane, butane, and others. Methane, ethane, propane, butane, and others. Gas floats on top of oil in a reservoir. Gas floats on top of oil in a reservoir. Below the oil window, hydrocarbons are turned into gas. Below the oil window, hydrocarbons are turned into gas. Natural gas is more abundant than oil; a cleaner fuel. Natural gas is more abundant than oil; a cleaner fuel. Utilization requires expensive, high-pressure pipelines. Utilization requires expensive, high-pressure pipelines.


Alternative HydrocarbonsAlternative Hydrocarbons Gas hydrate – Methane (CHGas hydrate – Methane (CH44) in a cage of water ice.) in a cage of water ice.

CHCH44 is from bacterial decomposition of organic matter. is from bacterial decomposition of organic matter. Methane hydrate forms in water depths exceeding 300 m.Methane hydrate forms in water depths exceeding 300 m. Stores more carbon than all other reservoirs combined. Stores more carbon than all other reservoirs combined. Recovery is not currently feasible. Recovery is not currently feasible.


CoalCoal Black, brittle, carbonaceous sedimentary rock.Black, brittle, carbonaceous sedimentary rock. Remains of organic matter from vegetation. Remains of organic matter from vegetation. Important global energy source; COImportant global energy source; CO2 2 emitter. emitter. Only found in rocks younger than 420 Ma.Only found in rocks younger than 420 Ma.


CoalCoal Coal-forming eras.Coal-forming eras.

Carboniferous (354 – 286 Ma).Carboniferous (354 – 286 Ma).Warm climate.Warm climate.Broad epicontinental seas. Broad epicontinental seas. Tropical deltaic wetlands.Tropical deltaic wetlands.

Cretaceous (144 – 65 Ma).Cretaceous (144 – 65 Ma).


Coal FormationCoal Formation Vegetation accumulates in an OVegetation accumulates in an O22-free setting. -free setting. Absence of oxygen prevents organic matter decay.Absence of oxygen prevents organic matter decay.

Marine deltas.Marine deltas. Tropical coastal wetlands. Tropical coastal wetlands.

Sea level rise and fall buries wetland deposits.Sea level rise and fall buries wetland deposits.


Coal FormationCoal Formation Coal formation requires heat and pressure. Coal formation requires heat and pressure. Compaction and decay turns plant debris into peat.Compaction and decay turns plant debris into peat.

Approximately 50% carbon.Approximately 50% carbon. Readily cut out of a wetland deposit.Readily cut out of a wetland deposit.


Coal FormationCoal Formation Peat is buried several km in a subsiding basin. Peat is buried several km in a subsiding basin. Burial compaction squeezes out water. Burial compaction squeezes out water. At depth, heat alters the plant material.At depth, heat alters the plant material.

H, N, and S are expelled as gases; C content increases. H, N, and S are expelled as gases; C content increases. At 70% carbon, this solid material becomes coal.At 70% carbon, this solid material becomes coal.


Coal RankCoal Rank Classification based on the carbon content.Classification based on the carbon content.

PeatPeat 50% C50% CLigniteLignite 70% C70% CBituminousBituminous 85% C85% CAnthraciteAnthracite 95% C95% C

Anthracite forms by metamorphism in an orogenic belt.Anthracite forms by metamorphism in an orogenic belt. Higher-rank coal yields more energy when burned.Higher-rank coal yields more energy when burned.


Coal RankCoal Rank


Coal MiningCoal Mining Coal is part of a specific sedimentary sequence. Coal is part of a specific sedimentary sequence.

Shallow marine, coastal, fluvial, and deltaic environments.Shallow marine, coastal, fluvial, and deltaic environments. Tropical to subtropical. Tropical to subtropical.

To be mined, coal must be…To be mined, coal must be… Within reach.Within reach. Thick enough (1 – 3 m).Thick enough (1 – 3 m).


Coal MiningCoal Mining Huge coal reserves have been discovered.Huge coal reserves have been discovered. Mining type depends on the depth of the coal seam.Mining type depends on the depth of the coal seam.

Within 100 m, coal is strip mined.Within 100 m, coal is strip mined. For deeper coal seams, underground mining is required. For deeper coal seams, underground mining is required.


Coal MiningCoal Mining Strip mining – Landscape destroyed to reach coal. Strip mining – Landscape destroyed to reach coal.

A large drag line bucket is used to scrape off overburden.A large drag line bucket is used to scrape off overburden.Spoil is stockpiled nearby for later use during reclamation. Spoil is stockpiled nearby for later use during reclamation.

Exposed coal is removed and the excavation is reclaimed. Exposed coal is removed and the excavation is reclaimed. Excavation is backfilled with spoil and soil, then planted. Excavation is backfilled with spoil and soil, then planted.


Coal MiningCoal Mining Underground mining – Coal removed by tunneling.Underground mining – Coal removed by tunneling.

For coal deeper than 100 m, shafts are advanced to seam. For coal deeper than 100 m, shafts are advanced to seam. Tunnels excavated along the seam remove the coal.Tunnels excavated along the seam remove the coal. Coal mining is specialized, expensive, and dangerous.Coal mining is specialized, expensive, and dangerous.

Tunnels can collapse.Tunnels can collapse.Methane gas.Methane gas.

Asphyxiation.Asphyxiation. Explosions.Explosions.

Black lung disease. Black lung disease.


CoalCoal Coal can yield energy without direct combustion.Coal can yield energy without direct combustion.

Coalbed methane – Natural gas trapped in buried coal.Coalbed methane – Natural gas trapped in buried coal. Coal gasification – Coal is changed to a combustible gas.Coal gasification – Coal is changed to a combustible gas.

Old coal gas plants in many cities are now waste sites.Old coal gas plants in many cities are now waste sites.Modern coal gasification is much less polluting. Modern coal gasification is much less polluting.


Coalbed FiresCoalbed Fires Runaway coal combustion underground.Runaway coal combustion underground.

Coal can be ignited in place by lightning, spontaneous Coal can be ignited in place by lightning, spontaneous combustion, gas explosions, or deliberate ignition.combustion, gas explosions, or deliberate ignition.

Difficult to extinguish, these fires may burn for decades.Difficult to extinguish, these fires may burn for decades. Produce hazards like toxic fumes and ground collapse.Produce hazards like toxic fumes and ground collapse.


Nuclear PowerNuclear Power Energy from breaking apart atomic nuclei. Energy from breaking apart atomic nuclei.

Neutrons strike the fuel and start fission. Neutrons strike the fuel and start fission. Fission splits a large nucleus into smaller fragments.Fission splits a large nucleus into smaller fragments.

Nuclear reactors are contained in a domed Nuclear reactors are contained in a domed building. building.

Reactors are loaded with uranium oxide fuel rods. Reactors are loaded with uranium oxide fuel rods.


Nuclear PowerNuclear Power A high-speed neutron initiates fission creating…A high-speed neutron initiates fission creating…

Nuclear fragments.Nuclear fragments. A large yield of energy.A large yield of energy. More high-speed neutrons. More high-speed neutrons.

Neutrons fuel a sustainedNeutrons fuel a sustained

nuclear chain reaction.nuclear chain reaction. Control rods absorb Control rods absorb

neutrons, slowing fission. neutrons, slowing fission.


Nuclear PowerNuclear Power Fission produces enormous amounts of energy.Fission produces enormous amounts of energy.

High-pressure steam is created in a closed reactor loop.High-pressure steam is created in a closed reactor loop. Heat is transferred to an external water loop.Heat is transferred to an external water loop. Steam in the external loop is used to spin electrical turbines.Steam in the external loop is used to spin electrical turbines.


Nuclear PowerNuclear Power Nuclear power is a major source of electricity.Nuclear power is a major source of electricity. Nuclear power emits zero greenhouse gases.Nuclear power emits zero greenhouse gases. Nuclear power use likely to increase in the future.Nuclear power use likely to increase in the future.


Nuclear PowerNuclear Power The geology of uranium.The geology of uranium.

Uranium – 235 (Uranium – 235 (235235U) is the most common nuclear fuel.U) is the most common nuclear fuel. Uranium has 2 major isotopes.Uranium has 2 major isotopes.

238238U – 99.3% (not fissionable).U – 99.3% (not fissionable). 235235U – 0.7% (fissionable).U – 0.7% (fissionable).

235235U must be enriched 2 to 3 times to be fissionable.U must be enriched 2 to 3 times to be fissionable.


Nuclear PowerNuclear Power The geology of uranium.The geology of uranium.

Uranium occurs naturally in all rocks; amount varies.Uranium occurs naturally in all rocks; amount varies.Uranium dissolved from minerals is transported by water. Uranium dissolved from minerals is transported by water. Dissolved uranium solidifies in mineral veins and fractures. Dissolved uranium solidifies in mineral veins and fractures.

Radiation detectors are used to find uranium.Radiation detectors are used to find uranium.


Nuclear ProblemsNuclear Problems Nuclear power is expensive.Nuclear power is expensive. Loss of reactor control may start core “meltdown.” Loss of reactor control may start core “meltdown.”

Molten reactor materials could bore through containment.Molten reactor materials could bore through containment. A steam explosion could then spread radioactivity.A steam explosion could then spread radioactivity.


Nuclear ProblemsNuclear Problems Plant safety is a major concern.Plant safety is a major concern. Extensive efforts applied to thwart terrorism. Extensive efforts applied to thwart terrorism. Nuclear accidents are rare but have occurred.Nuclear accidents are rare but have occurred.

1986 – Chernobyl (Ukraine) spread radioactivity globally.1986 – Chernobyl (Ukraine) spread radioactivity globally. 1979 – Three Mile Island (Pennsylvania, U.S.).1979 – Three Mile Island (Pennsylvania, U.S.).


Nuclear ProblemsNuclear Problems Generates highly radioactive wastes.Generates highly radioactive wastes.

Extremely toxic, wastes are poisonous for 1,000s of years.Extremely toxic, wastes are poisonous for 1,000s of years. High-level waste storage is a major societal issue.High-level waste storage is a major societal issue.

Wastes also generated by processing uranium ore.Wastes also generated by processing uranium ore.


Other Energy SourcesOther Energy Sources There are a number of other energy options.There are a number of other energy options.

Geothermal energy.Geothermal energy. Hydroelectric power.Hydroelectric power. Wind energy.Wind energy. Solar power.Solar power.


Geothermal EnergyGeothermal Energy Energy from Earth's internal heat.Energy from Earth's internal heat.

Geothermal gradient: Earth becomes hotter with depth.Geothermal gradient: Earth becomes hotter with depth. Geothermal gradients vary (15Geothermal gradients vary (15ooC/km to 50C/km to 50ooC/km).C/km). High geothermal gradients: hotter at shallower depths. High geothermal gradients: hotter at shallower depths.

No wastes; no greenhouse gases or air pollution.No wastes; no greenhouse gases or air pollution.


Geothermal EnergyGeothermal Energy Geothermal energy is utilized in 2 ways.Geothermal energy is utilized in 2 ways.

Hot water is pumped and used to heat buildings.Hot water is pumped and used to heat buildings. Steam is used to drive electric turbines. Steam is used to drive electric turbines.

Geothermal is a dominant energy source in some Geothermal is a dominant energy source in some areas (e.g., Iceland, New Zealand).areas (e.g., Iceland, New Zealand).


Hydroelectric PowerHydroelectric Power Flowing water turns potential energy into kinetic energy.Flowing water turns potential energy into kinetic energy. This energy works by eroding and moving sediment. This energy works by eroding and moving sediment. Hydroelectric power dams arrest the flow of water. Hydroelectric power dams arrest the flow of water. Water is directed past turbines to create electricity.Water is directed past turbines to create electricity. Some dams generate electricity via tidal flux. Some dams generate electricity via tidal flux.


Hydroelectric PowerHydroelectric Power Positive aspects. Positive aspects.

Reduces the risk of floods. Reduces the risk of floods. Impounds water for drinking, Impounds water for drinking,

irrigation, and recreation.irrigation, and recreation. Provides renewable energy Provides renewable energy

without creating wastes.without creating wastes.


Hydroelectric PowerHydroelectric Power Negative aspects :Negative aspects :

Dams destroy valued landscapes and alter ecosystems.Dams destroy valued landscapes and alter ecosystems. Reservoirs accumulate the sediment load of the river.Reservoirs accumulate the sediment load of the river.

Sediments added to reservoirs require expensive dredging.Sediments added to reservoirs require expensive dredging.Erosion is accelerated downstream of dams. Erosion is accelerated downstream of dams.


Wind EnergyWind Energy High-tech wind farms are sprouting worldwide. High-tech wind farms are sprouting worldwide.

Wind drives a large turbine to produce electricity.Wind drives a large turbine to produce electricity. Wind-derived electricity is renewable and carbon-free.Wind-derived electricity is renewable and carbon-free.

Drawbacks.Drawbacks. Wind farms have negative aesthetic impacts.Wind farms have negative aesthetic impacts. Turbine blades are noisy and kill birds.Turbine blades are noisy and kill birds.


Solar PowerSolar Power By far the most abundant source of energy to the surface.By far the most abundant source of energy to the surface. Solar energy dwarfs that of hydrocarbon resources.Solar energy dwarfs that of hydrocarbon resources. But solar energy is hard to utilize because it is…But solar energy is hard to utilize because it is…

Diffuse.Diffuse.Highly variable on a seasonal and daily basis.Highly variable on a seasonal and daily basis.Difficult to convert into more usable forms of energy.Difficult to convert into more usable forms of energy.


Solar PowerSolar Power There are two ways to use solar energy directly.There are two ways to use solar energy directly.

Solar collectors concentrate sulight for heating.Solar collectors concentrate sulight for heating.Photovoltaic (PV) cells convert light directly into electricity.Photovoltaic (PV) cells convert light directly into electricity.

Both are useful for small buildings; not large cities. Both are useful for small buildings; not large cities.


BiomassBiomass Biomass – Energy from plant and animal matter. Biomass – Energy from plant and animal matter.

Early humans used biomass (wood, charcoal, dung).Early humans used biomass (wood, charcoal, dung). To be useful today, biomass must be grown quickly.To be useful today, biomass must be grown quickly. Ethanol – Alcohol derived from corn.Ethanol – Alcohol derived from corn.

Burned as a motor fuel.Burned as a motor fuel.Produced in large quantities.Produced in large quantities.Unproven as a gasoline replacement. Unproven as a gasoline replacement.


Hydrogen Fuel CellsHydrogen Fuel Cells Produce electricity via chemical reactions.Produce electricity via chemical reactions. Hydrogen reacts with oxygen in an electrolyte bath.Hydrogen reacts with oxygen in an electrolyte bath.

Generates electricity, heat, and HGenerates electricity, heat, and H22O.O. The reaction is environmentally benign.The reaction is environmentally benign.

Fuel cells are useful as engines for motor vehicles.Fuel cells are useful as engines for motor vehicles. Technological issues must be addressed 1Technological issues must be addressed 1stst. .

Safely storing compressed hydrogen. Safely storing compressed hydrogen. Producing hydrogen efficiently.Producing hydrogen efficiently.Distributing hydrogen.Distributing hydrogen.


Energy ProblemsEnergy Problems Global energy use increased dramatically. Global energy use increased dramatically. Use reflects rapid expansion of industrialization. Use reflects rapid expansion of industrialization. Oil, the dominant energy source, is dwindling. Oil, the dominant energy source, is dwindling. Many countries import Many countries import

oil to meet demands. oil to meet demands.


Energy ProblemsEnergy Problems The 1970s energy crisis.The 1970s energy crisis.

In 1973, the Organization of Petroleum-Exporting In 1973, the Organization of Petroleum-Exporting Countries (OPEC) began to limit the volume of exports.Countries (OPEC) began to limit the volume of exports.

The price of oil skyrocketed, resulting in fuel shortages. The price of oil skyrocketed, resulting in fuel shortages. Gas stations witnessed long lines for the 1Gas stations witnessed long lines for the 1stst time. time.


Energy ProblemsEnergy Problems The 1970s energy crisis.The 1970s energy crisis.

The result was a new understanding of energy by all.The result was a new understanding of energy by all.Regulations lowered speed limits and raised mileage stds.Regulations lowered speed limits and raised mileage stds.Goods tended to be smaller and more energy-efficient.Goods tended to be smaller and more energy-efficient.A new consumer ethos was born.A new consumer ethos was born.

Reducing home energy usage.Reducing home energy usage. Carpooling.Carpooling. Public transportation.Public transportation.


Energy ProblemsEnergy Problems The oil crunch - Renewable vs. nonrenewable. The oil crunch - Renewable vs. nonrenewable.

Renewable – Can be replaced within months to years.Renewable – Can be replaced within months to years.Biomass, solar, wind, geothermal, hydroelectric.Biomass, solar, wind, geothermal, hydroelectric.

Nonrenewable – Replacement requires hundreds to Nonrenewable – Replacement requires hundreds to millions of years. millions of years. Oil, natural gas, coal, uranium ores.Oil, natural gas, coal, uranium ores.


Energy ProblemsEnergy Problems The oil crunch.The oil crunch.

We consume nonrenewable resources too rapidly.We consume nonrenewable resources too rapidly. We face running out of nonrenewable resources. We face running out of nonrenewable resources. For each resource, the question is “When?” For each resource, the question is “When?” The answer, for oil, may be “Soon.”The answer, for oil, may be “Soon.”


Energy ProblemsEnergy Problems The oil crunch.The oil crunch.

Oil extinction will occur by 2050 to 2150.Oil extinction will occur by 2050 to 2150. Future historians will see the “Oil Age” as a 200-year era.Future historians will see the “Oil Age” as a 200-year era. We are now close to the peak of global oil production.We are now close to the peak of global oil production. Humanity faces many changes as oil runs out.Humanity faces many changes as oil runs out.


Energy ProblemsEnergy Problems The oil crunch: What can humanity do?The oil crunch: What can humanity do? There are many sources of energy that we can use.There are many sources of energy that we can use.

Tar sands and oil shales.Tar sands and oil shales. Coal.Coal. Natural gas.Natural gas. Coalbed methane.Coalbed methane. Uranium.Uranium. Renewables.Renewables.

Each energy source has associated difficulties.Each energy source has associated difficulties. Society faces difficult choices.Society faces difficult choices.


Environmental IssuesEnvironmental Issues Energy production creates environmental insults. Energy production creates environmental insults.

Oil drilling and production scars the landscape.Oil drilling and production scars the landscape. Spills from oil storage tanks, pipelines, and ships...Spills from oil storage tanks, pipelines, and ships...

Contaminate surface water and ground water.Contaminate surface water and ground water.May devastate large areas of coastline.May devastate large areas of coastline.

Coal mining creates pits, spoil piles, and acid mine runoff.Coal mining creates pits, spoil piles, and acid mine runoff.


Environmental IssuesEnvironmental Issues Air pollution results from fossil fuel combustion.Air pollution results from fossil fuel combustion.

Unburned hydrocarbons add to photochemical smog.Unburned hydrocarbons add to photochemical smog. Sulfur dioxide (SOSulfur dioxide (SO22) from coal yields acid rain. ) from coal yields acid rain.

COCO22 addition fuels global warming and climate change. addition fuels global warming and climate change.


Chapter 14Squeezing Power from a Stone:

Energy Resources

©2008 W. W. Norton & Company, Inc.

Portrait of a PlanetThird Edition

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