ENERGY & THE ENVIRONMENT

Unit Review

Contents

Electricity Fossil Fuels Alternative Energy

TransportationEnvironment

Creating Electricity

Flow of electrons = electricity Generator spins copper coil inside magnets knocking

loose electrons

A loop of wire spinning through a magnetic field will create an alternating current. Note: current will flow only if the circuit connected to the generator is complete.

Creating Electricity: Methods

Heat (makes steam and drive turbines): fossil fuel combustion, solar heat, nuclear reaction

Creating Electricity: Methods

Mechanical: hydroelectricity, wind turbines

Creating Electricity: Methods

Solar light: photovoltaic cells (PVCs)

Fossil fuels

Highly concentrated carbon sources Plants and animals decayed millions of years ago Reliance is dangerous

Running out of resources Causes high levels of pollution Often from unstable or unfriendly governments

Coal Natural GasOil

Coal

Dirty, about 35% efficiency Huge formations in U.S., Russia, China Most electricity in China from coal, polluting U.S.

World coal reserves

Types of Coal

Anthracite (in Appalachia) Bituminous (large reserves in IL, WY) Sub-bituminous Lignite Peat

HARDEST

SOFTEST

Strip mining

Underground mine

Oil

Formed from algae buried in sediment and cooked U.S. supply sources: Canada, Mexico, Saudi Arabia,

Venezuela

World oil reserves

Non-fuel petroleum products

Plastics Fertilizer Asphalt Cosmetics Medicine Clothing (polyester,

nylon, polypropylene)

Natural Gas Forms above oil bearing rock Promoted as substitute for other fossil fuels Emits about 50% less carbon than oil or coal

World natural gas reserves

Uses of Natural Gas

Power plants Domestic

Cooking Heating

Fertilizer Transportation

CNG, LNG Making hydrogen fuel

Non-polluting power sources

Nuclear Wind

GeothermalWater

Solar

Nuclear Energy

Earliest use = weapon Nuclear reaction creates heat

Nuclear Reactions

Fission = splitting of atoms; primary method for nuclear energy use

Fusion = joining atomic nuclei to make heavier atoms, releases excess matter as energy

FUSION

Nuclear Fuels

Uranium: mined & refined Plutonium: produced from uranium MOX (mixed oxide fuel): recycled nuclear waste

Advantages of Nuclear Energy

Long-lasting, more predictable Clean and efficient, environmentally friendly Cost effective, a lot of energy is produced quickly

Disadvantages of Nuclear Energy

Operational issues Plants are more expensive than solar or wind farms Expensive to decommission Radiation containment, waste disposal

Potential problems Shortens life, causes cancer, damages genetics Plutonium (optional fuel) can be used in weapons Nuclear accidents can be catastrophic

Solar Energy

Types Light: Photovoltaic cells (PVC) convert light to electricity Heat: Solar ponds, solar collectors (mirrors) collect heat

Best place Lots of sunshine, open environment, warm climate (ponds) Good example: greenhouse

Uses: heating, cooling, light, electricity

Advantages of Solar Energy

No harmful effects to humans/environment Can be used in space

Installing major solar arrays in the marked locations would supply all the world’s energy needs.

Disadvantages of Solar Energy

Not all parts of the world are reliably sunny PVCs are not very powerful nor efficient Limited infrastructure

Using Solar Energy

Passive Shine on walls for radiant heat Natural light

Active Store PVC energy in batteries Heat water Pump to other areas

Wind Energy

Early uses: grinding corn, pumping well water

Preparing blades for installation

Wind

Advantages: free, unlimited source Disadvantages

Need constant winds between 10 and 30 mph. Danger to birds Wind farms take a lot space (no shadowing) Noisy

Hydroelectric

Potential energy converted to kinetic energy

Grand Coulee Dam, WA

barrage

wavesdam

pumped storage

tidal exchange

Advantages of Hydroelectricity

Low operating cost (fuel) Flood control No combustion pollution Gathers water for tourism & agriculture

Disadvantages of Hydroelectricity

Needs lots of moving water

Failure risk Lack of public

support Fish need

ladders Decomposing

vegetation creates greenhouse gases (new dams)

Geothermal

From Earth’s mantle

Used for hot water, heating, electricity

Near surface in limited areas

Can be depleted

Environment

Pollution EffectsSmog Greenhouse Gases

Global WarmingGreenhouse Effect World Efforts

Smog

Smog Partially burned fuels (smoke) + atmospheric moisture (fog) Photochemical smog: sunlight interacting with air pollutants. Industrial smog: burning hydrocarbons

New York City

Pollution Effects

Damages humans Burning lungs, coughing Respiratory irritation, asthma Headaches

Damages environment Stunts plants Acid rain

Greenhouse Gases

Primary Carbon dioxide (CO2)

Methane (CH4)

Nitrogen oxide (NO)

Secondary Water vapor Ozone Chlorofluorocarbons Others

Greenhouse Effect

Ozone layer lets sun’s heat in, keeps radiation out

Natural occurrence, accelerated by human activity

Greenhouse gases harm ozone layer

Global Warming

When Greenhouse Effect keeps in too much heat Gases thicken stratosphere, damage ozone layer Not enough heat can escape Earth gradually warms

Only 2° global increase will: Melt ice caps Flood low lying areas Cause deforestation Decrease arable land

Reduction Drive less; use public transportation, walk, carpool Reduce use of gasoline powered machines, pesticides, chemical

solvents, other polluting technology

World Efforts

U.N. Framework Convention on Climate Change Kyoto Protocol (1997) Global pollution reduction plan US didn’t ratify

U.N. Intergovernmental Panel on Climate Change Paris 2007

Scientists reported that Global Warming is being accelerated by human activity

Governments must now take action Durban (S. Africa) 2012

Sea levels rising faster than predicted Kyoto Protocol not re-ratified by all countries

Alternative Transportation Fuels

BiofuelsHydrogenNatural GasElectricity

Alternative Fuel Vehicles

Hybrid: Uses gasoline and electricity from batteries. Electric plug-ins Hydrogen Air car

Electricity for Transportation

Plug-in to outlets may stress power grid Lacking infrastructure for recharging Most methods of electricity generation still pollute

Coal-fired plant

Natural Gas for Transportation

CNG cleaner than gasoline As powerful as gasoline if compressed Not as powerful as diesel LNG used in airplanes, jets Used to make hydrogen

Hydrogen for Transportation

Made from water with electricity or directly from fossil fuels

Colorless, odorless, non-metallic, tasteless, highly flammable

Advantages does not pollute when burned, creates only water

Disadvantages Difficult to produce in quantity Difficult to distribute Best method burns fossil fuels Highly flammable

Biomass Sources

Plant, wood and animal waste (agricultural waste, landfill gases)

Organic oils Forest byproducts Certain crops

Corn Sugar cane Soybeans Switchgrass

switchgrass

Creating Biomass

Fertilizer Needed to increase

production Run-off pollutes rivers

Food vs. Fuel Prices may be better

for fuel use than food Not enough arable

land to support both uses

Natural crop failures increase problem

Deforestation: cutting down rainforest for arable land

2000200320052008

Biofuels for Transportation

Ethanol Methanol Biodiesel

Ethanol

Primary biofuel Plant alcohol from corn, sugar cane, soybeans,

agricultural waste Mixed w/gasoline 10 – 85% (E85) 1:1 CO2 exchange More expensive to make than gasoline Uses fossil fuels in production

Methanol

Alcohol made from animal waste Toxic to humans if ingested Can be converted to transportation fuel Required for supercharged engines in monster trucks,

dragsters

Biodiesel

Advantages Reduces car emissions, smoke, noxious fumes Safe to store and handle (non-toxic, biodegradable, non-

flammable) Diesel engines are more efficient than gasoline engines

Disadvantages Biodiesel used only in diesel engines Does not replace gasoline.

Nuclear

Solar heat

toaster

• efficient• non-renewable• pollution

• renewable• limited

house wiring power lines transformer

heat water

power plantgeneratorturbine

compressed steam

Water = hydroelectricity

Wind = wind turbines

CombustionCoalOilNatural gasBiofuels

Solar light

(PVC)

Fossil Fuel Formation

Age MYA Fuel Type Flora/Fauna Land Development

Carboniferous

300 Bituminous & anthracite

Thick-barked trees (lignin) resisted decay & consumption by animals, fell & fossilized to coal

Pangaea formed

Jurassic 200 - 145 (no fuels formed) Age of dinosaurs Pangaea breaks into Gwandanaland & Laurasia

Cretaceous 145 - 65 Sub-bituminous, tar sands, oil shale

Mammals appear, age ended w/mass extinction; sediment in shallow seas led to oil & gas formation

Gwandanaland breaks up, Laurasia begins to form N. America, Europe & Asia

Eocene 33 – 55 Brown coal & lignite, crude oil

Neogene 5 - 23 Crude oil Formed in Venezuela, Russia, N. Africa, Mid East

Pleistocene .12 – 2.5 Humans appear Continents in modern position, repeated ice ages

Oil Consumption/Capita

Darker colors show higher consumption

Nuclear Incident Levels

When Disaster Strikes

Chernobyl 1986(Ukraine)

3-Mile Island 1979(Pennsylvania)

Fukushima 2011(Japan)

Human error during testing, explosion

Failure of reactor coolant, meltdown

Tsunami after earthquake, damaged fuel storage

Level 7 Level 5 Level 7

30 people died within 2 weeks

No one died Radiation injuriesNo one died

Nearby towns evacuated permanently

5 mi. radius evacuated temporarily

12 mi. radius evacuated temporarily

Land quarantined for about 2700 sq. mi.

U.S. nuclear plant safety questioned

Natural disaster and operator errors

Last reactor closed 2000 Tourism started 2011

Second reactor resumed operation in 1985

Clean-up will take up to 40 years

Available Wind Resources

Global Carbon Emissions