Transcript ENERGY & THE ENVIRONMENT
ENERGY & THE ENVIRONMENT
Unit Review
Updated 12/6/2013
Contents Electricity Fossil Fuels Alternative Energy Environment
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
: p hoto v oltaic c ells (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 Oil Natural Gas
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 Underground mine HARDEST SOFTEST Strip mining
Oil
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
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
Alternative power sources Nuclear Solar Wind Water Geothermal Biofuels
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) G ood 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
between 10 and 30 mph.
Danger to birds Wind farms take a lot of space (no shadowing) Noisy
Hydroelectric Potential energy converted to kinetic energy
Grand Coulee Dam, WA
dam waves pumped storage tidal exchange barrage
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
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 Deforestation: cutting down rainforest for arable land 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
Biofuels Ethanol: mixed with gasoline in some states Methanol: used in race cars Biodiesel: used only in diesel engines Some cars Large trucks Farm machinery
Environment Smog Greenhouse Gases Greenhouse Effect Global Warming 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
Greenhouse Gases Primary
Methane (CH 4 ) Nitrogen oxide (NO) Secondary Water vapor Ozone Chlorofluorocarbons Others
Greenhouse Effect Greenhouse gases in stratosphere let sun’s heat in, keeps radiation out Natural occurrence, makes life on Earth possible
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
(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
toaster house wiring power lines transformer Solar light (PVC) turbine compressed steam heat water Water = hydroelectricity Wind = wind turbines generator Combustion Coal Oil Natural gas Biofuels Nuclear Solar heat power plant • efficient • non-renewable • pollution • renewable • limited
Fossil Fuel Formation
Age
Carboniferous Jurassic
MYA
300
Fuel Type
Bituminous & anthracite 200 - 145 (no fuels formed)
Flora/Fauna
Thick-barked trees (lignin) resisted decay & consumption by animals, fell & fossilized to coal
Land Development
Pangaea formed Age of dinosaurs Pangaea breaks into Gwandanaland & Laurasia Cretaceous Eocene Neogene Pleistocene 145 - 65 33 – 55 5 - 23 .12 – 2.5
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 Brown coal & lignite, crude oil Crude oil Humans appear Formed in Venezuela, Russia, N. Africa, Mid East Continents in modern position, repeated ice ages
Oil Consumption/Capita Darker colors show higher consumption
Nuclear Incident Levels
When Disaster Strikes
Chernobyl 1986 (Ukraine)
Human error during testing, explosion
30 people died within 2 weeks Nearby towns evacuated permanently Land quarantined for about 2700 sq. mi.
Last reactor closed 2000 Tourism started 2011
3-Mile Island 1979 (Pennsylvania)
Failure of reactor coolant, meltdown Level 5 No one died 5 mi. radius evacuated temporarily U.S. nuclear plant safety questioned Second reactor resumed operation in 1985
Fukushima 2011 (Japan)
Tsunami after earthquake, damaged fuel storage Level 7 Radiation injuries No one died
12 mi. radius evacuated temporarily
Natural disaster and operator errors Clean-up will take up to 40 years
Sharing the Disaster
Available Wind Resources
Kyoto Protocol Ratification Parties; Annex I & II countries with binding targets Parties; Developing countries without binding targets States not Party to the Protocol Signatory country with no intention to ratify the treaty, with no binding targets Countries that have renounced the Protocol, with no binding targets Parties with no binding targets in the second period, which previously had targets
Global Carbon Emissions