Question of the Day 1. One advantage of nuclear energy = 2. One disadvantage of nuclear energy = 4-19.

Question of the Question of the DayDay

1.1. One advantage of One advantage of nuclear energy =nuclear energy =

2.2. One disadvantage of One disadvantage of nuclear energy = nuclear energy =

4-19

Question of the Question of the DayDay

1.1. Where does the energy Where does the energy come from when we:come from when we:• burn a fossil fuel?burn a fossil fuel?• use a hydroelectric dam?use a hydroelectric dam?• use ground source use ground source

geothermal? geothermal?

4-26

Announcement:Announcement:

TEST WILL BE TUESDAY 5-3 TEST WILL BE TUESDAY 5-3 (EVEN) AND WEDNESDAY (EVEN) AND WEDNESDAY

5-4 (ODD)5-4 (ODD)

4-26

Alternative Energy Alternative Energy SourcesSources

SolarSolar: Using solar / photovoltaic cells to : Using solar / photovoltaic cells to convert suns energy into electricityconvert suns energy into electricity

Sun excites electrons causing them to flow Sun excites electrons causing them to flow electricity electricity

AdvantagesAdvantages::– RenewableRenewable– No emissions produced (no greenhouse No emissions produced (no greenhouse

gasses)gasses)

DisadvantagesDisadvantages::– Photovoltaic cells are Photovoltaic cells are

expensive up front expensive up front– No electricity at night / No electricity at night /

cloudy days cloudy days– Not all locations are Not all locations are

suitable suitable

Solar Thermal power plantsSolar Thermal power plants – mirrors – mirrors concentrate suns heat energy on an oil, concentrate suns heat energy on an oil, which gets extremely hot. Then oil is which gets extremely hot. Then oil is used to produce steam, steam turns used to produce steam, steam turns turbine and produces electricityturbine and produces electricity

Does not use Does not use photovoltaic photovoltaic cells cells

Alternative Energy Alternative Energy SourcesSources

WindWind – use wind to turn a turbine – use wind to turn a turbine turns turns generator generator producing electricity producing electricity

How is wind created?How is wind created? Sun - warmed air rises and colder air flows Sun - warmed air rises and colder air flows

in behind = windin behind = wind

AdvantagesAdvantages:: No emission / pollutionNo emission / pollution RenewableRenewable

DisadvantagesDisadvantages:: Not suitable for all locations Not suitable for all locations NoiseNoise

Alternative Energy Alternative Energy SourcesSources

BiofuelsBiofuels – converting plant matter into – converting plant matter into fuels as an alternative to gasolinefuels as an alternative to gasoline

Plants used = corn, sugarcane, switchgrassPlants used = corn, sugarcane, switchgrass

BiodieselBiodiesel – using vegetable oil instead of diesel – using vegetable oil instead of diesel

EthanolEthanol – alcohol produced from sugars – alcohol produced from sugars of the plant – used as alternative to of the plant – used as alternative to gasoline. gasoline.

Carbon NeutralCarbon Neutral – even though burning – even though burning biofuels releases CO biofuels releases CO22, biofuels come , biofuels come from plants, which take in CO from plants, which take in CO22… = … = carbon neutral carbon neutral

– problem = farm machinery, fertilizers, problem = farm machinery, fertilizers,

pesticides all use fossil fuels … = not neutralpesticides all use fossil fuels … = not neutral

Alternative Energy Alternative Energy SourcesSources

AdvantagesAdvantages::– RenewableRenewable– ““Neutral” EmissionsNeutral” Emissions– Reduce dependency on foreign Reduce dependency on foreign countries for oilcountries for oil

DisadvantagesDisadvantages::– Land limitations (not enough)Land limitations (not enough)– Cause food prices to rise Cause food prices to rise (use corn for fuel(use corn for fuel instead of food) instead of food)

– Still produces emissionsStill produces emissions

Alternative Energy Alternative Energy SourcesSources

HydroelectricHydroelectric – – using falling water to using falling water to turn turbines turn turbines turn generator turn generator electricityelectricity

AdvantagesAdvantages:: No emissions / pollutionNo emissions / pollution RenewableRenewable Flood controlFlood control

DisadvantagesDisadvantages:: Expensive to buildExpensive to build Dam floods huge areaDam floods huge area Limited locationsLimited locations Damage ecosystems / organisms (ex. Damage ecosystems / organisms (ex.

Migrating salmon) … fish ladderMigrating salmon) … fish ladder

Alternative Energy Alternative Energy SourcesSources

GeothermalGeothermal – – using earths heat using earths heat to produce steam, which to produce steam, which turns a turbine turns a turbine electricityelectricity AdvantagesAdvantages::

– few greenhouse gas emissionsfew greenhouse gas emissions– No fuel neededNo fuel needed– Renewable Renewable

DisadvantagesDisadvantages::– Limited locationsLimited locations– Location may cool offLocation may cool off– Still produces some greenhouse Still produces some greenhouse

gassesgasses

Alternative Energy Alternative Energy SourcesSources

Period 4O stopped on 4-26

Ground Source GeothermalGround Source Geothermal – using – using the constant temperatures of the the constant temperatures of the ground to heat or cool your ground to heat or cool your house.house.

Alternative Energy Alternative Energy SourcesSources

NuclearNuclear – – splitting of uranium atom (fission splitting of uranium atom (fission reaction) to produce heat reaction) to produce heat boils water boils water steam turns turbines steam turns turbines turns generator turns generator electricityelectricity

AdvantagesAdvantages:: No emissionsNo emissions Very efficient energy productionVery efficient energy production Cost effective (electricity is about the same price as coal)Cost effective (electricity is about the same price as coal)

DisadvantagesDisadvantages:: Nonrenewable (uranium Nonrenewable (uranium

supply will run out)supply will run out) Radioactive waste (must Radioactive waste (must

store for years) store for years) Possible meltdown Possible meltdown

spreading radioactivity spreading radioactivity (like Chernobyl, Three (like Chernobyl, Three Mile Island, Japan) Mile Island, Japan)

Alternative Energy Alternative Energy SourcesSources

Periods 3E, 4E, 6O, 4O & 6E

Extra Notes…Extra Notes… Three Mile Island (1979)Three Mile Island (1979)

– Nuclear power plant that melted down Nuclear power plant that melted down (radiation leak)…(radiation leak)…

– ……but NO explosion spreading the but NO explosion spreading the radioactive materialsradioactive materials

Extra Notes…Extra Notes… Chernobyl, Russia (1986)Chernobyl, Russia (1986)

– Nuclear meltdown Nuclear meltdown AND explosionAND explosion– 336,000 people had to move336,000 people had to move– About 30 direct deathsAbout 30 direct deaths– Predicted 4,000 extra cancer Predicted 4,000 extra cancer

deaths in exposed people deaths in exposed people

TidalTidal – – use coming in and out of the tides to use coming in and out of the tides to turn a turbine turn a turbine turn generator turn generator electricity electricityAdvantagesAdvantages:: RenewableRenewable No emissionNo emission

DisadvantagesDisadvantages:: Limited locations (need large Limited locations (need large

difference between high and low difference between high and low tide) tide)

Only produce energy when tides Only produce energy when tides are moving are moving

Costs of maintaining Costs of maintaining

Alternative Energy Alternative Energy SourcesSources

WaveWave – – using up and down motion of waves using up and down motion of waves to create electricityto create electricity

How are waves created?How are waves created?– Created by the windCreated by the wind

AdvantagesAdvantages:: RenewableRenewable No emissionsNo emissions

DisadvantagesDisadvantages:: Need large wavesNeed large waves Must survive storms + salt HMust survive storms + salt H22OO

… … cost of maintainingcost of maintaining

Alternative Energy Alternative Energy SourcesSources

Previewing Previewing AssignmentAssignmentRead pages 37-47 and answer #s 1-12 of the Lesson Review on page 47.

Question of the DayQuestion of the Day

1. Which energy sources 1. Which energy sources involve the production of involve the production of steamsteam use notes from use notes from presentations if necessarypresentations if necessary

11-12

Extra NotesExtra Notes Carbon FootprintCarbon Footprint

– Amount of carbon dioxide you are Amount of carbon dioxide you are responsible for producingresponsible for producing

Carbon FootprintCarbon Footprint

http://www.kohler.com/video/indehttp://www.kohler.com/video/index.jsp?bcpid=823619074&bclid=2x.jsp?bcpid=823619074&bclid=203710843&bctid=76936933203710843&bctid=769369332

http://www.kohler.com/video/indehttp://www.kohler.com/video/index.jsp?bcpid=823619074&bclid=2x.jsp?bcpid=823619074&bclid=203710843&bctid=76936933203710843&bctid=769369332

Where did the energy Where did the energy in fossil fuels come in fossil fuels come from?from? Fossil fuels were originally ……..Fossil fuels were originally ……..

– …….plants and animals..plants and animals. These organisms got their energy from These organisms got their energy from

the…the…– ……sun.sun.

They died, and didn’t…They died, and didn’t…– ……fully decomposefully decompose

So the sun’s energy never was So the sun’s energy never was recycled and is now in the fossil fuelsrecycled and is now in the fossil fuels

Where does all the Where does all the carbon in the fossil fuel carbon in the fossil fuel come from? come from? Plants need...Plants need...

– ……Soil, water, sun and CO2!Soil, water, sun and CO2! CO2 was taken from the CO2 was taken from the

atmosphereatmosphere by plants millions of by plants millions of years ago.years ago.

Plants were never decomposed, Plants were never decomposed, thus the C (carbon) was stored for thus the C (carbon) was stored for millions of years. millions of years.

RIVER

RESERVOIR