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

2. Question of the Day 1. Where does the energy come from when we: burn a fossil fuel? burn a fossil fuel? use a hydroelectric dam? use a hydroelectric dam? use ground source geothermal? use ground source geothermal? 4-26

3. Announcement: TEST WILL BE TUESDAY 5-3 (EVEN) AND WEDNESDAY 5-4 (ODD) 4-26

5. Alternative Energy Sources Solar: Using solar / photovoltaic cells to convert suns energy into electricity Sun excites electrons causing them to flow  electricity Advantages: Advantages: –Renewable –No emissions produced (no greenhouse gasses) Disadvantages: Disadvantages: –Photovoltaic cells are expensive up front –No electricity at night / cloudy days –Not all locations are suitable

6. Solar Thermal power plants – mirrors concentrate suns heat energy on an oil, which gets extremely hot. Then oil is used to produce steam, steam turns turbine and produces electricity Solar Thermal power plants – mirrors concentrate suns heat energy on an oil, which gets extremely hot. Then oil is used to produce steam, steam turns turbine and produces electricity Does not use photovoltaic cells Does not use photovoltaic cells Alternative Energy Sources

7. Wind – use wind to turn a turbine  turns generator  producing electricity  How is wind created?  Sun - warmed air rises and colder air flows in behind = wind  Advantages:  No emission / pollution  Renewable  Disadvantages:  Not suitable for all locations  Noise Alternative Energy Sources

8. Biofuels – converting plant matter into fuels as an alternative to gasoline Plants used = corn, sugarcane, switchgrass Plants used = corn, sugarcane, switchgrass Biodiesel – using vegetable oil instead of diesel Biodiesel – using vegetable oil instead of diesel Ethanol – alcohol produced from sugars of the plant – used as alternative to gasoline. Ethanol – alcohol produced from sugars of the plant – used as alternative to gasoline. Carbon Neutral – even though burning biofuels releases CO 2, biofuels come from plants, which take in CO 2 … = carbon neutral Carbon Neutral – even though burning biofuels releases CO 2, biofuels come from plants, which take in CO 2 … = carbon neutral –problem = farm machinery, fertilizers, pesticides all use fossil fuels … = not neutral Alternative Energy Sources

9. Advantages: –Renewable –“Neutral” Emissions –Reduce dependency on foreign countries for oil Disadvantages: –Land limitations (not enough) –Cause food prices to rise (use corn for fuel instead of food) –Still produces emissions Alternative Energy Sources

10. Hydroelectric – using falling water to turn turbines  turn generator  electricity Advantages: No emissions / pollution No emissions / pollution Renewable Renewable Flood control Flood control Disadvantages: Expensive to build Expensive to build Dam floods huge area Dam floods huge area Limited locations Limited locations Damage ecosystems / organisms (ex. Migrating salmon) … fish ladder Damage ecosystems / organisms (ex. Migrating salmon) … fish ladder Alternative Energy Sources

11. Geothermal – using earths heat to produce steam, which turns a turbine  electricity Advantages: Advantages: –few greenhouse gas emissions –No fuel needed –Renewable Disadvantages: Disadvantages: –Limited locations –Location may cool off –Still produces some greenhouse gasses Alternative Energy Sources Period 4O stopped on 4-26

12. Ground Source Geothermal – using the constant temperatures of the ground to heat or cool your house. Alternative Energy Sources

13. Nuclear – splitting of uranium atom (fission reaction) to produce heat  boils water  steam turns turbines  turns generator  electricity Nuclear – splitting of uranium atom (fission reaction) to produce heat  boils water  steam turns turbines  turns generator  electricity Advantages: No emissions No emissions Very efficient energy production Very efficient energy production Cost effective (electricity is about the same price as coal) Cost effective (electricity is about the same price as coal) Disadvantages: Nonrenewable (uranium supply will run out) Nonrenewable (uranium supply will run out) Radioactive waste (must store for years) Radioactive waste (must store for years) Possible meltdown spreading radioactivity (like Chernobyl, Three Mile Island, Japan) Possible meltdown spreading radioactivity (like Chernobyl, Three Mile Island, Japan) Alternative Energy Sources Periods 3E, 4E, 6O, 4O & 6E

14. Extra Notes… Three Mile Island (1979) Three Mile Island (1979) –Nuclear power plant that melted down (radiation leak)… –…but NO explosion spreading the radioactive materials

15. Extra Notes… Chernobyl, Russia (1986) Chernobyl, Russia (1986) –Nuclear meltdown AND explosion –336,000 people had to move –About 30 direct deaths –Predicted 4,000 extra cancer deaths in exposed people

16. Tidal – use coming in and out of the tides to turn a turbine  turn generator  electricity Advantages: Renewable Renewable No emission No emission Disadvantages: Limited locations (need large difference between high and low tide) Limited locations (need large difference between high and low tide) Only produce energy when tides are moving Only produce energy when tides are moving Costs of maintaining Costs of maintaining Alternative Energy Sources

17. Wave – using up and down motion of waves to create electricity How are waves created? –Created by the wind Advantages: Renewable Renewable No emissions No emissions Disadvantages: Need large waves Need large waves Must survive storms + salt H 2 O Must survive storms + salt H 2 O … cost of maintaining Alternative Energy Sources

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

19. Question of the Day 1. Which energy sources involve the production of steam  use notes from presentations if necessary 11-12

20. Extra Notes Carbon Footprint Carbon Footprint –Amount of carbon dioxide you are responsible for producing

21. Carbon Footprint http://www.kohler.com/video/index.js p?bcpid=823619074&bclid=20371084 3&bctid=769369332 http://www.kohler.com/video/index.js p?bcpid=823619074&bclid=20371084 3&bctid=769369332 http://www.kohler.com/video/index.js p?bcpid=823619074&bclid=20371084 3&bctid=769369332 http://www.kohler.com/video/index.js p?bcpid=823619074&bclid=20371084 3&bctid=769369332 http://www.kohler.com/video/index.jsp ?bcpid=823619074&bclid=203710843 &bctid=769369332 http://www.kohler.com/video/index.jsp ?bcpid=823619074&bclid=203710843 &bctid=769369332 http://www.kohler.com/video/index.jsp ?bcpid=823619074&bclid=203710843 &bctid=769369332 http://www.kohler.com/video/index.jsp ?bcpid=823619074&bclid=203710843 &bctid=769369332

22. Where did the energy in fossil fuels come from? Fossil fuels were originally …….. Fossil fuels were originally …….. –….plants and animals. These organisms got their energy from the… These organisms got their energy from the… –…sun. They died, and didn’t… They died, and didn’t… –…fully decompose So the sun’s energy never was recycled and is now in the fossil fuels So the sun’s energy never was recycled and is now in the fossil fuels

23. Where does all the carbon in the fossil fuel come from? Plants need... Plants need... –…Soil, water, sun and CO2! CO2 was taken from the atmosphere by plants millions of years ago. CO2 was taken from the atmosphere by plants millions of years ago. Plants were never decomposed, thus the C (carbon) was stored for millions of years. Plants were never decomposed, thus the C (carbon) was stored for millions of years.

25. RIVER RESERVOIR