1. “new” alternative energy sources

2. How do energy conscious people feel about wind power? They were blown away

3. SOLAR - from sun’s radiation WIND - from wind GEOTHERMAL - from heat & heated water below ground OCEAN - from tides & waves HYDROGEN FUEL CELLS - from hydrogen

4. Most of the renewable generated electricity is from hydropower.

6. SOLAR - if all of sun’s energy that reaches earth could be captured, we could meet current humans demands at a rate of 27 years/day of sunlight. History: First known thermal solar collector: 1767 First commercial solar water heaters: 1890

7. Sun-tracking mirrors (heliostats) reflect sunlight to a receiver that heats to the tower & heats salt to a liquid. Hot salt is pumped to a steam generating system which turns the turbine...

8. Photovoltaic cells (PV cells) Convert solar energy into electrical energy using the photoelectric effect. Photons (units of light) strike a metal (such as selenium) causing an electron to be emitted. P- type is positive, N-type is negative. Electrodes attached allow electricity to flow.

9. PASSIVE SOLAR Windows, walls and floors are made to collect, store & distribute solar energy. Does NOT use mechanical or electrical devices

10. PROS Renewable if sun is shining Abundant Allows for local control over power Solar cookers lessen work loads in developing nations No direct greenhouse gas emissions CONS Not everywhere is sunny Initial investment is high. Takes several years to pay for itself.

12. wind power Converts kinetic energy to electrical energy Fastest growing power source today Wind turbine blades spin a generator

13. generator disc brake.

14. Mostly used in Germany, then the U.S. and Spain.

16. PROSCONS Renewable if wind blows Windy sites need to be near population centers No emissions after installed Aesthetics and noise More local controlBlades may kill birds, bats Costs low and dropping after initial investment High start up cost

17. GEOTHERMAL ENERGY Radioactive decay of elements in core creates heat that rises toward the surface magma geyser

18. Geothermal power plants Maintains pressure

19. geothermal pros Renewable Lower greenhouse emissions than fossil fuels Inexpensive in some areas (Iceland) Cons Hot spots of heated water migrate Aquifer pressure drops Salts in water corrode equipment Limited to geographic regions where heating naturally occurs

21. Energy from Oceans Tidal Power: twice-daily tides create water movement that can be used to turn turbines... (similar to hydroelectric dam) Wave Power: Motion at ocean shores can be used to turn turbines...

22. Tidal power plant, estuary of Rance River, Bretagne, France water movement 4 times daily

23. Oahu, Hawaii

24. OCEAN POWER PROS: Renewable No greenhouse gas emissions CONS: Development takes up coast line that is valuable for other uses. Could interfere with ecology of estuaries and intertidal shorelines

26. How many APES students does it take to change a light bulb? None! They’re smart enough to use energy- efficient compact fluorescent bulbs, which rarely need to be replaced.