1. 26.2 Alternative Energy Resources Pages 690 - 697

2. Objective 1.0 Describe alternative energy resources

3. 1.Solar energy –Advantages Freely available No pollution –Disadvantages Nighttime Cloudy days Difficult to store solar energy

4. Passive solar heating –Building materials store and release heat Concrete Adobe Brick Stone Tile

5. Active solar heating –Solar panels absorb energy Heat water Stores energy as heat in rock or water tanks

6. Solar cookers –Reflective materials concentrate sunlight to heat pans

8. Photovoltaic cells –Convert sunlight energy to electrical energy

9. 2. Energy from Water –Advantages Little pollution Recreation Drinking water Irrigation

10. –Disadvantages Sediment accumulation above dam Stream bed erosion below dam Water quality degrades Environmental effects

11. Hydroelectric dams –Water moves past turbines –Turbines turn a generator –Generator produces electricity –20% of world’s electricity –U.S. 10% of electricity –Canada 70% of electricity

12. Image is PD-gov, by TVA

14. Barrier / tidal dams –Use of ocean waves Wave action moves a lever arm Lever arm turns turbines of generator –Use of tides Trapped tidal water is released over turbines

16. 3. Geothermal energy –Advantages Abundant and reliable at geothermal sites –Disadvantages Storage of cooled water Air and water pollution Disrupts ecosystems Hard to transport geothermal energy

17. Geothermal steam plant –Steam from vents turn turbines

18. 4. Wind energy –Advantages Readily available at favorable sites Cheap Easy to build Pollution free –Disadvantages Steady winds needed

19. Wind Farms –Flat, windy areas –Use of wind turbines to generate electricity

20. 5. Nuclear energy –Advantages No air pollution –Disadvantages Expensive, time consuming to build Time limits on nuclear plant operation Radioactive materials Waste product storage

21. Nuclear power plants –Nuclear fission reaction releases heat –Water turns to steam –Steam turns turbines to generate electricity –Water recycled

22. Boiling Water Reactor

23. A Typical Power Plant

24. 6. Biomass –Advantage Renewable –Disadvantages Air pollution

25. Biogas –Gas + methane mixture –Bacteria in a “digester” container create methane –Methane piped into home for burning

28. Ethanol and Methanol –Grain alcohols from crops –Used in gasoline “gasohol” –Extend gas supplies

29. 7. Oil shale and Tar Sand –Advantages Supplies petroleum-like substance –Disadvantages Processing is expensive Air and water pollution

30. Oil Shale –Kerogen substance found in oil shale –Kerogen vaporized then condensed –Result is “shale oil” Image: PD-gov

31. Tar Sand –“Bitumen” found in tar sand –Bitumen is high- sulfur content oil –Can be refined into a type of crude oil

32. Image: PD-gov