RENEWABLE ENERGY

1. RENEWABLE ENERGY CH. 12

4. PASSIVE SOLAR HEATING BUILDING PLACEMENT, MATERIAL, AND DESIGN ex: LARGE SOUTH-FACING WINDOWS (N. Hemisphere) WITH GOOD INSULATION; HEAT MOVES BY CONVECTION Prevent heat loss at night Attract heat in day

6. ACTIVE SOLAR HEATING ACTIVE SOLAR

7. SOLAR PROS CONS No air pollutants Little maintenance Not all areas get enough reliable sun High start-up costs INCENTIVES: tax break or rebate for installation New technology should lower costs

8. Photovoltaic Solar Cells • Can be incorporated into building materials • Roofing shingles • Tile • Window glass

10. wind • Fastest growing alt. • Costly to build, loud, bird flight patterns • No pollution, muliple use land • 19% world

11. HYDROGEN FUEL CELLS • SPLIT H2O (photovoltaic cells or wind); requires energy; needs to be cheaper • No Sox, no CO2, some Nox (N + O + heat) Hydrogen powered cars

12. Hydrogen as a Fuel Source-Electrolysis

13. HYDROELECTRIC

14. No pollutants • Thermal pollution • Dams rivers  destruction of habitats, people uprooted • Silting • Salmon • Water loss due to evaporation • Flood control (also, channels, identify flood prone areas, levees, wetlands intact) • Breeding for disease vectors (mosquitoes & snails): malaria and schistosomiasis • Many rivers in US protected under Wild and Scenic Rivers Act CASE STUDY: THREE GORGES DAM, CHINA

15. Small scale hydroelectric • No dams - no reduced salmon populations, no reduced silt/nutrients down stream • so no reservoir – no flooding of ecosystem upstream, no excessive water evaporation, no water-borne disease vectors • Less river flow (less snow melt) in summer = less energy in summer

16. BIOMASS • Any carbon-based, biologically derived fuel source (wood, manure, charcoal, biogas – biodiesel, ethanol) • ½ of renewable in US; 3% of all US energy • Common plants – corn/sugarcane. • Modern carbon vs fossil carbon • +: could use wastes, reduce ff use, offset CO2 by planting trees, no SOx • -: requires land/water/ff to grow, competes with growing food, take crops waste from soil, deforestation, ethanol = less energy content • Biogas (like methane) produced using a biogas digester (right pH, moisture) for bacteria • Or liquid (biodiesel, ethanol) for engines. • Gasoline + ethanol = gasohol

17. BRAZIL

18. Ocean waves

19. Ocean Thermal Energy (OTEC) • future • Temperature gradients between top and bottom (from sun) • Top water pumped (takes energy) into power plant to boil liquid (ammonia) to create steam and drive a turbine.

21. Renewable, but not direct/indirect solar TIDAL GEOTHERMAL POPULAR IN ICELAND; US MAKES MOST

22. ENERGY CONSERVATION and EFFICIENCY • Reduce emissions, buy time, save energy for later • Energy consumption greatest in HDC, but quickly growing in LDC as standard of living increases • Efficient appliances (Energy Star) • Efficient vehicles • Florescent lightbulbs use 25% energy of incandescent bulbs • 2001 refrigerator 75% less energy than 1970s (save $135 per yr)

23. Efficiency calculations • Percent efficiency = Output/input (100%) that is…. • (Useful energy produced/total energy inputted)

24. Saving Energy at Home

27. THE ROLE OF RENEWABLE ENRGY CONSUMPTION IN THE NATION’S ENERGY SUPPLY, 2004 AND 2009. 2009 2004

28. ENERGY AND VEHICLES2/3 OF US PETROLEUM USAGE IS FOR TRANPORTATION

29. 3% US; primary transportation for others • Buses, trolleys, trains, subways – carry more MASS TRANSIT