Renewable Energy Sources

1. Renewable Energy Sources

2. Cleaner Cars, Cleaner Fuels • Cars release a lot of pollution • 2005 • Bush administration • 7% improvement in mileage • 22.2 mpg • Diesel engines need work

3. Electrical Generation Costs

4. Solar Energy • Energy directly from the sun • Pros • Tremendous amount • Always available • Doesn’t pollute • Cons • Must be collected • Expensive to set up

5. Passive Solar Heating • No mechanical devices to distribute heat • New home design • Room temperature is steady • Convection • Save on heating!

6. A Passive Solar Home

7. Photovoltaic (PV) Solar Cells • Convert sunlight into electricity • Thin wafers or films • No pollution • Minimal maintenance

8. Photovoltaic (PV) Solar Cells • Can be used in remote areas • Good choice for developing countries: why? • School, home use

9. Photovoltaic (PV) Solar Cells • Can look like conventional roofing • Prices are coming down • Future progress is critical

10. Solar Thermal Electric Generation • Sun’s energy concentrated by mirrors, lenses • Heat a working fluid • Fluid is circulated to boil water • Steam generates electricity

11. Solar Thermal Electric Generation • Backup system needed • Very efficient • No pollution produced • Must be cost- competitive

12. Hydrogen As A Fuel Source • Could be the fuel of the future • Where does the hydrogen come from? • Electrolysis • Must use renewable fuel source to obtain the hydrogen! • Few pollutants produced when burned • Can be used for transportation

13. Biomass Energy • Wood, plants, animal wastes • Half of human population relies on for Cooking, heating • Pros • Potentially renewable: why? • Cons • Burned to release energy & pollutants

14. Biogas • Mixture of gases • Similar to natural gas • Animal wastes • Biogas digesters • Decompose wastes • Use gas for cooking, lighting • Solid remains are fertilizer • Can also be used to power fuel cells

15. Biogas Digester

16. Biomass As A Liquid Fuel • Methanol, ethanol • Gasohol: mix gasoline and ethanol • Biodiesel • Plant, animal oils • Becoming more popular • Burns cleaner than regular diesel

17. Ethanol • Sugarcane, corn, wood, agricultural and municipal wastes • Government subsidizes • Good outlet for some wastes • Problems • Land and water use • Soil erosion • Decreased food production

18. Wind Energy • Need steady winds • Fastest growing energy source • Pro: • No waste, emissions • Costs are declining • Denmark is a world leader • Great Plains of U.S.

19. Wind Power Is On The Rise!

20. Wind Energy Problems • Birds and bats killed by turbines • Avoid migration routes • Operate only at certain times • Monitor the project • Visual pollution • Maple Ridge, NY • Massachusetts coast

21. Hydropower • Flowing or falling water spins turbines • Most efficient way to produce electricity • 19% world’s electricity • 2200 U.S. plants

22. Hydropower Problems • Damages ecosystem, species • Displaces people: Three Gorges Dam • High construction cost • Reduces downstream flow • Reservoirs eventually fill in • Danger of collapse • Degrades river • Increase in waterborne disease: schistosomiasis

23. Geothermal Energy • Use energy from Earth’s interior • Pro • Big potential source • Hydrothermal reservoir: hot fluid • Bring fluid to surface to generate electricity

24. Geothermal Energy

25. Geothermal Energy • Cons: • Not located everywhere • Could run out…

26. Tidal Energy • Use power of the tides to generate electricity • Pros: • No pollution, free • France, Russia, China, Canada • Cons: • Very few ideal locations • May be damaging to ecosystems

27. Nuclear energy – Splits apart heavy atoms such as Uranium to release energy. Pros: - Produces largeamounts of power -Very little air or water pollution Cons: - Radioactive waste is produced -Possibility of radioactive meltdown.

28. Conservation & Efficiency • Energy conservation • Using less energy • Reduce use, waste • Carpooling • Energy efficiency • Using less energy for a task • More fuel-efficient cars • Both very important!

29. Energy Consumption Trends • Use is on the increase • Greatest increase in developing countries: why?

30. Energy-Efficient Technologies • Appliances, automobiles, light bulbs, furnaces, etc… • “Superinsulated” buildings • May cost more, but will save money!

31. Energy-Efficient Technologies • National Appliance Energy Conservation Act • Sets national standards • Much greater efficiency today • Invest in energy improvements now to save money in the long run

32. Automobile Efficiency • Has improved since 1970s: why? • Increased use of minivans, trucks, SUVs • Efficiency must continue to improve

33. Electric Companies & Energy Efficiency • Make more money, generate less electricity • Incentives for conservation • Help consumers save electricity • Light bulbs, furnaces • Company doesn’t have to invest in new power generation

34. Electric Companies & Energy Efficiency • Use cogeneration to save energy • Improve electricity grids • Some energy lost in transmission • Plan for future use

35. Energy Conservation At Home • Average household: $1500/year on utilities • Use energy-efficient technologies • Better insulation, windows • Seal cracks • Replace inefficient appliances

36. Energy Conservation At Home

37. Case Study: Green Architecture • Consider the environment when building • Energy conservation • Indoor air quality • Water conservation • Building materials

38. Case Study: Green Architecture • Adam Joseph Lewis Center for Environmental Studies, Oberlin College • Geothermal heat pump • PV cells for electricity • Triple-paned windows • Motion sensors • Recycle wastewater • Sustainable wood • Recycled carpet • http://www.oberlin.edu/ajlc/ajlcHome.html