1. Sustainable Energy Chapter 20

2. Everyday Ways to Save Energy ● LEDs (light-emitting diodes) ● Compact fluorescent bulbs ● limiting “vampire currents” ● Energy efficiency: a measure of energy produced compared to energy consumed.

3. Cogeneration Cogeneration: the simultaneous production of both electricity and steam or hot water in the same plant.

4. Green Buildings According to U.S. EPA ● 39% of total energy use ● 12% of total water consumption ● 68% of total electricity consumption ● 38% of the carbon dioxide emissions Updated: 10/9/2014

5. Regents Hall of Natural Sciences

6. Transportation

7. Solar Energy Ways of Obtaining Solar Energy: ● Passive heat absorption ● Active solar systems ● Concentrating Solar Power (CSP) plants ● Photovoltaic Cells

8. Passive Heat Absorption Using materials that collect and hold heat naturally. Ex: ● Stone or adobe dwellings ● Greenhouses ● Stone floors ● Barrels of water

9. Passive Solar Designs

10. Active Solar Systems Pumping a heat absorbing liquid (water or antifreeze) through a small heat collector.

11. Concentrating Solar Power (CSP) Mirrors shine on a tube or central tower filled with a heat absorbing fluid. Fluid goes through a heat exchanger, releasing steam and turning a turbine.

12. Advantages of CSP ● Store heat ● Seawater can be used to cool the system ● Produce drinking water

13. Great Solar Areas

14. Photovoltaic Cells Solar energy is converted directly into electricity.

15. Solar Energy in MN ● Minnesota Renewable Energy Society ● Minnesota Department of Commerce ● Xcel Energy

16. Northfield Solar Energy

17. Biomass Energy Includes: ● Wood, wood chips, bark, branches, leaves, starchy roots, and other plant and animal material

18. Burning Biomass Biomass with coal reduces greenhouse gas emissions and improves combustions properties. Smoke can be noxious and contribute to air pollution.

19. Creating Methane The anaerobic decomposition of any moist organic material creates methane:

20. Biofuels Ethanol and Biodiesel made from corn, soybeans, and sunflower. Palm oils are 8-10 times more productive, but are endangering native animals. Jatropha is 3 times more productive than palm oil, but is prone to disease.

21. Cellulosic Ethanol Sugarcane and sugar beets can be fermented into ethanol. Miscanthus may be the alternative.

22. The Future of Biomass Single-celled algae can grow 30 times as fast as higher plants. They are carbon negative. But, algal bioreactors are expensive.

23. Hydropower Dams ● Water turbines invented during the nineteenth century ● Generates 20% of world’s electric power ● Largest dam: Three Gorges Dam in China

24. Hydropower Dams Pros ● Renewable ● Clean Energy ● Reliable Cons ●Human displacement ●Ecosystem destruction ●Wildlife losses ●Floods ●Difficult to maintain water quality

25. Alternative Hydropower low-head hydropower: extracts energy from small headwater dams. micro-hydro generators: small turbines that can provide power for a single home run-of-the-river flow: high-efficiency turbines submerged directly in the stream.

26. Wind Energy ● kinetic energy-->electrical ● settlers used wind energy ● modern wind turbines: new and improved ● China leads world in wind energy market ● Offshore wind farms ● Windmills support farms Utilizing Wind in the US such windmills. very energy. wow.

27. Pros ● wind energy is very abundant ● the US is a good place for windmills ● uses least land, and provides most jobs ● no fuels costs or emissions ● shorter construction time than fossil fuel/nuclear facilities ● windmills can produce power for 90% of the day Cons ●high bird mortality ●not everywhere has strong winds ●the whooshing from windmills annoys people (heachaches, insomnia, panic attacks, digestive problems, other vague health issues) ●unsightly ●high initial down payment

28. Wind Energy in MN Wind Resources for Continental US ●National Leader in the wind energy industry ●large wind farms in Minnesota include the Buffalo Ridge Wind Farm, Fenton Wind Farm, Nobles Wind Farm, and the Bent Tree Wind farm ●Wind turbine on St. Olaf Campus! ● Carleton has 2 wind turbines (boo)

29. Fuel Cells ● Fuel cells use ongoing chemical reactions to produce an electric current. ● reverse electrolysis ● small size, high efficiency, no moving parts, highly reliable, quiet, clean operation ● no waste, only produces water ● fuel cells to power cars? ● fuel cells can be stacked to reach desired power level Stationary Fuel Cell System

30. Other Renewable Resources! Geothermal Energy -Energy drawn from the internal heat of earth -deep wells that pump heated ground water -earthquakes Tides and Waves -contain enormous amounts of energy -best locations for this energy: west coasts of Canada, US, South Africa, Australia -possible for waves to power 16% of global electrical output -variety of floating buoys, barges, cylinders Pelamis Wave Converter

31. The Future of Energy ● Wind, water, and Solar energy could supply 100% of world’s energy by 2030 ● We need political leaders to take global warming seriously ● Electric energy is much more efficient than burning fuels Renewable Energy Scenario for 2030