Successfully reported this slideshow.
Chapter 20 Energy Efficiency & Renewable Energy
Where are we going? 1.  Energy efficiency 2.  Solar energy 3.  Hydropower 4.  Wind Power 5.  Biomass 6. Solar–hydrogen rev...
1. Energy Efficiency percentage of energy input that does useful work in an energy conversion system Fig. 20–4 © Brooks/Co...
 
Net Energy Efficiency Fig. 20–5 © Brooks/Cole Publishing Company / ITP
Net Energy Efficiency Fig. 20–5 © Brooks/Cole Publishing Company / ITP
Energy Waste 43% in U.S. Fig. 20–2 © Brooks/Cole Publishing Company / ITP
 
Reducing Waste <ul><li>allows nonrenewable fuels to last longer </li></ul><ul><li>gives time to phase in renewable energy ...
Improving Efficiency <ul><li>cogeneration </li></ul><ul><ul><li>production of two useful forms of energy from the same fue...
2. Solar Energy © Brooks/Cole Publishing Company / ITP
Costs Fig. 20–15 © Brooks/Cole Publishing Company / ITP
Passive Fig. 20–16 sunlight captured directly & used for space heating © Brooks/Cole Publishing Company / ITP
Suitability Fig. 20–19 best when more than 60% of daylight hours sunny © Brooks/Cole Publishing Company / ITP
Active Fig. 20–17 uses fans or pumps to distribute heat © Brooks/Cole Publishing Company / ITP
<ul><li>Pros </li></ul><ul><li>solar energy free </li></ul><ul><li>net energy yield high for passive, moderate for active ...
Photovoltaic Cells (PVs) Fig. 20–23 © Brooks/Cole Publishing Company / ITP
Fig.20–23 © Brooks/Cole Publishing Company / ITP
High Temperature Systems Fig. 20–21 © Brooks/Cole Publishing Company / ITP
3. Hydropower <ul><li>hydroelectric dams </li></ul><ul><li>tides & waves </li></ul><ul><li>ocean thermal energy conversion...
<ul><li>Pros </li></ul><ul><li>do not emit polluting or greenhouse gases  </li></ul><ul><li>high net energy yields for dam...
4. Wind Fig. 20–29 © Brooks/Cole Publishing Company / ITP
Pros <ul><li>unlimited source of energy at favorable sites </li></ul><ul><li>moderate to high net energy yield </li></ul><...
Cons <ul><li>economical only in areas with steady winds </li></ul><ul><li>back–up energy sources are necessary </li></ul><...
5. Biomass Fig. 20–31 © Brooks/Cole Publishing Company / ITP
Burning Wastes <ul><li>crop residues & animal manure can be burned or converted into biofuels </li></ul><ul><li>urban wast...
<ul><li>Pros </li></ul><ul><li>potentially renewable </li></ul><ul><li>high net energy yield if burned near source </li></...
6. Geothermal Fig. 20–35 © Brooks/Cole Publishing Company / ITP
<ul><li>Pros </li></ul><ul><li>vast, reliable, sometimes renewable </li></ul><ul><li>produces low pollution & carbon dioxi...
7. Solar – hydrogen revolution Fig. 20–33 © Brooks/Cole Publishing Company / ITP
<ul><li>Pros </li></ul><ul><li>source of hydrogen: water, plentiful </li></ul><ul><li>produces no carbon dioxide & low pol...
In the long run, humanity has no choice but to rely on renewable energy.  No matter how abundant they seem today, eventual...
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Upcoming SlideShare
Loading in …5
×

Energy

530 views

Published on

Published in: Education, Technology, Business
  • Be the first to comment

  • Be the first to like this

Energy

  1. 1. Chapter 20 Energy Efficiency & Renewable Energy
  2. 2. Where are we going? 1. Energy efficiency 2. Solar energy 3. Hydropower 4. Wind Power 5. Biomass 6. Solar–hydrogen revolution 7. Geothermal 8. Sustainability © Brooks/Cole Publishing Company / ITP
  3. 3. 1. Energy Efficiency percentage of energy input that does useful work in an energy conversion system Fig. 20–4 © Brooks/Cole Publishing Company / ITP
  4. 5. Net Energy Efficiency Fig. 20–5 © Brooks/Cole Publishing Company / ITP
  5. 6. Net Energy Efficiency Fig. 20–5 © Brooks/Cole Publishing Company / ITP
  6. 7. Energy Waste 43% in U.S. Fig. 20–2 © Brooks/Cole Publishing Company / ITP
  7. 9. Reducing Waste <ul><li>allows nonrenewable fuels to last longer </li></ul><ul><li>gives time to phase in renewable energy </li></ul><ul><li>decreases dependence on oil imports </li></ul><ul><li>reduces environmental damage </li></ul><ul><li>slows global warming </li></ul><ul><li>saves money </li></ul>© Brooks/Cole Publishing Company / ITP
  8. 10. Improving Efficiency <ul><li>cogeneration </li></ul><ul><ul><li>production of two useful forms of energy from the same fuel source </li></ul></ul><ul><li>energy conservation; efficient lighting & appliances </li></ul><ul><li>increases in vehicle fuel efficiency; use of alternative fuels </li></ul><ul><li>better insulation </li></ul>© Brooks/Cole Publishing Company / ITP
  9. 11. 2. Solar Energy © Brooks/Cole Publishing Company / ITP
  10. 12. Costs Fig. 20–15 © Brooks/Cole Publishing Company / ITP
  11. 13. Passive Fig. 20–16 sunlight captured directly & used for space heating © Brooks/Cole Publishing Company / ITP
  12. 14. Suitability Fig. 20–19 best when more than 60% of daylight hours sunny © Brooks/Cole Publishing Company / ITP
  13. 15. Active Fig. 20–17 uses fans or pumps to distribute heat © Brooks/Cole Publishing Company / ITP
  14. 16. <ul><li>Pros </li></ul><ul><li>solar energy free </li></ul><ul><li>net energy yield high for passive, moderate for active </li></ul><ul><li>technology well developed & easily installed </li></ul><ul><li>takes up little land space </li></ul><ul><li>does not emit polluting or greenhouse gases </li></ul><ul><li>Cons </li></ul><ul><li>low economic incentive </li></ul><ul><li>need solar rights </li></ul><ul><li>solar collectors ugly to some </li></ul><ul><li>active systems costly </li></ul>© Brooks/Cole Publishing Company / ITP
  15. 17. Photovoltaic Cells (PVs) Fig. 20–23 © Brooks/Cole Publishing Company / ITP
  16. 18. Fig.20–23 © Brooks/Cole Publishing Company / ITP
  17. 19. High Temperature Systems Fig. 20–21 © Brooks/Cole Publishing Company / ITP
  18. 20. 3. Hydropower <ul><li>hydroelectric dams </li></ul><ul><li>tides & waves </li></ul><ul><li>ocean thermal energy conversion & solar ponds </li></ul><ul><li>see Fig. 20–27 </li></ul>© Brooks/Cole Publishing Company / ITP
  19. 21. <ul><li>Pros </li></ul><ul><li>do not emit polluting or greenhouse gases </li></ul><ul><li>high net energy yields for dams & moderate for solar ponds </li></ul><ul><li>Cons </li></ul><ul><li>dams flood upstream habitats & alter downstream habitats </li></ul><ul><li>few areas right conditions to use tides & waves </li></ul><ul><li>thermal energy from bodies of water cannot compete economically </li></ul>© Brooks/Cole Publishing Company / ITP
  20. 22. 4. Wind Fig. 20–29 © Brooks/Cole Publishing Company / ITP
  21. 23. Pros <ul><li>unlimited source of energy at favorable sites </li></ul><ul><li>moderate to high net energy yield </li></ul><ul><li>easy to build & expand </li></ul><ul><li>emit no pollutants or greenhouse gases </li></ul><ul><li>land can also be used for agriculture </li></ul>© Brooks/Cole Publishing Company / ITP
  22. 24. Cons <ul><li>economical only in areas with steady winds </li></ul><ul><li>back–up energy sources are necessary </li></ul><ul><li>mass production takes up large land space </li></ul><ul><li>noise pollution </li></ul><ul><li>interference with migrating birds </li></ul>© Brooks/Cole Publishing Company / ITP
  23. 25. 5. Biomass Fig. 20–31 © Brooks/Cole Publishing Company / ITP
  24. 26. Burning Wastes <ul><li>crop residues & animal manure can be burned or converted into biofuels </li></ul><ul><li>urban wastes can be burned in incinerators to produce electricity & heat </li></ul>© Brooks/Cole Publishing Company / ITP
  25. 27. <ul><li>Pros </li></ul><ul><li>potentially renewable </li></ul><ul><li>high net energy yield if burned near source </li></ul><ul><li>Cons </li></ul><ul><li>currently exploited in nonrenewable & unsustainable ways </li></ul><ul><li>single–species biomass plantations reduce biodiversity </li></ul><ul><li>burning wood produces air pollutants & greenhouse gases </li></ul>© Brooks/Cole Publishing Company / ITP
  26. 28. 6. Geothermal Fig. 20–35 © Brooks/Cole Publishing Company / ITP
  27. 29. <ul><li>Pros </li></ul><ul><li>vast, reliable, sometimes renewable </li></ul><ul><li>produces low pollution & carbon dioxide </li></ul><ul><li>Cons </li></ul><ul><li>scarcity of suitable sites </li></ul><ul><li>noise, odor, & local climate change </li></ul><ul><li>mostly not economically feasible </li></ul>© Brooks/Cole Publishing Company / ITP
  28. 30. 7. Solar – hydrogen revolution Fig. 20–33 © Brooks/Cole Publishing Company / ITP
  29. 31. <ul><li>Pros </li></ul><ul><li>source of hydrogen: water, plentiful </li></ul><ul><li>produces no carbon dioxide & low pollution </li></ul><ul><li>Cons </li></ul><ul><li>hydrogen only way to store energy </li></ul><ul><li>some air pollution (especially nitrogen oxides) </li></ul><ul><li>currently nonrenewable energy sources used to generate hydrogen </li></ul>© Brooks/Cole Publishing Company / ITP
  30. 32. In the long run, humanity has no choice but to rely on renewable energy. No matter how abundant they seem today, eventually coal & uranium will run out. –– Daniel Deudney & Christopher Flavin © Brooks/Cole Publishing Company / ITP

×