1. Chapter 16 Energy Efficiency and Renewable Energy

2. We Waste Huge Amounts of Energy (1)
Energy efficiency
Advantages of reducing energy waste:
Quick and clean
Usually the cheapest to provide more energy
Reduce pollution and degradation
Slow global warming
Increase economic and national security

3. We Waste Huge Amounts of Energy (2)
Four widely used devices that waste energy
Incandescent light bulb
Motor vehicle with internal combustion engine
Nuclear power plant
Coal-fired power plant

4. Flow of Commercial Energy through the U.S. Economy
Figure 16.2: This diagram shows how commercial energy flows through the U.S. economy. Only 16% of all commercial energy used in the United States ends up performing useful tasks; the rest of the energy is unavoidably wasted because of the second law of thermodynamics (41%) or is wasted unnecessarily (43%). Question: What are two examples of unnecessary energy waste? (Data from U.S. Department of Energy)
Fig. 16-2, p. 399

5. Advantages of Reducing Energy Waste
Figure 16.3: Reducing unnecessary energy waste and thereby improving energy efficiency provides several benefits. Amory Lovins estimates that in the United States “we could save at least half the oil and gas and three-fourths of the electricity we use at a cost of only about an eighth of what we’re now paying for these forms of energy.” Questions: Which two of these benefits do you think are the most important? Why?
Fig. 16-3, p. 399

6. We Can Save Energy and Money in Industry and Utilities (1)
Cogeneration or combined heat and power (CHP)
Two forms of energy from same fuel source
Replace energy-wasting electric motors
Recycling materials
Switch from low-efficiency incandescent lighting to higher-efficiency fluorescent and LED lighting

7. LEDs
Figure 16.4: These small, light-emitting diodes (LEDs) come in different colors (left) and contain no toxic elements. They are being used for industrial and household lighting, and also in Christmas tree lights, traffic lights (right), street lights, and hotel conference and dining room lighting. LEDs last so long (about 100,000 hours) that users can install them and forget about them. LED bulbs are expensive but prices are projected to drop because of newer designs and mass production. Shifting to energy-efficient fluorescent lighting in homes, office buildings, stores, and factories and to LEDs in all traffic lights would save enough energy to close more than 700 of the world’s coal-burning electric power plants.
Fig. 16-4, p. 401

8. We Can Save Energy and Money in Industry and Utilities (2)
Electrical grid system: outdated and wasteful
Utility companies switching from promote use of energy to promoting energy efficiency
Spurred by state utility commissions

9. Case Study: Saving Energy and Money with a Smarter Electrical Grid
Smart grid
Ultra-high-voltage
Super-efficient transmission lines
Digitally controlled
Responds to local changes in demand and supply
Two-way flow of energy and information
Smart meters show consumers how much energy each appliance uses
U.S cost -- $200-$800 billion; save $100 billion/year

10. Proposed U.S. Smart Grid
Figure 20, Supplement 8

11. We Can Save Energy and Money in Transportation
Corporate average fuel standards (CAFE) standards
Fuel economy standards lower in the U.S. countries
Fuel-efficient cars are on the market
Hidden prices in gasoline: $12/gallon
Car manufacturers and oil companies lobby to prevent laws to raise fuel taxes
Should there be a feebate?

12. Average Fuel Economy of New Vehicles Sold in the U. S
Average Fuel Economy of New Vehicles Sold in the U.S. and Other Countries
Figure 16.5: This diagram shows changes in the average fuel economy of new vehicles sold in the United States, 1975–2008 (left) and the fuel economy standards in other countries, 2002–2008 (right). (Data from U.S. Environmental Protection Agency, National Highway Traffic Safety Administration, and International Council on Clean Transportation)
Fig. 16-5, p. 402

13. More Energy-Efficient Vehicles Are on the Way
Superefficient and ultralight cars
Gasoline-electric hybrid car
Plug-in hybrid electric vehicle
Energy-efficient diesel car
Electric vehicle with a fuel cell

14. Solutions: A Hybrid-Gasoline-Electric Engine Car and a Plug-in Hybrid Car
Figure 16.6: Solutions.
A conventional gasoline–electric hybrid vehicle (left) has a small internal combustion engine and a battery. A plug-in hybrid vehicle (right) has a smaller internal combustion engine with a second and more powerful battery that can be plugged into a 110-volt or 220-volt outlet and recharged. This allows it to run farther on electricity alone.
Fig. 16-6, p. 403

15. Science Focus: The Search for Better Batteries
Current obstacles
Storage capacity
Overheating
Flammability
Cost
In the future
Lithium-ion battery
Viral battery
Ultracapacitor

16. We Can Design Buildings That Save Energy and Money
Green architecture
Living or green roofs
Superinsulation
U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED)

17. A Green Roof in Chicago
Figure 16.8: City Hall in Chicago, Illinois (USA), has a green or living roof—an important part of the city’s efforts to become a more sustainable green city. Such a roof can save energy used to heat and cool the building. It absorbs heat from the summer sun, which would otherwise go into the building, and it helps to insulate the structure and retain heat in the winter. In addition, it absorbs precipitation, which would normally become part of the city’s storm water runoff and add to pollution of its waterways.
Fig. 16-8, p. 405

18. A Thermogram Shows Heat Loss
Figure 16.9: This thermogram, or infrared photo, shows heat losses (red, white, and orange) around the windows, doors, roofs, and foundations of houses and stores in Plymouth, Michigan (USA). Many homes and buildings in the United States and other countries are so full of leaks that their heat loss in cold weather and heat gain in hot weather are equivalent to what would be lost through a large, window-sized hole in a wall of the house. Question: How do you think the place where you live would compare to these buildings in terms of heat loss and the resulting waste of money spent on heating and cooling bills?
Fig. 16-9, p. 406

19. Individuals Matter: Ways in Which You Can Save Money Where You Live
Figure 16.10: Individuals matter.
You can save energy where you live. Question: Which of these things do you do?
Fig , p. 407

20. Why Are We Still Wasting So Much Energy?
Energy remains artificially cheap
Government subsidies
Tax breaks
Prices don’t include true cost
Few large and long-lasting incentives
Rebates
Low-interest loans

21. We Can Use Renewable Energy to Provide Heat and Electricity
Solar energy: direct or indirect
Geothermal energy
Benefits of shifting toward renewable energy
Renewable energy cheaper if we eliminate
Inequitable subsidies
Inaccurate prices
Artificially low pricing of nonrenewable energy

22. We Can Heat Buildings and Water with Solar Energy
Passive solar heating system
Active solar heating system

23. Solutions: Passive and Active Solar Heating for a Home
Figure 16.11: Solutions.
Homes can be heated with passive or active solar systems.
Fig , p. 409

24. Passive Solar Home in Colorado
Figure 16.12: This passive solar home (left) in Golden, Colorado (USA), collects and stores incoming solar energy which provides much of its heat in a climate with cold winters. Such homes also have the best available insulation in their walls and ceilings, and energy-efficient windows to slow the loss of stored solar energy. Notice the solar hot water heating panels in the yard. Some passive solar houses like this one (see photo on right) in Dublin, New Hampshire (USA), have attached sunrooms that collect incoming solar energy.
Fig , p. 410

25. Rooftop Solar Hot Water on Apartment Buildings in Kunming, China
Figure 16.13: Rooftop solar hot water heaters, such as those shown here on apartment buildings in the Chinese city of Kunming in the province of Yunnan, are now required on all new buildings in China, and their use is growing rapidly in urban and rural areas.
Fig , p. 410

26. Trade-Offs: Passive or Active Solar Heating
Figure 16.14: Heating a house with a passive or active solar energy system has advantages and disadvantages (Concept 16-3). Questions: Which single advantage and which single disadvantage do you think are the most important? Why?
Fig , p. 411

27. World Availability of Direct Solar Energy
Figure 22, Supplement 8

28. U.S. Availability of Direct Solar Energy
Figure 23, Supplement 8

29. We Can Cool Buildings Naturally
Technologies available
Open windows when cooler outside
Use fans
Superinsulation and high-efficiency windows
Overhangs or awnings on windows
Light-colored roof
Geothermal pumps

30. We Can Use Sunlight to Produce High-Temperature Heat and Electricity
Solar thermal systems
Central receiver system
Collect sunlight to boil water, generate electricity
1% of world deserts could supply all the world’s electricity
Require large amounts of water – could limit
Wet cooling
Dry cooling
Low net energy yields

31. Solar Thermal Power in California Desert
Figure 16.15: Solar thermal power: In this desert solar power plant (left) near Kramer Junction, California (USA), curved (parabolic) solar collectors concentrate solar energy and use it to produce electricity. The concentrated solar energy heats a fluid-filled pipe that runs through the center of each trough. The concentrated heat in the fluid is used to produce steam that powers a turbine that generates electricity. Such plants also exist in desert areas of southern Spain, Australia, and Israel. In another approach (right), an array of computer-controlled mirrors tracks the sun and focuses reflected sunlight on a central receiver, sometimes called a power tower. This tower near Daggett, California (USA), can collect enough heat to boil water and produce steam for generating electricity. Excess heat in both systems can be released to the atmosphere by cooling towers. The heat can also be used to melt a certain kind of salt stored in a large insulated container. The heat stored in this molten salt system can then be released as needed to produce electricity at night. Such plants also exist in desert areas of southern Spain and North Africa. Because a power tower heats water to higher temperatures, it can have a higher net energy ratio than a parabolic trough system has.
Fig , p. 411

32. Trade-Offs: Solar Energy for High Temperature Heat and Electricity
Figure 16.16: Using solar energy to generate high-temperature heat and electricity has advantages and disadvantages (Concept 16-3). Questions: Which single advantage and which single disadvantage do you think are the most important? Why? Do you think that the advantages of using these technologies outweigh their disadvantages?
Fig , p. 412

33. Solutions: Solar Cooker in India
Figure 16.17: Solutions.
This woman in India is using a solar cooker to prepare a meal for her family.
Fig , p. 412

34. We Can Use Sunlight to Produce Electricity (1)
Photovoltaic (PV) cells (solar cells)
Convert solar energy to electric energy
Design of solar cells
Sunlight hits cells and releases electrons into wires
Benefits of using solar cells
Solar-cell power plants around the world

35. Solutions: Solar Cells on Rooftop and for Many Purposes
Figure 16.18: Solutions.
Photovoltaic (PV) or solar cells can provide electricity for a house or building using conventional solar panels such as those shown here (left) on the roof of a U.S. Postal Service processing and distribution center in Inglewood, California. They can also be incorporated into metal roofing materials that can simulate the look of ceramic roof tiles, as well as slate, wooden shake, or asphalt shingles in a wide variety of colors. A new plug-and-play light-weight modular rooftop solar cell system can be snapped together and installed in a few hours. In addition, new, flexible, thin-film solar cells (right) or even more efficient tiny silicon nanorods (made with the use of nanotechnology) can be applied to roofs, windows, building walls, bridges—almost any surface, even T-shirts.
Fig , p. 413

36. Solar Cell Array in Niger, West Africa
Figure 16.19: Solutions.
This system of solar cells provides electricity for a remote village in Niger, Africa. Question: Do you think your government should provide aid to help poor countries obtain solar-cell systems? Explain.
Fig , p. 413

37. Solar-Cell Power Plant in Arizona
Figure 16.20: This solar-cell power plant in the U.S. state of Arizona near the city of Springerville has been in operation since 2000 and is the world’s largest solar-cell power plant. Analysis shows that the plant, which is connected to the area’s electrical grid, paid back the energy needed to build it in less than 3 years.
Fig , p. 414

38. We Can Use Sunlight to Produce Electricity (2)
Key problems
High cost of producing electricity
Need to be located in sunny desert areas
Fossil fuels used in production
Solar cells contain toxic materials
Will the cost drop with
Mass production
New designs
Government subsidies and tax breaks

39. We Can Use Sunlight to Produce Electricity (3)
2040: could solar cells produce 16%?
Nanosolar: California (U.S.)
Germany: huge investment in solar cell technology
General Electric: entered the solar cell market

40. Global Production of Solar Electricity
Figure 11, Supplement 9

41. Trade-Offs: Solar Cells
Figure 16.21: Using solar cells to produce electricity has advantages and disadvantages (Concept 16-3). Questions: Which single advantage and which single disadvantage do you think are the most important? Why?
Fig , p. 414

42. We Can Produce Electricity from Falling and Flowing Water
Hydropower
Uses kinetic energy of moving water
Indirect form of solar energy
World’s leading renewable energy source used to produce electricity
Advantages and disadvantages
Micro-hydropower generators

43. Tradeoffs: Dams and Reservoirs
Figure 13.13: Trade-offs.
Large dams and reservoirs have advantages (green) and disadvantages (orange) (Concept 13-3). The world’s 45,000 large dams (15 meters (49 feet) or higher) capture and store about 14% of the world’s surface runoff, provide water for almost half of all irrigated cropland, and supply more than half the electricity used in 65 countries. The United States has more than 70,000 large and small dams, capable of capturing and storing half of the country’s entire river flow. Question: Which single advantage and which single disadvantage do you think are the most important?
Fig , p. 328

44. Trade-Offs: Large-Scale Hydropower, Advantages and Disadvantages
Figure 16.22: Using large dams and reservoirs to produce electricity has advantages and disadvantages (Concept 16-4). Questions: Which single advantage and which single disadvantage do you think are the most important? Why?
Fig , p. 415

45. Tides and Waves Can Be Used to Produce Electricity
Produce electricity from flowing water
Ocean tides and waves
So far, power systems are limited
Disadvantages
Few suitable sites
High costs
Equipment damaged by storms and corrosion

46. Using Wind to Produce Electricity Is an Important Step toward Sustainability (1)
Wind: indirect form of solar energy
Captured by turbines
Converted into electrical energy
Second fastest-growing source of energy
What is the global potential for wind energy?
Wind farms: on land and offshore

47. World Electricity from Wind Energy
Figure 12, Supplement 9

48. Solutions: Wind Turbine and Wind Farms on Land and Offshore
Figure 16.23: Solutions.
A single wind turbine (left) can produce electricity. Increasingly, they are interconnected in arrays of tens to hundreds of turbines. These wind farms or wind parks can be located on land (middle) or offshore (right). The land beneath these turbines can still be used to grow crops or to raise cattle. Questions: Would you object to having a wind farm located near where you live? Why or why not?
Fig , p. 417

49. Wind Turbine
Figure 16.24: Maintenance workers get a long-distance view from atop a wind turbine, somewhere in North America, built by Suzlon Energy, a company established in India in 1995.
Fig , p. 417

50. Using Wind to Produce Electricity Is an Important Step toward Sustainability (2)
Countries with the highest total installed wind power capacity
Germany
United States
Spain
India
Denmark
Installation is increasing in several other countries

51. Using Wind to Produce Electricity Is an Important Step toward Sustainability (3)
Advantages of wind energy
Drawbacks
Windy areas may be sparsely populated – need to develop grid system to transfer electricity
Winds die down; need back-up energy
Storage of wind energy
Kills migratory birds
“Not in my backyard”

52. Trade-Offs: Wind Power
Figure 16.25: Using wind to produce electricity has advantages and disadvantages (Concept 16-5). With sufficient and consistent government incentives, wind power could supply more than 10% of the world’s electricity and 20% of the electricity used in the United States by Questions: Which single advantage and which single disadvantage do you think are the most important? Why?
Fig , p. 418

53. United States Wind Power Potential
Figure 24, Supplement 8

54. We Can Get Energy by Burning Solid Biomass
Plant materials and animal waste we can burn or turn into biofuels
Production of solid mass fuel
Plant fast-growing trees
Biomass plantations
Collect crop residues and animal manure
Advantages and disadvantages

55. Trade-Offs: Solid Biomass
Figure 16.26: Burning solid biomass as a fuel has advantages and disadvantages (Concept 16-6a). Questions: Which single advantage and which single disadvantage do you think are the most important? Why?
Fig , p. 420

56. We Can Convert Plants and Plant Wastes to Liquid Biofuels (1)
Biodiesel
Ethanol
Biggest producers of biofuel
The United States
Brazil
The European Union
China

57. We Can Convert Plants and Plant Wastes to Liquid Biofuels (2)
Major advantages over gasoline and diesel fuel produced from oil
Biofuel crops can be grown almost anywhere
No net increase in CO2 emissions if managed properly
Available now

58. We Can Convert Plants and Plant Wastes to Liquid Biofuels (3)
Studies warn of problems:
Decrease biodiversity
Increase soil degrading, erosion, and nutrient leaching
Push farmers off their land
Raise food prices
Reduce water supplies, especially for corn and soy

59. Case Study: Is Biodiesel the Answer?
Biodiesel production from vegetable oil from various sources
95% produced by the European Union
Subsidies promote rapid growth in United States
Advantages and disadvantages

60. Trade-Offs: Biodiesel
Figure 16.27: Using biodiesel as a vehicle fuel has advantages and disadvantages compared to gasoline. Questions: Which single advantage and which single disadvantage do you think are the most important? Why? Do you think that the advantages of biodiesel fuel outweigh its disadvantages?
Fig , p. 421

61. World Ethanol Production
Figure 13, Supplement 9

62. Bagasse is Sugarcane Residue
Figure 16.28: Bagasse is a sugarcane residue that can be used to make ethanol.
Fig , p. 421

63. Natural Capital: Rapidly Growing Switchgrass
Figure 16.29: Natural capital.
The cellulose in this rapidly growing switchgrass can be converted into ethanol, but further research is needed to develop affordable production methods. This perennial plant can also help to slow projected climate change by removing carbon dioxide from the atmosphere and storing it as organic compounds in the soil.
Fig , p. 423

64. Trade-Offs: Ethanol Fuel
Figure 16.30: Using ethanol as a vehicle fuel has advantages and disadvantages compared to using gasoline (Concept 16-6b). Questions: Which single advantage and which single disadvantage do you think are the most important? Why?
Fig , p. 423

65. Case Study: Getting Gasoline and Diesel Fuel from Algae and Bacteria (1)
Algae remove CO2 and convert it to oil
Not compete for cropland = not affect food prices
Wastewater/sewage treatment plants
Could transfer CO2 from power plants
Algae challenges
Need to lower costs
Open ponds vs. bioreactors
Affordable ways of extracting oil
Scaling to large production

66. Case Study: Getting Gasoline and Diesel Fuel from Algae and Bacteria (2)
Bacteria: synthetic biology
Convert sugarcane juice to biodiesel
Need large regions growing sugarcane
Producing fuels from algae and bacteria can be done almost anywhere

67. Getting Energy from the Earth’s Internal Heat (1)
Geothermal energy: heat stored in
Soil
Underground rocks
Fluids in the earth’s mantle
Geothermal heat pump system
Energy efficient and reliable
Environmentally clean
Cost effective to heat or cool a space

68. Natural Capital: A Geothermal Heat Pump System Can Heat or Cool a House
Figure 16.31: Natural capital.
A geothermal heat pump system can heat or cool a house almost anywhere. It heats the house in winter by transferring heat from the ground into the house (shown here). In the summer, it cools the house by transferring heat from the house to the ground.
Fig , p. 425

69. Getting Energy from the Earth’s Internal Heat (2)
Hydrothermal reservoirs
U.S. is the world’s largest producer
Hot, dry rock
Geothermal energy problems
High cost of tapping hydrothermal reservoirs
Dry- or wet-steam geothermal reservoirs could be depleted
Could create earthquakes

70. Geothermal Sites in the United States
Figure 26, Supplement 8

71. Geothermal Sites Worldwide
Figure 25, Supplement 8

72. Geothermal Power Plant in Iceland
Figure 16.32: This geothermal power plant in Iceland produces electricity and heats a nearby spa called the Blue Lagoon.
Fig , p. 425

73. Trade Offs: Geothermal Energy
Figure 16.33: Using geothermal energy for space heating and for producing electricity or high-temperature heat for industrial processes has advantages and disadvantages (Concept 16-7). Questions: Which single advantage and which single disadvantage do you think are the most important? Why?
Fig , p. 426

74. Will Hydrogen Save Us? (1)
Hydrogen as a fuel
Eliminate most of the air pollution problems
Reduce threats of global warming
Some challenges
Chemically locked in water and organic compounds = net negative energy yield
Expensive fuel cells are the best way to use hydrogen
CO2 levels dependent on method of hydrogen production

75. Will Hydrogen Save Us? (2)
Net negative energy yield
Production and storage of H2
Hydrogen-powered vehicles: prototypes available
Can we produce hydrogen on demand?
Larger fuel cells – fuel-cell stacks

76. A Fuel Cell Separates the Hydrogen Atoms’ Electrons from Their Protons
Figure 16.34: A fuel cell takes in hydrogen gas and separates the hydrogen atoms’ electrons from their protons. The electrons flow through wires to provide electricity, while the protons pass through a membrane and combine with oxygen gas to form water vapor. Note that this process is the reverse of electrolysis, the process of passing electricity through water to produce hydrogen fuel. The photo (right) shows a fuel-cell concept car introduced by Honda Motor Company in 2009 at an international car show in Toronto, Canada. All of the exhaust from this car is water vapor.
Fig , p. 427

77. Trade-Offs: Hydrogen, Advantages and Disadvantages
Figure 16.35: Using hydrogen as a fuel for vehicles and for providing heat and electricity has advantages and disadvantages (Concept 16-8). Questions: Which single advantage and which single disadvantage do you think are the most important? Why?
Fig , p. 428

78. Solutions: Decentralized Power System
Figure 16.36: Solutions.
During the next few decades, we will probably shift from dependence on a centralized macropower system, based on a few hundred large coal-burning and nuclear power plants to a decentralized micropower system, in which electricity is produced by a large number of dispersed, small-scale, local power generating systems. Some of the smaller systems would produce power on site; others would feed the power they produce into a modern electrical distribution system. Over the next few decades, many energy and financial analysts expect a shift to this type of power system, largely based on locally available renewable energy resources. Question: Can you think of any disadvantages of a decentralized power system?
Fig , p. 430

79. Solutions: Making the Transition to a More Sustainable Energy Future
Figure 16.37: Energy analysts have made a number of suggestions for helping us make the transition to a more sustainable energy future (Concept 16-9). Questions: Which five of these solutions do you think are the most important? Why?
Fig , p. 431

80. Economics, Politics, Education, and Sustainable Energy Resources
Government strategies:
Keep the prices of selected energy resources artificially low to encourage their use
Keep energy prices artificially high for selected resources to discourage their use
Consumer education

81. What Can you Do? Shifting to More Sustainable Energy Use
Figure 16.38: Individuals matter.
You can reduce your use and waste of energy. Questions: Which three of these items do you think are the most important? Why? Which things in this list do you already do or plan to do?
Fig , p. 432