1. MILLER/SPOOLMAN
LIVING IN THE ENVIRONMENT 17TH
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
1. Incandescent light bulb
2. Motor vehicle with internal combustion engine
3. Nuclear power plant
4. Coal-fired power plant
5. 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. 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• Electrical grid system: outdated and wasteful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
8. 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
• 2016 - 39 miles per gallon for cars and 30 mpg for
trucks
• Hidden prices in gasoline: $12/gallon
• Car manufacturers and oil companies lobby to
prevent laws to raise fuel taxes
9. Average Fuel Economy of New Vehicles Sold in
the U.S. and Other Countries
Fig. 16-5, p. 402
10. 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
13. 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)
14. A Green Roof in Chicago-City Hall
Fig. 16-8, p. 405
15. We Can Save Money and Energy in Existing
Buildings (1)
• Conduct an energy survey
• Insulate and plug leaks
• Use energy-efficient windows
• Stop other heating and cooling losses
• Heat houses more efficiently
16. We Can Save Money and Energy in Existing
Buildings (2)
• Heat water more efficiently
• Use energy-efficient appliances
• Use energy-efficient lighting
19. 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
• Tax breaks
• Rebates
• Low-interest loans
20. We Can Use Renewable Energy to Provide
Heat and Electricity
• Renewable energy
• 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
21. We Can Heat Buildings and Water with
Solar Energy
• Passive solar heating system
• Active solar heating system
26. 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
27. 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
32. 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
34. 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
36. 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
37. 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
41. 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
42. 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”
43. Case Study: The Astounding Potential of
Wind Power in the United States
• “Saudi Arabia of wind power”
• North Dakota
• South Dakota
• Kansas
• Texas
• How much electricity is possible with wind farms in
those states?
• Could create up to 500,000 jobs
45. We Can Get Energy by Burning Solid
Biomass
• 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
46. We Can Convert Plants and Plant Wastes
to Liquid Biofuels (1)
• Liquid biofuels
• Biodiesel
• Ethanol
• Biggest producers of biofuel
• The United States
• Brazil
• The European Union
• China
47. We Can Convert Plants and Plant Wastes
to Liquid Biofuels (2)
• Major advantages over gasoline and diesel fuel
produced from oil
1.Biofuel crops can be grown almost anywhere
2.No net increase in CO2 emissions if managed properly
3.Available now
48. 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
51. 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
1. Need to lower costs
2. Open ponds vs. bioreactors
3. Affordable ways of extracting oil
4. Scaling to large production
52. 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
53. Natural Capital: A Geothermal Heat Pump
System Can Heat or Cool a House
Fig. 16-31, p. 425
54. 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
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 Energ y)
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.
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 )
Figure 16.6: S olutions. 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.
Figure 16.7: The body on this concept car, made of carbon-fiber composite, is much safer and stronger than a traditional car body and the car gets better mileage because of its greatly reduced weight. Such car bodies are expensive but further research and mass production could bring their prices down.
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.
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?
Figure 16.10: Individuals matter. You can save energy where you live. Question: Which of these things do you do?
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.
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.
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.
Figure 16.17: S olutions. This woman in India is using a solar cooker to prepare a meal for her family.
Figure 16.19: S olutions. 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.
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 .
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?
Figure 16.23: S olutions. 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?
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.
Figure 16.28: Bagasse is a sugarcane residue that can be used to make ethanol.
Figure 16.29: N atural 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.
Figure 16.31: N atural 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.
Figure 16.32: This geothermal power plant in Iceland produces electricity and heats a nearby spa called the Blue Lagoon.
