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Chapter 16 Energy Efficiency and Renewable Energy. 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 - PowerPoint PPT Presentation
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17THMILLER/SPOOLMAN
LIVING IN THE ENVIRONMENT
Chapter 16Energy Efficiency and Renewable Energy
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
We Waste Huge Amounts of Energy (2)• Four widely used devices that waste energy
1. Incandescent light bulb2. Motor vehicle with internal combustion engine3. Nuclear power plant4. Coal-fired power plant
Flow of Commercial Energy through the U.S. Economy
Fig. 16-2, p. 399
Advantages of Reducing Energy Waste
Fig. 16-3, p. 399
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
LEDs
Fig. 16-4, p. 401
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• Electrical grid system: outdated and wasteful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
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
Proposed U.S. Smart Grid
Figure 20, Supplement 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
• Hidden prices in gasoline: $12/gallon• Car manufacturers and oil companies lobby to prevent
laws to raise fuel taxes
• Should there be a feebate?
Average Fuel Economy of New Vehicles Sold in the U.S. and Other Countries
Fig. 16-5, p. 402
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
Solutions: A Hybrid-Gasoline-Electric Engine Car and a Plug-in Hybrid Car
Fig. 16-6, p. 403
Science Focus: The Search for Better Batteries
• Current obstacles• Storage capacity• Overheating• Flammability • Cost
• In the future• Lithium-ion battery• Viral battery• Ultracapacitor
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)
A Green Roof in Chicago
Fig. 16-8, p. 405
A Thermogram Shows Heat Loss
Fig. 16-9, p. 406
Individuals Matter: Ways in Which You Can Save Money Where You Live
Fig. 16-10, p. 407
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
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
We Can Heat Buildings and Water with Solar Energy
• Passive solar heating system
• Active solar heating system
Solutions: Passive and Active Solar Heating for a Home
Fig. 16-11, p. 409
Passive Solar Home in Colorado
Fig. 16-12, p. 410
Rooftop Solar Hot Water on Apartment Buildings in Kunming, China
Fig. 16-13, p. 410
Trade-Offs: Passive or Active Solar Heating
Fig. 16-14, p. 411
World Availability of Direct Solar Energy
Figure 22, Supplement 8
U.S. Availability of Direct Solar Energy
Figure 23, Supplement 8
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
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
Solar Thermal Power in California Desert
Fig. 16-15, p. 411
Trade-Offs: Solar Energy for High Temperature Heat and Electricity
Fig. 16-16, p. 412
Solutions: Solar Cooker in India
Fig. 16-17, p. 412
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
Solutions: Solar Cells on Rooftop and for Many Purposes
Fig. 16-18, p. 413
Solar Cell Array in Niger, West Africa
Fig. 16-19, p. 413
Solar-Cell Power Plant in Arizona
Fig. 16-20, p. 414
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
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
Global Production of Solar Electricity
Figure 11, Supplement 9
Trade-Offs: Solar Cells
Fig. 16-21, p. 414
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
Tradeoffs: Dams and Reservoirs
Fig. 13-13, p. 328
Trade-Offs: Large-Scale Hydropower, Advantages and Disadvantages
Fig. 16-22, p. 415
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
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
World Electricity from Wind Energy
Figure 12, Supplement 9
Solutions: Wind Turbine and Wind Farms on Land and Offshore
Fig. 16-23, p. 417
Wind Turbine
Fig. 16-24, p. 417
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
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”
Trade-Offs: Wind Power
Fig. 16-25, p. 418
United States Wind Power Potential
Figure 24, Supplement 8
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
Trade-Offs: Solid Biomass
Fig. 16-26, p. 420
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
We Can Convert Plants and Plant Wastes to Liquid Biofuels (2)
• Major advantages over gasoline and diesel fuel produced from oil1. Biofuel crops can be grown almost anywhere2. No net increase in CO2 emissions if managed
properly3. Available now
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
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
Trade-Offs: Biodiesel
Fig. 16-27, p. 421
World Ethanol Production
Figure 13, Supplement 9
Bagasse is Sugarcane Residue
Fig. 16-28, p. 421
Natural Capital: Rapidly Growing Switchgrass
Fig. 16-29, p. 423
Trade-Offs: Ethanol Fuel
Fig. 16-30, p. 423
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 challenges1.Need to lower costs2.Open ponds vs. bioreactors3.Affordable ways of extracting oil4.Scaling to large production
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
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
Natural Capital: A Geothermal Heat Pump System Can Heat or Cool a House
Fig. 16-31, p. 425
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
Geothermal Sites in the United States
Figure 26, Supplement 8
Geothermal Sites Worldwide
Figure 25, Supplement 8
Geothermal Power Plant in Iceland
Fig. 16-32, p. 425
Trade Offs: Geothermal Energy
Fig. 16-33, p. 426
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
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
A Fuel Cell Separates the Hydrogen Atoms’ Electrons from Their Protons
Fig. 16-34, p. 427
Trade-Offs: Hydrogen, Advantages and Disadvantages
Fig. 16-35, p. 428
Solutions: Decentralized Power System
Fig. 16-36, p. 430
Solutions: Making the Transition to a More Sustainable Energy Future
Fig. 16-37, p. 431
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
What Can you Do? Shifting to More Sustainable Energy Use
Fig. 16-38, p. 432