17 TH MILLER/SPOOLMAN LIVING IN THE ENVIRONMENT Chapter 16
Energy Efficiency and Renewable Energy
Slide 2
16-4 What Are the Advantages and Disadvantages of Using
Hydropower Concept 16-4 We can use water flowing over dams, tidal
flows, and ocean waves to generate electricity, but environmental
concerns and limited availability of suitable sites may limit the
use of these energy resources.
Slide 3
We Can Produce Electricity from Falling and Flowing Water
Hydropower Uses kinetic energy of moving water Indirect form of
solar energy Worlds leading renewable energy source used to produce
electricity Advantages and disadvantages Micro-hydropower
generators
Slide 4
Tradeoffs: Dams and Reservoirs Fig. 13-13, p. 328
Slide 5
Fig. 13-13b, p. 328 Powerlines Reservoir Dam Intake Powerhouse
Turbine
Slide 6
Trade-Offs: Large-Scale Hydropower, Advantages and
Disadvantages Fig. 16-22, p. 415
Slide 7
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
Slide 8
16-5 What Are the Advantages and Disadvantages of Using Wind
Power? Concept 16-5 When we include the environmental costs of
using energy resources in the market prices of energy, wind power
is the least expensive and least polluting way to produce
electricity.
Slide 9
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
Slide 10
World Electricity from Wind Energy Figure 12, Supplement 9
Slide 11
Solutions: Wind Turbine and Wind Farms on Land and Offshore
Fig. 16-23, p. 417
Slide 12
Fig. 16-23a, p. 417 Gearbox Electrical generator Power cable
Wind turbine
Slide 13
Fig. 16-23b, p. 417 Wind farm
Slide 14
Fig. 16-23c, p. 417 Wind farm (offshore)
Slide 15
Wind Turbine Fig. 16-24, p. 417
Slide 16
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
Slide 17
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
Slide 18
Trade-Offs: Wind Power Fig. 16-25, p. 418
Slide 19
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
Slide 20
United States Wind Power Potential Figure 24, Supplement 8
Slide 21
16-6 Advantages and Disadvantages of Using Biomass as an Energy
Source Concept 16-6A Solid biomass is a renewable resource for much
of the worlds population, but burning it faster than it is
replenished produces a net gain in atmospheric greenhouse gases,
and creating biomass plantations can degrade soil biodiversity.
Concept 16-6B We can use liquid biofuels derived from biomass in
place of gasoline and diesel fuels, but creating biofuel
plantations can degrade soil and biodiversity and increase food
prices and greenhouse gas emissions.
Slide 22
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
Slide 23
Trade-Offs: Solid Biomass Fig. 16-26, p. 420
Slide 24
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
Slide 25
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
CO 2 emissions if managed properly 3.Available now
Slide 26
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
Slide 27
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
Slide 28
Trade-Offs: Biodiesel Fig. 16-27, p. 421
Slide 29
Case Study: Is Ethanol the Answer? (1) Ethanol from plants and
plant wastes Brazil produces ethanol from sugarcane Environmental
consequences United States: ethanol from corn Low net energy yield
Reduce the need for oil imports? Harm food supply Air pollution and
climate change?
Slide 30
Case Study: Is Ethanol the Answer? (2) Cellulosic ethanol:
alternative to corn ethanol Switchgrass Crop residues Municipal
wastes Advantages and disadvantages
Slide 31
World Ethanol Production Figure 13, Supplement 9
Slide 32
Bagasse is Sugarcane Residue Fig. 16-28, p. 421
Slide 33
Natural Capital: Rapidly Growing Switchgrass Fig. 16-29, p.
423
Slide 34
Trade-Offs: Ethanol Fuel Fig. 16-30, p. 423
Slide 35
Case Study: Getting Gasoline and Diesel Fuel from Algae and
Bacteria (1) Algae remove CO 2 and convert it to oil Not compete
for cropland = not affect food prices Wastewater/sewage treatment
plants Could transfer CO 2 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
Slide 36
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
Slide 37
16-7 What Are the Advantages and Disadvantages of Geothermal
Energy? Concept 16-7 Geothermal energy has great potential for
supplying many areas with heat and electricity, and it has a
generally low environmental impact, but sites where it can be used
economically are limited.
Slide 38
Getting Energy from the Earths Internal Heat (1) Geothermal
energy: heat stored in Soil Underground rocks Fluids in the earths
mantle Geothermal heat pump system Energy efficient and reliable
Environmentally clean Cost effective to heat or cool a space
Slide 39
Natural Capital: A Geothermal Heat Pump System Can Heat or Cool
a House Fig. 16-31, p. 425
Slide 40
Getting Energy from the Earths Internal Heat (2) Hydrothermal
reservoirs U.S. is the worlds 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
Slide 41
Geothermal Sites in the United States Figure 26, Supplement
8
Geothermal Power Plant in Iceland Fig. 16-32, p. 425
Slide 44
Trade Offs: Geothermal Energy Fig. 16-33, p. 426
Slide 45
16-8 The Advantages and Disadvantages of Using Hydrogen as an
Energy Source Concept 16-8 Hydrogen fuel holds great promise for
powering cars and generating electricity, but for it to be
environmentally beneficial, we would have to produce it without the
use of fossil fuels.
Slide 46
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 CO 2 levels dependent on method of hydrogen
production
Slide 47
Will Hydrogen Save Us? (2) Net negative energy yield Production
and storage of H 2 Hydrogen-powered vehicles: prototypes available
Can we produce hydrogen on demand? Larger fuel cells fuel-cell
stacks
Slide 48
A Fuel Cell Separates the Hydrogen Atoms Electrons from Their
Protons Fig. 16-34, p. 427
Slide 49
Trade-Offs: Hydrogen, Advantages and Disadvantages Fig. 16-35,
p. 428
Slide 50
Science Focus: The Quest to Make Hydrogen Workable Bacteria and
algae can produce hydrogen through biodegrading organic material
Use electricity from renewable energy sources to produce hydrogen
Storage options for hydrogen
Slide 51
16-9 How Can We Make the Transition to a More Sustainable
Energy Future? Concept 16-9 We can make the transition to a more
sustainable energy future if we greatly improve energy efficiency,
use a mix of renewable energy resources, and include environmental
costs in the market prices of all energy resources.
Slide 52
Choosing Energy Paths (1) How will energy policies be created?
Hard energy path Soft energy path
Slide 53
Choosing Energy Paths (2) General conclusions Gradual shift to
smaller, decentralized micropower systems Transition to a diverse
mix of locally available renewable energy resources Improved energy
efficiency Fossil fuels will still be used in large amounts Natural
gas is the best choice
Slide 54
Solutions: Decentralized Power System Fig. 16-36, p. 430
Slide 55
Small solar-cell power plants Bioenergy power plantsWind farm
Fuel cells Rooftop solar- cell arrays Solar-cell rooftop systems
Smart electrical and distribution system Commercial Small wind
turbine Residential Industrial Microturbines
Slide 56
Bioenergy power plants Smart electrical and distribution system
Small solar-cell power plants Solar-cell rooftop systems Commercial
Fuel cells Rooftop solar- cell arrays Residential Small wind
turbine Stepped Art Industrial Microturbines Wind farm Fig. 16-36,
p. 430
Slide 57
Solutions: Making the Transition to a More Sustainable Energy
Future Fig. 16-37, p. 431
Slide 58
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
Slide 59
What Can you Do? Shifting to More Sustainable Energy Use Fig.
16-38, p. 432
Slide 60
Three Big Ideas 1.We should evaluate energy resources on the
basis of their potential supplies, how much net useful energy they
provide, and the environmental impacts of using them. 2.Using a mix
of renewable energy sources especially solar, wind, flowing water,
sustainable biofuels, and geothermal energycan drastically reduce
pollution, greenhouse gas emissions, and biodiversity losses.
Slide 61
Three Big Ideas 3.Making the transition to a more sustainable
energy future will require sharply reducing energy waste, using a
mix of environmentally friendly renewable energy resources, and
including the harmful environmental costs of energy resources in
their market prices.