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Energy Efficiency and Renewable Energy

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Title: Energy Efficiency and Renewable Energy


1
Energy Efficiency and Renewable Energy
  • Chapter 16

2
ICELAND
3
Iceland
  • No known reserves of oil, natural gas or coal
  • 200 miles from the arctic circle
  • Warmed by the Gulf Stream
  • Sits on top of a divergent boundary between the
    European and North American plate and a hot spot
    in the Earths mantle
  • What kind of energy resources should they use?

4
Icelands Vision of a Renewable-Energy Economy (1)
  • Supplies 75 of its primary energy and almost all
    of its electrical energy using
  • Geothermal energy
  • Hydroelectric power
  • Wind power
  • Imports oil to run transportation, factories,
    make products
  • Bragi Arnason Dr. Hydrogen
  • Vision to use in country resources to produce
    hydrogen fuel to run everything by 2060

5
Core Case Study Icelands Vision of a
Renewable-Energy Economy (2)
  • 2003 Worlds first commercial hydrogen filling
    station
  • 20032007 three prototype fuel-cell buses
  • 2008 10 Toyota Prius test vehicles
  • Hydrogen-fueled
  • Whale-watching boat partially powered by a
    hydrogen fuel cell

6
The Krafla Geothermal Power Station in Northern
Iceland
7
Visions
  • Do you think Icelands energy vision should be
    ours? Explain
  • What do you think would be the easiest change For
    the US that would move us towards a more
    self-sustaining, environmentally positive
    existence

8
16-1 Why Is Energy Efficiency an Important Energy
Resource?
  • Concept 16-1 We could save as much as 43 of all
    the energy we use by improving energy efficiency.

9
Energy Waste in the last 24 hours
  • What have you witnessed? Done?

10
Where do you waste the most energy?
  • Using non-recyclable material, (why?)
  • Living in a prepackaged, throw-away society
    (why?)
  • Having a house not properly insulated (why?)
  • Driving alone in a large car/SUV (why?)
  • Solutions?

11
We Waste Huge Amounts of Energy (1)
  • Energy conservation
  • 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

12
Energy Inputs
System
Outputs
9
7
41
85
U.S. economy
43
8
4
3
Nonrenewable fossil fuels
Useful energy
Nonrenewable nuclear
Petrochemicals
Hydropower, geothermal, wind, solar
Unavoidable energy waste
Biomass
Unnecessary energy waste
Fig. 16-2, p. 401
13
Waste
  • Unavoidable Waste?
  • Examples
  • How is it related to the law of Entropy?
  • Avoidable Waste?
  • Examples
  • How do constructing individual homes in the
    suburbs increase the avoidable waste of the
    system?

14
We Waste Huge Amounts of Energy (2)
  • Four widely used devices that waste energy
  • Incandescent light bulb (90)
  • Motor vehicle with an internal combustion engine
    (94)
  • Nuclear power plant (why?) (83)
  • Coal-fired power plant (why?) (66)
  • Possible alternatives for the outdated four

15
List as many advantages we gain by reducing
avoidable waste
16
Advantages
Reducing Energy Waste
Prolongs fossil fuel supplies
Reduces oil imports and improves energy security
Very high net energy yield
Low cost
Reduces pollution and environmental degradation
Buys time to phase in renewable energy
Creates local jobs
Fig. 16-3, p. 401
17
Net Energy EfficiencyHonest Energy Accounting
  • Net energy efficiency
  • the only energy that counts

18
Electricity from Nuclear Power Plant
Uranium processing and transportation (57)
Uranium mining (95)
Power plant (31)
Transmission of electricity (85)
Resistance heating (100)
Uranium 100
14
14
17
95
54
Waste heat
Waste heat
Waste heat
Waste heat
Passive Solar
Window transmission (90)
Sunlight 100
90
Waste heat
Fig. 16-4, p. 402
19
What can the school do to reduce energy waste?
  • Are all suggestions practical?

20
16-2 How Can We Cut Energy Waste?
  • Concept 16-2 We have a variety of technologies
    for sharply increasing the energy efficiency of
    industrial operations, motor vehicles, and
    buildings.

21
What kind of car do you drive, if you drive?
  • What kind of car do you want to drive in the
    future?

22
We Can Save Energy and Money in Industry (1)
  • 30 or worlds and 38 of US energy consumption
  • Cogeneration or combined heat and power (CHP)
    (capturing waste heat ? steam)

23
Recycling materials
  • Uses 75 less energy to produce steel out of
    recycled materials than dig more out of the earth

24
Better Engines
  • Replace energy-wasting electric motors
  • Consume1/4 of all electricity created in US
  • Most run at full speed, more power output than
    needed

25
Switch the Types of lights
  • LED (light emitting diodes)
  • 1/7th as much energy
  • 100 times as long
  • Compact Fluorescent bulbs
  • 1/4th as much energy
  • 10 times as long

26
We Can Save Energy and Money in Industry (2)
  • Electrical grid system outdated and wasteful
    It takes energy moving electricity through wires
  • Utility companies promote use of energy, not
    energy efficiency
  • -Wireless distribution of energy
  • -Smaller distance between source and end use
  • Dow Chemical has cut energy consumption by 25 in
    8 years What does that do for profits?

27
25
Average fuel economy (miles per gallon)
Cars
Cars, trucks, and SUVs
20
Trucks and SUVs
15
10
1985
1975
1980
1990
1995
2000
2005
Year
Fig. 16-5a, p. 404
28
Fig. 16-5b, p. 404
29
We Can Save Energy and Money in Transportation
  • Corporate average fuel standards (CAFE) standards
  • Fuel economy standards lower in the U.S. than
    many other countries
  • Fuel-efficient (35 mpg) cars are on the market
  • 1 of cars, trucks are fuel-efficient

30
What would you pay for gas
  • What costs have to be included to determine the
    true price we pay for gasoline
  • ____________________ (gov)
  • ____________________ (dam)
  • ____________________ (mil)
  • ____________________ (med)
  • How much do you think the average person truly
    pays for a gallon of gas today?

31
  • Should there be tax breaks for buying
    fuel-efficient cars?
  • Should there be tax breaks for buy fuel
    inefficient cars?
  • What do you think is a feebate?

32
More Energy-Efficient Vehicles Are on the Way
  • Superefficient and ultra light cars
  • Gasoline-electric hybrid car
  • Plug-in hybrid electric vehicle
  • Energy-efficient diesel car
  • Electric vehicle with a fuel cell

33
Ultra light, Ultra strong car
  • How does ultra light car gain advantages?

34
Gas-hybrid car
  • Gas is main source of energy
  • Motor also acts as generator, converting motion
    of car back into energy
  • New energy stored in battery

35
How a gasoline-hybrid works
  • The electric motor applies resistance to the
    drive-train causing the wheels to slow down.
  • In return, the energy from the wheels turns the
    motor,
  • which functions as a generator, converting energy
    normally wasted during coasting and braking into
    electricity,
  • which is stored in a battery until needed by the
    electric motor.

36
Plug in electric hybrid
  • electric car is powered by an electric motor
    instead of a gasoline engine
  • Still use motor as generator to recycle energy

37
Stepped Art
Fig. 16-6, p. 405
38
Compare Electric to gas cars
  • Any other comparisons?

39
Energy efficient diesel cars
  • This fuel can be made out of coal, plant material
    or cooking oil
  • 45 of new passenger sales in Europe
  • Modern diesel engines are
  • Quieter
  • 30 more fuel efficient
  • 20 less CO2 emissions
  • Biodiesel (more detail)
  • Hybrid-diesel

40
Fuel Cells
  • What do you think they are?
  • How do you think they produce energy?
  • What waste products result from fuel cell use?

41
Fuel Cells
  • At least twice as efficient as an internal
    combustion engine
  • Has no moving parts, requires little maintenance
  • Uses hydrogen gas as fuel
  • Does not produce CO2 or other toxins as
    pollutants
  • In show rooms by 2012
  • Very expensive
  • Discuss in more detail later in chapter

42
Science Focus The Search for Better Batteries
  • Current obstacles
  • Storage capacity
  • Overheating
  • Flammability
  • In the future
  • Lithium-ion battery
  • Ultracapacitor
  • Viral battery
  • Using nanotechnology

43
Lithium Ion batteries
  • Found in laptops and cell phones
  • Less weight, space as Ni-Cd batteries
  • Occasional tendency to overheat, burst into flames

44
Other battery types
  • Using nanotechnology to make a nonflammable
    battery
  • Nanophosphate material
  • Not heat up or release oxygen
  • Genetically engineered virus
  • MIT
  • Coat itself with conductive materials (nanowire)
  • Grow themselves
  • Use water as a solvent
  • Yield none of the toxic residue in disposal

45
Questions
  • 1) What car do you have access to drive?
  • 2) can it be considered fuel efficient?
  • 3) If so, what features make it fuel efficient?
    If not, what features do not make it fuel
    efficient
  • 4) What are the differences between the different
    types of hybrid cars?
  • 5) What makes the diesel cars in the future more
    efficient?
  • 6) What is the difference between a fuel cell and
    a battery?
  • 7) What kind of car do you want in the future?
    What features will it have to promote a healthy
    environment?

46
We Can Design Buildings That Save Energy and
Money (1)
  • Green architecture energy-efficient, money
    savings designs, uses recycled building
    materials, rainwater collection, nontoxic paint,
    glues
  • Living or green roofs capture energy,
    rainwater, green space
  • Straw bale houses
  • U.S. Green Building Councils Leadership in
    Energy and Environmental Design (LEED)

47
We Can Design Buildings That Save Energy and
Money (2)
  • Two buildings that were designed with energy in
    mind
  • Georgia Power Company in Atlanta, GA (U.S.)
  • Ministry of Science and Technology Building in
    Beijing, China

48
A Green or Living Roof in Chicago, IL (U.S.)
49
Straw bale house
  • Renewable
  • Insulation
  • Moisture, Movement

50
We Can Save Energy and Money in Existing
Buildings (1)
  • Insulate and plug leaks
  • Use energy-efficient windows
  • Stop other heating and cooling losses
  • Heat houses more efficiently

51
We Can Save Energy and Money in Existing
Buildings (2)
  • Heat water more efficiently
  • Use energy-efficient appliances
  • Use energy-efficient lighting

52
A Thermogram Showing Heat Loss Around Houses and
Stores
53
Ways to save money where you live
54
Attic Hang reflective foil near roof to reflect
heat. Use house fan. Be sure attic insulation
is at least 30 centimeters (12 inches).
Outside Plant deciduous trees to block summer
sun and let in winter sunlight.
Bathroom Install water-saving toilets,
faucets, and shower heads. Repair water leaks
promptly.
Other rooms Use compact fluorescent lightbulbs
or LEDs and avoid using incandescent
bulbs wherever possible. Turn off lights,
computers, TV, and other electronic devices when
they are not in use. Use high efficiency
windows use insulating window covers and close
them at night and on sunny, hot days. Set
thermostat as low as you can in winter and as
high as you can in summer. Weather-strip and
caulk doors, windows, light fixtures, and wall
sockets. Keep heating and cooling vents free of
obstructions. Keep fireplace damper closed when
not in use. Use fans instead of, or along with,
air conditioning.
Kitchen Use microwave rather than stove or
oven as much as possible. Run only full loads
in dishwasher and use low- or no-heat drying.
Clean refrigerator coils regularly.
Basement or utility room Use front-loading
clothes washer. If possible run only full loads
with warm or cold water. Hang clothes on racks
for drying. Run only full loads in clothes
dryer and use lower heat setting. Set water
heater at 140 if dishwasher is used and 120 or
lower if no dishwasher is used. Use water
heater thermal blanket. Insulate exposed hot
water pipes. Regularly clean or replace furnace
filters.
Fig. 16-9, p. 409
55
Homework
  • What is used around your home?

56
Why Are We Still Wasting So Much Energy?
  • Energy remains artificially cheap
  • Few large and long-lasting government incentives
    (Door, window, insulation incentive just stopped
    January)
  • What about the rebound effect?
  • Use more energy because of savings

57
We Can Use Renewable Energy in Place of
Nonrenewable Energy Sources
  • Renewable energy
  • Solar energy direct or indirect
  • Geothermal energy
  • Moving water or wind
  • Benefits of shifting toward a variety of locally
    available renewable energy resources
  • Decentralization of supply less vulnerable to
    natural disasters, supply cutoffs
  • Creation of high quality jobs

58
Cost of renewable energy
  • Forms of renewable energy would be cheaper if we
    eliminate
  • Inequitable subsidies Oil, Nuclear vs Solar
  • Inaccurate prices environmental and health costs

59
What do you know?
  • BY Friday
  • Definition, equipment
  • How does it produce heat or energy
  • Limitations of use
  • Advantages
  • Disadvantages
  • Sources
  • A) Passive solar heating
  • B) Solar cells
  • C) Hydroelectric sources
  • D) Wind
  • E) Geothermal

60
16-3 What Are the Advantages and Disadvantages of
Solar Energy?
  • Concept 16-3 Passive and active solar heating
    systems can heat water and buildings effectively,
    and the costs of using direct sunlight to produce
    high-temperature heat and electricity are coming
    down.

61
We Can Heat Buildings and Water with Solar Energy
  • Passive solar heating system absorbs and stores
    heat from sun directly
  • Active solar heating system absorbs heat into
    water/antifreeze and then pumps liquid to other
    areas
  • Energy is moderate with planning

62
Passive Solar heating
  • South Facing
  • Window types
  • Window size
  • Summer/winter
  • Windows for air

63
We Can Cool Buildings Naturally
  • Technologies available
  • Superinsulation and high-efficiency windows
  • Overhangs or awnings on windows
  • Light-colored roof
  • Reflective insulating foil in an attic
  • Geothermal pumps
  • Plastic earth tubes underground

64
Rooftop Solar Hot Water on Apartment Buildings in
Kunming, China
65
Solutions Passive and Active Solar Heating for a
Home
66
Vent allows hot air to escape in summer
Heavy insulation
Summer sun
Winter sun
Superwindow
Superwindow
Stone floor and wall for heat storage
PASSIVE
Fig. 16-10a, p. 411
67
Solar collector
Heat to house (radiators or forced air duct)
Pump
Heavy insulation
Super- window
Hot water tank
Heat exchanger
ACTIVE
Fig. 16-10b, p. 411
68
TRADE-OFFS
Passive or Active Solar Heating
Advantages
Disadvantages
Need access to sun 60 of time
Energy is free
Net energy is moderate (active) to high (passive)
Sun can be blocked by trees and other structures
Environmental costs not included in market price
Quick installation
No CO2 emissions Very low air and water pollution
Need heat storage system
Very low land disturbance (built into roof or
windows)
High cost (active)
Active system needs maintenance and repair
Moderate cost (passive)
Active collectors unattractive
Fig. 16-11, p. 412
69
Solutions Woman in India Uses a Solar Cooker
70
We Can Use Sunlight to Produce High-Temperature
Heat and Electricity
  • Solar thermal systems
  • Central receiver system
  • Other collecting systems
  • Unfeasible for widespread use
  • High cost
  • Low new energy yields
  • Limited suitable sites
  • Sunny, desert sites

71
Solar oven on steroids
72
Commercial Solar Power Tower Plant Near Seville
in Southern Spain
73
Trade-Offs Solar Energy for High-Temperature
Heat and Electricity
74
Case Study The Rocky Mountain InstituteSolar
Powered Office and Home
  • Location Snowmass, CO (U.S.)
  • No conventional heating system 90 of
    electricity, 99 of hot water from sun
  • Heating bills lt50/year (costs)
  • How is this possible? Combination of energy
    efficiency, passive and active solar heating and
    solar cells

75
Sustainable Energy Rocky Mountain Institute in
Colorado, U.S.
76
Solar Panels
77
Fig. 16-17a, p. 415
78
We Can Use Solar Cells to Produce Electricity (1)
  • Photovoltaic (PV) cells (solar cells)
  • Convert solar energy to electric energy
  • Solar-cell power plants
  • Near Tucson, AZ (U.S.)
  • 2007 Portugal
  • Solar-cell systems being built or planned in
  • Leipzig, Germany
  • South Korea
  • South California (U.S.)
  • China

79
Solar-Cell Power Plant in Arizona, U.S., Is the
Largest Solar-Cell Power Plant
80
How panel works
  • Photons of sunlight enter panel (UV, Vis,
    Infrared)
  • Absorbed by silicon material which in turn
    emitted energized electrons
  • Metal layer gathers energy from electrons
  • electric current is created

81
We Can Use Solar Cells to Produce Electricity (3)
  • Uses solar panels work everywhere, do not have
    to be connected to grid
  • Key problem
  • High cost of producing electricity
  • Will the cost drop with
  • Mass production
  • New designs
  • Nanotechnology (multiple layers, size of panels)

82
TRADE-OFFS
Solar Cells
Disadvantages
Advantages
Need access to sun
Fairly high net energy yield
Low efficiency
Work on cloudy days
Need electricity storage system or backup
Quick installation
Easily expanded or moved
Environmental costs not included in market price
No CO2 emissions
High costs (but should be competitive in 515
years)
Low environmental impact
Last 2040 years
High land use (solar-cell power plants) could
disrupt desert areas
Low land use (if on roof or built into walls or
windows)
Reduces dependence on fossil fuels
DC current must be converted to AC
Fig. 16-20, p. 417
83
Solutions Solar Cells Used to Provide
Electricity for a Remote Village in Niger
84
Total Costs of Electricity from Different Sources
in 2004
85
The Solar Power Industry Is Expanding Rapidly
  • Solar cells 0.2 of the worlds electricity
  • 2040 could solar cells produce 16?
  • Nanosolar California (U.S.)
  • Germany huge investment in solar cell technology
  • General Electric entered the solar cell market

86
Exit Questions 16.3
  • What is the difference between active and passive
    solar heating
  • What is a photovoltaic cell?
  • Name 3 advantages and disadvantages of generating
    electricity by photovoltaic cells?

87
16-4 Advantages and Disadvantages of Producing
Electricity from the Water Cycle
  • Concept 16-4 Water flowing over dams, tidal
    flows, and ocean waves can be used to generate
    electricity, but environmental concerns and
    limited availability of suitable sites may limit
    the use of these energy resources.

88
We Can Produce Electricity from Falling and
Flowing Water
  • Hydropower
  • Worlds leading renewable energy source used to
    produce electricity
  • Hydroelectric power Iceland
  • Advantages
  • Disadvantages
  • Micro-hydropower generators

89
Trade-Offs Large-Scale Hydropower, Advantages
and Disadvantages
90
TRADE-OFFS
Large-Scale Hydropower
Disadvantages
Advantages
High construction costs
Moderate to high net energy
High environmental impact from flooding land to
form a reservoir
High efficiency (80)
Large untapped potential
Environmental costs not included in market price
Low-cost electricity
Long life span
High CO2 emissions from rapid biomass decay in
shallow tropical reservoirs
No CO2 emissions during operation in temperate
areas
Danger of collapse
Uproots people
Can provide flood control below dam
Decreases fish harvest below dam
Provides irrigation water
Decreases flow of natural fertilizer (silt) to
land below dam
Reservoir useful for fishing and recreation
Fig. 16-21, p. 418
91
16-4 Advantages and Disadvantages of Producing
Electricity from the Water Cycle
  • Concept 16-4 Water flowing over dams, tidal
    flows, and ocean waves can be used to generate
    electricity, but environmental concerns and
    limited availability of suitable sites may limit
    the use of these energy resources.

92
We Can Produce Electricity from Falling and
Flowing Water
  • Hydropower
  • Worlds leading renewable energy source used to
    produce electricity
  • Hydroelectric power Iceland, Quebec-Canada
  • Advantages
  • Disadvantages
  • Micro-hydropower generators suitcase sized
    turbines, portable generators

93
Micro hydro power
94
TRADE-OFFS
Large-Scale Hydropower
Disadvantages
Advantages
High construction costs
Moderate to high net energy
High environmental impact from flooding land to
form a reservoir
High efficiency (80)
Large untapped potential
Environmental costs not included in market price
Low-cost electricity
Long life span
High CO2 emissions from rapid biomass decay in
shallow tropical reservoirs
No CO2 emissions during operation in temperate
areas
Danger of collapse
Uproots people
Can provide flood control below dam
Decreases fish harvest below dam
Provides irrigation water
Decreases flow of natural fertilizer (silt) to
land below dam
Reservoir useful for fishing and recreation
Fig. 16-21, p. 418
95
Tides and Waves Can Be Used to Produce
Electricity (1)
  • Produce electricity from flowing water
  • Ocean tides and waves
  • Tidal flow in rivers
  • So far, power systems
  • are limited
  • Norway
  • New York City

96
Tides and Waves Can Be Used to Produce
Electricity (2)
  • Disadvantages
  • Few suitable sites
  • High costs
  • Equipment damaged by storms and corrosion
  • Ecosystem interaction

97
16-5 Advantages and Disadvantages of Producing
Electricity from Wind
  • Concept 16-5 When environmental costs of energy
    resources are included in market prices, wind
    energy is the least expensive and least polluting
    way to produce electricity.

98
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
  • Jobs, idled factories
  • What is the global potential for wind energy?
  • Europe leading the way
  • Wind farms on land and offshore

99
Fig. 16-22a, p. 420
100
Solutions Wind Turbine and Wind Farms on Land
and Offshore
101
Using Wind to Produce Electricity Is an Important
Step toward Sustainability (2)
  • Saudi Arabia of wind power
  • North Dakota
  • South Dakota
  • Kansas
  • Texas
  • Delaware?
  • How much electricity is possible with wind farms
    in those states?

102
Gearbox
Electrical generator
Power cable
Wind turbine
Fig. 16-22a, p. 420
103
Wind farm
Fig. 16-22b, p. 420
104
Wind farm (offshore)
Fig. 16-22c, p. 420
105
Producing Electricity from Wind Energy Is a
Rapidly Growing Global Industry
  • Countries with the highest total installed wind
    power capacity
  • Germany
  • United States
  • Spain
  • India
  • Denmark
  • Installation is increasing in several other
    countries

106
Wind Energy Is Booming but Still Faces Challenges
  • Advantages of wind energy
  • Put in my back yard (PIMBY)
  • Drawbacks
  • Windy areas may be sparsely populated
  • Need to upgrade the electric grid
  • Winds die down need back-up energy
  • Storage of wind energy
  • Kills migratory birds (perches, nests, speeds,
    locations)
  • Not in my backyard (NIMBY)

107
Birds and turbines
  • 40,000 birds/bats a year
  • Old designs
  • Placed in migratory paths
  • Windows 1 billion birds
  • Transmission lines 175 million

Feral Cats 100 million Global warming more
dangerous
108
TRADE-OFFS
Wind Power
Advantages
Disadvantages
Moderate to high net energy yield
Steady winds needed
Backup systems needed when winds are low
High efficiency
Moderate capital cost
Plastic components produced from oil
Low electricity cost (and falling)
Environmental costs not included in market price
Very low environmental impact
High land use for wind farm
No CO2 emissions
Quick construction
Visual pollution
Easily expanded
Noise when located near populated areas
Can be located at sea
Land below turbines can be used to grow crops or
graze livestock
Can kill birds and interfere with flights of
migratory birds
Fig. 16-23, p. 421
109
According to energy analysts
  • Wind has more benefits and fewer serious
    drawbacks than any other energy resource, except
    energy efficiency

110
16-6 Advantages and Disadvantages of Biomass as
an Energy Source (1)
  • Concept 16-6A Solid biomass is a renewable
    resource, but burning it faster than it is
    replenished produces a net gain in atmospheric
    greenhouse gases, and creating biomass
    plantations can degrade soil biodiversity.

111
16-6 Advantages and Disadvantages of Biomass as
an Energy Source (2)
  • Concept 16-6B Liquid biofuels derived from
    biomass can be used in place of gasoline and
    diesel fuels, but creating biofuel plantations
    could degrade soil and biodiversity and increase
    food prices and greenhouse gas emissions.

112
We Can Convert Plants and Plant Wastes to Liquid
Biofuels (1)
  • Liquid biofuels
  • Biodiesel (oils extracted from soybean, palm)
  • Ethanol (alcohol, fermentation of sugars)
  • Biggest producers of biofuel
  • Brazil
  • The United States
  • The European Union
  • China

113
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 (farm/processing concerns)
  • Available now

114
We Can Convert Plants and Plant Wastes to Liquid
Biofuels (3)
  • Studies warn of problems
  • Decrease biodiversity
  • Increase soil degrading, erosion, and nutrient
    leaching
  • What fuel is used to grow crops?
  • Raise food prices

115
Case Study Is Biodiesel the Answer?
  • Biodiesel production from vegetable oil from
    various sources
  • Soybeans
  • Sunflowers
  • Oil palms
  • Used vegetable oils from restaurants
  • 95 produced by The European Union
  • Rapeseeds and sunflowers

116
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117
Jatropha shrub promising new source for biodiesel
  • Advantages
  • oil burned without refining
  • grown in hot dry tropical areas
  • unlikely to threaten rain forests, displace food
    crops
  • does not need a lot of fertilizers
  • Disadvantages
  • Invasive species
  • Ecosystems damaged thru land development

118
Jatropha Plant, other possible sources
119
Algae farms
120
Palm Oils
121
Problems with palm oil
122
Trade-Offs Biodiesel, Advantages and
Disadvantages
123
TRADE-OFFS
Biodiesel
Advantages
Disadvantages
Reduced CO emissions
Increased NOx emissions and more smog
Reduced CO2 emissions (78)
Higher cost than regular diesel
High net energy yield for oil palm crops
Environmental costs not included in market price
Low net energy yield for soybean crops
Moderate net energy yield for rapeseed crops
May compete with growing food on cropland and
raise food prices
Reduced hydrocarbon emissions
Loss and degradation of biodiversity from crop
plantations
Better gas mileage (40)
Can make engines hard to start in cold weather
Potentially renewable
Fig. 16-25, p. 424
124
Solid Biomass
  • Wood, Dung, Farm industry, timber industry and
    Urban wastes
  • Trash to steam
  • Its environmental impact relates to its source
    (waste -vs- plantation)
  • Burning waste and chemical residues
  • Plantations and competition with crops

125
TRADE-OFFS
Solid Biomass
Advantages
Disadvantages
Large potential supply in some areas
Nonrenewable if harvested unsustainably
Moderate to high environmental impact
Moderate costs
Environmental costs not included in market price
No net CO2 increase if harvested, burned, and
replanted sustainably
Increases CO2 emissions if harvested and burned
unsustainably
Plantation can be located on semiarid land not
needed for crops
Low photosynthetic efficiency
Soil erosion, water pollution, and loss of
wildlife habitat
Plantation can help restore degraded lands
Plantations could compete with cropland
Can make use of agricultural, timber, and urban
wastes
Often burned in inefficient and polluting open
fires and stoves
Fig. 16-24, p. 422
126
Case Study Is Ethanol the Answer? (1)
  • Ethanol converted to gasohol (15 ethanol)
  • Flexible fuel cars can run on pure ethanol (15
    gasoline)

127
Brazil Saudi Arabia of sugarcane
  • Brazil ethanol from sugarcane
  • Saved 50 billion in oil import costs since the
    1970s
  • 45 of cars run on residue grown on 1 of arable
    land
  • Bagasse (sugarcane residue) has a net energy
    yield favorable to gasoline
  • United States ethanol from corn
  • Generous subsidies
  • Provides net energy yield about 1/4th as much as
    bagasse
  • Net increase in global warming gases
  • Competes with food production

128
Case Study Is Ethanol the Answer? (2)
  • Cellulosic ethanol alternative to corn ethanol
  • Sources
  • Switchgrass
  • Crop residues
  • Municipal wastes (sawdust)
  • Advantages Higher net yield, less crop, land
    fertilizers
  • Disadvantages large amounts of land, difficult
    to break down

129
TRADE-OFFS
Ethanol Fuel
Advantages
Disadvantages
High octane
Lower driving range
Low net energy yield (corn)
Some reduction in CO2 emissions (sugarcane
bagasse)
Higher CO2 emissions (corn)
Much higher cost
Environmental costs not included in market price
High net energy yield (bagasse and switchgrass)
May compete with growing food and raise food
prices
Reduced CO emissions
Higher NOx emissions and more smog
Can be sold as E85 or pure ethanol
Corrosive
Potentially renewable
Can make engines hard to start in cold weather
Fig. 16-27, p. 426
130
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 generally has a low environmental
    impact, but locations where it can be exploited
    economically are limited.

131
Basement heat pump
Fig. 16-28, p. 427
132
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

133
Geothermal energyHow does it work for an
individual home?
  • Underground is at a constant temp
  • Pump water or antifreeze into ground to gain or
    lose heat
  • Pump cold or hot material back into house and use
    blowers to move hot/cool air into home
  • Needs electricity to run pumps

134
Geothermal energyHow does it work on larger
scale?
  • Hydrothermal reservoirs
  • Dry air, wet steam or hot water heated by magma

135
Advantages
  • Can be very efficient in producing
    heat/electricity
  • Low disturbance of land
  • Moderate emissions, low compared to gas/coal

136
Hydrothermal plants in Iceland
137
Getting Energy from the Earths Internal Heat (2)
  • Geothermal energy problems
  • High cost of tapping large-scale hydrothermal
    reservoirs
  • Dry- or wet-steam geothermal reservoirs could be
    depleted
  • Hot water has minerals dissolved into it
  • Limited resources/places
  • Can Delaware produce large scale geothermal
    plants

138
TRADE-OFFS
Geothermal Energy
Advantages
Disadvantages
Very high efficiency
Scarcity of suitable sites
Can be depleted if used too rapidly
Moderate net energy at accessible sites
Environmental costs not included in market price
Lower CO2 emissions than fossil fuels
CO2 emissions
Low cost at favorable sites
Moderate to high local air pollution
Low land use and disturbance
Noise and odor (H2S)

High cost except at the most concentrated and
accessible sources
Moderate environmental impact
Fig. 16-29, p. 428
139
16-8 The Advantages and Disadvantages of Hydrogen
as an Energy Source
  • Concept 16-8 Hydrogen fuel holds great promise
    for powering cars and generating electricity, but
    to be environmentally beneficial, it would have
    to be produced without the use of fossil fuels.

140
Hydrogen Is a Promising Fuel but There Are
Challenges (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
  • Fuel cells are the best way to use hydrogen
  • CO2 levels dependent on method of hydrogen
    production

141
Hydrogen Is a Promising Fuel but There Are
Challenges (2)
  • Production and storage of H2
  • Hydrogen-powered vehicles prototypes available
  • Can we produce hydrogen on demand?
  • Larger fuel cells

142
A Fuel Cell Separates the Hydrogen Atoms
Electrons from Their Protons
143
Electrons
Anode
Hydrogen gas (H2) in
Polymer Electrolyte Membrane
Cathode
Water (H2O) out
Protons
Air (O2) in
Fig. 16-30, p. 429
144
Trade-Offs Hydrogen, Advantages and
Disadvantages
145
TRADE-OFFS
Hydrogen
Advantages
Disadvantages
Fuel cell
Can be produced from plentiful water
Not found as H2 in nature
Energy is needed to produce fuel
Low environmental impact
Negative net energy
Renewable if produced from renewable energy
resources
CO2 emissions if produced from carbon-containing
compounds
No CO2 emissions if produced from water
Environmental costs not included in market price
Good substitute for oil
Nonrenewable if generated by fossil fuels or
nuclear power
Competitive price if environmental and social
costs are included in cost comparisons
High costs (that may eventually come down)
Will take 25 to 50 years to phase in
Easier to store than electricity
Short driving range for current fuel-cell cars
Safer than gasoline and natural gas
No fuel distribution system in place
Nontoxic
Excessive H2 leaks may deplete ozone in the
atmosphere
High efficiency (4565) in fuel cells
Fig. 16-31, p. 430
146
16-9 How Can We Make a Transition to a More
Sustainable Energy Future?
  • Concept 16-9 We can make a transition to a more
    sustainable 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.

147
Choosing Energy Paths (1)
  • How will energy policies be created?
  • Supply-side, hard-path approach
  • Demand-side, soft-path approach

148
Choosing Energy Paths (2)
  • General conclusions about possible energy paths
  • Gradual shift to smaller, decentralized
    micropower systems
  • Transition to a diverse mix of locally available
    renewable energy resources Improved energy
    efficiency
  • How?
  • Fossil fuels will still be used in large amounts
  • Why?

149
Solutions Decentralized Power System
150
Small solar-cell power plants
Bioenergy power plants
Wind farm
Fuel cells
Rooftop solar-cell arrays
Solar-cell rooftop systems
Transmission and distribution system
Commercial
Small wind turbine
Residential
Industrial
Microturbines
Fig. 16-32, p. 431
151
Solutions Making the Transition to a More
Sustainable Energy Future
152
SOLUTIONS
Making the Transition to a More Sustainable
Energy Future
More Renewable Energy
Improve Energy Efficiency
Greatly increase use of renewable energy
Increase fuel-efficiency standards for vehicles,
buildings, and appliances
Provide large subsidies and tax credits for use
of renewable energy
Include environmental costs in prices for all
energy resources
Mandate government purchases of efficient
vehicles and other devices
Encourage government purchase of renewable energy
devices
Greatly increase renewable energy research and
development
Provide large tax credits or feebates for buying
efficient cars, houses, and appliances
Reduce Pollution and Health Risk
Offer large tax credits for investments in energy
efficiency
Cut coal use 50 by 2020
Phase out coal subsidies
Reward utilities for reducing demand for
electricity
Levy taxes on coal and oil use
Phase out nuclear power subsidies, tax breaks,
and loan guarantees
Greatly increase energy efficiency research and
development
Fig. 16-33, p. 432
153
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

154
What Can you Do? Shifting to Sustainable Energy
Use
155
Case Study Californias Efforts to Improve
Energy Efficiency
  • High electricity costs
  • Reduce energy waste
  • Use of energy-efficient devices
  • Strict building standards for energy efficiency
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