Figure 18-2 Page 380

1
Figure 18-2Page 380
Solutions
Solutions
Reducing Energy Waste
Reducing Energy Waste
Prolongs fossil fuel supplies
Reduces oil imports
Very high net energy
Low cost
Reduces pollution and environmental degradation
Buys time to phase in renewable energy
Less need for military protection of Middle East
oil resources
Improves local economy by reducing flow of money
out to pay for energy
Creates local jobs
2
Figure 18-3Page 381
Energy Inputs
System
Outputs
9
7
41
U.S. economy and lifestyles
86
43
8
3
3
Nonrenewable fossil fuels
Useful energy
Petrochemicals
Nonrenewable nuclear
Unavoidable energy waste
Hydropower, geothermal, wind, solar
Unnecessary energy waste
Biomass
3
Figure 18-4Page 381
1.4
1.2
Energy useper capita
1.0
Index of energy use per capita andper dollar of
GDP (Index 19701)
0.8
0.6
0.4
Energy useper dollar of GDP
0.2
0
1970
1980
1990
2000
2010
2020
Year
4
Figure 18-5aPage 381
H2
O2
H2O
KOH
Fuel cell
45-65
5
Figure 18-5bPage 381
Steam turbine
45
6
Figure 18-5cPage 381
Human body
2025
7
Figure 18-5dPage 381
Fluorescent light
22
8
Figure 18-5ePage 381
Internal combustion engine
(gasoline) 20-25
9
Figure 18-5fPage 381
Incandescent light
5
10
Stepped ArtFigure 18-6Page 382
Window transmission (90)
11
Figure 18-7Page 383
30
25
Cars
Average fuel economy (miles per gallon, or mpg)
20
Both
15
Pickups, vans, and sport utility vehicles
10
1985
1970
1975
1980
2000
2005
1990
1995
Model Year
12
Figure 18-8Page 383
2.2
2.0
1.8
1.6
Dollars per gallon (in 1993 dollars)
1.4
1.2
1.0
0.8
1920
1930
1940
1950
1960
1970
1980
1990
2000
2010
Year
13
Figure 18-9Page 385
Fuel
Electricity
14
Figure 18-10aPage 385
Hydrogen gas
H2
Cell splits H2 into protons and electrons.
Protons flow across catalyst membrane.
3
1
O2
React with oxygen (O2).
2
Produce electrical energy (flow of electrons)
to power car.
4
H2O
Emits water (H2O) vapor.
15
Figure 18-10bPage 385
Fuel
Electricity
16
Figure 18-11aPage 386
Universal docking connection Connects the chassis
with the Drive-by-wire system in the body
Body attachments Mechanical locks that secure
the body to the chassis
Rear crush zone absorbs crash energy
Air system management
Fuel-cell stack Converts hydrogen fuel into
electricity
Drive-by-wire system controls
Cabin heating unit
Side mounted radiators Release heat generated by
the fuel cell, vehicle electronics, and
wheel motors
Front crush zone Absorbs crash energy
Hydrogen fuel tanks
Electric wheel motors Provide four-wheel
drive Have built-in brakes
17
Figure 18-11bPage 386
18
Figure 18-12Page 387
R-60 or higher insulation
R-30 to R-43 insulation
Small or no north-facing windows or superwindows
Insulated glass, triple-paned or superwindows (pas
sive solar gain)
R-30 to R-43 insulation
House nearly airtight
R-30 to R-43 insulation
Air-to-air heat exchanger
19
Figure 18-13Page 387
DO NOT POST TO INTERNET
20
Figure 18-14Page 388
DO NOT POST TO INTERNET
21
Net Energy Efficiency
Superinsulated house(100 of heat R-43)
98
Geothermal heat pumps (100 of heating and
cooling))
96
Passive solar (100 of heat)
90
Passive solar (50 of heat) plus high- efficiency
natural gas furnace(50 of heat)
87
Natural gas with high-efficiency furnace
84
Electric resistance heating (electricity from
hydroelectric power plant)
82
Natural gas with typical furnace
70
Passive solar (50 of heat) plus high-efficiency
wood stove (50 of heat)
65
Oil furnace
53
Electric heat pump (electricity from coal-fired
power plant)
50
High-efficiency wood stove
39
Active solar
35
Electric heat pump (electricity from nuclear
plant)
30
Typical wood stove
26
Electric resistance heating (electricity from
coal-fired power plant)
25
Electric resistance heating (electricity from
nuclear plant)
14
Figure 18-15Page 389
22
Figure 18-16aPage 389
Summer sun
Heavy insulation
Superwindow
Winter sun
Superwindow
Stone floor and wall for heat storage
PASSIVE
23
Figure 18-16bPage 389
Heat to house (radiators or forced air duct)
Pump
Heavy insulation
Hot water tank
Super- window
Heat exchanger
ACTIVE
24
Figure 18-17aPage 392
Direct Gain
Ceiling and north wall heavily insulated
Summer sun
Hot air
Super insulated windows
Winter sun
Warm air
Cool air
Earth tubes
25
Figure 18-17bPage 392
Greenhouse, Sunspace, or Attached Solarium
Summer cooling vent
Warm air
Insulated windows
Cool air
26
Figure 18-17cPage 392
Earth Sheltered
Reinforced concrete, carefully waterproofed walls
and roof
Earth
Triple-paned or superwindows
Flagstone floor for heat storage
27
Figure 18-18Page 392
Trade-offs
Passive or Active Solar Heating
Advantages
Disadvantages
Energy is free Net energy is moderate (active)
to high (passive) Quick installation No CO2
emissions Very low air and water pollution
Very low land disturbance (built into roof or
window) Moderate cost (passive)
Need access to sun 60 of time Blockage of sun
access by other structures Need heat storage
system High cost (active) Active system needs
maintenance and repair Active collectors
unattractive
28
Figure 18-19Page 393
Trade-Offs
Solar Energy for High-Temperature Heat and
Electricity
Advantages
Disadvantages
Moderate net energy Moderate environmental Impact
No CO2 emissions Fast construction (1-2
years) Costs reduced with natural gas turbine
backup
Low efficiency High costs Needs backup or
storage system Need access to sun most of the
time High land use May disturb desert areas
29
Figure 18-20aPage 394
Single Solar Cell
Boron-enriched silicon
Sunlight
Junction
Cell
Phosphorus- enriched silicon
DC electricity
30
Figure 18-20bPage 394
Roof Options
Panels of Solar Cells
Solar Cells
31
Figure 18-20cPage 394
Solar Cell Roof
32
Figure 18-21Page 395
Trade-Offs
Solar Cells
Advantages
Disadvantages
Fairly high net energy Work on cloudy days
Quick installation Easily expanded or moved
No CO2 emissions Low environmental impact
Last 20-40 years Low land use (if on roof or
built into walls or windows) Reduce dependence
on fossil fuels
Need access to sun Low efficiency Need
electricity storage system or backup High land
use (solar cell power plants) could disrupt
desert areas High costs (but should
be competitive in 5-15 years) DC current
must be converted to AC
33
Trade-Offs
Large-Scale Hydropower
Advantages
Disadvantages
Moderate to high net energy High efficiency
(80) Large untapped potential Low-cost
electricity Long life span No CO2 emissions
during operation May provide flood control
below dam Provides water for year-round irrigatio
n of crop land Reservoir is useful for fishing
and recreation
High construction costs High environmental
impact from flooding land to form a
reservoir High CO2 emissions from biomass decay
in shallow tropical reservoirs Floods natural
areas behind dam Converts land habitat to lake
habitat Danger of collapse Uproots
people Decreases fish harvest below
dam Decreases flow of natural fertilizer (silt)
to land below dam
Figure 18-22Page 396
34
Figure 18-23aPage 396
Gearbox
Electrical generator
Power cable
Wind Turbine
35
Figure 18-23bPage 396
Wind Farm
36
Figure 18-24Page 397
Trade-Offs
Wind Power
Advantages
Disadvantages
Moderate to high net energy High
efficiency Moderate capital cost Low
electricity cost (and falling) Very low
environmental impact No CO2 emissions Quick
construction Easily expanded Land below
turbines can be used to grow crops or graze
livestock
Steady winds needed Backup systems when needed
winds are low High land use for wind
farm Visual pollution Noise when located near
populated areas May interfere in flights of
migratory birds and kill birds of prey
37
Figure 18-25Page 398
38
Figure 18-26Page 399
Trade-Offs
Solid Biomass
Advantages
Disadvantages
Large potential supply in some areas Moderate
costs No net CO2 increase if harvested and
burned sustainably Plantation can be located on
semiarid land not needed for crops Plantation
can help restore degraded lands Can make use of
agricultural, timber, and urban wastes
Nonrenewable if harvested unsustainably
Moderate to high environmental impact CO2
emissions if harvested and burned unsustainably
Low photosynthetic efficiency Soil erosion,
water pollution, and loss of wildlife habitat
Plantations could compete with cropland Often
burned in inefficient and polluting open fires
and stoves
39
Figure 18-27Page 399
Trade-Offs
Ethanol Fuel
Advantages
Disadvantages
High octane Some reduction in CO2
emission Reduced CO emissions Can be sold as
gasohol Potentially renewable
Large fuel tank needed Lower driving range Net
energy loss Much higher cost Corn supply
limited May compete with growing food on
cropland Higher NO emission Corrosive Hard to
start in colder weather
40
Figure 18-28Page 400
Trade-Offs
Methanol Fuel
Advantages
Disadvantages
High octane Some reduction in CO2
emissions Lower total air Pollution
(30-40) Can be made from natural gas,
agricultural wastes, sewage sludge, and
garbage Can be used to produce H2 for fuel cells
Large fuel tank needed Half the driving
range Corrodes metal, rubber, plastic High CO2
emissions if made from coal Expensive to
produce Hard to start in cold weather
41
Figure 18-29Page 401
Trade-Offs
Geothermal Fuel
Advantages
Disadvantages
Very high efficiency Moderate net energy at
accessible sites Lower CO2 emissions than fossil
fuels Low cost at favorable sites Low land
use Low land disturbance Moderate environmental
impact
Scarcity of suitable sites Depleted if used too
rapidly CO2 emissions Moderate to high local
air pollution Noise and odor (H2S) Cost too
high except at the most concentrated and
accessible source
42
Figure 18-30Page 401
Trade-Offs
Hydrogen
Advantages
Disadvantages
Can be produced from plentiful water Low
environmental impact Renewable if produced From
renewable energy resources No CO2 emissions if
produced from water Good substitute for oil
Competitive price if environmental and social
costs are included in cost comparisons Easier
to store than electricity Safer than gasoline
and natural gas Nontoxic High efficiency
(65-95) in fuel cells
Not found in nature Energy is needed to produce
fuel Negative net energy CO2 emissions if
produced from carbon-containing
compounds Nonrenewable if generated by fossil
fuels or nuclear power High costs (but expected
to come down) Will take 25 to 50 years to phase
in Short driving range for current fuel cell
cars No distribution system in place Excessive
H2 leaks may deplete ozone
43
Figure 18-31Page 403
44
Figure 18-32Page 405
Wind farm
Bioenergy Power plants
Small solar cell power plants
Fuel cells
Rooftop solar cell arrays
Solar cell rooftop systems
Transmission and distribution system
Commercial
Small wind turbine
Residential
Industrial
Microturbines
45
Figure 18-33Page 406
Small modular units Fast factory production Fast
installation (hours to days) Can add or remove
modules as needed High energy efficiency
(6080) Low or no CO2 emissions Low air
pollution emissions Reliable Easy to repair Much
less vulnerable to power outages Increase
national security by dispersal of targets Useful
anywhere Especially useful in rural areas in
developing countries with no power Can use
locally available renewable energy
resources Easily financed (costs included in
mortgage and commercial loan)
46
Figure 18-34Page 407
73 billion
Nuclear energy (fission and fusion)
32 billion
Fossil fuels
19 billion
Renewable energy
Energy efficiency (conservation)
15 billion
47
Figure 18-35Page 407
More Renewable Energy
Improve Energy Efficiency
Increase renewable energy to 20 by 2020 and 50
by 2050
Increase fuel-efficiency standards for
vehicles, buildings, and appliances
Provide large subsidies and tax credits for
renewable energy
Use full-cost accounting and life cycle cost for
comparing all energy alternatives
Mandate government purchases of efficient
vehicles and other devices
Encourage government purchase of renewable
energy devices
Provide large tax credits for buying efficient
cars, houses, and appliances
Greatly increase renewable energy research and
development
Offer large tax credits for investments in
efficiency
Reduce Pollution and Health Risk
Reward utilities for reducing demand
Cut coal use 50 by 2020
Phase out coal subsidies
Encourage independent power producers
Levy taxes on coal and oil use
Phase out nuclear power or put it on hold until
2020
Greatly increase efficiency research and
development
Phase out nuclear power subsidies
48
Figure 18-36Page 408
What Can You Do?
Energy Use ad Waste

• Drive a car that gets at least 15 kilometers per
  liter (35 miles per gallon) and join a carpool.
• Use mass transit, walking, and bicycling.
• Superinsulate your house and plug all air leaks.
• Turn off lights, TV sets, computers, and other
  electronic equipment when they are not in use.
• Wash laundry in warm or cold water.
• Use passive solar heating.
• For cooling, open windows and use ceiling fans or
  whole-house attic or window fans.
• Turn thermostats down in winter and up in summer.
• Buy the most energy-efficient homes, lights,
  cars, and appliances available.
• Turn down the thermostat on water heaters to
  43-49ºC (110-120ºF) and insulate hot water
  heaters and pipes.