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Nonrenewable Resources
Definition – things human use that
have a limited supply; they cannot be
regrown or replenished by man
Conservation
Definition – using less of a resource or
reusing a resource, ex. refilling plastic
laundry jugs, reusing plastic bags, etc.
Part of the solution
Problems – this requires a change in our
lifestyle and some people will resist.
Dealing with Nonrenewable Resources
Restoration Definition – recycling our resources
Examples – aluminum, glass, tin, steel, plastics,
etc.
Part of the solution
Problems – recycling a resource often costs more
than using the raw material; we don’t have the
technology to recycle everything
Sustainability
Definition – prediction of how long specific
resources will last; ex. we have a 200 year
supply of coal in the U.S.
Knowing this helps people make decisions in
resource use
Problems – these are only predictions; they may
not be accurate
ENVIRONMENTAL EFFECTS OF
USING MINERAL RESOURCES
The extraction, processing, and use of mineral
resources has a large environmental impact.
Figure 15-9
Fig. 15-10, p. 344
Natural Capital Degradation
Extracting, Processing, and Using Nonrenewable Mineral and Energy Resources
Steps Environmental effects
Mining Disturbed land; mining accidents; health hazards, mine waste dumping, oil spills and blowouts; noise; ugliness; heat
Exploration,
extraction
Processing
Solid wastes; radioactive material; air, water, and soil pollution; noise; safety and health hazards; ugliness; heat
Transportation,
purification,
manufacturing
Use
Noise; ugliness; thermal water pollution; pollution of air, water, and soil; solid and radioactive wastes; safety and health hazards; heat
Transportation or
transmission to
individual user,
eventual use, and
discarding
Costs Ownership costs – equipment, labor, safety
(insurance), environmental costs (reclamation,
pollution control, air monitors, water treatment, etc.),
taxes
External costs – processing the resource, transporting
the resource
Marginal costs – research: finding new sources of the
resource and new ways to harvest it
Harvesting Nonrenewable Resources
Benefits Direct – money received for resources;
provides many jobs
Indirect – land can be reclaimed
(brought back to original condition)
and sold for profit.
Minerals Defined Mineral Resource- concentration of
naturally occurring material from the
earth’s crust that can be extracted and
processed at an affordable cost
Fossil fuels, metallic minerals, nonmetallic
minerals
Ore- rock that contains large enough
concentration of mineral to make it
profitable for mining and processing
High-grade; low-grade
ENVIRONMENTAL EFFECTS OF
USING MINERAL RESOURCES
Minerals are removed through a variety of methods
that vary widely in their costs, safety factors, and
levels of environmental harm.
A variety of methods are used based on mineral
depth.
Surface mining: shallow deposits are removed.
Subsurface mining: deep deposits are removed.
Methods Surface Mining
Description – if resource is <200 ft. from the surface, the topsoil is removed (and saved), explosives are used to break up the rocks and to remove the resource, reclamation follows
Benefits – cheap, easy, efficient
Costs – tears up the land (temporarily), byproducts produce an acid that can accumulate in rivers and lakes
Extracts 90% of nonfuel mineral and rock resources
Extracts 60% of coal used in the USA
Open-pit Mining Machines dig
holes and
remove ores,
sand, gravel,
and stone.
Toxic
groundwater
can accumulate
at the bottom.
Figure 15-11
Area Strip Mining Earth movers strips
away overburden, and
giant shovels removes
mineral deposit.
Often leaves highly
erodible hills of
rubble called spoil
banks.
Used mostly in flat
areas
Figure 15-12
Contour Strip Mining
Used on hilly or
mountainous
terrain.
Unless the land
is restored, a
wall of dirt is left
in front of a
highly erodible
bank called a
highwall.
Figure 15-13
Mountaintop Removal Machinery removes
the tops of mountains
to expose coal.
The resulting waste
rock and dirt are
dumped into the
streams and valleys
below.
Seen mostly in the
Appalachian Mtns. Figure 15-14
Methods (Continued) Underground Mining
Description – digging a shaft down to the
resource, using machinery (and people) to tear
off and remove the resource
Benefits – can get to resources far underground
Costs – more expensive, more time-consuming,
more dangerous
Methods (Continued)
Reclamation
Description – returning the rock layer
(overburden) and the topsoil to a surface
mine, fertilizing and planting it
Benefits – restores land to good condition
Costs – expensive, time-consuming
How long will they last?
5 countries supply most of the non-renewable
mineral resources used by modern societies.
Factors effecting future supply
Economic depletion
Graph pg. 361
Mining subsidies (US General Mining Law 1872)
Mine lower-grade ores?
Sustainable Use
Substitutes
Recycle/Reuse
Fig. 15-18, p. 351
Solutions
Sustainable Use of Nonrenewable Minerals
• Do not waste mineral resources.
• Recycle and reuse 60–80% of mineral resources.
• Include the harmful environmental costs of
mining and processing minerals in the prices
of items (full-cost pricing).
• Reduce subsidies for mining mineral resources.
• Increase subsidies for recycling, reuse, and
finding less environmentally harmful substitutes.
• Redesign manufacturing processes to use less
mineral resources and to produce less pollution
and waste.
• Have the mineral-based wastes of one
manufacturing process become the raw
materials for other processes.
• Sell services instead of things.
• Slow population growth.
Specific Resources & Their Uses Limestone – abundant locally, formed from layers of
seashells and organisms under pressure as they were covered; used in sidewalks, fertilizers, plastics, carpets, and more
Lead – used in batteries and cars
Clay – used to make books, magazines, bricks, and linoleum
Gold – besides being used as money and for jewelry, gold is used in medicine (lasers, cauterizing agents) and in electronics (circuits in computers, etc.)
Texas
Central – limestone, tin, clay, lead, garnets,
freshwater pearls, amethysts, calcium carbonate
West – talc, mercury, silver, petroleum, sulfur
East – lignite coal, petroleum
South – lignite coal, petroleum, uranium, limestone
North – helium, uranium, petroleum, bituminous
coal
United States
Central – diamonds (Arkansas), bituminous
coal
West – bituminous and subbituminous coal,
gold, silver, copper
East – anthracite coal, bituminous coal
South – some gold (SC), bituminous coal
North – bituminous coal, some gold (SD, WI)
Core Case Study:
How Long Will the Oil Party Last? Supplies 1/3 of the world’s energy
Geologists predict we will have depleted 80% of the
reserves between 2050 and 2100
Saudi Arabia could supply the world with oil for
about 10 years.
The Alaska’s North Slope could meet the world oil
demand for 6 months (U.S.: 3 years).
Alaska’s Arctic National Wildlife Refuge would
meet the world demand for 1-5 months (U.S.: 7-25
months).
Commercial Energy
% renewable vs. % non-renewable
3 largest users
Net Energy…understand ratios
Evaluation
Supply
Environmental impact
Useful energy produced
Primary Sources
Definition – the original sources that
are used to make electricity or heat
Energy Resources
Secondary Sources
Definition – the heat and
electricity that we use for energy
Cogeneration
Production of two useful forms of energy,
such as high-temperature heat or steam and
electricity, from the same fuel source.
Ex. An industry using natural gas for
manufacturing and using the waste heat to
produce electricity.
OIL
Crude oil (petroleum) is a thick liquid containing hydrocarbons that we extract from underground deposits and separate into products such as gasoline, heating oil and asphalt.
OIL Crude Oil- thick liquid with
hydrocarbons that we extract
from underground deposits.
Refining crude oil:
Based on boiling points,
components are removed at
various layers in a giant
distillation column.
The most volatile
components with the lowest
boiling points are removed
at the top.
Figure 16-5
Fig. 16-5, p. 359
Gases
Gasoline
Aviation fuel
Heating oil
Diesel
oil
Naptha
Grease
and wax
Asphalt
Heated
crude oil
Furnace
OIL Eleven OPEC (Organization of Petroleum Exporting
Countries) have at least 60% of the world’s proven oil
reserves and most of the world’s unproven reserves.
Algeria, Angola, Indonesia, Iran, Iraq, Kuwait, Libya, Nigeria,
Quatar, Saudi Arabia, UAE, Venezuela.
Since most of the world’s oil is controlled by government
and OPEC’s secrecy, the amout of reserves are very hard
to confirm.
After global production peaks and begins a slow decline,
oil prices will rise and could threaten the economies of
countries that have not shifted to new energy alternatives.
U.S. Oil Supplies The U.S. – the world’s largest oil user – has only 2.4%
of the world’s proven oil reserves.
U.S oil production peaked in 1974 (halfway production
point).
Potential reserves are beneath federal lands or coastal
waters; could significantly boost reserves, price to bring
it to consumer would be huge
$7.50-$10/barrel on land, 4X higher in deep water --
compare to $2/barrel in Saudi Arabia
This is why we import approx. 60% of our oil
Increase recovery & engineered bacteria
U.S. Arctic National Wildlife
Refuge
Not available to drilling/exploration
Alaska’s representatives
Is the benefit worth the cost?
Increase reserves
Degraded land
Heavy Oils from Oil Sand and Oil
Shale: Will Sticky Black Gold Save Us? Heavy and tarlike oils from oil sand and oil shale could
supplement conventional oil, but there are environmental problems.
Bitumen is the combustible organic material
Canada has ¾ of the world’s oil sands, oil sands are considered reserves of conventional oil so Canada has 15% of world’s oil reserves
High sulfur content.
Produces 3x more CO2/barrel than conventional oil
Extracting and processing produces: Toxic sludge
Uses and contaminates larges volumes of water
Requires large inputs of natural gas which reduces net energy yield.
Oil Shales
Oil shales contain a solid
combustible mixture of
hydrocarbons called
kerogen.
72% of estimated reserves
are in the western U.S.
Estimates say reserve could
meet current U.S. oil
demand for 110 years
Low net energy bc most is
locked up in low grade ore,
high environmental impact,
requires a lot of water Figure 16-9
NATURAL GAS Natural gas, consisting mostly of methane, is often
found above reservoirs of crude oil.
Often viewed as an unwanted by-product and burned off
When a natural gas-field is tapped, gasses are liquefied
and removed as liquefied petroleum gas (LPG).
To be transferred across oceans natural gas is converted
to liquefied natural gas (LNG) at low temp and high
pressure
Low net energy yield
NATURAL GAS
Russia and Iran have almost half of the
world’s reserves of conventional gas, and
global reserves should last 62-125 years.
Natural gas is versatile and clean-burning
fuel, but it releases the greenhouse gases
carbon dioxide (when burned) and methane
(from leaks) into the troposphere.
Unconventional Natural Gas
Methane hydrate
Found in coal beds near earth’s surface in the U.S. and Canada
Methane trapped in icy structures of water molecules
Buried under tundra/arctic permafrost
Expensive and release of methane is too high
Coal beds methane
Scars the land
Pollution of air and water public backlash in western U.S.
COAL
Coal is a solid fossil fuel that is formed in several stages as the buried remains of land plants that lived 300-400 million years ago.
Largest coal burning countries are China, United States, & India
Produces 49% of the energy in the U.S.
Most abundant fossil fuel, the U.S. is the Saudi Arabia of coal
Dirty fuel; tax each unit of carbon dioxide produced.
Figure 16-12
Fig. 16-12, p. 368
Increasing heat and carbon content
Increasing moisture content
Peat
(not a coal)
Lignite
(brown coal)
Bituminous
(soft coal)
Anthracite
(hard coal)
Heat Heat Heat
Pressure Pressure Pressure
Partially decayed
plant matter in
swamps and bogs;
low heat content
Low heat content;
low sulfur content;
limited supplies in
most areas
Extensively used as
a fuel because of its
high heat content
and large supplies;
normally has a high
sulfur content
Highly desirable
fuel because of
its high heat
content and low
sulfur content;
supplies are
limited in most
areas
Fig. 16-13, p. 369
Waste heat
Coal bunker Turbine Cooling tower
transfers waste
heat to
atmosphere
Generator
Cooling loop
Stack
Pulverizing
mill Condenser Filter
Boiler
Toxic ash disposal
COAL
Cheap, plentiful, large distibution
Severe impact on air quality, water, and
land
Can be converted to synthetic natural gas
(SNG)
Coal gasification or liquefication
Requires a lot of coal to creat
TYPES OF ENERGY
RESOURCES
About 99% of the energy we use for heat
comes from the sun and the other 1% comes
mostly from burning fossil fuels.
Solar energy indirectly supports wind power,
hydropower, and biomass.
About 76% of the commercial energy we
use comes from nonrenewable fossil fuels
(oil, natural gas, and coal) with the
remainder coming from renewable sources.
TYPES OF ENERGY RESOURCES
Nonrenewable energy resources and geothermal
energy in the earth’s crust. Figure 16-2
Fig. 16-2, p. 357
Oil and natural gas Floating oil drilling
platform Oil storage Coal
Contour
strip mining Oil drilling
platform on
legs
Geothermal
energy
Hot water storage Oil well
Pipeline Geothermal
power plant
Gas
well Valves Mined coal
Pump Area strip
mining Drilling
tower
Pipeline
Coal seam Water
penetrates
down through
the rock
TYPES OF ENERGY RESOURCES
Commercial energy use by source for the
world (left) and the U.S. (right).
Figure 16-3
REDUCING ENERGY WASTE
AND IMPROVING ENERGY
EFFICIENCY Four widely used devices waste large
amounts of energy:
Incandescent light bulb: 95% is lost as heat.
Internal combustion engine: 94% of the
energy in its fuel is wasted.
Nuclear power plant: 92% of energy is wasted
through nuclear fuel and energy needed for
waste management.
Coal-burning power plant: 66% of the energy
released by burning coal is lost.
USING RENEWABLE SOLAR
ENERGY TO PROVIDE HEAT
AND ELECTRICITY A variety of renewable-energy resources are
available but their use has been hindered by
a lack of government support compared to
nonrenewable fossil fuels and nuclear
power.
Direct solar
Moving water
Wind
Geothermal
USING RENEWABLE SOLAR
ENERGY TO PROVIDE HEAT
AND ELECTRICITY
The European Union had set a goal to get 22% of its electricity from renewable energy by 2010.
Costa Rica gets 92% of its energy from renewable resources.
China aims to get 10% of its total energy from renewable resources by 2020.
In 2004, California got about 12% of its electricity from wind and plans to increase this to 50% by 2030.
USING RENEWABLE SOLAR
ENERGY TO PROVIDE HEAT
AND ELECTRICITY
Denmark now gets 20% of its electricity
from wind and plans to increase this to 50%
by 2030.
Brazil gets 20% of its gasoline from
sugarcane residue.
In 2004, the world’s renewable-energy
industries provided 1.7 million jobs.
Solar
Types – photovoltaic cells (convert sunlight directly to electricity with a 10% efficiency) and solar thermal systems (sun’s heat is used to heat bodies of water enough to produce steam that can be used to make electricity)
Energy conversion – radiant/heat to electrical, heat or mechanical
Benefits – pollution-free, unlimited source
Costs – not useful in cloudy areas or at night, we do not have the technology needed to use very efficiently
Producing Electricity with Solar Cells
Photovoltaic (PV) cells can provide
electricity for a house of building using
solar-cell roof shingles. Figure 17-17
Fig. 17-17, p. 398
Single solar cell Solar-cell roof
–
Boron
enriched
silicon
+
Junction
Phosphorus
enriched silicon
Roof options
Panels of
solar cells
Solar
shingles
Producing Electricity with Solar Cells
Solar cells can be
used in rural
villages with
ample sunlight
who are not
connected to an
electrical grid.
Figure 17-18
Core Case Study: The Coming Energy-
Efficiency and Renewable-Energy
Revolution
It is possible to get electricity from solar
cells that convert sunlight into electricity.
Can be attached like shingles on a roof.
Can be applied to window glass as a coating.
Can be mounted on racks almost anywhere.
Core Case Study: The Coming Energy-
Efficiency and Renewable-Energy
Revolution
The heating bill for this energy-efficient passive solar radiation office in Colorado is $50 a year.
Figure 17-1
Passive Solar
Heating
Passive solar heating
system absorbs and
stores heat from the
sun directly within a
structure without the
need for pumps to
distribute the heat.
Figure 17-13
Fig. 17-13, p. 396
Direct Gain
Summer
sun Hot air
Warm
air
Super-
insulated
windows
Winter
sun
Cool air
Earth tubes
Ceiling and north wall
heavily insulated
Fig. 17-13, p. 396
Greenhouse, Sunspace, or
Attached Solarium
Summer cooling vent
Warm air
Insulated
windows
Cool air
Fig. 17-13, p. 396
Earth Sheltered
Reinforced concrete,
carefully waterproofed
walls and roof
Triple-paned or
superwindows Earth
Flagstone floor for heat
storage
Fig. 17-14, p. 396
Trade-Offs
Passive or Active Solar Heating
Advantages Disadvantages
Energy is free Need access to sun
60% of time Net energy is
moderate
(active) to high
(passive)
Sun blocked by
other structures
Need heat storage
system
Quick installation
No CO2 emissions
Very low air and
water pollution High cost (active)
Very low land
disturbance
(built into roof
or window)
Active system
needs maintenance
and repair
Moderate cost
(passive)
Active collectors
unattractive
Cooling Houses Naturally
We can cool houses by:
Superinsulating them.
Taking advantages of breezes.
Shading them.
Having light colored or green roofs.
Using geothermal cooling.
Wind
Energy conversion – kinetic to electrical
Benefits – pollution-free, source is free (used in West Texas, Hawaii, California, and more)
Costs – can only be used in places with lots of wind
PRODUCING ELECTRICITY
FROM WIND
Wind power is the world’s most promising energy
resource because it is abundant, inexhaustible,
widely distributed, cheap, clean, and emits no
greenhouse gases.
Much of the world’s potential for wind power
remains untapped.
Capturing only 20% of the wind energy at the
world’s best energy sites could meet all the
world’s energy demands.
PRODUCING ELECTRICITY
FROM WIND
Wind turbines can be used individually to produce electricity. They are also used interconnected in arrays on wind farms.
Figure 17-21
PRODUCING ELECTRICITY
FROM WIND
The United States once led the wind power
industry, but Europe now leads this rapidly
growing business.
The U.S. government lacked subsidies, tax breaks and
other financial incentives.
European companies manufacture 80% of the
wind turbines sold in the global market
The success has been aided by strong government
subsidies.
Biomass
Description – any type of organic matter (forest products, crop wastes, animal wastes, people wastes, etc.) that can be used to produce energy; currently used for about 5% of U.S. energy
Energy conversion – chemical to electrical or heat
Benefits – cheap, less toxic pollutants, using wastes effectively, currently used in Rio Grande Valley with the burning of sugar cane residue, also produces food, feed, and fiber
Costs – we don’t have all the technology needed to use this well right now, not useful in every location, some pollution is produced
PRODUCING
ENERGY FROM
BIOMASS
Plant materials and
animal wastes can be
burned to provide heat
or electricity or
converted into
gaseous or liquid
biofuels. Figure 17-23
PRODUCING ENERGY FROM
BIOMASS
The scarcity of
fuelwood causes
people to make
fuel briquettes
from cow dung in
India. This
deprives soil of
plant nutrients. Figure 17-24
Fig. 17-25, p. 405
Trade-Offs
Solid Biomass
Advantages Disadvantages
Large potential supply in some
areas
Nonrenewable if harvested
unsustainably
Moderate costs Moderate to high environmental
impact
No net CO2 increase if harvested
and burned sustainably
CO2 emissions if harvested
and burned unsustainably
Low photosynthetic efficiency Plantation can be located on
semiarid land not needed for
crops Soil erosion, water pollution,
and loss of wildlife habitat
Plantation can help restore
degraded lands
Plantations could compete
with cropland
Often burned in inefficient
and polluting open fires and
stoves
Can make use of agricultural,
timber, and urban wastes
Water Energy conversion – kinetic to electrical or heat
Benefits – already have the technology to do this, pollution free, dams are also useful as water sources and flood controls; world’s largest source of electrical power
Costs – there are environmental costs to building new dams, there are not rivers located everywhere
Read James Bay Watershed Transfer Project Miller Page 304
PRODUCING ELECTRICITY
FROM THE WATER CYCLE
Water flowing in rivers and streams can be
trapped in reservoirs behind dams and
released as needed to spin turbines and
produce electricity.
There is little room for expansion in the
U.S. – Dams and reservoirs have been
created on 98% of suitable rivers.
Fig. 17-20, p. 400
Trade-Offs
Large-Scale Hydropower
Advantages Disadvantages
Moderate to high net energy High construction costs
Large untapped potential
High environmental impact
from flooding land to form a
reservoir
High efficiency (80%)
High CO2 emissions from
biomass decay in shallow
tropical reservoirs
Low-cost electricity
Long life span
No CO2 emissions during
operation in temperate areas
Floods natural areas behind dam
May provide flood control below
dam
Converts land habitat to lake
habitat
Danger of collapse
Provides water for year-round
irrigation of cropland
Uproots people
Decreases fish harvest below dam
Reservoir is useful for fishing
and recreation
Decreases flow of natural fertilizer
(silt) to land below dam
Geothermal
Description – heat from deep within the earth is used to produce electricity
This is the only energy source that doesn’t come from the sun!
Energy conversion – thermal to electrical and heat
Benefits – pollution-free, used near Waco and in Iceland
Costs – not available everywhere, we don’t have all the technology needed to use it
GEOTHERMAL ENERGY Geothermal energy consists of heat stored
in soil, underground rocks, and fluids in the
earth’s mantle.
We can use geothermal energy stored in the
earth’s mantle to heat and cool buildings
and to produce electricity.
A geothermal heat pump (GHP) can heat and
cool a house by exploiting the difference
between the earth’s surface and underground
temperatures.
Geothermal Heat Pump
The house is
heated in the
winter by
transferring heat
from the ground
into the house.
The process is
reversed in the
summer to cool
the house. Figure 17-31
Tidal Power
Energy conversion – kinetic to
electrical
Benefits – pollution-free, cheap,
renewable
Costs – only two places in the U.S.
have tides needed to do this
Wave Power
Energy conversion – kinetic to electrical
Benefits – pollution-free, cheap, renewable
Costs - only suitable in areas facing the
open ocean (especially on the West Coasts
of continents); tend to be destroyed in
storms
PRODUCING ELECTRICITY
FROM THE WATER CYCLE
Ocean tides and waves and temperature
differences between surface and bottom
waters in tropical waters are not expected to
provide much of the world’s electrical
needs.
Only two large tidal energy dams are
currently operating: one in La Rance,
France and Nova Scotia’s bay of Fundy
where the tidal amplitude can be as high as
16 meters (63 feet).
NUCLEAR ENERGY
When isotopes of uranium and plutonium
undergo controlled nuclear fission, the
resulting heat produces steam that spins
turbines to generate electricity.
The uranium oxide consists of about 97%
nonfissionable uranium-238 and 3% fissionable
uranium-235.
The concentration of uranium-235 is increased
through an enrichment process.
Fig. 16-16, p. 372
Small amounts of radioactive gases
Uranium fuel
input (reactor
core)
Control rods
Containment shell
Heat exchanger
Steam Turbine Generator
Waste heat
Electric
power
Useful energy
25%–30% Hot
water
output
Coolant
Moderator
Cool
water
input
Waste heat
Shielding Pressure
vessel
Coolant
passage
Water Condenser Periodic removal and
storage of radioactive
wastes and spent fuel
assemblies
Periodic removal
and storage of
radioactive liquid
wastes
Water source (river,
lake, ocean)
NUCLEAR ENERGY
After three or four
years in a reactor,
spent fuel rods are
removed and stored
in a deep pool of
water contained in
a steel-lined
concrete container.
Figure 16-17
NUCLEAR ENERGY
After spent fuel rods are cooled
considerably, they are sometimes moved to
dry-storage containers made of steel or
concrete. Figure 16-17
What Happened to Nuclear Power?
After more than 50 years of development
and enormous government subsidies,
nuclear power has not lived up to its
promise because:
Multi billion-dollar construction costs.
Higher operation costs and more malfunctions
than expected.
Poor management.
Public concerns about safety and stricter
government safety regulations.
Case Study: The Chernobyl Nuclear
Power Plant Accident
The world’s worst nuclear power plant
accident occurred in 1986 in Ukraine.
The disaster was caused by poor reactor
design and human error.
By 2005, 56 people had died from radiation
released.
4,000 more are expected from thyroid cancer
and leukemia.
NUCLEAR
ENERGY
A 1,000
megawatt
nuclear plant is
refueled once a
year, whereas a
coal plant
requires 80 rail
cars a day.
Figure 16-20
Fig. 16-20, p. 376
Coal vs. Nuclear
Trade-Offs
Coal Nuclear
Ample supply Ample supply of uranium
High net energy yield Low net energy yield
Very high air pollution Low air pollution (mostly
from fuel reprocessing)
High CO2 emissions Low CO2 emissions (mostly
from fuel reprocessing)
High land disruption from
surface mining Much lower land disruption
from surface mining
Low cost (with huge subsidies) High cost (even with
huge subsidies)
High land use Moderate land use
NUCLEAR ENERGY
Terrorists could attack nuclear power
plants, especially poorly protected pools
and casks that store spent nuclear fuel rods.
Terrorists could wrap explosives around
small amounts of radioactive materials that
are fairly easy to get, detonate such bombs,
and contaminate large areas for decades.
NUCLEAR ENERGY
When a nuclear reactor reaches the end of its useful life, its highly radioactive materials must be kept from reaching the environment for thousands of years.
At least 228 large commercial reactors worldwide (20 in the U.S.) are scheduled for retirement by 2012.
Many reactors are applying to extent their 40-year license to 60 years.
Aging reactors are subject to embrittlement and corrosion.
NUCLEAR ENERGY
Building more nuclear power plants will not
lessen dependence on imported oil and will
not reduce CO2 emissions as much as other
alternatives.
The nuclear fuel cycle contributes to CO2
emissions.
Wind turbines, solar cells, geothermal energy,
and hydrogen contributes much less to CO2
emissions.
NUCLEAR ENERGY Scientists disagree about the best methods for
long-term storage of high-level radioactive waste:
Bury it deep underground.
Shoot it into space.
Bury it in the Antarctic ice sheet.
Bury it in the deep-ocean floor that is geologically
stable.
Change it into harmless or less harmful isotopes.
Nuclear
Description – using fission to split large uranium atoms into smaller products and releasing tremendous amounts of heat energy which is used to make steam that turns turbines to create electricity
Energy conversion – nuclear to electrical and heat
Benefits – pollution-free, very, very efficient
Costs – risk of accidents (spread of radioactivity); transportation and disposal of radioactive wastes (Nimby!) It also produces a ton of thermal pollution!
WAYS TO IMPROVE ENERGY
EFFICIENCY
We can save energy in building by getting heat
from the sun, superinsulating them, and using
plant covered green roofs.
We can save energy in existing buildings by
insulating them, plugging leaks, and using
energy-efficient heating and cooling systems,
appliances, and lighting.
Strawbale House
Strawbale is a superinsulator that is made from
bales of low-cost straw covered with plaster or
adobe. Depending on the thickness of the bales, its
strength exceeds standard construction.
Figure 17-9
Living Roofs Roofs covered with
plants have been
used for decades in
Europe and Iceland.
These roofs are
built from a blend
of light-weight
compost, mulch and
sponge-like
materials that hold
water. Figure 17-10
Saving Energy in Existing
Buildings
About one-third of the heated air in typical
U.S. homes and buildings escapes through
closed windows and holes and cracks.
Figure 17-11
Definition
Any fuel that meets certain emissions
standards; i.e. they give off a certain
amount of pollution (or less)
Alternative Fuels
Laws Involved
Clean Air Act amendments of 1990
Energy Policy Act (EPACT) in Texas
of 1992
Such laws have led to more research
and development of these fuels
Examples of Alternative Fuels Biodiesel – made of vegetable oils and
alcohols; expensive
Diesel – cleaner than “normal” gasoline, being more refined
Biogas – by-product of decaying vegetation; need technology
Hydrogen – expensive and we need more technology
Ethanol/Methanol – alcohols; not as efficient (Miles per gallon) and we don’t have all the technology ; also, if our grain supplies are used to make fuel, will we have enough to feed the world?
Natural Gas – expensive and we need more technology
Reformulated Gasoline (RFG) – regular gas that has been further refined to remove some of the more toxic pollutants
Propane – most usable form of alternative fuel; not as efficient (mpg)
Syngas – manmade gas made of hydrogen and carbon monoxide; need more technology to use it
HYDROGEN
Some energy experts view hydrogen gas as
the best fuel to replace oil during the last
half of the century, but there are several
hurdles to overcome:
Hydrogen is chemically locked up in water an
organic compounds.
It takes energy and money to produce it (net
energy is low).
Fuel cells are expensive.
Hydrogen may be produced by using fossil
fuels.
Energy Laws
Public Utility Holding Company Act (PUHCA) – 1935; regulated the interstate flow of energy; 1st law of its kind; a law designed to protect consumers from corporate abuse of electricity markets
(so electric companies can’t price gouge.) This was happening during the great depression.
Corporate Average Fuel Economy Act (CAFÉ) –1975; focused attention on efficiency of cars; mpg stickers required
Public Utility Regulatory Policies Act (PURPA)–1978; higher utility rates for increased electricity use
Converting Plants and Plant Wastes
to Liquid Biofuels: An Overview
Motor vehicles can run on ethanol,
biodiesel, and methanol produced from
plants and plant wastes.
The major advantages of biofuels are:
Crops used for production can be grown almost
anywhere.
There is no net increase in CO2 emissions.
Widely available and easy to store and
transport.
Case Study: Producing Ethanol
Crops such as
sugarcane, corn, and
switchgrass and
agricultural, forestry
and municipal wastes
can be converted to
ethanol. Switchgrass can remove
CO2 from the
troposphere and store it
in the soil. Figure 17-26
Case Study: Producing Ethanol
10-23% pure ethanol makes gasohol which can be
run in conventional motors.
85% ethanol (E85) must be burned in flex-fuel
cars.
Processing all corn grown in the U.S. into ethanol
would cover only about 55 days of current
driving.
Biodiesel is made by combining alcohol with
vegetable oil made from a variety of different
plants..
Case Study: Biodiesel and
Methanol
Growing crops for biodiesel could
potentially promote deforestation.
Methanol is made mostly from natural gas
but can also be produced at a higher cost
from CO2 from the atmosphere which could
help slow global warming.
Can also be converted to other hydrocarbons to
produce chemicals that are now made from
petroleum and natural gas.
WAYS TO IMPROVE ENERGY
EFFICIENCY Average fuel
economy of new vehicles sold in the U.S. between 1975-2006.
The government Corporate Average Fuel Economy (CAFE) has not increased after 1985.
Figure 17-5
Fig. 17-5, p. 388
Cars
Both
Ave
rag
e f
ue
l e
co
no
my
(mil
es
pe
r g
all
on
, o
r m
pg
)
Model year
Pickups, vans, and
sport utility vehicles
WAYS TO IMPROVE ENERGY
EFFICIENCY
General features of a
car powered by a
hybrid-electric
engine.
“Gas sipping” cars
account for less than
1% of all new car
sales in the U.S.
Figure 17-7
Fig. 17-7, p. 389
Regulator: Controls flow of power between electric motor and battery bank.
Fuel tank: Liquid fuel such as gasoline, diesel, or ethanol runs small combustion engine. Transmission:
Efficient 5-speed automatic transmission.
Battery: High-density battery powers electric motor for increased power.
Combustion engine: Small, efficient internal combustion engine powers vehicle with low emmissions; shuts off at low speeds and stops.
Electric motor: Traction drive provides additional power for passing and acceleration; excess energy recovered during braking is used to help power motor.
Fuel Electricity
Hybrid Vehicles, Sustainable Wind
Power, and Oil imports
Hybrid gasoline-electric engines with an
extra plug-in battery could be powered
mostly by electricity produced by wind and
get twice the mileage of current hybrid cars.
Currently plug-in batteries would by generated
by coal and nuclear power plants.
According to U.S. Department of Energy, a
network of wind farms in just four states could
meet all U.S. electricity means.
Fuel-Cell Vehicles
Fuel-efficient vehicles powered by a fuel
cell that runs on hydrogen gas are being
developed.
Combines hydrogen gas (H2) and oxygen
gas (O2) fuel to produce electricity and
water vapor (2H2+O2 2H2O).
Emits no air pollution or CO2 if the
hydrogen is produced from renewable-
energy sources.
Fig. 17-8, p. 390
Body attachments
Mechanical locks that secure the
body to the chassis
Air system
management
Universal docking connection
Connects the chassis with the
drive-by-wire system in the body Fuel-cell stack
Converts hydrogen
fuel into electricity Rear crush zone
Absorbs crash energy
Drive-by-wire
system controls
Cabin heating unit
Side-mounted radiators
Release heat generated by the fuel cell,
vehicle electronics, and wheel motors Hydrogen
fuel tanks
Front crush zone
Absorbs crash energy
Electric wheel motors
Provide four-wheel drive;
have built-in brakes
National Appliance Energy Act – 1987; energy efficiency stickers on all appliances
Renewable Energy and Technology Competitiveness Act – 1989; effort to develop renewable energy nationally
Clean Air Act Amendments – 1990; set standards for cities and emissions
Energy Policy Act – 1992; comprehensive effort to find renewable energy resources
Hydrogen Future Act – 1996; develop hydrogen as an energy source
PROBLEM – FEW of these actually provide the money needed to research renewable resources