Download File

Energy
Resources
Chapter 5
Section 1
Natural Resources
Earth is a giant life support system
 Atmosphere – provides the air we breath,
maintains air temperatures & produces rain
 Water – provide food & needed fluids
 Solid crust – provide nutrients & minerals
 Natural Resources = any natural substance,
organism, or energy form that living things use.
 Few of the Earth’s natural resources are used in
their unaltered state.
Section 1
Renewable Resources
 Renewable
Resources = a natural resource that
can be used and replaced over a relatively short
time
 water;
trees; non-agricultural food; animals are
just a few of the renewable resources
 Although
many resources are renewable, humans
often use them more quickly than they can be
replaced.
Section 1
Nonrenewable Resources
 Nonrenewable
Resources = a natural resource
that cannot be replaced or that can be replaced
only over thousands or millions of years
 Fossil
fuels (coal, petroleum, natural gas) are an
example of nonrenewable resources
 When
these resources become scarce, humans
will have to find other resources to replace them.
Section 1
Conserving Natural Resources
To conserve natural resources:
 We
should try to use them only when necessary
 We
should recycle whenever possible
•
Recycling = the process by which used or
discarded materials are treated for reuse.
Section 1
Natural Resources Review
1.
How do humans use most natural resources?
2.
What is the difference between renewable &
nonrenewable resources?
3.
Name two ways to conserve natural resources
4.
List three renewable resources not mentioned in
this section.
Section 2
Fossil Fuels
 Energy
Resources = natural resources that
humans use to produce energy.
 Fossil Fuels = nonrenewable energy resources
that form in the Earth’s crust over millions of
years from the buried remains of once-living
organisms.
 Energy is released from fossil fuels when they
are burned.
 There are many types of fossil fuels, which exist
as liquids, gas, & solids
Section 2
Liquid Fossil Fuels – Petroleum
 Petroleum
= or crude oil, is an oily mixture of
flammable organic compounds from which liquid
fossil fuels & other products, such as asphalt, are
separated.
• Refineries separated petroleum into several
types of fossil fuels & other products
Gasoline, jet fuel, kerosene, diesel fuel, & fuel
oil
Section 2
Gaseous Fossil Fuels – Natural Gas
 Natural
Gas = gaseous fossil fuels (methane is
the main component but other compounds are in
natural gas, such as butane – used for camp
stoves – & propane – use as a heating fuel & as a
cooking fuel, especially for outdoor grills
 Most is used for heating & for generating
electricity
 Stoves can run on natural gas
 Cars that run on natural gas produce less air
pollution than those that use gasoline
Section 2
Solid Fossil Fuels – Coal
 Coal
= a solid fossil fuel formed underground
from buried, decomposed plant material (this is
the most used solid fossil fuel)
 Once
the US’s leading source of energy people
began to use coal less because burning coal
produces large amounts of air pollution & because
better energy sources were discovered.
 However
many power plants still burn coal to
produce electricity today
Section 2
How Do Fossil Fuels Form?
All fossil fuels form from the buried remains of
ancient organisms. BUT different types of fossil
fuels form in different ways & from different types
of organisms
 Petroleum & natural gas form mainly from the
remains of microscopic sea life.
Coal Formation
 Coal forms underground over millions of years
from decayed swamp plants
Section 2
Where Are Fossil Fuels Found?
 Fossil
fuels are found in many parts of he world,
both on land & beneath the ocean
 The US has large reserves of petroleum, natural
gas, & coal. (most oil & gas produced in the
continental US comes from California, Louisiana,
& Texas)
 In spite of all our petroleum reserves, we import
about ½ of our petroleum & petroleum products
from the Middle East, South America, & Africa.
Section 2
How Do Humans Obtain Fossil Fuels?
Humans use different methods to remove fossil fuel
from the Earth’s crust. Depends on the type of fuel
being obtained & its location
 Petroleum & natural gas are removed by drilling
wells into the rock that contains these resources.
Oil wells exist both on land & in the ocean
 Coal is obtained either by mining deep beneath
the Earth’s surface or by strip mining.
• Strip Mining = a process in which rock & soil
are stripped from the Earth’s surface to expose
the underlying materials to be mined.
Section 2
Problems with Fossil Fuels
Burning coal – releases sulfur dioxide. Which then
combines with moisture in the air to produce
sulfuric acid – one of the acids in acid precipitation.
 Acid Precipitation = rain or snow that has a high
acid content due to air pollutants
• Acid precipitation negatively affects wildlife,
plants, buildings, & statues
Section 2
Problems with Fossil Fuels: Cont.
Coal Mining
Strip mining – removes soil, which hurts plants &
wildlife. If not properly repaired afterward, it can
destroy wildlife habitats.
Coal mines that are deep underground can be
hazardous to men & women working in them. It can
also lower local water tables, pollute water supplies,
& cause the overlying earth to collapse.
Section 2
Problems with Fossil Fuels: Cont.
Petroleum Problems
Oil Spills – oil kills hundreds of thousands of
animals & damages local fishing industry.
Smog
Burning petroleum products – produces smog
 Smog = a photochemical fog produced by the
reaction of sunlight & air pollutants
Section 2
Dealing with Fossil-Fuel Problems
 Can’t
stop using fossil fuels any time soon – we
are too dependent on them.
 But there are things we can do to minimize the
negative effect of fossil fuels.
• By carpooling, riding a bike, walking, & using
mass-transit systems
 These measures reduce the number of cars on the
road which helps to reduce the negative effects of
using fossil fuels, but they do not eliminate the
problem
Section 2
Fossil Fuels Review
1.
Name a solid, liquid, & gaseous fossil fuel.
2.
What component of coal-forming organic material
increases with each step in coal formation?
3.
What is the difference between the organic
material from which coal forms & the organic
material from which petroleum & natural gas
mainly form?
4.
How do we obtain petroleum & natural gas? How
do we obtain coal?
Section 3
Alternative Resources
 The
energy needs of industry, transportation, &
housing are increasingly met by electricity.
 Electricity
is produced by fossil fuels, which are
nonrenewable & cause pollution when burned
 We
must find new sources of energy for people to
continue in their present lifestyles.
Section 3
Splitting the Atom
 Nuclear
Energy = an alternative source of energy
that comes from the nuclei of atoms
 Fission – a process in which the nuclei of
radioactive atoms are split & large amounts of
energy are released. The energy is used to
produced steam to run electric generators in
nuclear power plants.
Section 3
Splitting the Atom: Cont.
Pros & Cons
Nuclear power plants provide alternative sources of
energy without the problems that come with fossil
fuels.
Nuclear power plants produce radioactive wastes.
Nuclear wastes can remain radioactive for
thousands of years. These wastes must be removed
from the plant & stored so that the radiation cannot
escape into the environment unit they lose their
radioactivity.
Section 3
Combining Atoms
Fusion – the joining of nuclei of small atoms to
form larger atoms. (same process the sun uses)
Pro: Produces few dangerous wastes
Con: Very high temperatures are required for the
reaction to take place (no known material can
withstand temperatures that high, so the
reaction must occur within a special
environment, such as a magnetic field.
Section 3
Sitting in the Sun
 Solar
Energy = energy from the sun
 Earth receives more than enough solar energy to
meet all of our energy needs. It is considered a
renewable resource because we are always
receiving solar energy
Solar Cells
To power a calculator only a single solar cell is need
To power a home thousands of cells are need (some
people put them on their roofs)
Section 3
Sitting in the Sun: Cont.
Counting the Cost
Pro: are reliable, quiet, have no moving parts, can
last for years with little maintenance, produce
no pollution during use, and the pollution
produced during manufacture is very low
Con: while solar energy itself is free, solar cells are
expensive to make.
Section 3
Sitting in the Sun: Cont.
Solar Heating
 Solar collectors are dark-colored boxes with glass
or plastic tops. A common use of solar collectors
is heating water.
 Major problem with solar collectors is cost – but
they quickly pay for themselves.
Section 3
Sitting in the Sun: Cont.
Large-Scale Solar Power
 Experimental solar-powered facilities capable of
generating enough energy to power 10,000 homes
1. Design 1 – uses mirrors to focus sunlight onto
coated steel pipes filled with synthetic oil. The
heated oil is then used to turn water into steam.
Which is used to drive electric generators
2. Solar Two – uses mirrors to reflect sunlight onto a
receiver on a central tower. It captures the
sunlight’s energy & stores it in tanks of molten salt.
The stored energy is then used to create stem,
which drives a turbine in an electric generator.
Section 3
Capture the Wind
Wind Energy = energy in the wind (wind power)
Wind Turbines
 Wind farms – clusters of wind turbines
 Generate significant amounts of electricity
 Located in areas where winds are strong & steady
Steady Breezes
 Wind only strongly & steadily enough to produce
electricity on a large scale only in certain places
 Wind energy accounts for only small % of energy
in the US
Section 3
Hydroelectric Energy
Hydroelectric Energy = electricity produced by
falling water
Been around for thousands of years (water wheels)
Harnessing the Water Cycle
 Inexpensive & produces little pollution
 its renewable but not available everywhere
 Huge dams must be built on major rivers to
capture enough water to generate significant
amounts of electricity
Section 3
Hydroelectric Energy Cont.
At What Price?
 Increase use of hydroelectric energy could reduce
the demand for fossil fuel, but there are trade-offs.
• Construction of the large dams necessary for
hydroelectric power plants often destroy other
resources, such as forests & wildlife habitats
• Dams can also decrease water quality & create
erosion problems.
Section 3
Power Plants
 Biomass
= organic matter that contains stored
energy. (leaves, wood, other parts of plants, &
even the dung of plant-grazing animals)
Burning Biomass
 Most common way of heating homes & cooking
food on the Earth
 70% of people in developing countries; 5% in the
US – in total approximately 14% of the world’s
total energy use is)
Section 3
Power Plants: Cont.
Gasohol
 Plants can be changed into liquid fuel by making
into alcohol
 Gasohol = alcohol mixed with gasoline
 An acre of corn can produce more than 1,000L of
alcohol.
 In the US we use a lot of fuel for cars. It would
take about 40% of the entire US corn harvest to
produce enough alcohol to make just 10% of the
fuel we use in our cars. (we need our corn to eat)
Section 3
Deep Heat
Geothermal Energy = energy from within the
Earth
Geothermal Energy
1. Steam rises through a well
2. The steam drives turbines, which in turn drive
electric generators
3. The generators produce electricity
4. The steam escapes the power plant through vents
5. Left over liquid water is injected back into the hot
rock
Section 3
Alternative Resources Review
1.
Briefly describe two ways of using solar energy
2.
In addition to multiple turbines, what is needed to
produce electricity from wind energy on a large
scale?
3.
Nuclear power plants are rarely found in the
middle of deserts or other extremely dry areas. If
you were going to build a nuclear plant, why
would you not build it in the middle of a desert?
4.
Where is the production of hydroelectric energy
practical?
Section 3
Alternative Resources Review
1. Name
two ways to release biomass energy
2. Describe
3. List
two ways to use geothermal energy
four energy alternatives to fossil fuels, & give
one advantage & one disadvantage of each
alternative.