Objectives Recognize the Sun as the ultimate source of most energy on Earth. Conventional Energy Resources Describe how energy changes from one form to

Objectives• Recognize the Sun as the ultimate source of most

energy on Earth.

Conventional Energy Resources

• Describe how energy changes from one form to another.

• Identify materials that are used as fuels.

• Explain how fossil fuels form.

– fuel

– peat

– fossil fuel

Vocabulary

• Green plants, protists such as algae, and cyanobacteria are producers that capture the Sun’s energy in the process of photosynthesis.

• Trapped solar energy is transferred through the food chains when consumers eat producers.

• A food chain is a model that shows how solar energy flows from the Sun to producers and then to consumers in an ecosystem.

Transfer of Solar Energy• The energy that humans and all other organisms

use comes mostly from the Sun.


• The energy stored in organic materials is released when they are burned.

Transfer of Solar Energy• Traditional sources of energy, such as wood,

peat, and fossil fuels, are derived from producers such as plants.


Traditional Sources of Energy• Humans have been able to survive in cold

climates primarily because of their ability to alter the environment to meet their needs.


• Fuels are materials that are burned to produce heat or power.

• Humans have burned wood to cook their food for many thousands of years.

• Traditional fuels include renewable resources such as wood, dried field crops, and dried fecal material from animals such as cows and bison.

Traditional Sources of Energy• The total amount of living things in an ecosystem

is its biomass.


• Biomass fuels, which are fuels derived from living things, are widely used in many developing countries.

• Wood is the most commonly used traditional biomass fuel.

Traditional Sources of Energy

Wood


– Humans have been using wood as an energy source for thousands of years.

• People living in developing countries use half of the world’s wood supply as their primary source of fuel, which has led to deforestation in many areas.

• In industrialized countries, trees are cut down for lumber and paper production rather than fuel.


Field Crops


– Humans use other materials, including field crops, as fuel when wood is scarce.

• The simplest way to use field crops is to burn them directly.

• Crop residues left after harvest are other sources of energy. All of these can be burned to provide heat.


Fecal Material


– Feces are the solid wastes of animals.

– In many cases, dried feces contain undigested pieces of grass that help the material to burn.

– Fecal material from cows often meets the energy needs of people in developing countries that have limited forest resources.


Peat


– Bogs are poorly drained areas with spongy, wet ground that is composed mainly of dead and decaying plant matter.

– Plants in bogs including Sphagnum moss, which forms large mats on top of the water, accumulate as they die.

– Peat is a light, spongy material that is formed when dead plant material is compressed in a bog.

– Highly decomposed peat burns with greater fuel efficiency than wood and is still used to heat homes in Ireland, England, parts of northern Europe, and the United States.

Fossil Fuels• Fossil fuels are energy sources that formed

over geologic time as a result of the compression and partial decomposition of plants and other organic matter.


• Fossil fuels are considered to be nonrenewable because their formation occurred over thousands or even millions of years.

• Fossil fuels include peat, coal, natural gas, and petroleum.

Fossil Fuels• The high concentration of carbon and hydrogen

in fossil fuels makes them very efficient energy sources.


• All fossil fuels originated from organic matter trapped in sedimentary rock.

Fossil Fuels

Coal


– Coal formed from compressed organic matter at the bottom of ancient swamps in which the carbon concentration increased as oxygen and hydrogen were lost.

– Coal can be classified according to carbon concentration which is determined by the amount of pressure under which it formed and the amount of time involved.

– The higher the carbon concentration, the hotter and cleaner the coal burns.

Fossil Fuels

Coal


– Lignite is a soft, brown, low-grade coal that forms from peat and has carbon concentrations of around 40 percent.

– Bituminous coal is the most distributed coal in the United States and has carbon concentrations as high as 85 percent.

– Anthracite is the most efficient and most cleanly burning coal with carbon concentrations of 90 to 95 percent.

– Bituminous coal is the most widely used coal in the United States although carbon and sulfur and nitrogen oxides are released into the air when it burns.

Fossil Fuels

Petroleum and Natural Gas


– Petroleum refers to the natural crude oil found underground and on Earth’s surface.

– Crude oil is a mixture of compounds of hydrogen and carbon called hydrocarbons, which can be burned to release energy.

– Oil originated organically as organisms died and fell to the oxygen-poor environment at the bottom of the seas where they were compressed into sedimentary rocks.

– Bacteria that do not require oxygen partially decomposed the accumulated organisms and released methane, which is one of the components of natural gas.

Fossil Fuels

Migration


– Crude oil and natural gas migrate sideways and upward from their place of formation through the pores of permeable sedimentary rocks.

– Oil and gas continue to rise until they reach a barrier of impermeable rock, such as slate or shale, that prevents their continued upward movement.

– Geologic formations such as faults and anticlines can trap petroleum deposits.

Fossil Fuels

Migration


Section Assessment

1. Match the following terms with their definitions.

___ fuel

___ peat

___ fossil fuel

___ anthracite


A. a fuel that is cut from bogs and dried in the sun

B. materials that are burned to produce heat or power

C. energy sources formed over geologic time as a result of the compression and partial decomposition of organic matter

D. the cleanest-burning type of coal

B

A

C

D

Section Assessment

2. What is biomass fuel?


Biomass fuel is any fuel derived from living things.

______ Coal is a biomass fuel.

______ Bituminous coal is the most widely available coal in the United States.

______ Highly decomposed peat burns with greater fuel efficiency than wood.

______ The stored energy in petroleum originally came from the Sun.

Section Assessment

3. Identify whether the following statements are true or false.


false

true

true

true

Objectives• Identify alternative energy resources.

• Compare the advantages and disadvantages of the various alternative energy resources.

– photovoltaic cell

– geothermal energy

– biogas

– gasohol

Vocabulary

Alternative Energy Resources

Alternative Energy Resources• Most people rely on nonrenewable fossil fuels

for their energy needs which are being used up at an alarming rate.


• Some experts estimate that petroleum resources may be used up within the next 60 years.

• Renewable alternatives to traditional energy resources include solar energy, wind, water, geothermal energy, nuclear energy, and biomass.

Solar Energy• The Sun is the ultimate source of most energy

on Earth.


• The main advantages of solar energy are that it is free and it doesn’t cause any kind of pollution.

Solar Energy

Passive Solar Heating


– The Sun can heat up the inside of a car or a building just by shining through the windows.

– The Sun’s energy also can be captured to be released during the evening in floors and walls made of concrete, adobe, brick, stone, or tile, which have heat-storing capacities.

– Passive solar designs can provide up to 70 percent of the energy needed to heat a house, as well as up to 60 percent of the energy needed to cool it.

Solar Energy

Passive Solar Heating


Solar Energy

Active Solar Heating


– Active solar-heating systems include collectors such as solar panels that absorb solar energy and fans or pumps that distribute that energy throughout the house.

– Heat collected by the solar panels can be used to heat a house directly, or it can be stored for later use in insulated tanks that contain rocks, water, or a heat-absorbing chemical.

Solar Energy

Solar Cookers


– Solar cookers can be used effectively where fuels are scarce or expensive, as in countries that have cut down most of their forests.

– A solar cooker can be as simple as an enclosed box with reflectors to direct the Sun’s rays inside the box.

Solar Energy

Photovoltaic Cells


– An economical and practical method of storing large amounts of direct solar energy for long periods of time has not yet been developed.

– Photovoltaic cells, which are thin, transparent wafers made up of layers of boron- and phosphorus-enriched silicon, convert solar energy into electrical energy.

– The electricity produced by photovoltaic cells can be stored in batteries.

– It is estimated that power towers may someday supply 30 percent of the electric power used worldwide.

Energy from Water• Hydroelectric power is energy produced by water

moving through turbines that drive generators.


• Hydroelectric power currently provides about 20 percent of the world’s electricity and 6 percent of its total energy.

• One advantage of hydroelectric power is that it is nonpolluting.

• Dams built to harness hydroelectric power have negative impacts including flooding large areas, destroying wildlife habitats, and changing the natural pattern of water flow.

Energy from Water

Energy from the Oceans


– The kinetic energy in waves, which is created primarily by wind, can be used to generate electricity.

– Barriers built across estuaries or inlets can capture the energy associated with the ebb and flow of tides for use in tidal power plants.

– While power from moving ocean water is renewable and nonpolluting, barriers in the ocean can change the water level and may disrupt coastal and marine ecosystems.

Geothermal Energy• Geothermal energy is energy produced by

steam and hot water generated by Earth’s own internal heat.


• Abundant at some surface locations usually coinciding with plate boundaries, geothermal energy can be harnessed to heat homes and businesses and generate electricity.

• If developed, geothermal reservoirs in the United States could possibly provide up to 30 times as much energy as the country currently uses.

Geothermal Energy

Advantages and Disadvantages of Geothermal Energy


– Geothermal energy is abundant and reliable at the sites where it occurs but must be managed carefully.

– Water heated by geothermal energy frequently contains large amounts of minerals that can clog pipes and pollute surface water.

– Geothermal energy is useful only near sites where it exists, because transporting it is not practical.

Wind Energy• The wind turbines on a wind farm convert the

energy of the wind to mechanical energy, which is then used to produce electrical energy.


• Wind energy increases with the cube of the wind speed.

• Most of the wind farms in the United States are currently in California, although North Dakota, South Dakota, and Texas have the best locations.

• Wind power could supply more than 10 percent of the world’s electricity by the year 2050.

Wind Energy

Advantages and Disadvantages of Wind Energy


– Wind is a virtually unlimited energy resource at favorable sites worldwide.

– Wind farms are nonpolluting and can be built quickly and expanded as needed.

– Wind energy is one of the least expensive ways to produce electricity, but it is economical only in areas with steady winds.

– Wind farms are not very attractive and they have been shown to interfere with and even kill migrating birds, as well as birds of prey.

Nuclear Energy• During nuclear fission, a large amount of energy is

released when a heavy nucleus (mass number greater than 200) divides to form smaller nuclei and one or two neutrons.


• Uranium is a radioactive element that is commonly used in the production of nuclear energy.

• Nuclear power plants do not produce carbon dioxide or any other greenhouse gases.

• After 50 years, 424 nuclear reactors in 25 countries currently are producing only 17 percent of the world’s electricity.

Nuclear Energy• No new nuclear plants have been built in the

United States since 1978.


– Poor management, high operating costs, poor reactor designs, and public concerns about safety and disposal of radioactive wastes contributed to the decline of nuclear power.

– In addition, nuclear accidents such as those at Three Mile Island and at Chernobyl, Ukraine, in 1986, alerted people worldwide about the hazards of nuclear power plants.

Biomass• Biomass is a renewable energy resource as long

as the organisms that provide the biomass are replaced.


• Bacteria and chemical processes can be used to convert solid biomass into gaseous and liquid biofuels, such as biogas, liquid ethanol, and liquid methanol.

• A disadvantage of biomass fuels is that when they are burned, they release carbon dioxide and particulate matter into the atmosphere.

Biomass

Biogas


– Biogas is a mixture of gases that includes 50 to 70 percent methane gas and 30 to 48 percent carbon-dioxide gas.

– Plant and animal wastes can be converted into methane gas in simple containers, called digesters, by the action of bacteria.

– In the digesters, gas is separated from the solid wastes and piped into homes for use as a cooking fuel.

Biomass

Ethanol and Methanol


– Liquid ethanol is another name for grain alcohol that can be made from sugar and grain crops including sugar cane, sugar beets, sorghum, and corn.

– Gasohol is gasoline mixed with ethanol produced from corn, which can be burned more cleanly than pure gasoline in conventional gasoline engines.

– Liquid methanol, which is wood alcohol, is made mostly from natural gas, but it can also be made from wood, wood wastes, agricultural wastes, sewage sludge, garbage, or coal.

Energy from Oil Shale and Tar Sand• Oil shale is a fine-grained rock that contains a

solid, waxy mixture of hydrocarbon compounds called kerogen.


• When oil shale is heated, the kerogen vaporizes and can be condensed to form a heavy, slow-flowing, dark-brown oil known as shale oil.

• At present, the cost of processing oil shale is higher than the cost of traditional crude oil.

Energy from Oil Shale and Tar Sand• Tar sand is a mixture of clay, sand, water, and

bitumen, which is a heavy, black, high-sulfur oil.


• When heated, the bitumen fluid softens and floats to the top where it can be collected and upgraded into a type of crude oil.

• The processing of oil shale and tar sand requires large amounts of energy and produces air and water pollution.

Section Assessment


___ photovoltaic cell

___ geothermal energy

___ biogas

___ gasohol


A. a mixture of gases produced in a digester that includes 50 to 70 percent methane gas and 30 to 48 percent carbon-dioxide gas

B. energy produced by naturally occurring steam and hot water

C. a mixture of gasoline and ethanol that can be burned in conventional gasoline engines

D. thin, transparent wafers that convert solar energy into electrical energy

D

B

A

C

Section Assessment


2. How would you store large amounts of solar energy for long periods of time?

To store solar energy for long periods of time you would need to convert direct solar energy into electrical energy which can be stored in batteries.

Section Assessment



______ Hydroelectric power represents about 20 percent of the electricity in the United States.

______ No greenhouse gases are released from nuclear power plants.

______ Shale oil is profitable to extract and refine.

______ Burning biomass fuel produces approximately 10 percent of Hawaii’s electrical supply.

false

true

false

true

– energy efficiency

– cogeneration

– sustainable energy

Objectives• Recognize the need for the conservation of

energy resources.

• Identify ways to conserve energy resources.

Vocabulary

Conservation of Energy Resources

Conservation of Energy Resources• Although fossil fuels are nonrenewable and in

limited supply, industrialized countries continue to consume these resources at ever increasing rates.


Conservation of Energy Resources• The best way to meet energy needs is a

combination of improved energy efficiency and increased use of locally available, renewable energy resources.


Energy Efficiency• Energy efficiency is the use of energy resources

in the ways that are most productive.


• Using resources more efficiently is a type of conservation.

Energy Efficiency• How can energy efficiency be improved?


– People can recycle old appliances and vehicles and purchase newer, more energy-efficient models as well as improve the energy efficiency of older homes.

– Local power companies can use energy from alternative resources in areas where they are available to reduce dependence on petroleum.

– Governments can offer tax savings to people who buy more efficient vehicles and appliances, and provide funding for research and development projects related to energy efficiency.

Energy Efficiency



– There are many ways that you could conserve energy at home, at school, and in the workplace, such as simply turning lights off when you leave a room.

– Conserving energy is, in the long run, less expensive than finding new energy sources.

Getting More for Less• Higher energy demand requires a greater supply

and results in higher costs.


• In the United States, approximately 43 percent of the energy used by motor vehicles and to heat homes and businesses is wasted.

• Shifting to the more efficient use of energy rather than the search for more energy would reduce demand, thus lowering the total cost of energy.

Getting More for Less

Cogeneration


– Waste heat, which could be recovered and used to produce another form of energy, is given off when power plants generate electricity.

– Cogeneration is the production of two usable forms of energy, such as steam and electricity, at the same time from the same process.

– Cogeneration can produce income and reduce the need for additional energy resources.


Improving Efficiency in Transportation


– Conservation practices can help reduce dependency on the fuel resources used for transportation.• The use of fuel-efficient vehicles and driving at lower speeds reduces the amount of petroleum resources consumed by motor vehicles.

• Using bicycles, public transportation, or carpooling reduces the number of vehicles on the roads which in turn reduces gasoline consumption.

• Computers and access to the Internet allow more jobs to be performed from home.


Improving Efficiency in Industry


– Cogeneration has allowed some industries to increase production while leveling off their energy use in part by the use of more efficient machinery.

– Industries can further improve their energy efficiency by making greater efforts to reduce their use of both materials and the energy used to produce those materials.


Increasing Efficiency at Home


– The use of energy-efficient appliances can significantly reduce energy consumption.

– The use of building materials and windows with high insulation values (R-values) can significantly reduce energy consumption.

– Incorporating passive and active solar heating in new buildings can reduce the consumption of traditional energy resources.

– New buildings that are designed to save energy cost more initially, but they can save money and resources in the long run.

Sustainable Energy• Energy resources on Earth are interrelated,

meaning that they affect one another.


• Sustainable energy involves the global management of Earth’s natural resources to meet current and future energy needs without causing environmental damage.

• A good management plan incorporates both conservation and energy efficiency.

• Global cooperation can help ensure the necessary balance between protection of the environment and economic growth.

Section Assessment


___ energy efficiency

___ cogeneration

___ R-value

___ sustainable energy


A. the use of energy in ways that are most productive

B. global management of Earth’s natural resources to meet current and future energy needs without causing environmental damage

C. the production of two usable forms of energy at the same time from the same process

D. a rating that indicates the insulation abilities of building materials

A

C

D

B

Section Assessment

2. How does the use of renewable resources as a percentage of energy consumption in developing countries compare to industrialized countries?


A larger percentage (42 percent) of the energy used in developing countries comes from renewable resources compared to industrialized countries (10 percent). Most of the difference can be attributed to the higher use of biomass as a percentage of the total among developing countries (35 percent) compared to industrialized countries (3 percent).

Section Assessment



______ It is better to depend upon a single energy source that has been reliable in the past.

______ An insulation rated at R-13 has a higher insulation value than insulation rated at R-19.

______ It is more energy efficient to drive at higher speeds because your trip takes less time.

______ Cogeneration has allowed some industries to increase production while leveling off energy use.

false

false

false

true

Chapter Resources Menu

Chapter Resources Menu

Study Guide

Section 26.1

Section 26.2

Section 26.3

Chapter Assessment

Image Bank

Section 26.1 Main Ideas• The Sun is the ultimate source of most energy on Earth.

The Sun’s energy is transferred from photosynthetic organisms to all other living things.

• Materials derived from living things, known as biomass, have been used as renewable fuels by humans for thousands of years.

• Wood continues to serve as a fuel for over half of the world’s population.

• Fossil fuels, such as natural gas, coal, and petroleum, formed from organisms that lived millions of years ago. The burning of these fossil fuels releases sulfur into the atmosphere, and thus contributes to air pollution.

Section 26.1 Study Guide

Section 26.2 Main Ideas• Alternative energy resources, such as solar energy, water,

geothermal energy, wind, nuclear energy, and biomass, can supplement dwindling conventional energy resources.

• Solar energy is unlimited, but technological advances are needed to find practical solutions to collect and store it.

• Hydroelectric power is derived from the energy of moving water and is commonly used in the production of electricity. Geothermal energy is a product of Earth’s internal heat. Its usefulness is limited to areas where it is found near Earth’s surface. Wind is a source of energy in areas that have consistently strong winds.


Section 26.2 Main Ideas• Nuclear energy results when atoms of radioactive

elements emit particles in the process known as fission.

• Oil shale and tar sand contain secondary oil resources that are expensive to extract.


Section 26.3 Main Ideas• Energy resources will last longer if conservation and

energy efficiency measures are developed and used. Energy efficiency results in the use of fewer resources to provide more usable energy.

• Cogeneration, in which two usable forms of energy are produced at the same time from the same process, saves resources in the long run.

• The achievement of sustainable energy use will ensure that current and future energy needs are met while maintaining standards of living and at the same time protecting the environment.


1. Which type of coal is the most efficient and cleanest burning?

a. anthracite c. peat

b. lignite d. bituminous

Multiple Choice

Chapter Assessment

Peat, if continued to be compressed, becomes lignite which has carbon concentrations around 40 percent. Bituminous coal, the most abundant coal in the United States, has carbon concentrations as high as 85 percent. Anthracite has carbon concentrations as high as 95 percent. The higher the carbon concentration, the hotter and cleaner the coal burns.

2. Which of the following is a traditional energy source?

a. wind energy c. solar energy

b. geothermal energy d. biomass fuels

Wind, geothermal, and solar energy are all renewable alternative energy sources. Biomass fuels, including wood, field crops, fecal matter, and peat, are traditional energy sources.

Multiple Choice

Chapter Assessment

Multiple Choice

3. What percentage of the industrialized countries’ energy use is from oil?

a. 23 percent c. 44 percent

b. 37 percent d. 50 percent

Chapter Assessment

In industrialized countries, more energy comes from oil than any other source. In developing countries, biomass is the leading source of energy at 35 percent.

Multiple Choice

4. Which of the following states has the best conditions for a wind farm?

a. North Dakota c. Texas

b. South Dakota d. all of the above

Chapter Assessment

Nearly all of the energy needs of the country could be met if wind farms were built in just these three states which experience constant, steady winds.

Multiple Choice

5. When was the last nuclear plant built in the United States?

a. 1978 c. 1988

b. 1984 d. 1994

Chapter Assessment

Poor management, high operating costs, poor reactor designs, and public concerns about safety and disposal of radioactive wastes contributed to the decline of nuclear power. An accident at the nuclear plant at Three Mile Island near Harrisburg, Pennsylvania in 1979 further sealed the fate of nuclear power in the United States.

Short Answer

6. Why isn’t oil shale widely used as a source of oil?

Chapter Assessment

Oil shale is not widely used as a source of oil because the cost of processing oil shale is higher than the cost of crude oil sold by countries that have abundant oil supplies.

Short Answer

7. What is an active solar-heating system?

Chapter Assessment

An active solar-heating system includes collectors, such as solar panels, that absorb solar energy and fans or pumps that distribute that energy throughout the house.

True or False8. Identify whether the following statements are true or

false.

______ Almost everything you eat contains trapped solar energy.

______ The search for crude oil often begins in areas with thick layers of sedimentary rock.

______ Passive solar designs can only provide up to 40 percent of the energy needed to heat a house.

______ Roughly 2.5 billion people throughout the world use wood as their primary energy source.

______ In China, approximately 300 million bicycles are in use.

Chapter Assessment

true

true

false

false

true

Image Bank

Chapter 26 Images

Image Bank

Chapter 26 Images

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Documents

Objectives Recognize the Sun as the ultimate source of most energy on Earth. Conventional Energy Resources Describe how energy changes from one form to