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Nonrenewable EnergyChapter 17

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Section 17.1

Energy Resources and Fossil Fuels

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Fossil Fuels

Fossil fuels are the remains of ancient plants and animals that changed into coal, oil, natural gas and methane hydrates (look like ice)

Two problems with fossil fuels: 1. the supply is limited and 2. obtaining and using them causes environmental problems.

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Fuels for different uses

Cooking Transportation Manufacturing Heating and cooling Generating

electricity The fuel we use for

these purposes depends on energy content, cost, availability, safety, and by-products.

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Electricity-Power on Demand How is electricity

generated? An electric generator

is a machine that converts mechanical energy (turbine) into electrical energy.

A turbine is a wheel that changes the force of a moving gas or liquid into energy.

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Combustion Chamber of a Coal-Burning Power Plant

Inside the combustion chamber of a coal-fired power plant burning fossil fuels release energy in the form of heat

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Energy Use

Every product requires energy to produce.

The price of the product reflects the cost of the fuel.

Example: buying a plane ticket includes the cost of the fuel.

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Energy Use in the United States We use more

energy per person than any other country in the world except Canada and the United Arab Emirates.

Most of the energy consumed in the United States is used for industrial purposes.

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How Fossil Fuel Deposits Form

COAL FORMATION

Coal forms from the remains of plants that lived in swamps millions of years ago.

Layers of sediment compressed the plant remains; heat and pressure within the Earth’s crust caused coal to form.

OIL AND NATURAL GAS FORMATION

These form from the decay of tiny marine organisms that accumulated on the bottom of the ocean millions of years ago.

These remains were buried in sediments, heated until they became energy-rich carbon based molecules.

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COAL

Most abundant fossil fuel in world

Asia and North America very rich in coal.

Inexpensive Needs little

refining

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Coal Mining and the Environment

Underground mining has minimal effects on environment.

Surface mining does more damage

Move entire mountains and toxic chemical can leach into streams.

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Air Pollution

Higher-grade coals produce less pollution than lower-grade coals.

Burning any coal releases sulfur which leads to air pollution and acid precipitation.

Serious problems in China.

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Petroleum

Oil that is pumped out of ground is called crude oil, or petroleum

Anything made from petroleum is called a petroleum product.

Examples: fuels, chemicals, plastics

Petroleum is 45% of the world’s commercial energy use.

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Oil refinery

An oil refinery converts petroleum into fuel.

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Locating Oil Deposits

Most oil reserves are in Middle East.

Geologist gather data

Exploration wells are drilled

If oil can be extracted at profitable rate, oil is pumped and flows to surface.

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Natural Gas

20% of the world’s nonrenewable energy comes from natural gas (methane)

Burning methane produces fewer pollutants because it burns cleaner.

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Environmental Effects of Using Oil

Burning oil releases pollutants.

Driving cars leads to smog and health problems.

Released carbon dioxide leads to climate change.

Oil spills pollute our waters.

Remember more oil pollutes our water from daily activities.

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Fossil Fuels and the Future Fossil fuels supply

about 90% of the energy used in developed countries.

By 2050, the world energy demands may double (increased population and industry)

Cost of fossil fuels will increase

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Fossil Fuels and the FuturePREDICTING OIL PRODUCTION

Oil reserves are oil deposits that can be extracted profitably

Some oil deposits have not yet been discovered

We must also take into account changing technology

The law of supply and demand

FUTURE OIL RESERVES

Some are located under the ocean, but extracting this oil is much more expensive.

Technology needs to improve and oil extracted from the ocean will cost more than oil extracted from land.

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Time for a reading quiz

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Section 17.2

Nuclear Energy

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Nuclear Energy

In 1950s and 1960s seen as power for the future

Clean and plentiful In 1970s and 1980s, 120 nuclear

power plants were cancelled Why?

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Fission: Splitting Atoms

Nuclear energy is the energy contained in the nuclei of atoms.

Atoms of uranium are used as the fuel in nuclear power plants

Nuclear fission is the splitting of the atomic nuclei.

Releases a tremendous amount of energy.

New nuclei and neutrons result from this splitting.

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How Nuclear Energy Works A nuclear reactor

is surrounded by a thick pressure vessel that is filled with a cooling fluid.

This vessel contains the fission products in case of any accident.

Thick concrete walls surround the reactor

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How Nuclear Energy Works Metal fuel rods

containing solid uranium are bombarded with neutrons.

Chain reaction releases energy and more neutrons.

Rate of reaction is controlled in reactor.

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How Nuclear Energy Works

Heat released during reaction generates electricity.

The energy heats a closed loop of water that heats another body of water.

The water boils, produces steam, and the steam drives a turbine, creating electricity.

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Advantages of Nuclear Energy Very concentrated Does NOT produce

greenhouse gases. Release less

radioactivity than coal-burning power plants.

France generates 3/4ths of its electricity from nuclear power and produces way less air pollution than in U.S.

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Why Aren’t We Using More Nuclear Energy????

Building and maintaining safe reactors is very expensive.

Cost more than $3,000 per kilowatt of electrical capacity.

Wind (less than $1,000/kilowatt)

Natural gas (less than $600/kilowatt)

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Storing Waste

Very difficult to find safe place to store nuclear waste.

Fission products remain radioactive for thousands of years.

Storage sites must be located in areas that are extremely geologically stable.

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Safety Concerns

Fission process can get out of control.

Chernobyl (worst nuclear accident in the world 1986)

Three Mile Island (worst nuclear accident in U.S. 1979)

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Safety Concerns

CHERNOBYL

Ukraine (1986) All safety devices had

been shut off to conduct unauthorized test.

Caused explosion that destroyed reactor.

No containment building. Very old design. Northern Europe and

Ukraine are still contaminated

THREE MILE ISLAND

Pennsylvania (1979) Human error again Blocked valves and

broken pumps Only small amount of

radioactive gas escaped.

More than 300 safety improvements are required for new nuclear power plants.

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The Future of Nuclear Power Nuclear fusion: the

combining of atomic atoms.

A safer energy source due to less radioactive byproducts.

Can release tremendous amounts of energy.

Why don’t we do it????

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Technical Difficulties of Nuclear Fusion

Atomic nuclei must be heated to extremely high temperatures: 100 million degrees C.

Nuclei must be maintained at very high concentrations and confined.

Achieving all three of these simultaneously is extremely difficult.

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Time for a reading quiz