Chapter 17 Nonrenewable Energy

Section 17.1 Energy Resources and Fossil Fuels

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.

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.

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.

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

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.

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.

How Fossil Fuel Deposits Form Coal formation Oil and Natural Gas 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. 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.

COAL Most abundant fossil fuel in world Asia and North America very rich in coal. Inexpensive Needs little refining

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.

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.

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.

Oil refinery An oil refinery converts petroleum into fuel.

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.

Natural Gas 20% of the world’s nonrenewable energy comes from natural gas (methane) Burning methane produces fewer pollutants because it burns cleaner.

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.

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

Fossil Fuels and the Future Predicting Oil Production Future Oil Reserves 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 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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Section 17.2 Nuclear Energy

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?

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.

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

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.

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.

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.

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)

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.

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)

Safety Concerns Ukraine (1986) Chernobyl Three mile Island 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 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.

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????

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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