3Fossil FuelsFossil 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.
4Fuels for different uses CookingTransportationManufacturingHeating and coolingGenerating electricityThe fuel we use for these purposes depends on energy content, cost, availability, safety, and by-products.
5Electricity-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.
6Combustion 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
7Energy 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.
8Energy 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.
9How Fossil Fuel Deposits Form Coal formationOil and Natural Gas formationCoal 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.
10COAL Most abundant fossil fuel in world Asia and North America very rich in coal.InexpensiveNeeds little refining
11Coal Mining and the Environment Underground mining has minimal effects on environment.Surface mining does more damageMove entire mountains and toxic chemical can leach into streams.
12Air PollutionHigher-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.
13PetroleumOil that is pumped out of ground is called crude oil, or petroleumAnything made from petroleum is called a petroleum product.Examples: fuels, chemicals, plasticsPetroleum is 45% of the world’s commercial energy use.
14Oil refineryAn oil refinery converts petroleum into fuel.
15Locating Oil Deposits Most oil reserves are in Middle East. Geologist gather dataExploration wells are drilledIf oil can be extracted at profitable rate, oil is pumped and flows to surface.
16Natural Gas20% of the world’s nonrenewable energy comes from natural gas (methane)Burning methane produces fewer pollutants because it burns cleaner.
17Environmental 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.
18Fossil 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
19Fossil Fuels and the Future Predicting Oil ProductionFuture Oil ReservesOil reserves are oil deposits that can be extracted profitablySome oil deposits have not yet been discoveredWe must also take into account changing technologyThe law of supply and demandSome 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.
22Nuclear Energy In 1950s and 1960s seen as power for the future Clean and plentifulIn 1970s and 1980s, 120 nuclear power plants were cancelledWhy?
23Fission: Splitting Atoms Nuclear energy is the energy contained in the nuclei of atoms.Atoms of uranium are used as the fuel in nuclear power plantsNuclear fission is the splitting of the atomic nuclei.Releases a tremendous amount of energy.New nuclei and neutrons result from this splitting.
24How 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
25How 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.
26How 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.
27Advantages of Nuclear Energy Very concentratedDoes 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.
28Why 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)
29Storing WasteVery 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.
30Safety 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)
31Safety Concerns Ukraine (1986) ChernobylThree mile IslandUkraine (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 contaminatedPennsylvania (1979)Human error againBlocked valves and broken pumpsOnly small amount of radioactive gas escaped.More than 300 safety improvements are required for new nuclear power plants.
32The 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????
33Technical 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.