Chapter 17 Nonrenewable Energy Fossil Fuels Chapter 17

Chapter 17: Nonrenewable Energy

Fossil Fuels Chapter 17, Section 1

Discussion Prompt Contrast renewable and nonrenewable resources. n List some examples of each. n

Fossil Fuels Remains of organisms from millions of years ago n Changed through heat and pressure over a long period of time n Examples: coal, oil, natural gas n

Problems Limited supply n Extraction & use have environmental problems n Solutions n Use other energy sources l Use less fossil fuels l

Uses of Fossil Fuels Cooking n Transportation n Manufacturing n Heating and cooling buildings n Generating electricity n

Fossil Fuel Uses, cont. n The type of fossil fuel used for a task depends on its properties. l Example: even though coal is inexpensive, it would not work to fuel an airplane because it weighs too much.

Electricity Convert the energy of fossil fuels into electricity l More convenient to use n Can be transported long distances n Generated in a power plant and carried to uses on a distribution grid n Difficult to store and must use other energy sources to create n

How is Electricity Generated? n n n Electric Generator: machine that converts mechanical energy into electrical energy Turbine: wheel that changes the force of a moving gas or liquid into energy that can do work Fossil fuels burned to boil water l Usually use coal Steam turns the turbine Turbine spins metal in a magnetic field (electric generator) Electricity is easily transported

Energy Use Patterns n Developed > developing l n See Figure 4 on p. 469 Canada/USA > Japan/Switzerland Both developed, Japan actually has higher personal wealth l Read about on p. 469 l Low gas taxes in USA & Canada l n Could raise taxes to discourage wasteful use l Small country/rail system in Japan & Switzerland

Energy Use in the United States Read about on p. 469. n Explain at least 2 reasons why the US uses so much energy compared to other developed countries. n List 2 actions taken by the government that may cause you to decrease your energy usage. n

How Fossil Fuel Deposits Form Read p. 470. n Summarize how coal is formed. n Summarize how oil and natural gas are formed. n

Coal formation Eastern USA 320 – 300 million years ago when vast swampland covered this area n Western USA 100 – 40 million years ago on swamps also n Repeated sediment layers over swamps n

Oil & Natural Gas formation Result from the decay of tiny marine organisms that accumulated on the ocean floor millions of years ago n Deposits were heated until they became complex energy-rich carbon-based molecules n AK, TX, CA, and the Gulf of Mexico n

Coal n Most of the world’s fossil fuel reserves North America and Asia l Relatively inexpensive and needs little refining once mined l ½ of electricity in the US is from coal-fired power plants l n Mining l Underground n Safer l for environment Surface n Remove entire mountaintops n Toxic chemicals into streams

Burning coal n Coal quality varies l Bituminous coal is higher quality: provides more energy with less pollution Low quality coal releases more sulfur n Sulfur in all coal leads to acid rain n Larger problem in China n Cleaner burning coal in USA n

Petroleum: Crude Oil n Oil that is pumped from the ground n n n Location: in and around major geologic features like faults and folds l n Fuels, chemicals, plastics 45% of world’s commercial energy use trap oil as it moves in Earth’s crust Burning CO 2, Smog, Sulfur l Can contribute to global warming l n Oil spills: have been minimized

Natural Gas: Methane (CH 4) 20% of world’s nonrenewable energy use n Formerly burned off when found in an oil well n Now used as fuel because very practical n Transport via pipeline l Compress into tanks l n Burns cleaner than oil or coal

The Future of Fossil Fuels (p. 474 n 90% of energy production in n developed countries Predicted that by 2050, world demand will double l More humans and industry in developing countries l Slower increase of oil production Oil reserve: oil deposits that can be extracted profitably l No new oil reserves in the past decade Deep ocean reserves? Expensive with current technology

Section 17 -2: Nuclear Energy Discussion prompt: read the introduction on p. 476 n Write a 2 sentence reflection on this introduction. n

Changing Views n Nuclear Energy l 50 s and 60 s n Energy of the future n Clean and plentiful n Cheap l 70 s and 80 s n 120 planned plants canceled n 40 partially constructed l Today n 17% of energy

Nuclear Fission: Splitting Atoms n Nuclear energy: the energy in the nucleus of an atom l 1 million times stronger than chemical bonds Uranium (U) used a fuel n Nuclei of uranium bombarded with neutrons causing nuclei to split n Releases energy n Uncontrolled fission reactions are atomic bombs n

How Nuclear Energy Works n Nuclear reactor is surrounded by a thick pressure vessel filled with cooling fluid Thick in case of an accident l Inside, metal fuel rods contain uranium pellets that are bombarded by neutrons, splitting and releasing energy l Energy heats a closed loop of water n Boils water in a 2 nd loop n Steam turns turbine in generator n Generator converts mechanical energy into electrical energy n

Advantages Concentrated energy n No greenhouse gases n Less radiation than coal-burning plants n No reliance on fossil fuels n

Why aren’t we using it? n Expensive Nuclear power - $3, 000 per kilowatt l Wind power - $1, 000 per kilowatt l Natural gas - $600 per kilowatt l

Why aren’t we using it? n Storing waste Waste remains dangerous for 1, 000 s of years l Waste sites must be geologically stable l USA has researched a site for 2 decades in Nevada l Also considering a process called transmutation which recycles the radioactive material l

Safety n Chernobyl 1986 (Ukraine) Engineers turned off safety devices (Derp!) l Explosion l Radiation in the air l Old design l n Three Mile Island 1979 (PA) Human error, blocked valves, broken pumps l Smaller leak l n 300 safety improvements

The Future n Nuclear fusion 2 atoms combine to form a larger nucleus, releasing large amounts of energy l This process powers stars l Does not create radioactive waste like nuclear fission l Challenges: l n High temps required: 100 millionº C n High concentrations n Must be properly contained