Chapter Summary: Chapter 9
Nonrenewable Energy Resources
9-1 What is net energy and why is it important?
The sun provides an essentially inexhaustible supply of solar capital, providing nearly all the energy that heats the
earth and our buildings. Commercial energy comes primarily from fossil fuels (79%), because they are abundant,
transportable, and cheap. CONCEPT 9-1 Net energy is the amount of high-quality usable energy available from an
energy resource minus the amount of energy needed to make it available. See Science Focus: Net Energy is the Only
Energy That Really Counts, p. 190.
1. With what criteria should energy resources be evaluated?
2. What is the significance of the concept of net energy?
9-2 What are the advantages and disadvantages of using oil?
The United States uses 23% of global oil production, while only having 1.5% of proven global oil reserves. The U.S.
economy and many others in the developed world depend on inexpensive oil supplies. The growing demand in the
U.S. cannot be met by increasing domestic supplies. CONCEPT 9-2A Conventional oil is currently abundant, has a
high net energy yield, and is relatively inexpensive, but using it causes air and water pollution and releases
greenhouse gases into the atmosphere. CONCEPT 9-2B Heavy oils from oil sand and oil shale exist in potentially
large supplies but have low net energy yields and higher environmental impacts than conventional oil has.
3. What are several products we obtain from refining crude oil?
4. Why is petroleum useful as an energy resource? What are the disadvantages?
5. Distinguish between shale oil and tar sands. Despite their large worldwide reserves, these are not good
choices for supplying the world's oil. Why?
9-3 What are the advantages and disadvantages of using natural gas?
Conventional natural gas is found above most reservoirs of crude oil. Natural gas is a versatile fuel, yet it has a high
transportation costs. CONCEPT 9-3 Conventional natural gas is more plentiful than oil, has a high net energy yield
and a fairly low cost, and has the lowest environmental impact of all fossil fuels.
6. Distinguish between natural gas, liquefied petroleum gas, and liquefied natural gas.
7. List the advantages and disadvantages of using natural gas as an energy source.
9-4 What are the advantages and disadvantages of using coal?
Coal is a solid fossil fuel that cheap and plentiful in much of the world. Coal is burned in power plants to provide
about 42% of the world's electricity. However, burning coal releases large amounts of soot, carbon dioxide, and
trace amounts of toxic mercury and radioactive materials. CONCEPT 9-4A Conventional coal is plentiful and
produces a high net energy yield at a low cost, but it has a very high environmental impact. CONCEPT 9-4B
Synthetic fuels produced from coal have lower net energy yields and higher environmental impacts than
conventional coal.
8. Evaluate the usefulness of coal as an energy source.
9-5 What are the advantages and disadvantages of using nuclear energy?
To evaluate nuclear energy, we must consider safety, economic feasibility, and environmental feasibility of the
entire nuclear fuel cycle, from mining fuel to dealing with the waste. CONCEPT 9-5 Nuclear power has a low
environmental impact and a low accident risk, but high costs, public fear of accidents, radioactive wastes, and the
potential for spreading nuclear weapons technology have limited its use. Proponents claim nuclear power will
decrease U.S. dependence on foreign oil, while those opposed to nuclear power argue that the dangers are too high.
9. What are the advantages of nuclear power?
10. What are the challenges associated with using nuclear power? Be sure to consider all parts of the
nuclear fuel cycle.
11. What are important considerations in predicting the future of nuclear power?